DETAILED ACTION
Claims 1, 4, and 6-16 are presented for examination, wherein claim 1 is currently amended; plus, claim 16 is newly added. Claims 2-3 and 5 are cancelled.
The alternate 35 U.S.C. § 103 rejection of claims 1, 4, and 7-15 over Zeng is withdrawn, as a result of the amendments to claim 1, from which the other claims depend or incorporate by reference. However, see infra.
The applicant’s May 19, 2025 Request for Participation in the Patent Prosecution Highway was granted by the USPTO on June 10, 2025.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on October 22, 2025 has been entered.
Claim Rejections - 35 USC § 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 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 4, and 6-15 are rejected under 35 U.S.C. 103 as being unpatentable over Zeng (CN 113437254, published September 24, 2021) in view of Zhamu et al (US 2012/0171574); alternatively, Zeng (Id) in view of Kobayashi et al (US 2012/0082892) and Zhamu et al (Id).
Regarding newly amended independent claim 1, Zeng teaches a negative electrode plate for use in a rechargeable sodium-ion battery, and an electrochemical device incorporating said sodium-ion battery, said battery comprising:
(i) a positive electrode plate comprising a positive electrode current collector and a positive electrode active material layer formed on at least a portion of a surface of said positive electrode current collector,
wherein said positive electrode active material layer including a positive electrode active material that may be a polyanionic compounds, for example, at least one of NaFePO4, Na3V2 (PO4)3, NaM’PO4F (M’ is one or more of V, Fe, Mn and Ni), and Na3 (VOy)2 (PO4)2F3-2y (0≤y≤1);
(ii) an electrolyte that may include an organic solvent and an electrolyte sodium salt,
wherein said organic solvent may be one or more of e.g. diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether; and,
wherein said electrolyte sodium salt may be one or more of sodium hexafluorophosphate, sodium trifluoromethanesulfonate, sodium perchlorate; and,
(iii) said negative electrode plate comprising a negative electrode current collector (e.g. item 11) and a carbon material coating (e.g. item 12) formed on at least a portion of a surface of said negative electrode current collector,
wherein said carbon material coating on said surface of said negative electrode current collector, improving conductivity of sodium ion diffusion and preferentially combining with sodium ions to form uniform sodium metal nuclei, thereby reducing an overpotential of subsequent sodium intercalation reaction, improving uniformity of sodium metal deposition, inhibiting formation and growth of sodium dendrites, and improving the cycle performance of the sodium metal negative electrode; and,
wherein using two or more carbon materials expand the conductivity dimension of the carbon material and improve the conductivity of the carbon material,
(iii.a) said negative electrode current collector includes at least one of e.g. a porous aluminum foil, a porous copper foil, and a porous stainless steel foil,
said negative electrode current collector with a thickness of e.g. 3 μm to 15 μm
(iii.b) said carbon material coating comprising a carbon material and a polymer binder,
wherein said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, carbon nanotubes, and graphene,
noting hereinafter that said hard carbon, carbon fiber, carbon black, carbon nanotubes, and graphene are severably understood to be “particles;”
a mass proportion of said carbon material in said carbon material coating is 90% to 99%, such as 94-97%;
wherein said polymer binder may be e.g. sodium carboxymethyl cellulose; and,
said carbon material coating preferably has a thickness of 1-7 µm,
(iii.c) further, said negative electrode plate may include a sodium metal layer (e.g. item 13) deposited by nucleation on at least a portion of said surface of said carbon material coating away from said negative electrode current collector after said sodium-ion battery is charged for a first time, wherein sodium metal is deposited on said surface of said carbon material coating away from said negative electrode current collector
(e.g. ¶¶ 0001, 04-15, 21-23, 25, 33, 37-39, 43-46, 59-60, 68, and 101 plus e.g. Figure), reading on “negative electrode current collector,” said negative electrode current collector plate comprising:
(1) said negative electrode current collector (e.g. item 11) includes at least one of said porous aluminum foil, said porous copper foil, and said porous stainless steel foil, wherein said negative electrode current collector with a thickness of e.g. 3 μm to 15 μm (e.g. supra), reading on “a metal substrate;” and,
(2) said carbon material coating (e.g. item 12) formed on at least said portion of said surface of said negative electrode current collector,
wherein said carbon material coating on said surface of said negative electrode current collector, improving conductivity of sodium ion diffusion and preferentially combining with sodium ions to form uniform sodium metal nuclei, thereby reducing an overpotential of subsequent sodium intercalation reaction, improving uniformity of sodium metal deposition, inhibiting formation and growth of sodium dendrites, and improving the cycle performance of the sodium metal negative electrode; and,
wherein using two or more carbon materials expand the conductivity dimension of the carbon material and improve the conductivity of the carbon material;
wherein said carbon material coating comprising said carbon material and said polymer binder; and,
wherein said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, carbon nanotubes, and graphene; said mass proportion of said carbon material in said carbon material coating is 90% to 99%, such as 94-97%;
wherein said polymer binder may be e.g. sodium carboxymethyl cellulose; and,
said carbon material coating preferably has said thickness of 1-7 µm (e.g. supra), reading on “a conductive layer provided on at least one surface of the metal substrate” and establishing a prima facie case of obviousness of the claimed range, see also e.g. MPEP § 2144.05(I), reading on “the conductive layer has a thickness of 0.5 µm-6 µm.”
