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 § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3, 6, 10, 12-14, 17 and 19 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Guo et al. (hereinafter “Guo”) (CN 110828826 A, cited by Applicant; see English machine translation).
Regarding claims 1 and 12, Guo teaches a secondary battery (electrochemical apparatus) comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode and/or the negative electrode includes an electrode sheet (electrode plate) comprising a current collector (current collector), a first active material layer located on at least one surface of the current collector (second layer), and a second active material layer located on the first active material layer (see paragraphs 17 and 41). The electrode sheet further comprises at least one transition layer (first layer), the transition layer comprising a conductive material (conductive agent) (see paragraph 17). The transition layer may be disposed between the current collector and the first active material layer (see paragraph 34). The conductive material may have a specific surface area (BET) that is at least 40 m2/g and at most 100 m2/g (see paragraphs 19 and 20).
Regarding claims 2 and 13, Guo teaches that in the transition layer, the conductive material may present in an amount of 70%-80% by mass (see paragraph 27).
Regarding claims 3 and 14, FIGS. 1-3 of Guo illustrate a coverage of the transition layer on the current collector that is approximately 100%.
Regarding claims 6 and 17, Guo teaches that the conductive agent may comprise one or more of carbon black, acetylene black, Ketjen black, carbon nanotubes, carbon fibers, sheet graphite, and graphene (see paragraph 26). The binder may comprise one or more of polyacrylic acid, polyacrylate, and polymethyl acrylate (see paragraph 30).
Regarding claims 10 and 19, Guo teaches that the binder may be present of an amount of 20% to 40% by weight (see paragraph 31).
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.
Claims 4 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Guo as applied to claims 1-3, 6, 10, 12-14, 17 and 19 above, and further in view of Takeda et al. (hereinafter “Takeda”) (U.S. Pub. No. 2020/0403246 A1, cited by Applicant).
Regarding claims 4 and 15, Guo is silent as to a surface roughness of the first layer.
Takeda teaches a current collector for an electrical storage device including a sheet-shaped conductive substrate and a coating layer disposed on one or both sides of the conductive substrate. The coating layer includes a powdery carbon material, acid-modified polyvinylidene fluoride and polyvinylpyrrolidone (see paragraph 67). The surface roughness Ra which reflects the surface irregularities of the coating layer is preferably not more than 1.0 μm. The lower limit of the surface roughness Ra is preferably 0.1 μm. When the surface roughness Ra is 0.1 μm or above, the coating layer is effectively anchored with an electrode containing a positive electrode or negative electrode active material, and thereby effectively attains a reduction in interface resistance (see paragraph 80). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have adapted the coating layer surface roughness of Takeda to the transition layer of Guo because Takeda teaches that a surface roughness within this range effectively anchors the transition layer to the first active material layer while avoiding excessive surface irregularities which create a non-uniform thickness of the transition layer (see paragraph 80).
Claims 5, 7-9, 11, 16, 18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Guo as applied to claims 1-3, 6, 12-14, 17 and 19 above, and further in view of Yokouchi et al. (hereinafter “Yokouchi”) (U.S. 2015/0255788 A1).
Regarding claims 5 and 16, Guo is silent as to a thickness of the first layer that is 0.2 µm to 1 µm.
Yokouchi teaches a negative electrode for a secondary battery including a metal foil and a negative electrode active material layer that is formed on a single surface or both surfaces of the metal foil, and wherein a film containing a conductive material is formed between the metal foil and the negative electrode active material layer (see paragraph 36). The film containing a conductive material has a thickness that is preferably 0.5 µm to 2 µm (see paragraph 43). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have adapted the film thickness of Yokouchi to the transition layer of Guo because Yokouchi teaches that within the above range, a uniform film having no cracks or pinholes can be formed, and an increase in the weight of a battery, which is caused by the thickness of the film, and the internal resistance of the negative electrode can be reduced (see paragraph 43).
Regarding claim 7, Yokouchi further teaches that an average particle size of the conductive material is preferably 10 nm to 100 nm (see paragraph 50). In addition, Yokouchi teaches that the thickness of the film containing a conductive material and the particle size of the conductive material may be selected such that the binding property between the film and other materials in the film and between the film and the metal foil collector or negative electrode active material layer can be improved (see paragraph 52).
Regarding claim 8, although neither Guo nor Yokouchi explicitly teach an areal density of 0.03 mg/cm2 to 0.3 mg/cm2, the combination of Guo with Yokouchi provides an electrode sheet that is substantially to the claimed electrode plate in both structure and composition. As such, one of ordinary skill in the art would expect the electrode sheet of Guo and Yokouchi to exhibit the areal density as claimed. It has been held by the courts that where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. See In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977) (see MPEP § 2112.01).
Regarding claims 9 and 18, Yokouchi teaches that a polymer binder of the film containing a conductive material may have a molecular weight that is 10,000 to 200,000. Within this range, the workability during the formation of the film containing a conductive material and the strength of the film are superior (see paragraph 56).
Regarding claims 11 and 20, Yokouchi teaches that a dispersion stabilizer may be provided as ab additive to the film containing conductive material (see paragraph 65). Although Yokouchi does not explicitly teach an amount of the dispersion stabilizer, it is well within the ambit of the artisan to adjust the amount of the dispersion stabilizer based on the uniformity of the film containing conductive material.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHAN J ESSEX whose telephone number is (571)270-7866. The examiner can normally be reached Monday - Friday, 8:30 am - 6:00 pm.
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/STEPHAN J ESSEX/Primary Examiner, Art Unit 1727
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