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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 29 March 2024, 17 July 2025, 20 October 2025, and 22 January 2026 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
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 1-11, 13, 15, and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Endo et al. (JP 2022139794, hereinafter, Endo) in view of Xia et al. (CN 102074690, hereinafter, Xia).
Regarding claim 1, Endo teaches a positive electrode mixture containing a positive electrode active material comprising a lithium transition metal compound having a carbon-coated polyanion structure such as LiFePO4 (Endo Positive Electrode ¶ 6), and less than 1% by mass of conductive agent, including 0% (Endo Description of Embodiments ¶ 5).
Endo teaches a carbon shell but does not teach a graphitization degree of the carbon shell being between 10% and 50%. In a related field of endeavor, Xia teaches an alternate synthesis method of LiFePO4 and its use as a positive electrode material in batteries.
It would have been obvious to one of ordinary skill in the art before the filing date to combine the teachings of Endo with the carbon-coated LiFePO4 taught by Xia as this affords small particles having large capability (Xia Abstract) and one would have a reasonable expectation of success. Further, Xia teaches where the carbon-coated LiFePO4 is formed by roasting at 600 to 900 degrees centigrade for 6 to 15 hours (Xia Abstract) which overlaps with the temperature and time values applicant discloses in Table 1 of the specification as having the claimed graphitization degree and therefore modified Endo is expected to possess this feature as substantially identical materials treated in a substantially identical manner are expected to behave the same, absent an objective showing. See MPEP 2112.01.
Regarding claims 2-5, Endo in view of Xia teaches the positive electrode material composition of claim 1, wherein the degree of graphitization is between 25% and 45%, and the mass percentage of the positive electrode conductive agent is 0%. The roasting step of Xia ranges from 600 to 900 degrees centigrade for 6 to 15 hours (Xia Abstract), which overlaps with the range of time and temperatures to achieve between 25% to 45% graphitization from Table 1 of the instant disclosure, satisfying the claimed graphitization degree limitations of claims 2-5, and the conductive agent is present at 0% by mass (Endo Description of Embodiments ¶ 5), satisfying the claimed conductive agent limitations of claims 2-5.
Regarding claim 6, Endo in view of Xia teaches the positive electrode material composition of claim 1, wherein graphitization is determined using X-ray diffraction (Endo Negative Electrode ¶ 7).
Regarding claim 7, Endo in view of Xia teaches the positive electrode material composition of claim 1, but does not teach a powder resistivity of the positive electrode active material being greater than 0 and less than or equal to 30 Ω⋅cm. However, Endo in view of Xia teaches a positive electrode active material with a core-shell structure with the same lithium iron phosphate as the core and carbon as the shell with an overlapping thickness range (applicant’s disclosure ¶ 00128, 0 - 2 µm; Xia ¶ 9, 2 - 10 µm) which is substantially identical to the positive electrode active material which applicant claims and discloses in paragraph 00183 as having a powder resistivity greater than 0 and less than or equal to 30 Ω⋅cm. As such, one would expect the positive electrode active material of Endo in view of Xia to possess the claimed powder resistivity as a material and its properties are inseparable, absent an objective showing. See MPEP 2112.01.
Regarding claim 8, Endo in view of Xia teaches the positive electrode material composition of claim 1, wherein the average particle size of the positive electrode active material is 0.1 µm or more and 20 µm or less based on a value at which the volume-based integrated distribution calculated according to 50% (Endo Positive Electrode ¶ 9), encompassing the claimed Dv50 average particle size range of 0.5 µm to 10 µm. The lithium phosphate also comprises lithium iron phosphate (Endo Positive Electrode ¶ 6), and the additive is also exemplified as acetylene black, Ketjen black, carbon nanotubes, graphite, graphene, etc. (Endo Positive Electrode ¶ 13).
Regarding claim 9, Endo in view of Xia teaches the positive electrode material composition of claim 1, wherein the mass percentage of the positive electrode active material is 99% by mass or less (Endo Positive Electrode ¶ 11).
