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 .
Response to Amendment
The amendment filed 03/06/2026 has been entered. Claim 1 now partially combines the scope of previous claims 2 and 4, with support found therein.
The amendment overcomes the 35 USC 112(b) rejection to claim 3 of the previous Office actions, but a 35 USC 112(b) rejection to claim 4 is maintained below.
While the amendment overcomes the 35 USC 102 (anticipation) rejections of record, 35 USC 103 (obviousness) rejections are made below relying upon similar grounds as those relied upon in the previous Office action.
Response to Arguments
Applicant's arguments filed 03/06/2026 regarding amended claim 1 (which now partially combines the scope of previous claims 2 and 4) have been fully considered but they are not persuasive. While the amendment overcomes the 35 USC 102 (anticipation) rejections of record, 35 USC 103 (obviousness) rejections are made below relying upon similar grounds as those relied upon in the previous Office action.
In response to applicant's argument that Ajayan is nonanalogous art to Niimi, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case, Ajayan and Niimi are both in the field of endeavor of negative electrode active material, and both are pertinent to the problem of coating with polymethylmethacrylate. Examiner notes that Niimi already teaches the base structure of the silicon-based negative electrode active material coated with exemplary PMMA, while Ajayan is relied on only for teaching toward a thickness of said PMMA coating layer applicable to negative electrode material.
In response to applicant's argument that the PMMA coating layer of Ajayan would not be obvious to apply to the silicon-based negative electrode active material of Niimi, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). Here, Ajayan teaches toward benefits achieved (e.g., faster Li-ion kinetics and larger areal capacity, as cited in the below rejection) by the relatively thin PMMA layer.
As noted in the rejection of record, the molecular weight range in claim 3 is interpreted to be in atomic mass units [amu] or Daltons [Da], which are equivalent. Examiner thanks Applicant for agreeing with this interpretation in the 03/06/2026 remarks.
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.
Claim 4 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.
Regarding claim 4, the phrase "optionally" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d). Further, the claim 4 recitation “the silicon-based material” is indefinite because claim 1 (upon which claim 4 depends) does not positively require any silicon-based material (claim 1 only requires “the negative electrode active substance comprises at least one of graphite and a silicon-based material”).
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.
Claim(s) 1-2, 4, and 15-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Niimi et al. (US 2015/0188127 A1, cited in the 12/19/2025 action) in view of Ajayan et al. (US 2013/0017453 A1, cited in the 12/19/2025 action).
Regarding claim 1, Niimi teaches a negative electrode active material (a negative-electrode active material, Niimi [0068]), comprising:
a negative electrode active substance (preferable negative-electrode active material, [0074]) and a coating layer (coated by a carbonaceous substance, [0075]),
wherein the negative electrode active substance comprises at least one of graphite (graphite as carbonaceous substance example listed in [0070]) and a silicon-based material (preferable negative-electrode active material: lithium silicate, SiOx particles, Si particles; [0074-0078])
wherein the coating layer is coated on a surface of the negative electrode active substance (coating a carbonaceous substance onto lithium silicate particles is applicable to a mixture comprising lithium silicate particles and SiOx (where 0<“x”<2) particles or Si particles, so that the coating process makes possible coating a carbonaceous substance onto the respective surfaces of the lithium silicate particles and SiOx particles or Si particles, [0066, 0074]; SiOx particles coated by a carbonaceous substance on at least some of the surface or Si particles coated by a carbonaceous substance on at least some of the surface, [0075-0076]), and
the coating layer comprises at least one of polymethyl methacrylate, sodium maleate, and oleic diethanolamide borate (carbonaceous substance is formed by heating a carbon-containing compound … preferable carbon-containing compound example of polymethyl methacrylate (PMMA), [0047-0048, 0060]).