Regarding the limitation “the negative electrode current collector has a Vickers hardness of 400 Mpa-850 Mpa,” Zeng teaches said negative electrode current collector plate comprising
(1) said negative electrode current collector (e.g. item 11) includes at least one of said porous aluminum foil, said porous copper foil, and said porous stainless steel foil, wherein said negative electrode current collector with a thickness of e.g. 3 μm to 15 μm; and,
(2) said carbon material coating (e.g. item 12) formed on at least said portion of said surface of said negative electrode current collector,
wherein using two or more carbon materials expand the conductivity dimension of the carbon material and improve the conductivity of the carbon material;
wherein said carbon material coating comprising said carbon material and said polymer binder; and,
wherein said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, carbon nanotubes, and graphene; said mass proportion of said carbon material in said carbon material coating is 90% to 99%, such as 94-97%;
wherein said polymer binder may be e.g. sodium carboxymethyl cellulose; and,
wherein said carbon material coating preferably has said thickness of 1-7 µm
(e.g. supra), but does not expressly teach said limitation.
However, Zeng teaches a substantially identical negative electrode plate (see supra, incorporated herein by reference, compared with instant specification, at e.g. ¶¶ 0006-11, 21, 44, 46-52, 55-60, and 116-122), establishing a prima facie case of obviousness of the claimed limitation, see also e.g. MPEP § 2112.01; and/or,
Kobayashi teaches a lithium-ion secondary battery with a negative electrode plate comprising a negative electrode current collector comprising a substrate composed of a copper alloy and a surface layer composed of pure copper, said negative electrode current collector having a Vickers hardness of 300 MPa or greater to inhibit deformation, such as bending (e.g. ¶¶ 0001, 14, 20-21, 72, 80, and 91 plus e.g. Figure).
As a result, it would have been obvious to a person of ordinary skill in the art to optimize the Vickers hardness of the Zeng current collector to a range of 300 MPa or greater, since Kobayashi teaches the Vickers hardness of a current collector in a range of 300 MPa or greater may be optimized to inhibit deformation, such as bending, establishing a prima facie case of obviousness of the claimed range, see also e.g. MPEP § 2144.05(I), reading on said limitation.
The examiner appreciates that Kobayashi battery is a lithium-ion secondary battery, whereas the Zeng battery is a sodium-ion secondary battery. However, a person of ordinary skill in the art would appreciate that lithium and sodium are in the same column in the Periodic Table have similar characteristics and/or lithium-ion and sodium-ion batteries are similar at least in that inhibiting deformation, such as bending, is an improvement to consider between said batteries.
Regarding the Vicker’s hardness limitation, the instant specification provides the following, noting the importance of the instant conductive layer comprising a hard carbon composition and thickness of the instant conductive layer being thin, resulting in improved processing.
SUMMARY
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[0007] A first aspect of the present application provides a negative electrode current collector. The negative electrode current collector includes a metal substrate and a conductive layer provided on at least one surface of the metal substrate, where the negative electrode current collector has a Vickers hardness of 400 Mpa-850 Mpa, and the conductive layer has a thickness of 0.5 μm-6 μm, optionally 0.5 μm-5 μm.
[0008] In the above embodiment, on the basis of minimized increases in thickness of the conductive layer, the overall hardness of the negative electrode current collector is improved, thereby improving the processability of the negative electrode plate while ensuring the high-capacity characteristics of the battery. Moreover, the control on the hardness of the negative electrode current collector avoids the occurrence of a brittle failure during processing caused by excessive hardness of the negative electrode current collector. If the thickness of the conductive layer exceeds 6 μm, the negative electrode current collector is susceptible to breakage, and the negative electrode plate is prone to edge collapse, leading to severe separation between powder materials and the current collector and difficulties in cutting and subsequent processing.[0009] In any embodiment according to the first aspect, the conductive layer includes a conductive particle and a binder, the conductive particle includes a first conductive material and a second conductive material, the first conductive material includes any one or more selected from the group consisting of a hard carbon and a soft carbon, and the second conductive material includes any one or more selected from the group consisting of a conductive carbon black, a carbon dot, a graphene, a carbon nanotube, a carbon fiber, and a metal micro-nano particle; optionally, the conductive carbon black includes Ketjen black, acetylene black, and Super P carbon black. The first conductive material has a greater hardness, which increases the hardness of the conductive layer; the second conductive material, with better conductivity and a greater specific surface area, facilitates the material deposition and improves the cycle reversibility of metal sodium or metal lithium.
…
[0011] In any embodiment according to the first aspect, the hard carbon has a Vickers hardness of 450 Mpa-800 Mpa. In any embodiment according to the first aspect, the first conductive material has a DV50 particle size of 0.5 μm-6 μm.
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[0021] A second aspect of the present application provides a secondary battery. The secondary battery includes a positive electrode plate and a negative electrode plate, where the negative electrode plate includes a negative electrode current collector, and the negative electrode current collector includes any one of the negative electrode current collectors according to the first aspects. The increased hardness of the negative electrode current collector provided by the present application improves the processing performance of the negative electrode current collector; due to the control of the thickness of the conductive layer, the capacity of the battery is enhanced. Therefore, the secondary battery of the present application features high processability and high-capacity characteristics.
…
DETAILED DESCRIPTION
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[Negative Electrode Current Collector]
[0044] In order to increase the hardness of the negative electrode plate and improve its processability, the thickness of the conductive layer in the negative electrode current collector is generally increased. That is, the ratio of the conductive layer to the current collector is increased, which may result in a greater hardness of the electrode plate and easier processing. However, in the experiment of increasing the thickness of the conductive layer, it has been found that the capacity performance of the negative electrode battery is deteriorated by simply increasing the thickness. The reasons for this may be that when the thickness of the conductive layer is increased, the conductive layer consumes some lithium ions or sodium ions, resulting in an insufficient amount of lithium metal or sodium metal deposited on the conductive layer. Moreover, such a chemical reaction may be repeated during the charging and discharging process of the battery, ultimately leading to a decrease in the capacity of the battery and an imbalance between the battery performance and the processing performance.
