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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 23 September 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 is incorrect, any correction of the statutory basis 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.
Claims 1, 2 and 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over Kaiduka et al (US 2023/0006256 A1) in view of Yasushi et al (JP 2007214038 A) and Tokuda et al (US 2012/0308881 A1). These prior art references cited as Kaiduka, Yasushi (as provided on applicants IDS dated 06 June 2022), and Tokuda, respectively, in this Office Action hereinafter.
Regarding claim 1, Kaiduka discloses a nonaqueous electrolyte secondary battery (10 Fig. 1; “A non-aqueous electrolyte secondary battery 10” [0016]) comprising a positive electrode (“includes a wound electrode assembly 14 formed by winding a positive electrode 11” [0016]), a negative electrode (“and a negative electrode 12” [0016]), and a nonaqueous electrolyte (“a non-aqueous electrolyte solution” [0016]), wherein
the negative electrode comprises a negative electrode current collector (“The negative electrode 12 includes a negative electrode current collector 40” [0022]) and a negative electrode active material layer supported by the negative electrode current collector (“and a negative electrode active material layer 42 provided on the negative electrode current collector 40” [0022]),
when dividing the negative electrode active material layer into two layers of a first region and a second region having a same thickness (“the negative electrode active material layer 42 illustrated in FIG . 2 is divided into two equal parts in the thickness direction” [0038]), the second region is closer to the negative electrode current collector than the first region (“a region 42b which is a half region on the outer surface side than in a region 42a which is a half region on the negative electrode current collector side” [0038] wherein “region 42b” corresponds to the claimed first region and “region 42a” corresponds to the claimed second region),
the first region and the second region each contain graphite particles (“The negative electrode active material layer 42 contains graphite particles as a negative electrode active material.” [0024] and “a graphite particle in a negative electrode active material layer” [0025]),
the graphite particles consist of graphite particles A and graphite particles B (“The graphite particle 30 in the present embodiment includes a graphite particle A having an internal porosity of 5 % or less and a graphite particle B having an internal porosity of 8 % to 20 %” [0026]),
an inner porosity of the graphite particles A is 5% or less (“graphite particle A having an internal porosity of 5 % or less” [0026]),
an inner porosity of the graphite particles B is more than 5% and 20% or less (“graphite particle B having an internal porosity of 8 % to 20 %” [0026]), and
the graphite particles A are contained more in the first region than in the second region (“the graphite particles A are contained more in a region 42b which is a half region on the outer surface side” [0038]).
Kaiduka does not disclose:
a ratio P1/P2 of interparticle porosity P1 of the first region to interparticle porosity P2 of the second region is greater than 1, and
the nonaqueous electrolyte includes at least one additive selected from the group consisting of a sulfite compound and a sulfate compound.
However, Yasushi discloses a nonaqueous electrolyte secondary battery ([0009]) comprising a positive electrode (131 Fig. 3; [0035]), a negative electrode (141 Fig. 3; [0011]), and a nonaqueous electrolyte ([0030]), wherein
the negative electrode comprises a negative electrode current collector (142 Figs. 3 and 7; [0038]) and a negative electrode active material layer supported by the negative electrode current collector (143 Figs. 3 and 6-7; [0012] and [0038]-[0040]),
when dividing the negative electrode active material layer into two layers of a first region (145 Fig. 7) and a second region (144 Fig. 7) having a same thickness ([0039]), the second region is closer to the negative electrode current collector than the first region (144 comparatively to 145 in Fig. 7; [0019], [0039]),
the first region and the second region each contains graphite particles (Fig. 7; [0013] and [0039] reference both active material layers are natural graphite), and
the graphite particles consist of graphite particles A (“fk2” Fig. 7; “a negative electrode second active material powder fk2” [0039]) and graphite particles B (“fk1” Fig. 7; “a negative electrode first active material powder fk1” [0039]).
Yasushi teaches a ratio P1/P2 of interparticle porosity P1 of the first region to interparticle porosity P2 of the second region is greater than 1 ([0039] discloses that the void ratio of the first active material layer 144 is 52% and the void ratio of the negative electrode second active material layer 145 is 68%, such that a ratio P1/P2 would be 1.3), and that this combination of properties for the negative electrode active material layer results in lithium secondary battery high rate characteristics and increased negative electrode conductivity, which improves battery output compared to conventional batteries ([0040]).
