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 Interpretation
Claims 1-2 and 3 state “content rate”.
Applicant’s specification states “A content rate of the silicon-based material in the negative electrode active material is preferably greater than or equal to 3 mass% relative to a mass of the negative electrode active material from the viewpoints of increasing the battery capacity, inhibiting deterioration in the charge-discharge cycle characteristic, and the like” (P31), and “A content rate of the conductive agent in the negative electrode mixture layer 42 is, for example, greater than or equal to 0.05mass% and less than or equal to 1.5 mass%. Here, the content rate of the conductive agent is a percentage of a mass of the conductive agent relative to the mass of the negative electrode active material” (P35).
Therefore, the content rate of the silicon-based material is interpreted as a percentage of a mass of the silicon-based material relative to the mass of the negative electrode active material, and the content rate of the conductive agent is being interpreted as a percentage of a mass of the conductive agent relative to the mass of the negative electrode active material.
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.
Claim 1 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Fujimura et al (JP2013191396A as given in the 07/20/2023 IDS, using the provided machine English translation).
Regarding claim 1, Fujimura discloses a non-aqueous electrolyte secondary battery (lithium ion secondary battery 1 in Fig. 1(b); see entire disclosure and especially P18), comprising:
an electrode assembly in which a band-shaped positive electrode and a band-shaped negative electrode are wound with a separator interposed therebetween (“electrode group 10 in which strip-shaped positive electrodes 20 and negative electrodes 30 are wound in a spiral cross section around an electrically insulating hollow cylindrical shaft core 3 with a separator 35 interposed therebetween” in Fig. 1(b); see entire disclosure and especially P18, 23);
an electrolyte liquid (see entire disclosure and especially P22); and
an exterior housing the electrode assembly and the electrolyte liquid (cylindrical battery can 2 in Fig. 1(b); see entire disclosure and especially P18), wherein
the negative electrode has: a negative electrode current collector (negative electrode current collector 31 in Fig. 2(a)); and a negative electrode mixture layer formed on a surface of the negative electrode current collector and including a negative electrode active material and a conductive agent (negative electrode mixture layer 32 in Fig. 2(a); the negative electrode mixture layer contains a negative electrode active material and negative electrode conductive agent; see entire disclosure and especially P10, 30, 40), and
in the negative electrode mixture layer, a content rate of the conductive agent in an outer end of winding is higher than a content rate of the conductive agent in an inner end of winding (the temperature of the battery becomes highest in the radial direction near the center of the shaft core 3 (Fig. 1(b)), in a region slightly outside the center, P26; “the amount of negative electrode conductive agent in the negative electrode mixture layer is reduced in regions with higher temperatures in the negative electrode”, P10; therefore, in Fujimura, the content rate of the conductive agent in an outer end of the winding direction is higher than a content rate of the conductive agent in an inner end of winding), and
the negative electrode mixture layer has a region where a content rate of the conductive agent continuously increases from a side of the inner end of winding to a side of the outer end of winding (see entire disclosure and especially P32, 34 and Fig. 2(b)).
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.
Claims 2-3 are rejected under 35 U.S.C. 103 as being unpatentable over Fujimura et al (JP2013191396A as given in the 07/20/2023 IDS, using the provided machine English translation) as applied to claim 1, further in view of Kwon et al (US 20210376323 A1).
Regarding claims 2-3, Fujimura does not disclose wherein the content rate of the conductive agent in the outer end of winding is greater than or equal to 0.1 mass% and less than or equal to 3 mass% relative to a mass of the negative electrode active material.
In a similar field of endeavor, Kwon teaches a negative electrode active material for a lithium secondary battery (P20). Kwon teaches the negative electrode active material includes: an active material core particles, a conductive material provided on a surface of the active material core, an organic linker that connects the active material core and the conductive material, and an elastomer that covers at least a part of the active material core and the conductive material (P28). Kwon teaches this allows the conductive material to be able to stably provide electrical conductivity even when the volume of the negative electrode active material changes (P30).