[0045] One embodiment of the present application provides a negative electrode current collector. The negative electrode current collector includes a metal substrate and a conductive layer provided on at least one surface of the metal substrate, where the conductive layer includes a conductive particle and a binder, the negative electrode current collector has a Vickers hardness of 400 Mpa-850 Mpa, and the conductive layer has a thickness of 0.5 μm-6 μm.
[0046] In the above embodiment, on the basis of minimized increases in thickness of the conductive layer, the overall hardness of the negative electrode current collector is improved, thereby improving the processability of the negative electrode plate while ensuring the high-capacity characteristics of the battery. Moreover, the control on the hardness of the negative electrode current collector avoids the occurrence of a brittle failure during processing caused by excessive hardness of the negative electrode current collector. If the thickness of the conductive layer exceeds the range described above, the negative electrode current collector is susceptible to breakage, and the negative electrode plate is prone to edge collapse, leading to severe separation between powder materials and the current collector and difficulties in cutting and subsequent processing.
[0047] Optionally, the negative electrode current collector has a Vickers hardness of 400 Mpa-850 Mpa, including but not limited to, 400 Mpa, 450 Mpa, 460 Mpa, 480 Mpa, 500 Mpa, 550 Mpa, 600 Mpa, 650 Mpa, 700 Mpa, 750 Mpa, 800 Mpa, 810 Mpa, or 850 Mpa; optionally, the negative electrode current collector has a Vickers hardness of 460 Mpa-800 Mpa, 550 Mpa-800 Mpa, or 600 Mpa-760 Mpa.
…
[0050] In order to maximize the Vickers hardness of the conductive particle while improving the conductivity thereof, the conductive layer includes a conductive particle and a binder in some embodiments. The overall hardness of the negative electrode current collector may be improved by using a conductive particle with a greater hardness or a binder with a greater hardness or a metal substrate with a greater hardness in the art.
…
[0052] The first conductive material has a greater hardness, which increases the hardness of the conductive layer; the second conductive material, with better conductivity and a greater specific surface area, facilitates the material deposition and improves the cycle reversibility of metal sodium or metal lithium.
…
[0055] In some embodiments, a hard carbon particle with a greater Vickers hardness is selected to increase the hardness of the negative electrode current collector. For example, the hard carbon has a Vickers hardness of 450 Mpa-800 Mpa. By using a hard carbon with a greater Vickers hardness, the hardness of the conductive layer is increased, which increases the overall hardness of the negative electrode current collector is increased. Moreover, the increased hardness of the conductive layer allows an easier control of the conductive layer's thickness in a smaller range less than 6 μm, which is beneficial for improving the capacity performance of the battery.
(Instant specification, at e.g. ¶¶ 0007-09, 11, 21, 44-47, 50, 52, and 55, emphasis added.)
Regarding the previously added limitation incorporating the subject matter of former claim 2, “the conductive layer comprises a conductive particle and a binder, the conductive particle comprises a first conductive material and a second conductive material, the first conductive material comprises any one or more selected from the group consisting of a hard carbon and a soft carbon, and the second conductive material comprises any one or more selected from the group consisting of a conductive carbon black, a carbon dot, a graphene, a carbon nanotube, a carbon fiber, and a metal micro-nano particle,” Zeng teaches said carbon material coating comprising said carbon material and said polymer binder, wherein said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, carbon nanotubes, and graphene (e.g. supra), noting hereinafter that said hard carbon, carbon fiber, carbon black, carbon nanotubes, and graphene are severably understood to be “particles,” reading on said previously added limitation.
Regarding the previously added limitations incorporating a modified subject matter of former claim 3, providing two options (two limitations separated by an “or” conjunction), denoted as “option 1” and “option 2.”
[option 1]: “the conductive particle comprises the hard carbon and the conductive carbon black, the hard carbon is present in the conductive particle at a mass content of 50%-90%, and the conductive carbon black is present in the conductive particle at a mass content of 10%-50%; or”
[option 2]: “the conductive particle comprises the hard carbon, the conductive carbon black, and the carbon nanotube, and the hard carbon is present in the conductive particle at a mass content of 50%- 90%, the conductive carbon black is present in the conductive particle at a mass content of 10%-50%, and the carbon nanotube is present in the conductive particle at a mass content of 0.001%-1%,”
Regarding option 1, Zeng teaches said carbon material coating comprising said carbon material and said polymer binder, wherein said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, carbon nanotubes, and graphene (e.g. supra), reading on “the conductive particle comprises the hard carbon and the conductive carbon black,” but does not expressly teach “the hard carbon is present in the conductive particle at a mass content of 50%-90%, and the conductive carbon black is present in the conductive particle at a mass content of 10%-50%.”
However, Zeng expressly teaches the carbon material is “preferably…at least two of” components that include hard carbon and carbon black, wherein “the mixed use of two or more carbon materials can expand the conductivity dimension of the carbon material and improve the conductivity of the carbon material” and further teaches an express example including three carbon materials, wherein each of the three carbon materials is present in equal amounts (“a mass ratio of 1:1:1”).
