DETAILED ACTION
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 Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 10 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 10 recites: The negative electrode for a lithium secondary battery of claim 1, wherein the first negative electrode active material layer and the second negative electrode active material layer have a continuous concentration gradient of the active material at an interface therebetween.
It is unclear what material(s) of each layer is/are being referred to as “the active material” in Claim 10. Claim 1 recites a first and second graphite-based active material, and a first and second silicon-based active material. Claim 10 could be interpreted as a gradient of the graphite-based active materials, a gradient of the silicon-based active materials, or a gradient of both active materials. Applicant’s published specification (US 20250336957 A1) discloses “the continuous concentration gradient of the active material means that the first and second silicon-based active materials and the first and second graphite-based active materials have a continuous concentration gradient” ([0054]). The claim will be examined as such, with “the active material” being both the graphite-based and silicon-based active materials.
Appropriate correction is required.
Claim Rejections - 35 USC § 103
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 1-5, 10, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Takahata, US 20140186702 A1 and further in view of Jeschull et al., “Electrochemistry and morphology of graphite negative electrodes containing silicon as capacity-enhancing electrode additive,” Electrochimica Acta, Vol 320, 2019 (both references cited by Applicant in IDS received 7/3/2025).
Regarding Claim 1, Takahata discloses a negative electrode for a lithium secondary battery (lithium-ion secondary battery 100A and negative electrode sheet 240A/B [0032-0033, 0095-0098], Figs. 10 and 11), comprising:
a current collector (negative electrode current collector 241A [0041, 0068])
a first negative electrode active material layer disposed on the current collector (first region A1 in negative electrode active material layer 243A/B [0064-0075, 0122]) and including a first graphite-based active material containing artificial graphite and natural graphite (natural and artificial graphite [0064, 0097, 0120-0122]) and;
a second negative electrode active material layer disposed on the first negative electrode active material layer (second region A2 in negative electrode active material layer 243A/B [0064, 0122]) and including a second graphite-based active material containing artificial graphite and natural graphite (natural and artificial graphite [0064, 0097, 0120-0122]), and
wherein the first graphite-based active material has a content of the artificial graphite equal to or less than that of the natural graphite (first region A1 contains natural graphite in a weight ratio of equal to or greater than 80% of the graphite material [0011, 0069, 0120-0122]), and the second graphite-based active material has a content of the artificial graphite greater than that of the natural graphite (second region A2 contains artificial graphite in a weight ratio of equal to or greater than 80% of the graphite material [0011, 0069, 0120-0122]),
wherein the second graphite-based active material contains the artificial graphite and the
natural graphite in a weight ratio of 97.5:2.5 to 55:45 (80:20 weight ratio of artificial graphite to natural graphite [0011, 0122]).
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) [MPEP 2144.05].
Regarding the limitation “a thickness ratio between the first negative electrode active material layer and the second negative electrode active material layer is greater than 3:7 and less than 7:3,” see Fig. 13 showing 0% to 40% thickness of the second region A2 in the negative electrode active material layer. Takahata teaches an A2 thickness (30%) within the claimed range is preferable for maintaining capacity retention after storage and a low resistance increase rate after cycling ([0110-0112]). Takahata also teaches an embodiment with a 40% thickness of the second region A2 (Fig. 13).
A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill the art, including nonpreferred embodiments. 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 423 (CCPA 1971) [see MPEP 2123].
Takahata does not disclose the first and second negative electrode active material layer includes a first silicon-based active material, and also does not disclose the second negative electrode active material layer includes a second silicon-based active material. However, these limitations are taught by Jeschull et al.
Jeschull teaches silicon nanopowder can be used as a capacity-enhancing additive in graphite-based negative electrodes due to silicon’s high theoretical specific charge (Abstract, Introduction). Jeschull also teaches a large fraction of a conductive component (i.e., graphite) in a negative electrode can mitigate electronic contact losses, and experiments with Si-graphite anode compositions having 75 wt% to 90 wt% of graphite and 5 wt% to 20 wt % silicon (Introduction, Experimental, Table 1).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to add silicon to the negative electrode active material layers comprising graphite, as taught by Jeschull, in the negative electrode of Takahata, in order to achieve the high energy density capabilities of the silicon additive.
Regarding Claim 2, modified Takahata discloses all limitations as set forth above. Modified Takahata discloses the first graphite-based active material contains the artificial graphite and the natural graphite in a weight ratio within the claimed range of range of “5:95 to 50:50” (Takahata, the proportion of natural graphite in A1 is high in the graphite material [0064], 80% or greater [0122]).
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) [MPEP 2144.05].
