Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Status
Applicant’s arguments and claim amendments submitted on July 15th, 2026 have been entered into the file. Currently, claims 1, 12-13 are amended, claims 10-11 are cancelled, and claims 15-18 are new, resulting in claims 1-9, 12-18 pending for examination.
Response to Amendment
The amendments filed July 15th, 2026 have been entered into the file.
Applicant’s arguments and amendments submitted in the Remarks filed July 15th, 2026 have overcome the 35 U.S.C. 102(a)(1) rejection or in the alternative 35 U.S.C. 103 rejection of claims 1-6, 8-10, and 14 over Kinoshita. Therefore, the 35 U.S.C. 103 rejection of dependent claim 7 as being unpatentable over Kinoshita in view of Rim and claims 11-13 as being unpatentable over Kinoshita in view of Takanobu are subsequently withdrawn.
Claim Rejections - 35 USC § 102/103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-6, 8-9, 13-15 are rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative under 35 U.S.C. 103 as obvious over Han (Korean Patent Publication No. 20200028258 A).
Regarding claim 1, Han teaches a negative electrode for a rechargeable lithium battery, the negative electrode (Paragraph 0001) comprising:
a current collector;
a first negative active material layer on at least one surface of the current collector; and
a second negative active material layer on the first negative active material layer (Paragraph 0098).
Han teaches the negative electrode active material particles comprising graphite (Paragraph 0011), which is known in the art to possess a crystal structure. Han teaches the active material particles may be a complex of metal and carbon, where the carbon is graphite and the metal is Si (Paragraph 0028), which is considered to meet the instant claimed limitations of the first negative active material layer or the second negative active material layer comprises a crystalline carbon-based negative active material and a Si-based negative active material.
Han teaches the flake-type active material particles in the second negative electrode active material layer are arranged in a vertical direction in order to reduce the resistance of the negative electrode, improve the diffusion rate of lithium ions, and improve rapid charging characteristics (Paragraph 0020).
Han does not explicitly teach:
the first negative active material layer is a non-oriented layer, and the second negative active material layer is an oriented layer,
wherein a DD (Degree of Divergence) value of the first negative active material layer and a DD value of the second negative active material layer have a relationship expressed in Equation 1:
Equation 1
A≥10
wherein, in Equation 1, A is the DD value of the second negative active material layer – the DD value of the first negative active material layer,
wherein the DD value is defined by Equation 2:
Equation 2
DD (Degree of Divergence) = (Ia/Itotal) * 100, and
wherein in Equation 2, Ia is a sum of peak intensities at non-planar angles measured by X-ray diffraction (XRD) utilizing a CuKα ray, and Itotal is a sum of peak intensities at all angles measured by XRD utilizing a CuKα ray.
However, it is reasonable to presume the aforementioned features are inherent to Han. Support for said presumption is found in that Han teaches a similar method of manufacturing the negative electrode as the instant invention, particularly related to the materials and the process conditions, and therefore the negative electrode is expected to have the same properties as the claimed invention.
The instant disclosure provides the active material in the first and second negative active material layers include crystalline carbon-based negative active material and an Si-based active material (Paragraph 0055). The instant disclosure teaches a binder improved binding properties of the negative active material particles with one another and with the current collector, present between 1 wt% to 5 wt% based on the total weight of each negative active material layer. The instant disclosure provides suitable binder examples such as polyvinylchloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an ethylene oxide-containing polymer, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, styrene-butadiene rubber, an acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, an acryl rubber, a butyl rubber, an ethylene propylene copolymer, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, an ethylene propylenediene copolymer, polyvinyl pyridine, chlorosulfonated polyethylene, latex, a polyester resin, an acryl resin, a phenol resin, an epoxy resin, polyvinyl alcohol, an acrylate-based resin (Paragraphs 0071-0074). The instant disclosure provides that a cellulose-based compound such as carboxymethyl cellulose is used to accompany an aqueous binder or may act as a binder itself in order to control viscosity comprised between 0.1 to 3 parts by weight based on 100 parts by weight of the negative electrode active material (Paragraphs 0074-0075).
Han teaches first and second negative electrode active material layers comprise flake-type active material particles including plate-shaped graphite (Paragraph 0011) and may also include a silicon material (Paragraph 0013). Han also teaches a binder used in addition to the negative electrode active material (Paragraph 0042), such as polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluorine rubber (Paragraph 0044), which overlaps with the suitable binders and conductive material provided above. Further, Han teaches the binder added at 1% to 50% by weight based on the total weight of the negative electrode active material layer, which also overlaps the teachings of the instant disclosure provided above.
Additionally, the instant disclosure provides that the first negative active material layer is coated on the current collector without utilizing a magnet, which results in a non-oriented layer. The instant disclosure provides that after the first negative active material layer is formed, the second negative active material layer is coated while utilizing a magnetic field in order to form an oriented layer (Paragraph 0079). The instant disclosure teaches that the magnetic field may have a strength of about 1000 Gauss to about 10,000 Gauss and is applied for between 3 seconds to 12 seconds (Paragraph 0081). In the examples of the instant disclosure, the negative active material layer slurries are prepared by mixing the binder, thickener, and graphite in a water solvent to form a negative active material slurry (Paragraphs 00122-00123).
Han teaches the negative electrode mixture paste is formed by dispersing the negative electrode active material, binder, and conductive active in water (Paragraph 0060), which aligns with the method discussed above in the instant specification.
Further Han teaches a step (S3) in the method applying a magnetic field before the second negative electrode mixture paste is dried and solidified, makes it possible to arrange the graphite in the active material layer paste in the vertical direction (Paragraph 0016). Han teaches the strength of the magnetic field is between 1,000 to 100,000 Gauss (Paragraph 0048).
Thus, Han teaches the strength of applying the magnetic field which overlap with the suitable conditions disclosed by the instant disclosure. Further, Han teaches the magnetic field only applied to the second negative electrode active material layer prior to drying and does not utilize a magnetic field to form the first negative electrode active material layer (Step S(1)) (Paragraph 0016).
For these reasons, it is reasonable for the ordinary artisan to presume the negative electrode disclosed by Han possesses the following characteristics, meeting the instant claimed limitations:
the first negative active material layer is a non-oriented layer, and the second negative active material layer is an oriented layer,
wherein a DD (Degree of Divergence) value of the first negative active material layer and a DD value of the second negative active material layer have a relationship expressed in Equation 1:
Equation 1: A≥10
wherein, in Equation 1, A is the DD value of the second negative active material layer – the DD value of the first negative active material layer,
wherein the DD value is defined by Equation 2:
Equation 2 DD (Degree of Divergence) = (Ia/Itotal) * 100, and
wherein in Equation 2, Ia is a sum of peak intensities at non-planar angles measured by X-ray diffraction (XRD) utilizing a CuKα ray, and Itotal is a sum of peak intensities at all angles measured by XRD utilizing a CuKα ray.
Regarding claim 2, Han teaches the negative electrode as claimed in claim 1.
Han does not explicitly teach A is about 10 to about 40.
However it reasonable to presume this feature is inherent to Han. Support for said presumption is found, as discussed above, in that Han teaches:
the composition of the first negative active material layer, including the components and their respective quantities, overlap with that of the instant disclosure
the composition of the second negative active material layer, including the components and their respective quantities, overlap with that of the instant disclosure
the first negative active material is coated on the current collector and dried without utilizing a magnetic field
the second negative active material is coated on the current collector and dried while utilizing a magnetic field
the strength of the magnetic field applied overlaps with that of the instant disclosure
Thus, the instant claimed limitations are met.
Regarding claim 3, Han teaches the negative electrode as claimed in claim 1.
Han does not explicitly teach the DD value of the first negative active material layer is less than about 30.