[0040] As an optional technical solution of the present application, the carbon material coating 12 includes a carbon material and a polymer binder.
The carbon material includes at least one of mesocarbon microbeads, graphite, natural graphite, expanded graphite, artificial graphite, glassy carbon, carbon-carbon composite materials, carbon fibers, hard carbon, porous carbon, highly oriented graphite, three-dimensional graphite, carbon black, carbon nanotubes and graphene.
It can be understood that by forming a carbon material coating on the surface of the negative electrode current collector, the conductivity of sodium ion diffusion can be improved, the sodium insertion overpotential can be reduced, and the formation and growth of sodium dendrites can be inhibited.
[0041] Preferably, the carbon material includes at least two of mesocarbon microbeads, graphite, natural graphite, expanded graphite, artificial graphite, glassy carbon, carbon-carbon composites, carbon fibers, hard carbon, porous carbon, highly oriented graphite, three-dimensional graphite, carbon black, carbon nanotubes and graphene.
In one embodiment, the carbon material may be a mixture of carbon black, graphene, and carbon nanotubes, with a mass ratio of 1:1:1.
It can be understood that compared with the use of a single carbon material, the mixed use of two or more carbon materials can expand the conductivity dimension of the carbon material and improve the conductivity of the carbon material.
(Zeng, at ¶¶ 0040-41, emphasis added.).
As a result, it would have been obvious to a person of ordinary skill in the art to incorporate two carbon materials in said carbon material layer, since Zeng expressly teaches it preferably may include two carbon materials.
Further, it would have been obvious to a person of ordinary skill in the art to incorporate the expressly taught hard carbon and carbon black as the specific two carbon materials, since they are expressly taught to be suitable for use in said carbon material layer, and are two of only a limited choice of expressly taught carbon materials.
Finally, it would have been obvious to a person of ordinary skill in the art to incorporate said hard carbon and carbon black in equal amounts within said carbon material layer, since Zeng expressly teaches an example that provides carbon materials provided in equal amounts (i.e. 50% each) to one another (see supra, the express example providing three carbon materials in a 1:1:1 mass ratio to one another).
As a result, Zeng or Zeng as modified providing for said hard carbon and carbon black in equal amounts (i.e. 50% each) within said carbon material layer to one another (supra), severably establishing a prima facie case of obviousness of the claimed ranges, see also e.g. MPEP § 2144.05(I), reading on the limitation of option 1 “the conductive particle comprises the hard carbon and the conductive carbon black, the hard carbon is present in the conductive particle at a mass content of 50%-90%, and the conductive carbon black is present in the conductive particle at a mass content of 10%-50%.”
In comparison, the instant specification provides examples that expressly teach amounts of the claimed “hard carbon” and “conductive carbon black” that are outside the previously added claimed ranges.
(1) the amount of the claimed “hard carbon” in instant examples 11 and 17-18 outside the previously added claimed range; and,
(2) the amount of the “conductive carbon black” in examples 11 and 17-18 outside the previously added claimed range, including example 11, which does not include any carbon black (i.e. 0 mass%) and only includes carbon nanotubes (i.e. 5 mass%) as the second conductive material.
A portion of Table 1 reproduced below for ease of reference:
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343
837
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Further, the instant specification provides the claimed ranges of each the claimed “hard carbon” and “conductive carbon black” are merely optional, and does not appear to suggest the previously added claimed ranges are critical.
Zeng or Zeng as modified reading on the previously added limitations.
Regarding the newly added limitation “the first conductive material has a Dv50 particle size of 0.5 µm-6 µm,” incorporating the subject matter of former claim 5, Zeng teaches said carbon material coating preferably has said thickness of 1-7 µm (e.g. supra), so it is understood that a particle of said carbon material has at most a 1-7 µm particle size (i.e. the carbon material layer is one carbon material particle thick); and, Zeng teaches said carbon material coating on said surface of said negative electrode current collector, improving conductivity of sodium ion diffusion and preferentially combining with sodium ions to form uniform sodium metal nuclei, thereby reducing an overpotential of subsequent sodium intercalation reaction, improving uniformity of sodium metal deposition, inhibiting formation and growth of sodium dendrites, and improving the cycle performance of the sodium metal negative electrode (e.g. supra), but does not expressly teach said newly added limitation.
However, Zhamu teaches a metal ion exchanging battery, wherein said metal ion may be sodium, wherein the battery anode may include micron scaled hard carbon particles, carbon black, carbon nano-fiber, graphene, and carbon nanotubes, wherein said hard carbon particles—used in sodium-ion batteries—are conventionally about 5 microns in diameter; and, wherein said carbon nanotubes may have a high specific surface area of e.g. 100-1,500 m2/g, wherein said high specific surface area results in enabling receiving, deposition, and/or capturing large amounts of alkali ions (e.g. ¶¶ 0028, 32-33, 41, 44, 47, 50-52, 54-66, 91-92, 104-110, 114-118, 147-151, 158, 164, and 190).
As a result, it would have been obvious to a person of ordinary skill in the art to use said micron scaled hard carbon particles of Zhamu, which have a diameter of about 5 microns, as the hard carbon of Zheng or Zheng as modified, since Zhamu teaches said micron scaled hard carbon particles are conventionally used in sodium-ion batteries, which indicates that they are suitable for use with sodium-ion batteries and/or readily available to sodium-ion battery manufacturers, noting said teaching indicates said particle diameter is either an average or a uniform particle size distribution; and, further noting there does not appear to be patentable significance of the method of measuring the d50 particle size by volume, see e.g. instant specification, at e.g. ¶¶ 0059-60, 118, 141, and 143, establishing a prima facie case of obviousness of the claimed range, see also e.g. MPEP § 2144.05(I), reading on said newly added limitation.
