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 § 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 1-13 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2020/137321 (translation US 2022/0052314) (Ishikawa et al., hereinafter Ishikawa) in view of US 2021/0202932 (Fukumoto et al., hereinafter Fukumoto).
Regarding claim 1, Ishikawa teaches:
An anode for a secondary battery (¶ 23 negative electrode), comprising:
an anode current collector (¶ 23 negative electrode current collector);
a first anode mixture layer provided on at least one surface of the anode current collector (¶ 23 negative electrode mixture layer formed on the negative electrode current collector);
a second anode mixture layer provided on the first anode mixture layer (¶ 24 second layer formed on the first layer); and
a third anode mixture layer provided on the second anode mixture layer (¶ 27 a layer other than the first layer and the second layer may be included in the negative electrode mixture layer),
wherein each of the anode mixture layers includes a Si-containing anode active material and carbon nanotubes, and (¶ 24 First layer including a Si-based active material; The Si-based active material may be included in the second layer) (A third layer would have a similar composition to the first two layers and would also have a Si-containing anode active material and carbon nanotubes).
However, Ishikawa does not teach that the number of walls of the carbon nanotubes in the first layer is less than the number of walls in the second layer is less than the number of walls in the third layer. Ishikawa only teaches that the carbon nanotubes may be single-layered, double-layered, multi-layered, and a mixture thereof (¶ 43). In the same field of endeavor of secondary battery electrodes, Fukumoto teaches a negative electrode with carbon nanotubes in which single-walled carbon nanotubes are closer to the electrode core body and multi-walled carbon nanotubes are further away from the electrode core body (¶ 32). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the negative electrode of Ishikawa with the carbon nanotube distribution of Fukumoto to suppress the decrease in capacity during the charging and discharging cycle of the battery (¶13).
Regarding claim 2, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein the fibrous carbon (carbon nanotubes) may be included in the first layer, and also the second layer, but that the content ratio of the fibrous carbon in the second layer is preferably lower than that in the first layer (¶ 42), and that a layer other than the first layer and the second layer may be included in the negative electrode mixture layer (¶ 27). Following this teaching, the third layer with carbon nanotubes would then preferably have less fibrous carbon than the second layer, satisfying the relation that the first anode mixture layer has the most carbon nanotubes, the second layer has less, and the third layer having the least of the three.
Regarding claim 3, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein a content of fibrous carbon in the first layer is 0.01% by mass to 5% by mass (¶ 43). Ishikawa also teaches that the fibrous carbon may also be included in the second layer, and that a layer other than the first and second layer may be included in the negative electrode mixture layer (¶ 27), which would have a similar composition including carbon nanotubes. The reference range of 0.01% to 5% by mass overlaps the claimed ranges of 0.5 to 2 wt%, 2 to 4 wt%, and 4 to 6 wt%, and the courts have held that where claimed ranges overlap or lie inside of those in the prior art a prima facie case of obviousness exists. See MPEP 2144.05.
Regarding claim 4, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein the carbon nanotubes may be single-layered, double-layered, multi-layered, and a mixture thereof (¶ 43), with the single-layered and double-layered carbon nanotubes of Ishikawa corresponding to the claimed first carbon nanotubes, and the multi-layered carbon nanotubes corresponding to the claimed second and third carbon nanotubes.
Regarding claim 5, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein Fukumoto teaches a BET specific surface area of single wall fibrous carbon of 500 m2/g or more corresponding to the claimed specific surface area of the first carbon nanotubes of 400 to 600 m2/g, and a BET specific surface area of multiwalled fibrous carbon of 10 to 450 m2/g corresponding to the claimed specific surface area of the second carbon nanotubes of 200 to 500 m2/g and third carbon nanotubes 150 to 300 m2/g (¶ 44-45).
Regarding claim 6, Ishikawa in view of Fukumoto teaches the anode of claim 1, with single-layered, double-layered, and multi-layered carbon nanotubes having diameters ranging from 2 nm to 20 µm (¶ 43), overlapping the claimed average diameter of the first carbon nanotubes of 1 to 4 nm, and encompassing the claimed average diameter of the second carbon nanotubes of 5 to 10 nm and encompassing the claimed average diameter of the third carbon nanotubes of 7 to 15 nm, and the courts have held that where claimed ranges overlap or lie inside of those in the prior art a prima facie case of obviousness exists. See MPEP 2144.05.
Regarding claim 7, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein a first layer includes Si-based active material, and that the Si-based active material may be included in the second layer and that the second layer preferably has a lower content rate of the Si-based active material than the first layer (¶ 24), and that a layer other than the first and second layer may be included in the negative electrode mixture layer with a similar composition, and following the preferred trend, would have a lower content rate of the Si-based active material than the second layer.
Regarding claim 8, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein in the first layer, the proportion of Si-based active material in the negative electrode active material is preferably 5% by mass to 20% by mass (¶ 38), and that the Si-based active material may be included in the second layer, preferably at a lower content rate (¶ 24), and that a layer other than the first and second layer may be included in the negative electrode mixture layer with a similar composition, and following the preferred trend, would have a lower content rate of the Si-based active material than the second layer. The 5% by mass to 20% by mass range taught by Ishikawa encompasses the claimed 10 to 15 wt% range of the first layer, encompasses the claimed 5 to 10 wt% range of the second layer, and overlaps with the claimed 1 to 5 wt% range of the third layer, and the courts have held that where claimed ranges overlap or lie inside of those in the prior art a prima facie case of obviousness exists. See MPEP 2144.05.
Regarding claim 9, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein the Si-based active material is preferably an Si-containing compound represented by SiOx (0.5≤x≤1.5) (¶ 35), anticipating one member of the claimed group of Si, an Si-C complex, SiOx (0<x<2), and a Si alloy.
Regarding claim 10, claim 10 is rejected due to its dependency on claim 9 (See claim 9 above).
Regarding claim 11, Ishikawa in view of Fukumoto teaches the anode of claim 1, wherein a conductive carbon coating formed on the surfaces of the Si-containing compound particles (¶ 35, 37). Since Si-based active material is present in every layer, the conductive carbon coating is also present in each layer (See above reasoning for claims 7-9). Ishikawa also teaches binders including polyacrylic acid (PAA), carboxymethyl cellulose (CMC), styrene-butadiene copolymer (SBR), polyvinyl alcohol (PVA), and polyethylene oxide (PEO) in the first layer, and CMC, SBR, PVA, and PEO as binders in the second layer (¶ 39-40). In a third layer of similar composition, the CMC, SBR, PVA, and PEO may also be present.
Regarding claim 12, Ishikawa in view of Fukumoto teaches anode of claim 11, wherein the carboxymethyl cellulose (CMC) may be present in each layer, and is commonly used as a thickener in the industry (See above reasoning for claim 11).
Regarding claim 13, Ishikawa in view of Fukumoto teaches:
A secondary battery (¶ 60 laminate cell) comprising:
A cathode (¶ 60 positive electrode), an anode (¶ 60 negative electrode), and a separator interposed between the cathode and the anode (¶ 60 separators interposed therebetween), wherein the anode includes the anode for a secondary battery of claim 1 (the negative electrode of Ishikawa in view of Fukumoto).
Conclusion
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/M.F./Examiner, Art Unit 1784
/HUMERA N. SHEIKH/Supervisory Patent Examiner, Art Unit 1784
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