However it reasonable to presume this feature is inherent to Han. Support for said presumption is found, as discussed above, in that Han teaches:
the composition of the first negative active material layer, including the components and their respective quantities, overlap with that of the instant disclosure
the first negative active material is coated on the current collector and dried without utilizing a magnetic field
Thus, the instant claimed limitations are met.
Regarding claim 4, Han teaches the negative electrode as claimed in claim 1.
Han does not explicitly teach the DD value of the first negative active material layer is less than about 30, and about 10 or more.
However it reasonable to presume this feature is inherent to Han. Support for said presumption is found, as discussed above, in that Han teaches:
the composition of the first negative active material layer, including the components and their respective quantities, overlap with that of the instant disclosure
the first negative active material is coated on the current collector and dried without utilizing a magnetic field
Thus, the instant claimed limitations are met.
Regarding claim 5, Han teaches the negative electrode as claimed in claim 1.
Han does not explicitly teach wherein the DD value of the second negative active material layer is about 30 or more.
However it reasonable to presume this feature is inherent to Han. Support for said presumption is found, as discussed above, in that Han teaches:
the composition of the second negative active material layer, including the components and their respective quantities, overlap with that of the instant disclosure
the second negative active material is coated on the current collector and dried while utilizing a magnetic field
the strength of the magnetic field applied overlaps with that of the instant disclosure
Thus, the instant claimed limitations are met.
Regarding claim 6, Han teaches the negative electrode as claimed in claim 1.
Han does not explicitly teach wherein the DD value of the second negative active material layer is about 30 to about 60.
However it reasonable to presume this feature is inherent to Han. Support for said presumption is found, as discussed above, in that Han teaches:
the composition of the second negative active material layer, including the components and their respective quantities, overlap with that of the instant disclosure
the second negative active material is coated on the current collector and dried while utilizing a magnetic field
the strength of the magnetic field applied overlaps with that of the instant disclosure
Thus, the instant claimed limitations are met.
Regarding claim 8, Han teaches the negative electrode as claimed in claim 1.
Han is silent as to Ia is the sum of peak intensities at 2θ = 42.4±0.2°, 43.4±0.2°, 44.6±0.2°, and 77.5±0.2° measured by XRD utilizing the CuKα ray, and
Itotal is the sum of peak intensities at 2θ=26.5±0.2°, 42.4±0.2°, 43.4±0.2°, 44.6±0.2°, 54.7±0.2°, and 77.5±0.2° measured by XRD utilizing the CuKα ray.
However, it is reasonable to presume that the aforementioned claimed limitations are inherent to Han. Support for said presumption is found in that the negative electrode disclosed by Han is manufactured with similar materials in similar proportions which undergo process steps with similar conditions as those disclosed by the instant application, as discussed above. Therefore, the ordinary artisan would expect the instant claimed property to have the same result if measured in the same way due to the structural similarities of the negative electrode of Han and that of the instant application owing to the similar process of producing the negative electrode.
Regarding claim 9, Han teaches the negative electrode as claimed in claim 1.
Han is silent as to the peak intensities at the non-planar angles and the peak intensities at all the angles are peak integral area values.
However, it is reasonable to presume that the aforementioned claimed limitations are inherent to Han. Support for said presumption is found in that the negative electrode disclosed by Han is manufactured with similar materials in similar proportions which undergo process steps with similar conditions as those disclosed by the instant application, as discussed above. Therefore, the ordinary artisan would expect the instant claimed property to have the same result if measured in the same by due to the structural similarities of the negative electrode of Han and that of the instant application owing to the similar process of producing the negative electrode
Regarding claim 13, Han teaches the negative electrode as claimed in claim 1, wherein the Si-based negative active material is Si, a Si-C composite, SiOx (0<x<2), or a combination thereof (Paragraph 0028).
Regarding claim 14, Han teaches a rechargeable lithium battery, comprising: the negative electrode of claim 1; a positive electrode comprising a positive active material; and a non-aqueous electrolyte (Paragraphs 0004, 0009, and 0018).
Regarding claim 15, Han teaches the negative electrode as claimed in claim 1.
As discussed above in the rejection of claim 1, Han teaches the first negative active material layer may be a combination of a carbon-based material and silicon (Paragraph 0028). Han teaches natural and artificial graphite as suitable examples of carbonaceous materials commonly used in lithium secondary batteries, which are known in the art to have some crystallinity. Therefore, Han was considered to teach the first negative active material layer comprising the crystalline carbon-based negative active material and the Si-based negative active material.
Claim Rejections - 35 USC § 103
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Han as applied to claims 1-6, 8-9, and 13-15 above, and further in view of Rim (Korean Patent Publication No. 20190121068 A).
Regarding claim 7, Han teaches the negative electrode as claimed in claim 1.
Han is silent as to the first negative active material layer has a thickness of about 10 μm to about 30 μm.
However, Rim discloses a negative electrode for a lithium secondary battery comprising a first negative electrode active material layer positioned on the current collector and a second negative electrode active material positioned on the first negative electrode active material layer, the active material for the negative electrode comprising crystalline carbon (Page 1, Paragraph 8) which may be natural or artificial graphite (Page 2, Paragraph 12). Rim teaches the thickness of the first negative electrode active material is preferably between 30 µm to 60 µm (Page 1, Paragraph 10) with Example 1 specifically embodying the thickness of the first negative electrode active material is 30 µm (Page 8). Rim teaches the thickness of the first electrode active material in this range to provide desirable adhesive force without increasing ionic resistance (Page 3, Paragraphs 3 and 7).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first negative electrode active material layer of Han to incorporate the teachings of Rim in which the thickness is provided at 30 µm as embodied in Example 1. Doing so would advantageously result in increased adhesion without increased ionic resistance, as recognized by Rim. The result of the modification is a thickness of the first negative active layer which lies within the instant claimed range, meeting the instant claimed limitations.
Claims 12, 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Han as applied to claims 1-6, 8-9, 13-15 above, and further in view of Takanobu (Japanese Patent No. 5158460 B2).
Regarding claim 12, Han teaches the negative electrode as claimed in claim 1.
Han is silent as to a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90 : 10 in a weight ratio.
However, Takanobu discloses a negative electrode material for a lithium secondary battery with the negative electrode material having excellent cycle characteristics obtained by adding silicon to a graphite base material (Paragraph 2). Takanobu discloses that by using silicon fine powder as an additive to accompany graphite as a base material for a negative electrode material, the capacity may be increased (Paragraph 12). Takanobu teaches the amount of silicon added is preferably 1 to 20 parts by weight with respect to 100 parts by weight of graphite. If the amount is less than 1 part by weight, the effect of increasing the discharge capacity is scarce, and if it exceeds 20 parts by weight, the cycle characteristics are undesirably deteriorated (Paragraph 15).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the silicon material of the negative electrode active material composition of Han to incorporate the teachings of Takanobu in which the silicon is present between 1 to 20 parts by weight with respect to 100 parts by weight of graphite. Doing so would advantageously obtain the desired effects of increasing the discharge capacity and maintaining cycle characteristics. The modification thus teaches the ratio of graphite (crystalline carbon material) to silicon is 100:1 to 80:20, which overlaps the instant claimed range and thus establishes prima facie obviousness. See MPEP 2144.05 (I).
Regarding claim 16, Han teaches the negative electrode as claimed in claim 15.
Han is silent as to in the first negative active material layer, a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90:10 in a weight ratio.