Regarding the Dv50 limitation, the instant specification provides the following, noting its importance is in improving the quality of sodium metal deposition, so that it is smoother and reduces sodium dendrites, similar to the teaching of Zeng (improving uniformity of sodium metal deposition, inhibiting formation and growth of sodium dendrites).
[0059] Due to its high hardness, the first conductive material, as a particle, has an increased wetting angle with metal sodium or metal lithium, which affects the deposition of the sodium metal or lithium metal. In order to minimize this effect, in some embodiments, the first conductive material has a DV50 particle size of 0.5 μm-6 μm. The first conductive material has a DV50 particle size controlled at 0.5 μm-6 μm, which ensures a wetting angle between the first conductive material and sodium or lithium of less than 90 degrees. As a result, sodium or lithium deposited on the first conductive material is smoother, thus effectively reducing sodium dendrite and damages to a separation film. Moreover, a smaller DV50 particle size of the first conductive material within the above range may result in a dispersed distribution in the conductive layer that is desirable for improving the Vickers hardness of the negative electrode current collector. In some embodiments, the DV50 particle size of the first conductive material is optionally 1 μm-6 μm, 0.5 μm-5 μm, or 1 μm-2 μm, for example, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, or 6 μm. The above DV50 is measured using a laser particle size analyzer.
(Instant specification, at e.g. ¶0059, emphasis added.)
Regarding claim 4, Zeng as modified teaches the negative electrode plate of claim 1, wherein Zeng teaches a substantially identical negative electrode plate (see supra, incorporated herein by reference, compared with instant specification, at e.g. ¶¶ 0006, 10, 46-51, 56-60, and 116-122), establishing a prima facie case of obviousness of the claimed limitation, see also e.g. MPEP § 2112.01; and/or, said current collector of Zeng as modified has said Vickers hardness of a current collector in a range of 300 MPa or greater, establishing a prima facie case of obviousness of the claimed range, see also e.g. MPEP § 2144.05(I), reading on the limitation “the hard carbon has a Vickers hardness of 450 Mpa-800 Mpa.”
Regarding claim 6, as modified teaches the negative electrode plate of claim 1, wherein Zeng teaches said carbon material coating comprising said carbon material and said polymer binder, wherein said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, carbon nanotubes, and graphene (e.g. supra), but does not expressly teach the limitation “the second conductive material has a BET specific surface area of 5 m2/g-3000 m2/g.”
However, Zhamu teaches said metal ion exchanging battery, wherein said metal ion may be sodium, wherein the battery anode may include micron scaled hard carbon particles, carbon black, carbon nano-fiber, graphene, and carbon nanotubes, wherein said hard carbon particles—used in sodium-ion batteries—are conventionally about 5 microns in diameter (e.g. supra); and, wherein said carbon nanotubes may have a high specific surface area of e.g. 100-1,500 m2/g, wherein said high specific surface area results in enabling receiving, deposition, and/or capturing large amounts of alkali ions (e.g. supra).
As a result, it would have been obvious to a person of ordinary skill in the art to use said carbon nanotubes of Zhamu, which may have said high specific surface area of e.g. 100-1,500 m2/g, as the carbon nanotubes of Zheng as modified, since Zhamu teaches said carbon nanotubes with said high specific surface area of e.g. 100-1,500 m2/g results in enabling receiving, deposition, and/or capturing large amounts of alkali ions; alternatively, are suitable for use with sodium-ion batteries, and/or readily available to sodium-ion battery manufacturers, severably establishing a prima facie case of obviousness of the claimed ranges, see also e.g. MPEP § 2144.05(I), reading on “the second conductive material has a BET specific surface area of 5 m2/g-3000 m2/g.”
Regarding claim 7, Zeng as modified teaches the negative electrode plate of claim 1, wherein Zeng teaches said carbon material coating comprising said carbon material and said polymer binder, wherein said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, carbon nanotubes, and graphene (e.g. supra), wherein the claimed carbon nanotubes is merely an option and not required (see also option 1 of claim 1, wherein the conductive particle is “the hard carbon and the conductive carbon black”), further noting that Zeng teaches said carbon material may include (1) hard carbon and further (2) at least one of carbon fiber, carbon black, and graphene (i.e. not including carbon nanotubes), so the claimed limitation “the carbon nanotube satisfies any one or more of the following conditions: the carbon nanotube has an average length of 0.5 µm-30 µm; the carbon nanotube has an average diameter of 1 nm-100 nm; the carbon nanotube has a BET specific surface area of 200 m2/g-3000 m2/g” does not patentably distinguish the instant invention, as claimed.
In the alternative, Zhamu teaches said metal ion exchanging battery, wherein said metal ion may be sodium, wherein the battery anode may include micron scaled hard carbon particles, carbon black, carbon nano-fiber, graphene, and carbon nanotubes, wherein said hard carbon particles—used in sodium-ion batteries—are conventionally about 5 microns in diameter (e.g. supra); and, wherein said carbon nanotubes may have a high specific surface area of e.g. 100-1,500 m2/g, wherein said high specific surface area results in enabling receiving, deposition, and/or capturing large amounts of alkali ions (e.g. supra).