Niimi fails to teach: wherein a thickness of the coating layer is 5 nm to 50 nm. Instead Niimi teaches that coating the carbonaceous substance onto a surface of the exemplary lithium silicate particles in a thickness of from 100 nm to 1,000 nm is possible (Niimi [0063]). As cited above, Niimi teaches in [0060] that polymethyl methacrylate (or PMMA) is a preferable carbon-containing compound.
Ajayan is analogous in the art of negative electrode active material and pertinent to the problem of coating with a PMMA (polymethylmethacrylate) polymer layer, and teaches the conformal PMMA layer being uniform in thickness, in the range from about 20 to about 100 nm or more specifically from 20 to about 30 nm (Ajayan [0027-0028, 0050]) which achieves a good interface between the thin PMMA layer around the electrode active material (Ajayan [0071]). Ajayan [0010] teaches that the relatively thin polymer coating layer conforming around the electrode nano-material beneficially improves lithium ion kinetics in the cell and also allows for larger capacities per unit area.
It would have been obvious, at the time of filing, for a person having ordinary skill in the art to modify the PMMA coating layer thickness of Niimi to be thinner, within 20 to 30 nm as taught by Ajayan, to improve lithium ion kinetics in the cell and also allow for larger capacities per unit area. This thickness range falls within that claimed (see MPEP 2144.05 I). Also, changes in size/proportion are obvious design choices within the ambit of a person having ordinary skill in the art per MPEP 2144.04 IV A.
Thereby, claim 1 is rendered obvious.
Regarding claim 2, modified Niimi teaches the limitations of claim 1 above and the thickness of the coating layer is 10 nm to 20 nm (20 to 30 nm as taught by Ajayan as applied above abuts the instantly claimed range at 20 nm. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists; Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close; MPEP 2144.05 I).
Also, per MPEP 2144.05 II, “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” Thus, since Ajayan teaches that the thickness of the polymeric (i.e., PMMA) coating layer is a variable which affects the resultant Li-ion kinetics and areal capacity of the negative electrode active material (see Anjayan [0010, 0071] as cited above), a person having ordinary skill in the art would have been motivated to find the optimal and relatively thin thickness thereof within modified Niimi to achieve desired battery characteristics. Thus, claim 2 is obvious.
Regarding claim 4, modified Niimi teaches the limitations of claim 1 above and wherein the silicon-based material comprises at least one of monatomic silicon (Si particles, [0074]), a silicon-oxygen compound (SiOx, [0074]); optionally, the silicon-oxygen compound comprises SiaOb, wherein a=1, 1<b<2 (SiOx where 0<“x”<2, [0074]).
Regarding claim 15, modified Niimi teaches the limitations of claim 1 above and teaches a negative electrode plate, comprising the negative electrode active material according to claim 1 (a common negative electrode is made by adhering onto a current collector a negative-electrode active-material layer made by binding together the aforementioned negative-electrode active material at least with a binding agent, [0079]).
Regarding claim 16, modified Niimi teaches the limitations of claim 15 above and teaches a battery cell, comprising the negative electrode plate according to claim 15 (in addition to the above-mentioned negative electrode, a nonaqueous-electrolyte secondary battery further comprises a positive electrode, a separator, and an electrolytic solution, as the battery constituent elements; [0085] – wherein “battery constituent elements” read on “a battery cell”).
Regarding claim 17, modified Niimi teaches the limitations of claim 16 above and teaches a battery, comprising the battery cell according to claim 16 (nonaqueous-electrolyte secondary battery, [0001-0002, 0085]).
Regarding claim 18, modified Niimi teaches the limitations of claim 17 above and teaches an electrical device, comprising the battery according to claim 17 (lithium-ion secondary batteries have been used mainly as a power source for portable electronic devices, [0002]).
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Niimi et al. (US 2015/0188127 A1, cited in the 12/19/2025 action) in view of Ajayan et al. (US 2013/0017453 A1, cited in the 12/19/2025 action) as applied to claim 1 above, and further in view of Yuan et al. ("Development of Synthesis and Application of High Molecular Weight Poly(Methyl Methacrylate)", Polymers 2022, 14(13), 2632; https://doi.org/10.3390/polym14132632; cited in and attached to the 12/19/2025 action).