Therefore, it would have been obvious to one of ordinary skill in the art to change the interparticle porosities of the first region (P1) and the second region (P2) of the negative electrode active material layer of Kaiduka in view of Yasushi in a manner that a ratio P1/P2 of interparticle porosity P1 of the first region to interparticle porosity P2 of the second region is greater than 1, in order to achieve improved battery output by increasing battery high rate characteristics and negative electrode conductivity.
Additionally, Tokuda discloses a nonaqueous electrolyte secondary battery (“nonaqueous-electrolyte secondary battery” [0470]) comprising a positive electrode (“a positive electrode” [0470]), a negative electrode (“a negative electrode” [0470]), and a nonaqueous electrolyte (“nonaqueous electrolytic solution” [0470]), wherein the negative electrode comprises a negative electrode current collector (“The negative electrode includes a current collector” [0472]) and a negative electrode active material layer supported by the negative electrode current collector (“a negative-electrode active-material layer disposed thereon” [0472]).
Tokuda teaches the nonaqueous electrolyte includes at least on additive selected from the group consisting of a sulfite compound and a sulfate compound (“sulfur-containing compounds such as
ethylene sulfite, … ethylene sulfate, vinylene sulfate…” [0466]), and that the use of sulfur-containing compounds such as ethylene sulfite and ethylene sulfate improves the capacity retentivity after high-temperature storage and cycle characteristics of the battery ([0466]).
Therefore, it would have been obvious, prior to the effective date of the claimed invention, to one of ordinary skill in the art, to substitute the electrolyte solution of modified Kaiduka with the nonaqueous electrolyte solution containing a sulfite or sulfate compound taught by Tokuda, in order to achieve improvements in capacity retention and cycle characteristics of the battery.
Regarding claim 2¸modified Kaiduka discloses the nonaqueous electrolyte secondary battery with all the features set forth in claim 1 above, and wherein the P1/P2 is 1.1 or more and 2.0 or less (Yasushi [0039] discloses that the void ratio of the first active material layer 144 is 52% and the void ratio of the negative electrode second active material layer 145 is 68%, such that a ratio P1/P2 would be 1.3).
Regarding claim 7, modified Kaiduka discloses the nonaqueous electrolyte secondary battery with all the features set forth in claim 1 above, and wherein the additive includes at least one selected from the group consisting of ethylene sulfite and ethylene sulfate (Tokuda “sulfur-containing compounds such as ethylene sulfite, … ethylene sulfate, vinylene sulfate…” [0466]).
Regarding claim 8, modified Kaiduka discloses the nonaqueous electrolyte secondary battery with all the features set forth in claim 1 above, but does not specifically disclose wherein a content of the additive in the nonaqueous electrolyte is 0.5 mass% or more and 2 mass% or less relative to the entire nonaqueous electrolyte.
However, Tokuda teaches this feature ([0156] and [0466]-[0467]), and that this mass% content range of the additive is sufficient to improve the cycle characteristics of the nonaqueous electrolyte secondary battery and decreases high load discharge of the battery ([0156] and [0466]-[0467]).
Therefore, it would have been obvious, prior to the effective date of the claimed invention, to one of ordinary skill in the art to add wherein a content of the additive in the nonaqueous electrolyte is 0.5 mass% or more and 2 mass% or less relative to the entire nonaqueous electrolyte to the nonaqueous electrolyte secondary battery of modified Kaiduka in further view of Tokuda, in order to achieve improved cycle characteristics of the battery and decreased high load discharge of the battery.
Claims 3, 4 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Kaiduka (US 2023/0006256 A1) in view of Yasushi (JP 2007214038 A) and Tokuda (US 2012/0308881 A1), and in further view of Wang et al (US 2017/125806 A1). The latter prior art reference cited as Wang (as provided on applicants IDS and ISR dated 06 June 2022) in this Office Action hereinafter.
Regarding claims 3-4, modified Kaiduka discloses the nonaqueous electrolyte secondary battery with all the features set forth in claim 1 above, but does not disclose the features:
wherein a ratio D1/D2 of packing density D1 of the first region to packing density D2 of the second region is 0.9 or more and 1.1 or less, and
wherein the first region and the second region each has a packing density of 1.3 g/cm3 or more and 2.0 g/cm3 or less.