As a result, it would have been obvious to a person of ordinary skill in the art to use said carbon nanotubes of Zhamu, which may have said high specific surface area of e.g. 100-1,500 m2/g, as the carbon nanotubes of Zheng or Zheng as modified, since Zhamu teaches said carbon nanotubes with said high specific surface area of e.g. 100-1,500 m2/g results in enabling receiving, deposition, and/or capturing large amounts of alkali ions; alternatively, are suitable for use with sodium-ion batteries, and/or readily available to sodium-ion battery manufacturers, severably establishing a prima facie case of obviousness of the claimed ranges, see also e.g. MPEP § 2144.05(I), reading on “the carbon nanotube satisfies any one or more of the following conditions: the carbon nanotube has an average length of 0.5 µm-30 µm; the carbon nanotube has an average diameter of 1 nm-100 nm; the carbon nanotube has a BET specific surface area of 200 m2/g-3000 m2/g.”
Regarding claim 8, Zeng as modified teaches the negative electrode plate of claim 1, wherein Zeng teaches said carbon material coating comprising said carbon material and said polymer binder, wherein said mass proportion of said carbon material in said carbon material coating is 90% to 99%, such as 94-97% (e.g. supra) and said binder is understood to be the remainder (e.g. ¶0042), severably establishing a prima facie case of obviousness of the claimed ranges, see also e.g. MPEP § 2144.05(I), reading on “the conductive particle is present in the conductive layer at a mass content of 75%-98%, and the binder is present in the conductive layer at a mass content of 2%-25%.”
Regarding claim 9, Zeng as modified teaches the negative electrode plate of claim 1, wherein Zeng teaches said carbon material coating comprising said carbon material and said polymer binder, wherein said polymer binder may be e.g. sodium carboxymethyl cellulose (e.g. supra), reading on “the binder comprises one or more selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, sodium carboxymethylcellulose, methyl acrylate, ethyl acrylate, and a methyl methacrylate-acrylonitrile copolymer.”
Regarding previously amended claim 10, Zeng as modified teaches the negative electrode plate of claim 1, wherein Zeng teaches said negative electrode current collector (e.g. item 11) includes at least one of said porous aluminum foil, said porous copper foil, and said porous stainless steel foil, wherein said negative electrode current collector with a thickness of e.g. 3 μm to 15 μm (e.g. supra), establishing a prima facie case of obviousness of the claimed range, see also e.g. MPEP § 2144.05(I), reading on the previously amended limitation “the metal substrate comprises any one of a copper foil, a porous copper, a copper nanowire, an aluminum foil, and an aluminum alloy foil, the copper foil comprises a double-sided rough copper foil, a double-sided smooth copper foil, and a carbon-coated copper foil; and the porous copper comprises a porous copper foam and a copper mesh; and/or the metal substrate has a thickness of 5µm-60 µm.”
Regarding claims 11-15, Zeng in view of Zhamu and/or Zeng in view of Kobayashi and Zhamu are applied as provided supra, with the following modifications.
Still regarding independent claim 11, Zeng teaches said rechargeable sodium-ion battery and said electrochemical device incorporating said sodium-ion battery (e.g. supra), reading on “secondary battery,” said rechargeable sodium-ion battery comprising:
(1) said positive electrode plate comprising said positive electrode current collector and said positive electrode active material layer formed on at least said portion of said surface of said positive electrode current collector,
wherein said positive electrode active material layer including said positive electrode active material that may be said polyanionic compounds, for example, at least one of NaFePO4, Na3V2 (PO4)3, NaM’PO4F (M’ is one or more of V, Fe, Mn and Ni), and Na3 (VOy)2 (PO4)2F3-2y (0≤y≤1) (e.g. supra), reading on “a positive electrode plate;” and,
(2) said negative electrode plate comprising said negative electrode current collector (e.g. item 11) and said carbon material coating (e.g. item 12) formed on at least said portion of said surface of said negative electrode current collector (e.g. supra), reading on “a negative electrode plate, wherein the negative electrode plate comprises a negative electrode current collector.”
Still regarding claim 12, Zeng teaches said rechargeable sodium-ion battery of claim 11, wherein said negative electrode plate may further include said sodium metal layer (e.g. item 13) deposited by nucleation on at least said portion of the surface of said carbon material coating away from said negative electrode current collector after said sodium-ion battery is charged for said first time, wherein said sodium metal is deposited on said surface of said carbon material coating away from said negative electrode current collector (e.g. supra), reading on “the negative electrode plate is formed by in-situ deposition of a sodium layer on the negative electrode current collector after the secondary battery has been subjected to the first charge and discharge cycle.”
In the alternative, the process limitation formed by in-situ deposition…after the secondary battery has been subjected to the first charge and discharge cycle” does not patentably distinguish the instant invention from the claimed product, see also e.g. MPEP § 2113.
Still regarding claim 13, Zeng teaches said rechargeable sodium-ion battery of claim 11, wherein said positive electrode active material layer including said positive electrode active material that may be said polyanionic compounds, for example, at least one of NaFePO4, Na3V2 (PO4)3, NaM’PO4F (M’ is one or more of V, Fe, Mn and Ni), and Na3 (VOy)2 (PO4)2F3-2y (0≤y≤1) (e.g. supra), severably establishing a prima facie case of obviousness of the claimed ranges, see also e.g. MPEP § 2144.05(I), reading on “a positive electrode active substance of the positive electrode plate comprises any one or more oxides having the chemical formula of NaxMyPmOn, wherein M denotes a transition metal element comprising any one or more selected from the group consisting of Mn, Fe, Co, Cu, Al, Ti, and V, 1≤x≤2, 0≤y≤1, 1≤m≤2, 4≤n≤8,and 0≤x/m≤1.”