Regarding claim 10, Endo in view of Xia teaches the positive electrode material composition of claim 1, wherein the positive electrode mixture layer may comprise a binder exemplified as fluorine resins, thermoplastic resins, sulfone elastomers, styrene-butadiene rubber, fluororubber, polysaccharide polymers, etc. (Endo Positive Electrode ¶ 13), and a dispersion medium exemplified as N-methylpyrrolidone (Endo Preparation of Positive Electrode ¶ 1).
Regarding claim 11, Endo in view of Xia teaches the positive electrode material composition of claim 1, wherein the positive electrode base material is coated with positive electrode mixture paste comprising the positive electrode active material, binder, and dispersion medium (Endo Preparation of Positive Electrode ¶ 1).
Regarding claim 13, Endo in view of Xia teaches the positive electrode plate of claim 11, wherein the positive electrode plate satisfies the claimed limitation of being equal to 0 due to w1/CW being 0 because of the mass percentage of conductive agent being 0 (see above rejection for claims 1-5).
Regarding claim 15, Endo in view of Xia teaches the positive electrode plate of claim 11, wherein the positive electrode satisfies the claimed limitation of being equal to 0 due to w1/H being 0 because of the mass percentage of conductive agent being 0 (see above rejection for claims 1-5).
Regarding claim 17, Endo in view of Xia teaches the positive electrode plate of claim 11, further comprising an intermediate layer arranged between the positive electrode substrate and the positive electrode material layer containing a conductive agent such as carbon particles to reduce contact resistance between the positive electrode substrate and the positive electrode mixture layer (Endo Positive Electrode ¶ 4).
Regarding claim 18, Endo in view of Xia teaches the positive electrode plate of claim 11, wherein the average thickness of the positive electrode current collector is 10 µm or more and 25 µm or less, encompassing the claimed thickness range of 10 µm – 18 µm (Endo Positive Electrode ¶ 3).
Regarding claim 19, Endo in view of Xia teaches the method for preparing a positive electrode plate comprising mixing the carbon-coated LiFePO4 of claim 1 as positive electrode active material, N-methylpyrrolidone as dispersion medium, and polyvinylidene fluoride as binder to form a positive electrode mixture paste, applying the mixture to both surfaces of an aluminum foil positive electrode base material, drying at 120 °C, and roll-pressing to form the positive electrode.
Regarding claim 20, Endo in view of Xia teaches the positive electrode of claim 1 used in a non-aqueous electrolyte secondary battery (Endo Preparation of Non-Aqueous Electrolyte Secondary Battery ¶ 1).
Claims 12, 14, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Endo (JP 2022139794) in view of Xia (CN 102074690) in further view of Pan et al. (WO 2021190490, hereinafter, Pan).
Regarding claim 12, 14, and 16, Endo in view of Xia teaches the positive electrode plate of claim 11, but does not teach that the areal density of the plate is greater than or equal to 300 mg / 1540.25 mm2, that the thickness of the electrode film layer is between 70 and 145 µm, or that the compaction density of the positive electrode plate is greater than 2.55 g/cm2. In a related field of endeavor, Pan teaches a lithium iron phosphate positive electrode sheet with ultra-high compaction density. The positive electrode sheet of Pan has a compaction density of 2.6 to 2.8 g/cm3, meeting the limitation of claim 16, and an areal density of 380 - 420 g/m2, or 585.3 – 646.9 mg / 1540.25 mm2, meeting the limitation of claim 12 (Pan Public Detailed Description ¶ 4); and by using the formula from (Pan Test Case ¶ 1), the thickness of the positive electrode film layer can be expressed as the areal density divided by the compaction density, with the range being from (0.038 g/cm2)/(2.8 g/cm3) = 0.01357 cm or 135.7 µm to (0.042 g/cm2)/(2.6 g/cm3) = 0.01615 cm or 161.5 µm, which overlaps the range limitation of 70 to 145 µm of claim 14.
It would be obvious to one of ordinary skill in the art before the filing date to combine the teachings of Endo in view of Xia with the positive electrode sheet of Pan. One would be motivated to do so because the ultra-high compaction density would result in a higher energy density and excellent cycle performance (Pan Public Content ¶ 11).
Conclusion
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/M.F./ Examiner, Art Unit 1784
/HUMERA N. SHEIKH/ Supervisory Patent Examiner, Art Unit 1784
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