DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/23/25 has been entered.
Response to Amendment
Claims 1, 2, 6, 8, and 9 are currently pending. Claims 3-5 and 7 have been cancelled. The amended claim 1 does overcome the previously stated 103 rejections. However, upon further consideration, claims 1, 2, 6, 8, and 9 are rejected under the following new 103 rejections.
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 1, 2, and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Maeda et al (US 2018/0351199) in view of Okamoto et al (US 2017/0331107), Tiruvannamalai et al (US 2020/0280063), and further in view of Sadakane (WO 2019/181278 A1) using (US 2021/0043970) as an equivalent English translation.
Regarding claims 1, 2, and 6, Maeda et al discloses a lithium secondary battery (nonaqueous electrolyte secondary battery) comprising a positive electrode, a negative electrode, and an electrolyte solution (nonaqueous electrolyte); wherein the positive electrode includes a positive electrode active substance that is a lithium transition metal composite oxide (composition represented by a general formula: LiNixCoyM1-x-yO2, M is at least one selected from the group consisting of Al and Mn) such as LiCo1-xNixO2 (0.01<x<1), LiNixCoyMnzO2 (x+y+z=1, 0.01<x, 0.01<y, 0.01<z), LiNiβCoγAlδO2 (β+γ+δ=1, 0.70≤β<1, 0<γ≤0.2, 0<δ≤0.1) wherein examples include LiNi1/3Co1/3Mn1/3O2 and LiNi0.8Co0.15Al0.05O2 which inherently has a layered rock salt type crystal structure; and a lithium metaphosphate (additive) covering at least a portion of a surface of the positive electrode active substance (composite oxide); the lithium metaphosphate includes a lithium salts of cyclophosphoric acid (cyclic inorganic phosphoric acid compound) and lithium salts of polyphosphoric acid (cyclic polyphosphoric acid and a salt); wherein the electrolyte solution includes lithium (oxalate)difluoroborate which includes a lithium ion and an anion of an oxalate complex including difluorooxalate borate anion ([0034],[0041]-[0049],[0097],[0131],[0134]). Examiner’s note: as evidenced by Momma et al (US 2022/0181619), a composite oxide represented by LiMO2, wherein M is one or more elements selected from Al and Mn in addition to one or more elements selected from Co and Ni such as LiNixMnyCozO2 is a material having a layered rock-salt crystal structure ([0199],[0200]).
However, Maeda et al does not expressly teach a cyclic polyphosphoric acid that includes hexametaphosphoric acid (claim 1).
Okamoto disclose a lithium manganese nickel composite oxide particle and a organic phosphate compound adhered to the surface of the lithium manganese nickel composite oxide particle; wherein the organic phosphate compound is cyclic polyphosphate typified by hexametaphosphate (hexametaphosphoric acid when O-- is bound to H+) ([0041],[0044]).
Therefore, the invention as a whole would have been obvious to one of ordinary skill in the art at the time the invention was made because the disclosure of Okamoto indicates that hexametaphosphoric acid is a suitable material for use as a compound for covering the surface of a composite oxide. The selection of a known material based on its suitability for its intended use has generally been held to be prima facie obvious (MPEP §2144.07). As such, it would be obvious to use hexametaphosphoric acid.
However, Maeda et al as modified by Okamoto does not expressly teach a phosphorus content relative to a total of the composite oxide and the additive that is 0.1 mass% or more and 0.75 mass% or less (claim 1).
However, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Maeda/Okamoto positive electrode active substance to include a phosphorus content relative to a total of the composite oxide and the additive that is 0.1 mass% or more and 0.75 mass% or less because it has been held that the discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art. In re Boesch, 205 USPQ 215 (CCPA 1980). The amount of phosphorus content is a result effect variable of reducing the impairing of original properties of the positive electrode active substance and attaining a sufficient coating effect ([0049]). Where 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. In re Aller, 220 F.2d 454. 456, 105 USPQ 233, 235 (CCPA 1955)). There is no evidence of criticality of the claimed phosphorus content.
However, Maeda et al as modified by Okamoto does not expressly teach a negative electrode including a negative electrode current collector and lithium metal foil attached to a surface of the negative electrode current collector (claim 1).
Tiruvannamalai et al discloses an anode (negative electrode) including a lithium foil attached to a surface of a current collector (negative electrode current collector) ([0154]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Maeda/Okamoto battery to include a negative electrode including a negative electrode current collector and lithium metal foil attached to a surface of the negative electrode current collector in order to enable the utilization of lower-cost and more commonly available lithium metal foil thickness, while still achieving high cell cycle life at a significantly reduced cost (Abstract).
However, Maeda et al as modified by Okamoto and Tiruvannamalai et al does not expressly teach a concentration of the anion of the oxalate complex in the nonaqueous electrolyte that is 0.05 mol/L or more and 1 mol/L or less (claim 1).
Sadakane discloses an oxalate salt (anion of the oxalate complex) that is contained in the electrolyte at a concentration of 0.3 mol/L or more and 1 mol/L or less ([0017]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Maeda/Okamoto/ Tiruvannamalai battery to include a concentration of the anion of the oxalate complex in the nonaqueous electrolyte that is 0.3 mol/L or more and 1 mol/L or less in order to utilize a concentration of the oxalate salt where metallic lithium is more unlikely to deposit in a dendrite form ([0017]).
Examiner’s note: the limitation “during charging, lithium metal deposits on the negative electrode, and during discharging, the lithium metal dissolving into the nonaqueous electrolyte” is an inherent characteristic of the Maeda/Okamoto/ Tiruvannamalai/Sadakane battery because Maeda as modified by Okamoto, Tiruvannamalai, and Sadakane teaches the same positive electrode, negative electrode, nonaqueous electrolyte, and additive as the present invention.
Claims 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Maeda et al in view of Okamoto et al, Tiruvannamalai et al, and Sadakane as applied to claim 1 above, and further in view of Toyama et al (US 2011/0217574).
However, Maeda et al as modified by Okamoto et al, Tiruvannamalai et al, Sadakane does not expressly teach an additive that further includes Li3PO4 (claim 8); or an additive that further includes Li4P2O7 (claim 9).
Toyama et al discloses a coating layer for coating a composite oxide of a cathode, comprising Li3PO4 or Li4P2O7 ([0053],[0056]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the Maeda/Okamoto/Tiruvannamalai/Sadakane positive electrode to include an additive that further includes Li3PO4 or Li4P2O7 in order to suppress the increase of the resistance of the cathode as well as to prevent oxidative decomposition of the electrolyte solution under high voltage conditions ([0056],[0057]).
Response to Arguments
Applicant’s arguments with respect to claim(s) 1, 2, 6, 8, and 9 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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/T.S.C/Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 5/11/2026
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