Still regarding claim 14, Zeng teaches said rechargeable sodium-ion battery of claim 11, wherein said electrolyte that may include said organic solvent and said electrolyte sodium salt (e.g. supra), reading on “the secondary battery further comprises an electrolyte, the electrolyte comprises a solvent and an electrolyte salt,”
wherein said organic solvent may be one or more of e.g. diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether; and, said electrolyte sodium salt may be one or more of sodium hexafluorophosphate, sodium trifluoromethanesulfonate, sodium perchlorate (e.g. supra), severably reading on “the solvent comprises one or more selected from the group consisting of dimethyl sulfide, dimethoxyethane, dioxolane, acetonitrile, diethylene glycol dimethyl ether, methyl trifluoroethyl carbonate, fluorobenzene, tetraethylene glycol dimethyl ether, triethyl phosphate, sulfolane, 2-methyl tetrahydrofuran, tetrahydrofuran, 2,2,2,2-trifluoroethyl ether, ethylene glycol diethyl ether, dimethyl sulfoxide, N,N-dimethylacetamide, and triethylene glycol dimethyl ether; optionally, the solvent comprises tetrahydrofuran and/or dimethoxyethane; and/or the electrolyte salt comprises at least two selected from the group consisting of sodium hexafluorophosphate, sodium perchlorate, sodium bis(fluorosulfonyl)imide, sodium trifluoromethanesulfonate, sodium sulfide, and sodium nitrate.”
Still regarding independent claim 15, Zeng teaches said electrochemical device incorporating said sodium-ion battery (e.g. supra), reading on “electrical device, comprising a secondary battery.”
Allowable Subject Matter
Newly added claim 16 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: none of the timely art of record teaches or suggests the claimed negative electrode current collector with the specifically claimed range of mass content of the conductive particle concentration relative to the conductive particle plus binder, in conjunction with all of the limitations of claim 1.
Response to Arguments
Applicant’s arguments filed September 7, 2025 have been fully considered but they are not persuasive.
First, the applicant alleges the following.
Amended claim I is directed to a negative electrode current collector comprising a metal substrate and a conductive layer provided on at least one surface of the metal substrate, wherein the negative electrode current collector has a Vickers hardness of 400 Mpa-850 Mpa, and the conductive layer has a thickness of 0.5 µm-6 µm,
…
the conductive particle comprises the hard carbon, the conductive carbon black, and the carbon nanotube, the hard carbon is present in the conductive particle at a mass content of 50%-90%, the conductive carbon black is present in the conductive particle at a mass content of 10%-50%, and the carbon nanotube is present in the conductive particle at a mass content of0.001%-1%, and
wherein the first conductive material has a Dv50 particle size of 0.5 µm-6 µm.
Support for the amendment of claim 1 can be found at least at original claim 5 of the present application.
As set forth in MPEP 2144.05 (III), Applicants can rebut a prima facie case of obviousness based on overlapping ranges by showing the criticality of the claimed range.
Applicant respectfully submits that the negative electrode current collector having a Vickers hardness of 400 Mpa-850 Mpa, as recited in amended claim 1, is critical for the effect of the present application. Specifically, as shown in Table 1 of the present application, each of Examples 1-18 has a Vickers hardness being within the claimed range of 400 Mpa-850 Mpa. Each of Comparative Examples 1-4 has a Vickers hardness being outside the claimed range of 400 Mpa-850 Mpa. As shown in Table 2 of the present application, each of Examples 1-18 has unexpectedly both excellent number of folds before brittle failure (3 folds or higher) and no or moderate dendritic growth. In contrast, each of Comparative Examples 1-4 has either severe dendritic growth or very poor number of folds before brittle failure (2 folds or lower). Furthermore, claim 1 is herein amended to narrow its scope by reciting that “the first conductive material has a Dv50 particle size of 0.5 µm-6 µm.” Accordingly, the unexpected result as shown with data in Table 1 of the present application is commensurate with the scope of amended claim 1.
For the foregoing reasons, Applicant respectfully submits that the cited art would not have rendered obvious amended claim 1 of the present application.
(Remarks, at 6:5-7:4, emphasis in the original.)
In response, the examiner respectfully notes that the newly incorporated limitation addresses one of the issues discussed in the August 14, 2025 final Office action, see e.g. p.23, reproduced below for ease of reference.
Finally, there are other parameters—which are not claimed—that affect the hardness of the claimed negative electrode current collector, specifically the instant specification teaches the following.
[0143] As can be seen from the comparison of Examples 12 to 14, an excessive DV50 particle size of the hard carbon may lead to an increased Vickers hardness of the negative electrode current collector, but may cause sodium dendritic growth.
(Instant specification, at e.g. ¶0143, emphasis added.)
(August 14, 2025 final Office action, see e.g. p.23, emphasis in the original.)
However, the examiner respectfully reiterates from the August 14, 2025 final Office action that the argument is not commensurate with the scope of the initial filing and the scope of the claims, as claimed.
Claim 1 has been previously amended so that the hard carbon is “present in the conductive particle at a mass content of 50%-90%” (at claim 1, option 1, at line 12; or, option 2, at lines 15-16, emphasis added).
Further, claim 1 has been previously amended so that the conductive carbon black is “present in the conductive particle at a mass content of 10%-50%” (at claim 1, option 1, at lines 12-13;” or, option 2, at lines 16-17), and further in a second option wherein the carbon nanotube is “present in the conductive particle at a mass content of 0.001%-1%” (at claim 1, option 2, at lines 17-18).