However, Wang discloses a nonaqueous electrolyte secondary battery (“A non-aqueous electrolyte secondary battery” [0015]) comprising a positive electrode (“a positive electrode” [0015]), a negative electrode (“the negative electrode” [0015]), and a nonaqueous electrolyte (“a non-aqueous electrolyte containing a nonaqueous solvent” [0015]), wherein
the negative electrode comprises a negative electrode current collector (“the negative electrode 10 includes a negative-electrode current collector 11” [0023]) and a negative electrode active material layer supported by the negative electrode current collector (“and a negative-electrode mixture layer 12 formed on the current collector” [0023]),
when dividing the negative electrode active material layer into two layers of a first region and a second region having a same thickness (“a first region 12a that extends from the surface of the mixture layer remote from the negative-electrode current collector 11 in the thickness direction of the negative-electrode mixture layer 12 and has a thickness equal to 40% of the thickness of the mixture layer contains a larger amount of Si Ox than a second region 12b that extends from the surface of the mixture layer adjacent to the negative-electrode current collector 11 and has a thickness equal to 40% of the thickness of the mixture layer” [0034] with italics added for emphasis on the thickness amount of each layer), the second region is closer to the negative electrode current collector than the first region (“second region 12b” [0034] shown to be closer to the negative-electrode current collector 11 in Figs. 1 and 2),
the first region and the second region each contains graphite particles (“As graphite, graphite that has been used as a negative electrode active material for non-aqueous electrolyte secondary batteries can be used. Examples of the graphite include natural graphite, such as scaly graphite, weightive graphite, and earthy graphite; and artificial graphite, such as weightive artificial graphite (MAG) and graphitized mesophase carbon microbeads (MCMB).” [0027]).
Wang additionally discloses the negative electrode active material layer includes plural regions containing different amounts of SiOx, namely, a different ratio of graphite to SiOx. The first region contains a larger amount of SiOx than the second region, which provides the first region having a lower density than that of the second region ([0034]). The ratios of SiOx between the first and second regions provide advantageous improvements in capacity and cycle characteristics when the amount of SiOx in the first region is more than the amount of SiOx in the second region ([0036]). When a difference in the amount of SiOx between the regions is too large, the negative electrode mixture layer tends to fracture due to the difference in the volume change of the regions due to charging and discharging ([0037]).
Hence, Wang teaches wherein a ratio D1/D2 of packing density D1 of the first region to packing density D2 of the second region is 0.9 or more and 1.1 or less; and wherein the first region and second region each has a packing density of 1.3 g/cm3 or more and 2.0 g/cm3 or less ([0039]), and that the density of the first region is preferably 1.5 to 2.1 g/cm3 and more preferably 1.7 to 1.9 g/cm3, and the density of the second region is preferably 1.7 to 2.3 g/cm3 and more preferably 1.9 to 2.1 g/cm3, thus meeting the claim limitations of claims 3 & 4.
Although Wang discloses the range of the second region being preferably 1.9 to 2.1 g/cm3, which lies just outside the claimed range of 1.3 to 2.0 g/cm3, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. (see 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); and In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997)).
Therefore, it would have been obvious, prior to the effective date of the claimed invention, to one of ordinary skill in the art, to substitute the packing densities of the negative electrode active material in modified Kaiduka with the densities and construction of the plurality of layers taught in Wang to achieve the desired results while keeping in respect to the art overall. This modification provides improvements to the capacitance and cycle characteristics of the battery while also avoiding fracturing of the layers during charging and discharging.
Regarding claim 6, modified Kaiduka discloses the nonaqueous electrolyte secondary battery with all the features set forth in claim 1 above, but does not disclose the feature of wherein the first region and the second region each includes Si-based particles.
However, Wang teaches wherein the first region and the second region each includes Si-based particles ([0025]-[0026] and [0028]-[0030]), and that the use of Si-based particles aids in obtaining a high capacity and improves the rate characteristics as well as cycle characteristics of the battery ([0025]).
Therefore, it would have been obvious, prior to the effective date of the claimed invention, to one of ordinary skill in the art, to add to the negative electrode active material of modified Kaiduka a silicon-based material, in further view of Wang, in order to achieve a high capacity, as well as improved rate characteristics and cycle characteristics of the battery.
Response to Arguments
Applicant’s arguments with respect to claim 1 has been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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/CHARLENE BERMUDEZ/Examiner, Art Unit 1721
/DUSTIN Q DAM/Primary Examiner, Art Unit 1721