Kwon teaches the conductive material can be carbon fiber (P36). Kwon teaches the conductive material being a linear conductive material allows a conductive network to stably be formed, thereby improving the electrical connection between active materials (P38). Kwon further teaches the conductive material may be present in the negative electrode active material in a preferred amount of 0.1 parts by weight to 3 parts by weight relative to 100 parts by weight of the active material core particles (P39). Kwon teaches it is preferred that the content of the conductive material is in the above-described range because, within this range, it is possible to sufficiently form an electrical network of the active material while preventing the initial efficiency and capacity of the active material from being lowered due to an excessive addition of a conductive material (P39).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the teaching of Kwon and substituted the negative electrode mixture layer contents of Fujimura with the negative electrode active material layer contents of Kwon, given Kwon teaches this forms a negative electrode active material including a stable electrical network in the active material while preventing the initial efficiency and capacity of the active material from being lowered due to an excessive addition of a conductive material, and the simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007) (see MPEP § 2143, B.).
Regarding the limitation “wherein the content rate of the conductive agent in the outer end of winding is greater than or equal to 0.1 mass% and less than or equal to 3 mass% relative to a mass of the negative electrode active material”:
The amount of conductive agent in the whole of the negative electrode mixture layer of modified Fujimura (from Kwon’s teaching) is 0.1 parts by weight to 3 parts by weight relative to 100 parts by weight of the active material core particles (which can be written as: 0.1 mass% and less than or equal to 3 mass% relative to a mass of the negative electrode active material); therefore, the content rate of the conductive agent in the outer end of winding of modified Fujimura would fall within this range and meet the claimed limitation.
Regarding the limitation “wherein the conductive agent includes a fibrous carbon”:
The conductive agent of modified Fujimura (from Kwon’s teaching) is carbon fiber; therefore, the conductive agent of modified Fujimura meets the claimed limitation.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Fujimura et al (JP2013191396A as given in the 07/20/2023 IDS, using the provided machine English translation) as applied to claim 1, further in view of Amiruddin et al (US 20150050535 A1).
Regarding claim 4, Fujimura discloses wherein the negative electrode active material includes a carbon-based material and a silicon-based material (“graphite mixed with silicon”, P31). However, Fujimura does not disclose wherein a content rate of the silicon-based material in the negative electrode active material is greater than or equal to 3 mass% relative to a mass of the negative electrode active material.
In a similar field of endeavor, Amiruddin teaches it can be desirable to combine silicon based active material with a significant amount of graphitic carbon active material (P64). Amiruddin teaches it has been found that a combination of these two negative electrode active materials can stabilize the cycling a desirable degree, such as for consumer electronics applications, with only a modest decrease in the capacity (P64).
Amiruddin teaches to achieve desired cycling stabilization with modest decrease in capacity, the combined negative electrode active material generally comprises from about 5 wt % to about 70 wt % graphitic carbon relative to the total active material, with the remaining portion of the active material being a silicon based active material or a combination thereof (P66).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the teaching of Amiruddin and selected the amount of graphite mixed with silicon in the negative electrode active material of Fujimura to be from about 5 wt % to about 70 wt % relative to the total active material, given Amiruddin teaches this leads to achieving desired cycling stabilization with modest decrease in capacity.
Regarding the limitation “wherein a content rate of the silicon-based material in the negative electrode active material is greater than or equal to 3 mass% relative to a mass of the negative electrode active material”:
If the content of the active material includes 5 to 70 wt % of graphite, then the content of the active material includes 30 to 95 wt % of silicon. Therefore, the content rate of the silicon-based material in the negative electrode active material is 30 to 95 mass% relative to a mass of the negative electrode active material, which lies within the claimed range of greater than or equal to 3 mass% relative to a mass of the negative electrode active material.
Conclusion
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/MARY GRACE BYRAM/Examiner, Art Unit 1729