However, the instant specification provides examples that expressly teach amounts of the claimed “hard carbon” and “conductive carbon black” that are outside the previously added claimed ranges.
(1) the amount of the claimed “hard carbon” in instant examples 11 and 17-18 outside the previously added claimed range; and,
(2) the amount of the “conductive carbon black” in examples 11 and 17-18 outside the previously added claimed range, including example 11, which does not include any carbon black (i.e. 0 mass%) and only includes carbon nanotubes (i.e. 5 mass%) as the second conductive material.
A portion of Table 1 reproduced below for ease of reference:
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343
837
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Further, the instant specification provides the claimed ranges of each the claimed “hard carbon” and “conductive carbon black” are merely optional, and does not appear to suggest the previously added claimed ranges are critical; and, notes only in examples 1-3 (hard carbon: 70%, 80%, and 85%; carbon black: 15%, 20%, and 30%, further no carbon nanotubes) is there an express increase in Vicker’s hardness—but the examiner respectfully notes that examples 11 and 17—which have compositions outside the claimed ranges—have Vicker’s hardnesses outside those taught by instant examples 1-3.
[0009] In any embodiment according to the first aspect, the conductive particle includes the hard carbon and the conductive carbon black, and optionally, the hard carbon is present in the conductive particle at a mass content of 50%-90%, and the conductive carbon black is present in the conductive particle at a mass content of 10%-50%; or the conductive particle includes the hard carbon, the conductive carbon black, and the carbon nanotube, and optionally, the hard carbon is present in the conductive particle at a mass content of 50%-90%, the conductive carbon black is present in the conductive particle at a mass content of 10%-50%, and the carbon nanotube is present in the conductive particle at a mass content of 0.001%-1%. The conductive carbon black features good conductivity and cost-efficiency, and the addition of the carbon nanotube can improve the conductivity and the deposition effect of sodium on the negative electrode current collector.
…
[0055] In some embodiments, the conductive particle includes the hard carbon and the conductive carbon black, and optionally, the hard carbon is present in the conductive particle at a mass content of 50%-90%, and the conductive carbon black is present in the conductive particle at a mass content of 10%-50%; or the conductive particle includes the hard carbon, the conductive carbon black, and the carbon nanotube, and optionally, the hard carbon is present in the conductive particle at a mass content of 50%-90%, the conductive carbon black is present in the conductive particle at a mass content of 10%-50%, and the carbon nanotube is present in the conductive particle at a mass content of 0.001%-1%. The conductive carbon black features good conductivity and cost-efficiency, and the addition of the carbon nanotube can improve the conductivity and the deposition effect of sodium on the negative electrode current collector. However, the cost of the carbon nanotube is significantly greater than the conductive carbon black. Therefore, the content of the carbon nanotube in the conductive particle is controlled at 1% or less, so as to control the cost of the current collector. Certainly, regardless of the cost, the conductive particle may contain a greater amount of the carbon nanotube, such as 2%, 3%, 4%, 5%, and 10%.
…
[0122] The compositions of the negative electrode current collectors for the examples and comparative examples are described in Table 1.
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359
836
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702
837
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…
[0140] As can be seen from the data in Table 1 above, in Examples 1 to 3, the Vickers hardness of the negative electrode current collector can be effectively increased as the mass content of the hard carbon increases, thereby improving the processability of the battery.
(Instant specification, at e.g. ¶¶ 0009, 55, 12, and 140, emphasis added.)
Further, the examiner respectfully refers supra.
Second, the applicant alleges the following.
New claim 16 is added. Support for addition of new claim 16 can be found at least at previously presented claim 8 and paragraph [0117] of the originally filed application.
In contrast, Zeng discloses that the mass proportion of the carbon material in the carbon material coating is 90% to 99% (paragraph [0042]), which neither overlaps nor is close to the claimed range of a mass content of 75%-80%. Furthermore, Zeng teaches away from using the mass proportion of the carbon material in the carbon material coating being less than 90%. For example, Zeng criticizes it by reciting that “If the mass proportion of carbon material in the carbon material coating is too small, the conductivity of the carbon material coating will decrease, the sodium intercalation overpotential cannot be effectively improved, sodium dendrites are easily formed, and the battery cycle performance is reduced” (paragraph [0042]).
Zhamu and Kobayashi do not cure the deficiencies of Zeng.
For the foregoing reasons, Applicant respectfully submits that the cited art would not have rendered obvious new claim 16 of the present application.
(Remarks, at 7:5-8:3.)
In response, the examiner respectfully refers supra.
Third, the applicant alleges the following.
Claims 4 and 6-16 depend, directly or indirectly, from claim 1. Thus, these dependent claims are patentable due to at least the dependency.
(Remarks, at 8:4.)
In response, the examiner respectfully refers supra.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Zeng (US 2023/0327114);
Wable et al (US 2023/0253567);
Li et al (US 2022/0209226);
Li et al (US 2022/0102732);
Li et al (US 2022/0093932);
Liu et al (US 2022/0085384);
Liu et al (US 2022/0085380);
Tanaami et al (US 2021/0313574);
Liu et al (US 2021/0119219);
Liang et al (US 2019/0173093);
Liang et al (US 2019/0173092); and,
Hua et al (US 2012/0321913).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to YOSHITOSHI TAKEUCHI whose telephone number is (571)270-5828. The examiner can normally be reached M-F, 8-4.
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/YOSHITOSHI TAKEUCHI/Primary Examiner, Art Unit 1723