However, Takanobu discloses a negative electrode material for a lithium secondary battery with the negative electrode material having excellent cycle characteristics obtained by adding silicon to a graphite base material (Paragraph 2). Takanobu discloses that by using silicon fine powder as an additive to accompany graphite as a base material for a negative electrode material, the capacity may be increased (Paragraph 12). Takanobu teaches the amount of silicon added is preferably 1 to 20 parts by weight with respect to 100 parts by weight of graphite. If the amount is less than 1 part by weight, the effect of increasing the discharge capacity is scarce, and if it exceeds 20 parts by weight, the cycle characteristics are undesirably deteriorated (Paragraph 15).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the silicon material of the negative electrode active material composition of Han to incorporate the teachings of Takanobu in which the silicon is present between 1 to 20 parts by weight with respect to 100 parts by weight of graphite. Doing so would advantageously obtain the desired effects of increasing the discharge capacity and maintaining cycle characteristics. The modification thus teaches the ratio of graphite (crystalline carbon material) to silicon is 100:1 to 80:20, which overlaps the instant claimed range and thus establishes prima facie obviousness. See MPEP 2144.05 (I).
Claims 15-18 are rejected under 35 U.S.C. 103 as being unpatentable over Han as applied to claims 1-6, 8-9, 13-15 above, and further in view of Lee (U.S. Patent Publication No. 20210234191 A1).
Regarding claim 15, Han teaches the negative electrode as claimed in claim 1.
As discussed above in the rejection of claim 1, Han teaches the first negative active material layer may be a combination of a carbon-based material and silicon (Paragraph 0028). Han teaches natural and artificial graphite as suitable examples of carbonaceous materials commonly used in lithium secondary batteries, which are known in the art to have some crystallinity. Therefore, Han was considered to teach the first negative active material layer comprising the crystalline carbon-based negative active material and the Si-based negative active material.
However in the alternative, Lee discloses a lithium secondary battery comprising an anode which includes an anode current collector, a first anode active material layer and a second anode active material layer which is sequentially stacked (Paragraph 0012). Lee teaches the first anode active material layer including a carbon-based active material and a silicon-based active material (Paragraph 0048) and the second anode active material layer including a mixture of a carbon-based active material and the silicon-based active material (Paragraph 0049), which may be the same materials implemented in the first anode active material layer (Paragraph 0050). Lee teaches that silicon as an anode active material increases battery capacity but suffers from deformation occurring from repeated charging and discharging. To mitigate this issue, Lee teaches the inclusion of a large amount of artificial graphite improves the mechanical stability of the battery (Paragraph 0054).
Like Han, Lee teaches the silicon may be present as elemental silicon, silicon alloy, silicon oxide, silicon-carbon composite, and silicon alloy-based-carbon composite (Paragraph 00055). Also similar to Han, Lee teaches the active material including artificial graphite as the crystalline carbon-based negative active material (Paragraphs 0051-0052).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first negative active material layer of Han to incorporate the teachings of Lee in which the active material is comprised of both silicon and artificial graphite. Doing so would advantageously result in improved battery capacity and mechanical stability while reducing deformation brought on from charging and discharging, as recognized by Lee.
Regarding claim 16, Han teaches the negative electrode as claimed in claim 15.
Han is silent as to in the first negative active material layer, a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90:10 in a weight ratio.
However, as discussed above, Lee discloses a lithium secondary battery comprising an anode which includes an anode current collector, a first anode active material layer and a second anode active material layer which is sequentially stacked (Paragraph 0012). Lee teaches the first anode active material layer including a carbon-based active material and a silicon-based active material (Paragraph 0048) and the second anode active material layer including a mixture of a carbon-based active material and the silicon-based active material (Paragraph 0049), which may be the same materials implemented in the first anode active material layer (Paragraph 0050).
Lee teaches that the content of the silicon-based active material in the first anode active material may be 2 to 15% by weight based on the weight of the carbon-based active material included the first anode active material layer. Lee teaches if content of the silicon-based active material is less than about 2 wt. %, the effect of increasing the capacity/output through the silicon-based active material may not be sufficiently implemented, while if the content of the silicon-based active material exceeds about 15 wt. %, the effect of improving the stability of the anode through the anode active material layer having the multi-layered structure may not be implemented (Paragraph 0059).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first negative active material layer of Han in view of Lee to incorporate the additional teachings of Lee in which the content of the silicon-based active material in the first anode active material may be 2 to 15% by weight based on the weight of the carbon-based active material included the first anode active material layer. Doing so would advantageously result in sufficiently increasing the capacity and improving the stability of the silicon-containing anode.
The ordinary artisan would recognize that the result of such a modification is that the range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 20:3 (~6.67) (100 % by weight of carbon-based active material : 15 % by weight of the silicon-based active material) to 50:1 (50) (100 % by weight of carbon-based active material : 2 % by weight of the silicon-based active material), which overlaps the instant claimed range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material (9 (90:10) to 49 (98:2)). Therefore, prima facie obviousness is established and the instant claimed limitations are met. See MPEP 2144.05 (I).
Regarding claim 17, Han teaches the negative electrode as claimed in claim 15.
Han teaches the second negative electrode active material layer comprises a plurality of flake type active material particles (Paragraph 0033) such as plate-like natural or artificial graphite (Paragraph 0038). As graphite is known in the art to possess a crystal structure, Han is considered to teach the second negative active material layer comprises the crystalline carbon-based negative active material.
Han is silent as to the second negative active material layer comprises the Si-based negative active material.
However, as discussed above, Lee discloses a lithium secondary battery comprising an anode which includes an anode current collector, a first anode active material layer and a second anode active material layer which is sequentially stacked (Paragraph 0012). Lee teaches the first anode active material layer including a carbon-based active material and a silicon-based active material (Paragraph 0048) and the second anode active material layer including a mixture of a carbon-based active material and the silicon-based active material (Paragraph 0049), which may be the same materials implemented in the first anode active material layer (Paragraph 0050). Lee teaches that silicon as an anode active material increases battery capacity but suffers from deformation occurring from repeated charging and discharging. To mitigate this issue, Lee teaches the inclusion of a large amount of artificial graphite improves the mechanical stability of the battery (Paragraph 0054).
Like Han, Lee teaches the silicon may be present as elemental silicon, silicon alloy, silicon oxide, silicon-carbon composite, and silicon alloy-based-carbon composite (Paragraph 00055). Also similar to Han, Lee teaches the active material including artificial graphite as the crystalline carbon-based negative active material.
Lee teaches that the content of the silicon-based active material in the second anode active material may be 0.5 to 5% by weight based on the weight of the carbon-based active material included the second anode active material layer in order to increase the energy density of the battery due to an increase in the average discharge potential while also improving high-temperature storage performance of the anode (Paragraph 0060).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second negative active material layer of Han to incorporate the teachings of Lee in which the active material is comprised of both silicon and artificial graphite, with the content of the silicon-based active material in the second anode active material may be 0.5 to 5% by weight based on the weight of the carbon-based active material included the second anode active material layer. Doing so would advantageously result in improved battery capacity and mechanical stability while reducing deformation brought on from charging and discharging, as well as increase the energy density of the battery, as recognized by Lee.
Regarding claim 18, Han teaches the negative electrode as claimed in claim 17.
Han is silent as to in the second negative active material layer, a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90:10 in a weight ratio.
However, as discussed above, the modification of Han in view of Lee resulted in the content of the silicon-based active material in the second anode active material may be 0.5 to 5% by weight based on the weight of the carbon-based active material included the second anode active material layer.
The ordinary artisan would recognize that the result of such a modification is that the range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 20:1 (20) (100 % by weight of carbon-based active material : 5 % by weight of the silicon-based active material) to 200:1 (200) (100 % by weight of carbon-based active material : 0.5 % by weight of the silicon-based active material), which overlaps the instant claimed range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material (9 (90:10) to 49 (98:2)). Therefore, prima facie obviousness is established and the instant claimed limitations are met. See MPEP 2144.05 (I).