Regarding Claim 3, modified Takahata discloses all limitations as set forth above. Modified Takahata discloses the second graphite-based active material contains the artificial graphite and the natural graphite in a weight ratio of 80:20 to 60:40 (Takahata, 80:20 weight ratio of artificial graphite to natural graphite [0011, 0122]).
Regarding Claims 4 and 5, modified Takahata discloses all limitations as set forth above. Modified Takahata does not disclose the first negative electrode active material layer includes:
0.1 to 35% by weight of the first silicon-based active material, based on the total weight of the active material, and the second negative electrode active material layer includes 0.1 to 35% by weight of the second silicon-based active material, based on the total weight of the active material (Claim 4); or
6 to 30% by weight of the first silicon-based active material, based on the total weight of the active material, and the second negative electrode active material layer includes 6 to 30% by weight of the second silicon-based active material, based on the total weight of the active material (Claim 5).
However, the effect of the weight percentage of silicon is also taught by Jeschull. Jeschull teaches a silicon content of less than 50 wt% is sufficient to maximize the energy density of the negative electrode, but a negative electrode comprising 5 wt% to 20 wt% silicon nanopowders produces the highest gain in energy density (Section 3.1 – Energy-density considerations, Fig. 1). Through experimentation, Jeschull shows when the amount of silicon in the negative electrode layer increases, the contribution of graphite becomes smaller, and the cycle life of the electrode can decrease (Section 3.1 – Energy-density considerations, Fig. 1). With increasing Si contents, Jeschull also notes the Si nanoparticles segregate to larger domains and separate more prominently from the graphite matrix, creating a non-uniform electrode layer (Section 4 – Conclusions). Examiner notes Jeschull’s preferred range of 5 wt% to 20 wt% silicon overlaps with the ranges required by Claim 4 (0.1 wt% to 35%) and Claim 5 (6 wt% to 30 wt%).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to optimize, by routine experimentation, the silicon weight percentage relative to the total weight of the active material layer, in the negative electrode of modified Takahata, as Jeschull teaches adding silicon will achieve higher energy density, but adding too much silicon will reduce capacity over time and create a non-uniform electrode layer.
Where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art (In re Aller, 105 USPQ 223).
Regarding Claim 10, modified Takahata discloses all limitations as set forth above. Modified Takahata discloses mixing a first paste for layer A1 (Takahata, Step A: first paste [0070-0072]), and then mixing a second paste for layer A2 (Takahata, Step B: second paste [0070-0072]). Using modified Takahata’s process of making each electrode layer into a slurry/paste, one would not have any reason to expect a non-continuous concentration gradient of the graphite and Si particles within each active material layer, or between any other point in the active material layer and an interface between layers.
Regarding Claim 11, modified Takahata discloses all limitations as set forth above. Modified Takahata discloses the negative electrode may be used in a lithium secondary battery (Takahata, [0011, 0032]) further comprising a positive electrode (Takahata, [0034-0036]), a separator (Takahata, [0045-0046]), and an electrolyte (Takahata, [0052]).
Claims 6, 7, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over modified Takahata as applied to Claim 1 above, and further in view of Kim et al., US 20200176753 A1 (cited by Applicant in IDS received 7/3/2025).
Regarding Claims 6 and 7, modified Takahata discloses all limitations as set forth above. Modified Takahata does not disclose a third negative electrode active material layer includes a third graphite-based active material containing artificial graphite (Claim 6), wherein the artificial graphite is granular or bimodal and has a particle size of 13 μm to 20 μm (Claim 7). However, these limitations are taught by Kim et al.
Kim teaches a three-layer negative electrode for a lithium secondary battery, wherein a surface-coated granular-type artificial graphite is used as a second carbonaceous negative electrode active material for the third active material layer (Examples 1-1, 2-1, 5-1, 6-1 [0100, 0105, 0108, 0110]). Kim teaches the third negative electrode mixture layer, comprising the second carbonaceous negative electrode active material, inhibits volumetric swelling of the silicon-based negative electrode active material ([0030]). Kim teaches lithium ions can be intercalated into the negative electrode rapidly through the third layer, and can be deintercalated toward the positive electrode, resulting in significant improvement of the output characteristics of a battery ([0045]). Kim also teaches the second carbonaceous negative electrode active material particles preferably have an average particle diameter from 15 μm to 22 μm ([0047], Example 1-1 [0100]), which encompasses the claimed range.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to add a third negative electrode active material layer disposed on the second negative electrode active material layer, which includes the granular-type artificial graphite-based active material taught by Kim, in the negative electrode of modified Takahata, in order to prevent swelling, facilitate the rapid de-/intercalation of lithium ions, and improve the output characteristics of the battery.