Regarding claim 3, modified Niimi teaches the limitations of claim 1 above but fails to teach a molecular weight of the polymethyl methacrylate is 500,000 to 2,000,000, and optionally, the molecular weight of the polymethyl methacrylate is 1,000,000 to 1,500,000. Niimi appears silent toward a molecular weight of the PMMA of the carbonaceous coating substance.
Yuan is analogous in the art of polymethyl methacrylate (PMMA) and is pertinent to PMMA being used within electrochemical devices (Yuan pg. 16, 4th para.). Yuan teaches that high molecular weight PMMA importantly has excellent electrochemical performance and mechanical properties, making it useful in electronic equipment and polymer membrane areas (Yuan pg. 12, 1st para. in section 3 under Table 1). Here, Yuan teaches that the mechanical properties of PMMA are significantly affected by the molecular weight, showing that the tensile strength, fracture surface energy, shear modulus and Young’s modulus increase with the increase in molecular weight (Mυ) up to 106 Da (see last paragraph of Yuan pg. 12, and Fig. 7 on pg. 13; see also Yuan Abstract). Yuan teaches that the PMMA with a number-average molecular weight exceeding 106 Da can be defined as ultrahigh molecular weight PMMA and the PMMA with a number-average molecular weight exceeding 105 Da can be defined as high molecular weight PMMA, and that low molecular weight PMMA has limited applications because of its poor heat resistance, poor wear resistance, poor organic solvent resistance, low hardness and easy combustion features (Yuan pg. 1, para. 2 under section 1). Yuan Fig. 7 (pg. 13) shows datapoints for PMMA molecular weights from ~400,000 Da (~4 x 105 in Figs. 7(c-d)) to ~7,000,000 Da (~7 x 106 in Fig. 7(b)), which encompasses the claimed 500,000 to 2,000,000 range (see MPEP 2144.05 I).
In using PMMA as the carbonaceous coating substance within modified Niimi, a person having ordinary skill in the art would have found it obvious to use high or ultrahigh molecular weight PMMA as taught toward by Yuan – thus having molecular weight on the order of 105 and 106 (overlapping the claimed range, see MPEP 2144.05 I) – in order to attain desired strength, heat resistance, and organic solvent resistance (especially since Niimi teaches non-aqueous electrolyte; see Niimi [0092]) of the coating layer used within the negative electrode as taught toward by Yuan. Thus, molecular weight is a result-effective variable which influences the strength and resistance properties of the PMMA as taught by Yuan, such that a person having ordinary skill in the art would have also found it obvious to optimize the molecular weight of the PMMA used in Niimi to be high or ultrahigh as taught toward by Yuan to achieve desired strength and resistance properties. (See also MPEP 2144.05 II.)
Thereby, claim 3 is rendered obvious
Relevant Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Isshiki (US 20140023922 A1) teaches alloy-based active material which can be a lithium silicide of lithium carbide, with Si being preferable ([0052-0054,0057]) and teaches polymer coating on the surface of the metal powder which can be polymethylmethacrylate ([0090, 0317, 0319, 0321]) at a thickness of 1 to 200 nm but most preferably 10 to 50 nm ([0100, 0317, 0319, 0321]).
Zhamu (US 20180287142 A1) teaches Encapsulated Anode Active Material Particles (title), with Si and graphite particles being studied ([0012]) and silicon listed as an anode active material option ([0024]), and teaches coating with ultrahigh molecular weight PMMA polymer at a thickness from 0.5 nm to 10 μm and more preferably <10 nm ([0016-0017]).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jessie Walls-Murray whose telephone number is (571)272-1664. The examiner can normally be reached M-F, typically 10-4.
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/JESSIE WALLS-MURRAY/Primary Examiner, Art Unit 1728