Claims 1-9, 12-18 are rejected under 35 U.S.C. 103 as being unpatentable over Takahata (U.S. Patent Publication No. 2014017087 A1) in view of Takanobu (cited above, Japanese Patent No. 5158460 B2).
Regarding claim 1, Takahata teaches a negative electrode for a rechargeable lithium battery, the negative electrode comprising:
a current collector;
a first negative active material layer (first region) (Figure 10, Element A1) on at least one surface of the current collector (Figure 10, Element 241 A); and
a second negative active material layer (second region) (Figure 10, Element A2) on the first negative active material layer (Paragraph 0011).
Takahata teaches the negative electrode active material is flake graphite particles and the perpendicularity of the graphite particles in the first region differs from the perpendicularity of the graphite particles in the second region (Paragraph 0011). Takahata teaches the perpendicularity of the graphite particles is m1/m2, where m1 is the number of the graphite particles having an inclination θn of 60° ≤ θn ≤ 90° relative to a surface of the negative electrode current collector, and m2 is the number of the graphite particles having an inclination θn of 0° ≤ θn ≤ 30° relative to the surface of the negative electrode current collector (Paragraph 0013). Further, Takahata teaches the perpendicularity of the first region is N1 and the perpendicularity of the second region is N2 (Paragraph 0015).
The instant application recites the first negative active material layer is a non-oriented layer meaning the negative active material is substantially horizontal and parallel to the current collector while the second negative active material layer is an oriented layer meaning the negative active material stands vertically relative to the current collector (Paragraph 0052). Thus, the significance of non-oriented and oriented layers are interpreted by the Examiner consistent with the specification indicating layers which comprise substantially horizontally and vertically-oriented negative electrode active material particles, respectively.
In the embodiment exemplified in Figure 10 of Takahata, Takahata teaches the graphite particles (Figure 10, Element 710 A) lie flat (substantially horizontal and parallel to the current collector) in the first region (Figure 10, Element A1) neighboring the negative electrode current collector (Figure 10, Element 241 A), while the graphite particles stand upright (oriented vertically) in the second region (Figure 10, Element A2) neighboring the surface side.
Thus, Takahata is considered to teach the first negative active material layer is a non-oriented layer and the second negative active material layer is an oriented layer, meeting the instant claimed limitations.
Takahata teaches the negative electrode active material particles comprising graphite (Paragraph 0052), which is known in the art to possess a crystal structure, and therefore is considered to teach the instant claimed limitations of the first negative active material layer or the second negative active material layer comprises a crystalline carbon-based negative active material.
Takahata is silent as to the first negative active material layer and the second negative active material layer comprise a Si-based negative active material.
However, Takanobu discloses a negative electrode material for a lithium secondary battery with the negative electrode material having excellent cycle characteristics obtained by adding silicon to a graphite base material (Paragraph 2). Takanobu discloses that by using silicon fine powder as an additive to accompany graphite as a base material for a negative electrode material, the capacity may be increased (Paragraph 12).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first negative active material layer and the second negative active material layer of Takahata (which both contain graphite) to incorporate the teachings of Takanobu in which silicon fine powder is also comprised in the negative electrode layers. Doing so would advantageously result in excellent cycle characteristics and an increase in capacity, as recognized by Takanobu.
Takahata is silent as to a DD (Degree of Divergence) value of the first negative active material layer and a DD value of the second negative active material layer have a relationship expressed in Equation 1:
Equation 1
A≥10
wherein, in Equation 1, A is the DD value of the second negative active material layer – the DD value of the first negative active material layer,
wherein the DD value is defined by Equation 2:
Equation 2
DD (Degree of Divergence) = (Ia/Itotal) * 100, and
wherein in Equation 2, Ia is a sum of peak intensities at non-planar angles measured by X-ray diffraction (XRD) utilizing a CuKα ray, and Itotal is a sum of peak intensities at all angles measured by XRD utilizing a CuKα ray.
However, as seen in Figure 12 of Takahata, the angle θn is related to the orientation of the graphite particles, with a higher degree of θn associated with the graphite particles orientated more upright with respect to the current collector. As shown in Figure 1 of the instant application, the angle a corresponds to the orientation of the graphite with respect to the substrate, with the instant application providing that as the DD value of the negative electrode active material is increased, the angle a is increased as well (Paragraph 0050). Thus, the ordinary artisan would recognize that because the angle θn of Takahata and the angle a of the instant application are related to the angle in the orientation of the graphite negative electrode particles in the negative electrode layer, they are also related to each other.
Further, Takahata provides that the perpendicularity of the graphite particles can serve as an index for evaluating to what degree the graphite particles are upright relative to the negative electrode current collector in the negative electrode active material layer. More specifically, Takahata teaches that when the perpendicularity is greater than 1, more of the graphite particles stand upright relative to the negative electrode current collector and when perpendicularity is less than 1, more graphite particles lie flat relative to the negative electrode current collector (Paragraph 0084).
Takahata teaches the advantage of the graphite particles oriented horizontally in the first region A1 and oriented vertically in the second region A2 to be that lithium ions easily enter the negative electrode active material layer during charge and are easily released during discharge, as lithium ions are able to easily diffuse within the active material layer (Paragraph 0100). Takahata teaches it is preferable for the perpendicularity N1 in the first region to be ≤ 0.6 and the perpendicularity N2 in the second region to be ≥ 3.0 (Paragraphs 0102-0103). Takahata teaches that the greater the difference between N2 and N1, the lower the diffusion resistance of lithium ions in the lithium-ion secondary battery (Paragraph 0104).
Therefore, Takahata teaches that as the difference in perpendicularity between the first and second layers of negative electrode active material increases, the diffusion resistance of lithium ions in the lithium-ion secondary battery decreases. Absent unexpected results, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the perpendicularity of the graphite particles in the first layer (N1) and the second layer (N2) since it has been held that where general conditions of a claim are disclosed in the prior art, discovering the optimum or workable range involves only routine skill in the art. See MPEP 2144.05.
As discussed above, the ordinary artisan would recognize that by tuning the perpendicularity of the graphite particles according to the teachings of Takahata, the degree of divergence of the first negative active material layer, the degree of divergence of the second negative active material layer, and the difference between them (A of the instant claim) would necessarily also be tuned. In the present invention, one would have been motivated to optimize the orientation of the negative active material in the first and second layers within the claimed range of DD values of the instant claimed ranges in order to obtain increased lithium ions mobility and reduced resistance, as recognized by Takahata.
Regarding claim 2, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to A is about 10 to about 40.
However, as discussed above, Takahata teaches the first negative active material layer is a non-oriented layer with a perpendicularity N1 which is related to the DD value of the first negative active material layer. Takahata teaches the second negative active material layer is an oriented layer with a perpendicularity N2 which is related to the DD value of the second negative active material layer. Further discussed above was the relationship between the N2-N1 and the characteristics of the negative electrode.
Takahata teaches that as the difference in perpendicularity between the first and second layers of negative electrode active material increases, the diffusion resistance of lithium ions in the lithium-ion secondary battery decreases. Absent unexpected results, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the perpendicularity of the graphite particles in the first layer (N1) and the second layer (N2) since it has been held that where general conditions of a claim are disclosed in the prior art, discovering the optimum or workable range involves only routine skill in the art. See MPEP 2144.05.
As discussed above, the ordinary artisan would recognize that by tuning the perpendicularity of the graphite particles according to the teachings of Takahata, the degree of divergence of the first negative active material layer, the degree of divergence of the second negative active material layer, and the difference between them (A of the instant claim) would necessarily also be tuned. In the present invention, one would have been motivated to optimize the orientation of the negative active material in the first and second layers to result in a value of A within the claimed range in order to obtain increased lithium ions mobility and reduced resistance, as recognized by Takahata.