Regarding Claim 9, modified Takahata discloses all limitations as set forth above. See Claim 6 for Kim’s third negative electrode mixture layer being added to modified Takahata’s negative electrode structure. Modified Takahata (through Kim) discloses a thickness percentage of the third negative electrode active material layer based on a total thickness of the negative electrode active material layers.
Kim teaches a sum of the first, second, and third negative electrode mixture layers may have a total thickness of 50 μm to 300 μm, and the third negative electrode mixture layer has a preferred thickness of 30 μm to 60 μm ([0074]). Kim’s disclosed preference for the thickness of the third negative electrode active material layer, relative to the total thickness of the negative electrode active material layers, equates to a thickness of 10% or greater (i.e., a 30 μm third layer is 10% of a 300 μm total active material layer thickness), which overlaps with the claimed range.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over modified Takahata as applied to Claim 1 above, and further in view of Kitada et al., JP 2018225937 (English version EP 3 855 531 A1 used for citations; cited by Applicant in IDS received 7/3/2025).
Regarding Claim 8, modified Takahata discloses all limitations as set forth above. Modified Takahata does not disclose the third negative electrode active material layer has a density of 1.55 to 1.8 g/cm3. However, negative electrode density is disclosed by Kitada et al.
Kitada teaches a negative electrode including a negative electrode current collector and a negative electrode active material layer ([0038]), wherein the negative electrode active material layer includes artificial graphite, natural graphite, or both ([0042]), and a silicon-containing material ([0051]). Kitada discloses the volume density of the negative electrode active material layer is greater than or equal to 1.5 g/cm3, and preferably from 1.5 g/cm3 to 1.8 g/cm3. Kitada discloses although energy density is desirable, if the volume density is greater than 1.8 g/cm3, mobility of the electrolytic solution in the negative electrode may decrease ([0171]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to use a negative electrode active material layer with a density of 1.5 to 1.8 g/cm3, in the negative electrode of modified Takahata, since Kitada teaches this range allows the electrode to have a high energy density, but not so dense as to prevent mobility of the electrolyte.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-11 are rejected on the ground of nonstatutory double patenting as being unpatentable over Claims 1-9 of U.S. Patent No. 12 US,381,204 B2. Although the claims at issue are not identical, they are not patentably distinct from each other because each limitation of instant Claim 1 is met by the invention recited by patented Claim 1. Additionally, Claims 2-11 of the instant application are recited by limitations expressed in patented Claims 1-9.
Claim 1, Instant Application:
A negative electrode for a lithium secondary battery, comprising: a current collector; a first negative electrode active material layer disposed on the current collector and including a first graphite-based active material containing artificial graphite and natural graphite, and a first silicon-based active material; and a second negative electrode active material layer disposed on the first negative electrode active material layer and including a second graphite-based active material containing artificial graphite and natural graphite, and a second silicon-based active material, wherein the first graphite-based active material has a content of the artificial graphite equal to or less than that of the natural graphite, and the second graphite-based active material has a content of the artificial graphite greater than that of the natural graphite, wherein the second graphite-based active material contains the artificial graphite and the natural graphite in a weight ratio of 97.5:2.5 to 55:45, and wherein a thickness ratio between the first negative electrode active material layer and the second negative electrode active material layer is greater than 3:7 and less than 7:3.
Claim 1, U.S. Patent No. 12 US,381,204 B2:
1. (Currently Amended) A negative electrode for a lithium secondary battery, comprising: a current collector; a first negative electrode active material layer disposed on the current collector and including a first graphite-based active material containing artificial graphite and natural graphite, and a first silicon-based active material; and a second negative electrode active material layer disposed on the first negative electrode active material layer and including a second graphite-based active material containing artificial graphite and natural graphite, and a second silicon-based active material, wherein the first graphite-based active material has a content of the artificial graphite equal to or less than that of the natural graphite, and the second graphite-based active material has a content of the artificial graphite greater than that of the natural graphite, wherein the second graphite-based active material contains the artificial graphite and the natural graphite in a weight ratio of 80:20 to 60:40, wherein a thickness ratio between the first negative electrode active material layer and the second negative electrode active material layer is greater than 3:7 and equal to or less than 5:5, and further comprising a third negative electrode active material layer disposed on the second negative electrode active material layer and including a third graphite-based active material containing artificial graphite, wherein the third graphite-based active material is a granular-type artificial graphite.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BETHANY C GARCIA whose telephone number is (571)272-2475. The examiner can normally be reached Mon-Fri, 0800 - 1730 MT.
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/BETHANY C GARCIA/Examiner, Art Unit 1721
/ALLISON BOURKE/Supervisory Patent Examiner, Art Unit 1721
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