Regarding claim 3, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to the DD value of the first negative active material layer is less than about 30.
However, as discussed above, Takahata teaches the first negative active material layer is a non-oriented layer with a perpendicularity N1 which is related to the DD value of the first negative active material layer.
Takahata teaches that as the difference in perpendicularity between the first and second layers of negative electrode active material increases, the diffusion resistance of lithium ions in the lithium-ion secondary battery decreases. Absent unexpected results, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the perpendicularity of the graphite particles in the first layer (N1) (and therefore the difference N2-N1) since it has been held that where general conditions of a claim are disclosed in the prior art, discovering the optimum or workable range involves only routine skill in the art. See MPEP 2144.05.
As discussed above, the ordinary artisan would recognize that by tuning the perpendicularity of the graphite particles according to the teachings of Takahata, the degree of divergence of the first negative active material layer and the difference N2-N1 would necessarily also be tuned. In the present invention, one would have been motivated to optimize the orientation of the negative active material in the first negative active material layer to result in a value of DD within the claimed range in order to obtain increased lithium ions mobility and reduced resistance, as recognized by Takahata.
Regarding claim 4, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to the DD value of the first negative active material layer is less than about 30, and about 10 or more.
However, as discussed above, Takahata teaches the first negative active material layer is a non-oriented layer with a perpendicularity N1 which is related to the DD value of the first negative active material layer.
Takahata teaches that as the difference in perpendicularity between the first and second layers of negative electrode active material increases, the diffusion resistance of lithium ions in the lithium-ion secondary battery decreases. Absent unexpected results, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the perpendicularity of the graphite particles in the first layer (N1) (and therefore the difference N2-N1) since it has been held that where general conditions of a claim are disclosed in the prior art, discovering the optimum or workable range involves only routine skill in the art. See MPEP 2144.05.
As discussed above, the ordinary artisan would recognize that by tuning the perpendicularity of the graphite particles according to the teachings of Takahata, the degree of divergence of the first negative active material layer and the difference N2-N1 would necessarily also be tuned. In the present invention, one would have been motivated to optimize the orientation of the negative active material in the first negative active material layer to result in a value of DD within the claimed range in order to obtain increased lithium ions mobility and reduced resistance, as recognized by Takahata.
Regarding claim 5, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to the DD value of the second negative active material layer is about 30 or more.
However, as discussed above, Takahata teaches the second negative active material layer is an oriented layer with a perpendicularity N2 which is related to the DD value of the second negative active material layer.
Takahata teaches that as the difference in perpendicularity between the first and second layers of negative electrode active material increases, the diffusion resistance of lithium ions in the lithium-ion secondary battery decreases. Absent unexpected results, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the perpendicularity of the graphite particles in the second layer (N2) (and therefore the difference N2-N1) since it has been held that where general conditions of a claim are disclosed in the prior art, discovering the optimum or workable range involves only routine skill in the art. See MPEP 2144.05.
As discussed above, the ordinary artisan would recognize that by tuning the perpendicularity of the graphite particles according to the teachings of Takahata, the degree of divergence of the second negative active material layer and the difference N2-N1 would necessarily also be tuned. In the present invention, one would have been motivated to optimize the orientation of the negative active material in the second negative active material layer to result in a value of DD within the claimed range in order to obtain increased lithium ions mobility and reduced resistance, as recognized by Takahata.
Regarding claim 6, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to the DD value of the second negative active material layer is about 30 to about 60.
However, as discussed above, Takahata teaches the second negative active material layer is an oriented layer with a perpendicularity N2 which is related to the DD value of the second negative active material layer.
Takahata teaches that as the difference in perpendicularity between the first and second layers of negative electrode active material increases, the diffusion resistance of lithium ions in the lithium-ion secondary battery decreases. Absent unexpected results, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the perpendicularity of the graphite particles in the second layer (N2) (and therefore the difference N2-N1) since it has been held that where general conditions of a claim are disclosed in the prior art, discovering the optimum or workable range involves only routine skill in the art. See MPEP 2144.05.
As discussed above, the ordinary artisan would recognize that by tuning the perpendicularity of the graphite particles according to the teachings of Takahata, the degree of divergence of the second negative active material layer and the difference N2-N1 would necessarily also be tuned. In the present invention, one would have been motivated to optimize the orientation of the negative active material in the second negative active material layer to result in a value of DD within the claimed range in order to obtain increased lithium ions mobility and reduced resistance, as recognized by Takahata.
Regarding claim 7, Takahata teaches the negative electrode as claimed in claim 1.
Takahata teaches that the first negative active material layer comprises between 0% to 30% thickness of the negative electrode active material layer (first and second layers). Takahata teaches that the entire thickness of the negative electrode active material layer may be 100 µm (Paragraph 0078), and thus teaches the thickness of the first negative active material layer between 0 μm to about 30 μm, which overlaps with the thickness given in the instant claimed range. Therefore, prima facie obviousness is established and the claimed limitations are met.
Regarding claim 8, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to Ia is the sum of peak intensities at 2θ = 42.4±0.2°, 43.4±0.2°, 44.6±0.2°, and 77.5±0.2° measured by XRD utilizing the CuKα ray, and
Itotal is the sum of peak intensities at 2θ=26.5±0.2°, 42.4±0.2°, 43.4±0.2°, 44.6±0.2°, 54.7±0.2°, and 77.5±0.2° measured by XRD utilizing the CuKα ray.
However, as discussed above, the perpendicularity values of the graphite in the first negative electrode active layer and the second negative electrode active layer are related to the DD value of the first negative active material layer and the DD value of the second negative active material layer, respectively. Therefore, the ordinary artisan would expect the instant claimed property to have the same result if measured in the same way due to the structural similarities of the negative electrode of Takahata and that of the instant application.
Regarding claim 9, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to the peak intensities at the non-planar angles and the peak intensities at all the angles are peak integral area values.
However, as discussed above, the perpendicularity values of the graphite in the first negative electrode active layer and the second negative electrode active layer are related to the DD value of the first negative active material layer and the DD value of the second negative active material layer, respectively. Therefore, the ordinary artisan would expect the instant claimed property to have the same result if measured in the same way due to the structural similarities of the negative electrode of Takahata and that of the instant application.
Regarding claim 12, Takahata teaches the negative electrode as claimed in claim 1.
Takahata is silent as to a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90 : 10 in a weight ratio.
However, as discussed above, Takahata in view of Takanobu teaches the advantage of including a fine silicon powder to accompany graphite in the negative electrode composition.
Takanobu teaches the amount of silicon added is preferably 1 to 20 parts by weight with respect to 100 parts by weight of graphite. If the amount is less than 1 part by weight, the effect of increasing the discharge capacity is scarce, and if it exceeds 20 parts by weight, the cycle characteristics are undesirably deteriorated (Paragraph 15).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the negative electrode active material composition of Takahata in view of Takanobu to incorporate further teachings of Takanobu in which the silicon is present between 1 to 20 parts by weight with respect to 100 parts by weight of graphite. Doing so would advantageously obtain the desired effects of increasing the discharge capacity and maintaining cycle characteristics. The modification thus teaches the ratio of graphite (crystalline carbon material) to silicon is 100:1 to 80:20, which overlaps the instant claimed range and thus establishes prima facie obviousness. See MPEP 2144.05 (I).
Regarding claim 13, Takahata teaches the negative electrode as claimed in claim 1.
As discussed above, Takahata in view of Takanobu teaches the advantage of including a fine silicon powder to accompany graphite in the negative electrode composition, meeting the instant claimed limitations of the Si-based negative active material is Si.
Regarding claim 14, Takahata teaches a rechargeable lithium battery, comprising: the negative electrode of claim 1; a positive electrode comprising a positive active material; and a non-aqueous electrolyte (Paragraphs 0011, 0043, and 0062).
Regarding claim 15, Takahata teaches the negative electrode as claimed in claim 1.
As discussed above in the rejection of claim 1, Takahata teaches the negative electrode active material is flake graphite articles.
As discussed above in the rejection of claim 1, the modification of Takahata in view of Takanobu resulted in the first negative active material layer and the second negative active material layer of Takahata (which both contain graphite) to also comprise silicon fine powder in order to achieve excellent cycle characteristics and an increase in capacity, as recognized by Takanobu.
Thus, the instant claimed limitations of the first negative active material layer comprises the crystalline carbon-based negative active material and the Si-based negative active material is met.
Regarding claim 16, Takahata teaches the negative electrode as claimed in claim 15.
Takahata is silent as to in the first negative active material layer, a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90:10 in a weight ratio.
However, as discussed above, Takahata in view of Takanobu teaches the advantage of including a fine silicon powder to accompany graphite in the negative electrode composition.
Takanobu teaches the amount of silicon added is preferably 1 to 20 parts by weight with respect to 100 parts by weight of graphite. If the amount is less than 1 part by weight, the effect of increasing the discharge capacity is scarce, and if it exceeds 20 parts by weight, the cycle characteristics are undesirably deteriorated (Paragraph 15).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first negative active material layer of Takahata in view of Takanobu to incorporate further teachings of Takanobu in which the silicon is present between 1 to 20 parts by weight with respect to 100 parts by weight of graphite. Doing so would advantageously obtain the desired effects of increasing the discharge capacity and maintaining cycle characteristics. The modification thus teaches the ratio of graphite (crystalline carbon material) to silicon is 100:1 to 80:20, which overlaps the instant claimed range and thus establishes prima facie obviousness. See MPEP 2144.05 (I).
Regarding claim 17, Takahata teaches the negative electrode as claimed in claim 15.
As discussed above in the rejection of claim 1, Takahata teaches the negative electrode active material is flake graphite articles.
As discussed above in the rejection of claim 1, the modification of Takahata in view of Takanobu resulted in the first negative active material layer and the second negative active material layer of Takahata (which both contain graphite) to also comprise silicon fine powder in order to achieve excellent cycle characteristics and an increase in capacity, as recognized by Takanobu.
Thus, the instant claimed limitations of the second negative active material layer comprises the crystalline carbon-based negative active material and the Si-based negative active material is met.
Regarding claim 18, Takahata teaches the negative electrode as claimed in claim 17.
Takahata is silent as to in the first negative active material layer, a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90:10 in a weight ratio.
However, as discussed above, Takahata in view of Takanobu teaches the advantage of including a fine silicon powder to accompany graphite in the negative electrode composition.
Takanobu teaches the amount of silicon added is preferably 1 to 20 parts by weight with respect to 100 parts by weight of graphite. If the amount is less than 1 part by weight, the effect of increasing the discharge capacity is scarce, and if it exceeds 20 parts by weight, the cycle characteristics are undesirably deteriorated (Paragraph 15).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second negative active material layer of Takahata in view of Takanobu to incorporate further teachings of Takanobu in which the silicon is present between 1 to 20 parts by weight with respect to 100 parts by weight of graphite. Doing so would advantageously obtain the desired effects of increasing the discharge capacity and maintaining cycle characteristics. The modification thus teaches the ratio of graphite (crystalline carbon material) to silicon is 100:1 to 80:20, which overlaps the instant claimed range and thus establishes prima facie obviousness. See MPEP 2144.05 (I).
Claims 15-18 are alternately rejected under 35 U.S.C. 103 as being unpatentable over Takahata in view of Takanobu as applied to claims 1-9, 12-18 above, and further in view of Lee (cited above, U.S. Patent Publication No. 20210234191 A1).
Regarding claim 15, Takahata teaches the negative electrode as claimed in claim 1.
As discussed above in the rejection of claim 1, Takahata teaches the negative electrode active material is flake graphite articles.
In the alternative, Lee discloses a lithium secondary battery comprising an anode which includes an anode current collector, a first anode active material layer and a second anode active material layer which is sequentially stacked (Paragraph 0012). Lee teaches the first anode active material layer including a carbon-based active material and a silicon-based active material (Paragraph 0048) and the second anode active material layer including a mixture of a carbon-based active material and the silicon-based active material (Paragraph 0049), which may be the same materials implemented in the first anode active material layer (Paragraph 0050).
Lee teaches that silicon as an anode active material increases battery capacity but suffers from deformation occurring from repeated charging and discharging. To mitigate this issue, Lee teaches the inclusion of a large amount of artificial graphite improves the mechanical stability of the battery (Paragraph 0054).
Similar to Takanobu, Lee teaches the active material including graphite as the crystalline carbon-based negative active material (Paragraphs 0051-0052).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first negative active material layer of Takahata to incorporate the teachings of Lee in which the active material is comprised of both silicon and artificial graphite. Doing so would advantageously result in improved battery capacity and mechanical stability while reducing deformation brought on from charging and discharging, as recognized by Lee.
Regarding claim 16, Takahata teaches the negative electrode as claimed in claim 15.
Takahata is silent as to in the first negative active material layer, a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90:10 in a weight ratio.
However, as discussed above, Lee discloses a lithium secondary battery comprising an anode which includes an anode current collector, a first anode active material layer and a second anode active material layer which is sequentially stacked (Paragraph 0012). Lee teaches the first anode active material layer including a carbon-based active material and a silicon-based active material (Paragraph 0048) and the second anode active material layer including a mixture of a carbon-based active material and the silicon-based active material (Paragraph 0049), which may be the same materials implemented in the first anode active material layer (Paragraph 0050).
Lee teaches that the content of the silicon-based active material in the first anode active material may be 2 to 15% by weight based on the weight of the carbon-based active material included the first anode active material layer. Lee teaches if content of the silicon-based active material is less than about 2 wt. %, the effect of increasing the capacity/output through the silicon-based active material may not be sufficiently implemented, while if the content of the silicon-based active material exceeds about 15 wt. %, the effect of improving the stability of the anode through the anode active material layer having the multi-layered structure may not be implemented (Paragraph 0059).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first negative active material layer of Takahata in view of Lee to incorporate the additional teachings of Lee in which the content of the silicon-based active material in the first anode active material may be 2 to 15% by weight based on the weight of the carbon-based active material included the first anode active material layer. Doing so would advantageously result in sufficiently increasing the capacity and improving the stability of the silicon-containing anode.
The ordinary artisan would recognize that the result of such a modification is that the range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 20:3 (~6.67) (100 % by weight of carbon-based active material : 15 % by weight of the silicon-based active material) to 50:1 (50) (100 % by weight of carbon-based active material : 2 % by weight of the silicon-based active material), which overlaps the instant claimed range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material (9 (90:10) to 49 (98:2)). Therefore, prima facie obviousness is established and the instant claimed limitations are met. See MPEP 2144.05 (I).
Regarding claim 17, Takahata teaches the negative electrode as claimed in claim 15.
As discussed above in the rejection of claim 1, Takahata teaches the negative electrode active material is flake graphite particles.
In in the alternative, Lee discloses a lithium secondary battery comprising an anode which includes an anode current collector, a first anode active material layer and a second anode active material layer which is sequentially stacked (Paragraph 0012). Lee teaches the first anode active material layer including a carbon-based active material and a silicon-based active material (Paragraph 0048) and the second anode active material layer including a mixture of a carbon-based active material and the silicon-based active material (Paragraph 0049), which may be the same materials implemented in the first anode active material layer (Paragraph 0050).
Lee teaches that silicon as an anode active material increases battery capacity but suffers from deformation occurring from repeated charging and discharging. To mitigate this issue, Lee teaches the inclusion of a large amount of artificial graphite improves the mechanical stability of the battery (Paragraph 0054).
Similar to Takanobu, Lee teaches the active material including graphite as the crystalline carbon-based negative active material (Paragraphs 0051-0052).
Lee teaches that the content of the silicon-based active material in the second anode active material may be 0.5 to 5% by weight based on the weight of the carbon-based active material included the second anode active material layer in order to increase the energy density of the battery due to an increase in the average discharge potential while also improving high-temperature storage performance of the anode (Paragraph 0060).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second negative active material layer of Takahata to incorporate the teachings of Lee in which the active material is comprised of both silicon and artificial graphite, with the content of the silicon-based active material in the second anode active material may be 0.5 to 5% by weight based on the weight of the carbon-based active material included the second anode active material layer. Doing so would advantageously result in improved battery capacity and mechanical stability while reducing deformation brought on from charging and discharging, as well as increase the energy density of the battery, as recognized by Lee.
Regarding claim 18, Takahata teaches the negative electrode as claimed in claim 17.
Takahata is silent as to in the second negative active material layer, a mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 98 : 2 to about 90:10 in a weight ratio.
However, as discussed above, the modification of Takahata in view of Lee resulted in the content of the silicon-based active material in the second anode active material may be 0.5 to 5% by weight based on the weight of the carbon-based active material included the second anode active material layer.
The ordinary artisan would recognize that the result of such a modification is that the range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material is about 20:1 (20) (100 % by weight of carbon-based active material : 5 % by weight of the silicon-based active material) to 200:1 (200) (100 % by weight of carbon-based active material : 0.5 % by weight of the silicon-based active material), which overlaps the instant claimed range of the mixing ratio of the crystalline carbon-based negative active material and the Si-based negative active material (9 (90:10) to 49 (98:2)). Therefore, prima facie obviousness is established and the instant claimed limitations are met. See MPEP 2144.05 (I).
Response to Arguments
In the remarks filed July 15th, 2026, applicant argues that the cited reference Kinoshita fails to disclose or suggest at least (i) the claims DD value by Equation 2, (ii) the claimed A≥10 relationship calculated from the DD value of the second negative active material layer minus the DD value of the first negative active material layer, and (iii) the newly amended limitation that the second negative active material layer comprises a Si-based negative active material. Applicant argues that the Examiner set forth a rejection for the limitations of claims (i) and (ii) which improperly relies on inherency.
Applicant argues that the magnetic field of Kinoshita is applied parallel to the surface of the negative electrode while the embodiments of the present application apply the magnetic field vertical with the current collector. Applicant argues that Kinoshita’s orientation parameter is not Applicant’s claimed DD value, thus, even if Kinoshita controls some form of graphite orientation, Kinoshita does not necessarily disclose Applicant's claimed limitations. Applicant further provides that in Kinoshita, the first and second layers are oriented parallel to the surface of the negative electrode so that expansion and contraction of both layers is in a direction perpendicular to the surface of the negative electrode. Applicant provides that such a disclosure not only does Kinoshita fail to disclose the features of claim 1, e.g., the second negative active material layer more angled than the first negative active material layer due to A ≥10, but Kinoshita instead teaches away and/or discourages such an orientation, as Kinoshita provides that a parallel orientation increases lithium-ion acceptance, reduces delamination and improves cycle performance
Applicant’s arguments have been fully considered and are persuasive.
The 35 U.S.C. 102(a)(1) rejection of claims 1-6, 8-10, and 14 as being anticipated or obvious over Kinoshita has been withdrawn. Therefore, the 35 U.S.C. 103 rejections of the dependent claims 7 and 11-13 over Kinoshita have also been withdrawn. All other arguments directed toward Kinoshita described by applicant in the remarks filed July 15th, 2026 have been considered moot.
In the remarks filed July 15th, 2026, applicant argues that Hans fails to disclose the newly amended limitation of the first negative active material layer or the second negative active material layer comprises a crystalline carbon-based negative active material and an Si-based negative active material. Applicant provides that Han appears to provide that the first negative electrode active material layer may include Si or SiOx, inter alia, however does not appear to disclose that the first negative electrode active material layer 20 includes both a crystalline carbon-based negative active material and a Si-based negative active material.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner presents that as indicated in the Non-Final Rejection mailed April 21st, 2026, Paragraph 0028 of the disclosure of Hans indicates that the first negative electrode active material layer may be a material which is commonly used in lithium secondary batteries, including natural and artificial graphite as well as silicon Si, Si-C, or a mixture of metal and carbon. Particularly, Hans discloses that a commonly used metal in negative electrode active material layers including silicon, which may be used in combination with a carbon. Therefore, Hans exemplifies that it is possible to use silicon in combination with carbon in the first negative electrode active material layer, meeting the instant claimed limitations.
In the remarks filed July 15th, 2026, applicant argues that Han appears to teach away from adding a Si-based negative active material to the second negative active material layer 30 as Han provides that the flake- shaped graphite particles provide the pore structure and reduced tortuosity to reduce resistance in the negative electrode.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner presents that applicant’s presentation of the teachings of Han with respect to the flake-shaped graphite particles in the second negative active material layer does not constitute a teaching away because Hans does not criticize, discredit, or otherwise discourage the addition of silicon in the second active material layer. Thus, the modification to include silicon in addition to the crystalline carbon material discussed above is considered a proper obviousness rejection that meets the instant claimed limitations, as the prior art references of record do not expressly exclude their combination.
While Hans teaches a possible embodiment in which the second negative electrode active material layer may be substantially made of only flake-type active material particles, this does not preclude some amount of silicon included in the layer. Further, the invention of the prior art is not limited to or defined by only those embodiments disclosed in the Examples. Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 424 (CCPA 1971).
In the remarks filed July 15th, 2026, applicant argues that inherency is improperly relied upon in presuming that Han teaches the instant claimed limitations. Applicant provides that as discussed above, the present specification demonstrates that different magnetic-field treatments and layer orientations can produce materially different A values, including A=6 and A=-22 in the comparative examples.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner presents that in applicant’s arguments that inherency is improperly relied upon in the rejection of the instant claims over Han, applicant does not point said the supposed errors, instead providing that the specification shows that “different” magnetic-field treatments and layer orientations can produce materially different A values as exemplified in the comparative examples.
It appears to the Examiner that in the comparative examples 2 and 3, corresponding to A=6 and A=-22, respectively, the difference in the magnetic field treatments described above by applicant seems to be the act of applying the magnetic field itself. For Example, in Example 2 the first negative active material layer was coated on a Cu foil without applying a magnetic field, while in Comparative Example 2, the first negative active material slurry was coated on the Cu foil while being exposed to a magnetic field. As discussed in the Non-Final Rejection, Han teaches the magnetic field only applied to the second negative electrode active material layer prior to drying and does not utilize a magnetic field to form the first negative electrode active material layer. Further, also pointed out in the Non-Final Rejection was that the strength of the magnetic field of Han overlapped with that of the instant disclosure, which lends support to the Examiner’s inherency argument which underscores the similarity in the magnetic field treatment of Han compared to that of the instant disclosure which would lead the ordinary artisan to presume that the aforementioned properties are inherent to Hans.
Further, with respect to applicant’s argument that the layer orientations produce different A values, the Examiner submits that Hans teaches the layer orientations set forth by the instant application. The instant application provides that the first negative active material layer (bottom layer) is a non-orientated layer such that the active material is substantially horizontal and parallel to the current collector while the second negative active material layer is an orientated layer such that the active material is vertical relative to the current collector (Paragraph 0052). As discussed above, Han does not utilize a magnetic field to form the first negative electrode active material layer in order to not vertically align the particles and maintain contact with the current collector (thus it is non-oriented) (Paragraph 0021) and that the second negative electrode active material has its active material particles aligned in a vertical direction (Paragraph 0020).
Therefore, there is nothing in Han to suggest that the instant claimed limitations relating to the properties of the first and second active material layers of the negative electrode would not be inherent to Han nor has the applicant provided specific, convincing evidence that a different structure would result from the process materials and conditions as described by Han.
In the remarks filed July 15th, 2026, applicant argues that Takanobu does not cure the deficiencies. Applicant provides that Takanobu teaches silicon fine powder embedded in a graphite base material with voids formed around the silicon fine powder, not a second negative active material layer having the claimed DD/A relationship. Accordingly, Takanobu does not provide an apparent reason to modify Han's second negative active material layer to include a Si-based negative active material in the manner now claimed.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner presents that arguments directed toward the application of prior art to the newly amended limitations are moot, as the amendments facilitate a new grounds of rejection of the limitation of the second negative active material layer having the Si-based negative active material (as directed in new claim 17) which are presented above in the updated rejection.
Further, the Examiner presents that Takanobu provides the benefits of using silicon and graphite together as negative electrode active material, which thus motivated the Examiner to modify both layers of Han to incorporate these materials in order to obtain the benefits of increasing capacity, as recognized by Takanobu, in both layers. However, an alternate rejection in view of Lee was made in the rejection above which motivated the incorporation of silicon in addition to a crystalline carbon-based material in the second layer.
In the remarks filed July 15th, 2026, applicant argues that Takahata fails to disclose or suggest the instant amended features of claim 1. Applicant argues that the first region A1 appears to have graphite particles that lie flat relative to the negative electrode current collector 241 A and the second region A2 appears to have graphite particles that are relatively perpendicular to the negative electrode current collector 241 A. However, there is a region between the first region A1 and the second region A2 (approximately 40% of the negative electrode active material according to Takahata) in which groups of graphite particles having different perpendicularities are mixed. Applicant provides that Takahata's first region A1 and second region A2 are not separately recited negative active material layers directly on one another. Rather, they are sub-regions of a single negative electrode active material layer 243A, with A 1 defined as the 0%-30% thickness region from the current collector and A2 defined as the 70%-100% thickness region from the current collector.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner point out that applicant’s assertion that “Takahata's first region A1 and second region A2 are not separately recited negative active material layers directly on one another” is narrower in scope than the instant claimed limitations. The Examiner presents that as written, the claim provided that the second negative active material layer is on the first negative active material layer, where applicant’s own specifically describes “on” as allowing intervening elements.
Further in response to applicant’s arguments with respect to the lack of layers in the disclosure of Takahata, the Examiner presents that the instant claim does not provide any other structural limitations that define a layer that would preclude the ordinary artisan from considering the first and second regions of Takahata to be layers in accordance with the instant claimed limitations.
In the remarks filed July 15th, 2026, applicant argues that Takahata also does not disclose or suggest Applicant's claimed XRD-based DD metric. Takahata evaluates "perpendicularity" using an SEM-based particle-count ratio m1/m2, where m1 is the number of graphite particles having inclinations of 60° to 90° and m2 is the number of graphite particles having inclinations of 0° to 30°. Claim 1, by contrast, defines DD using XRD peak intensities, specifically Ia/Itotal, where la is a sum of peak intensities at non-planar angles and Itotal is a sum of peak intensities at all recited angles. Takahata's SEM-count perpendicularity metric is not Applicant's XRD-based DD metric, and Takahata does not disclose or suggest the claimed A~10 relationship calculated from DD values.
Applicant further argues the Office Action's optimization rationale is also insufficient because Takahata does not disclose Applicant's DD or A value as a result-effective variable. Takahata's perpendicularity N1/N2 values are based on SEM-counted particle inclinations, while Applicant's DD/A relationship is based on XRD peak intensities. The cited art therefore does not establish that optimizing Takahata's perpendicularity would have led a person of ordinary skill in the art to the claimed DD values or A~10.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner presents that in the rejection of record set forth in the Non-Final Rejection mailed April 21st, 2026, the Examiner did not equate the DD metric of the instant application with the perpendicularity of Takahata. The Examiner merely set forth that these parameters are related, as the instant application provides in the specification and the drawings that Dd and the angle a corresponding to the orientation of the graphite with respect to the substrate are directly related, with DD increasing as the angle a is increased as well. This is similar to θn of Takahata, which is directly proportional to the orientation of the graphite particles, with more upright graphite particles having a larger θn. As both θn of Takahata and angle a of the instant application increase as the active material particles are orientated more upright, away from a horizontal substrate, the Examiner was able to relate θn to the DD metric of the instant application.
Thus, the information in the disclosure of Takahata regarding the motivation (increased lithium ion mobility and reduced resistance) to tune the perpendicularity of the particles in the negative electrode active material layers would also result in the optimization of the DD values in these layers as well, as both of these values are related to the angle measured between the active material particle and the substrate/current collector. It is within the ambit of one of ordinary skill to tune θn (and therefore the DD value) to be within the instant claimed range in order to optimize the orientation of the negative active material to result in increased lithium ion mobility and reduced resistance.
In the remarks filed July 15th, 2026, applicant argues that Takanobu does not cure the deficiencies of Takahata. Applicant argues that Takanobu teaches silicon fine powder embedded in a graphite base material and voids formed around the silicon fine powder to absorb volume expansion. Takanobu does not teach Applicant's two-layer arrangement, a second negative active material layer directly on a first negative active material layer, an XRD-based DD value for either layer, or an A~10 relationship. Nor is there any apparent teaching, suggestion, disclosure, or reason in Takanobu that would have led a person of ordinary skill in the art to modify Takahata's graphite-region structure to provide the claimed second negative active material layer comprising a Si-based negative active material while also arriving at Applicant's DD/A relationship.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner presents that arguments directed toward the application of prior art to the newly amended limitations are moot, as the amendments facilitate a new grounds of rejection of the limitation of the second negative active material layer having the Si-based negative active material (as directed in new claim 17) which are presented above in the updated rejection.
Further, the Examiner presents that Takanobu provides the benefits of using silicon and graphite together as negative electrode active material, which thus motivated the Examiner to modify both layers taught by Takahata to incorporate these materials in order to obtain the benefits of increasing capacity, as recognized by Takanobu, in both layers. However, an alternate rejection in view of Lee was made in the rejection above which motivated the incorporation of silicon in addition to a crystalline carbon-based material in the second layer.
In the remarks filed July 15th, 2026, applicant argues the comparative data show that A~10 is not merely an arbitrary optimization: Examples 1-3 with A~10 exhibited reduced thickness increase and avoided severe separation, whereas Comparative Example 2 with A=6 exhibited severe separation and Comparative Example 3 with A=-22 exhibited a higher thickness increase rate.
These arguments have been fully considered but are not persuasive.
In response to applicant’s arguments, the Examiner presents that if applicant is attempting to argue unexpected results, the Examiner notes that it is the burden of Applicant to provide evidence that establishes that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance. See MPEP 716.02(b)(I). Applicants have the burden of explaining proffered data. See MPEP 716.02(b)(II). It is further noted that in order to establish unexpected results over a claimed range, Applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. See MPEP 716.02(d) II. Additionally, the claims must be commensurate in scope with the proffered data to provide a nexus between the claims and the data establishing evidence of unexpected results. See MPEP 716.02(d).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to OLIVIA A JONES whose telephone number is (571)272-1718. The examiner can normally be reached Mon-Fri 7:30 AM - 4:30 PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Marla McConnell can be reached at (571) 270-7692. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/O.A.J./Examiner, Art Unit 1789
/JENNIFER A BOYD/Supervisory Patent Examiner, Art Unit 1786
Prosecution Insights