DETAILED ACTION
Status of the Claims
Applicant’s amendment filed 23 July 2026 is acknowledged. Claims 1 and 2 have been amended and claims 1-12 remain pending.
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 § 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.
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.
Claim(s) 1, 2, 4, 5, and 8-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hiratsuka (WO 2020/003642 A1, listed in the IDS filed 24 September 2024; using US 2021/0265627, listed in the IDS filed 24 September 2024, for the English translation and citations), in view of Oh et al. (US 2013/0224585, hereinafter “Oh”).
Regarding claim 1, Hiratsuka teaches a positive electrode active material for a lithium secondary battery, comprising:
a mixture of microparticles having a predetermined average particle size (D50) (Ni-containing lithium composite oxide A, see Fig. 2A; [0028]-[0033]) and macroparticles having a larger average particle size (D50) than the microparticles (Ni-containing lithium composite oxide B, see Fig. 2B; [0028]-[0033]),
wherein the microparticles have the average particle size (D50) of 1 to 10 μm (the average particle size of the secondary particle of the Ni-containing lithium composite oxide A is 2 μm to 6 μm; see [0032]) and are at least one selected from the group consisting of particles having secondary particles formed by agglomeration of primary macroparticles (see Fig. 2A – primary particles 32; [0028]), having an average particle size (D50) of 1 μm or more (the average primary particle size A of the Ni-containing lithium composite A is 0.5 μm to 2 μm; [0033]), and a mixture of the particles having a carbon material coating layer on all or part of a surface of secondary particles formed by agglomeration of primary macroparticles having an average particle size (D50) of 1 μm or more and particles having a carbon material coating on all or a part of a surface of primary macroparticles having an average particle size (D50) of 1 μm or more,
the macroparticles are secondary particles having an average particle size (D50) of 5 to 20 μm (the Ni-containing lithium composite oxide B has an average secondary particle size of 10 μm to 20 μm, see Fig. 2B; [0032]) formed by agglomeration of primary microparticles having a smaller average particle size (D50) than the primary macroparticles (primary particles 33 with an average primary particle size B of the Ni-containing lithium composite oxide B is 0.05 μm to 0.5 μm, see Fig. 2B; [0028]-[0033]), and
the primary macroparticles and the primary microparticles comprise a nickel-based lithium transition metal oxide (see [0028]-[0033]).
Hiratsuka is silent to wherein the microparticles are particles having a carbon material coating layer on all or part of a surface of secondary particles formed by agglomeration of primary macroparticles.
Oh teaches a composite is formed by milling the layer-structured lithium manganese-based oxide with different kinds of carbon-based conductive materials, the layer-structured lithium manganese-based oxide is first milled into primary particles and surfaces thereof are then coated with the carbon-based conductive material, and the primary particles having the surfaces thereof coated with the carbon-based conductive material are agglomerated to form a secondary particle. Thus, since pathways of electrons are supplemented in the cathode active material, electrical conductivity may not be significantly decreased in the 3 V region even in the case that the phase transition into a spinel-like structure occurs after the initial charge and discharge (see [0055]).
In view of Oh’s teachings, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to modify the microparticles of Hiratsuka to include wherein the microparticles are particles having a carbon material coating layer on at least part of a surface of secondary particles formed by agglomeration of primary macroparticles, as taught by Oh, because it helps to prevent a decrease in electrical conductivity of the active material.
Regarding claim 2, the combination of Hiratsuka and Oh teaches wherein the average particle size (D50) of the primary macroparticles is 1 to 3 μm (Hiratsuka: The average particle size of the primary particles 32 of the Ni-containing lithium composite oxide A is 0.5 μm to 2 μm; see [0033]), and the average particle size (D50) of the microparticles is 3 to 8 μm (The average particle size of the secondary particle of the Ni-containing lithium composite oxide A is 2 μm to 6 μm; [0032]).
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP §2144.05(I).
Regarding claim 4, the combination of Hiratsuka and Oh teaches wherein the average particle size (D50) of the primary microparticles is 100 to 900 nm (Hiratsuka: the average primary particle size B of the Ni-containing lithium compose oxide B is 0.05 μm to 0.5 μm, which is equivalent to 50 nm to 500 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. See MPEP §2144.05(I).
Regarding claim 5, the combination of Hiratsuka and Oh teaches wherein a ratio of the average particle size (D50) of the macroparticles: the average particle size (D50) of the microparticles is 5:1 to 2:1 (Hiratsuka: Since the average particle size of the macroparticles is 10 μm to 20 μm (see [0032]), and the average particle size of the microparticles is 2 μm to 6 μm (see [0032]), this gives a ratio of 10:1 to 1.67:1).
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP §2144.05(I).
Regarding claim 8, the combination of Hiratsuka and Oh teaches wherein the nickel-based lithium transition metal oxide is represented by LiaNi1-b-c-dCobMncQdO2+δ, wherein 1.0≤a≤1.5, 0<b≤0.5, 0<c≤0.5, 0≤d≤0.1, 0<b+c+d≤0.5, −0.1≤δ≤1.0, and Q is at least one type of metal element selected from the group consisting of Al, Mg, V, Ti and Zr (Hiratsuka: wherein in the general formula in [0031], M is Mn and Al overlaps with the claimed oxide when Q is selected to be Al and δ = 0).
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP §2144.05(I).
Regarding claim 9, the combination of Hiratsuka and Oh teaches a positive electrode material mixture for a lithium secondary battery, comprising:
the positive electrode active material for a lithium secondary battery according to claim 1 (see rejection for claim 1); and
a conductive material (Oh: one or more selected from the group consisting of natural graphite and artificial graphite, see [0025]).
Regarding claim 10, the combination of Hiratsuka and Oh teaches wherein the conductive material is present in an amount of 1 to 30 weight % based on the total weight of the positive electrode material mixture (Oh: 1 wt % to 15 wt % based on a total weight of the cathode active material; see [0021]).
Regarding claim 11, the combination of Hiratsuka and Oh teaches a positive electrode (Hiratsuka: positive electrode 11, see Fig. 1; [0020]) for a lithium secondary battery comprising the positive electrode material mixture according to claim 10 (see rejection for claim 10 above).
Regarding claim 12, the combination of Hiratsuka and Oh teaches a lithium secondary battery (Hiratsuka: secondary battery 10, see Fig. 1; [0019]) comprising the positive electrode according to claim 11 (see rejection for claim 11 above).
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Hiratsuka and Oh as applied to claim 1 above, and further in view of Hiratsuka (US 2015/0221934; hereinafter “Hiratsuka ‘934”).
Regarding claim 3, the combination of Hiratsuka and Oh is silent to wherein an average crystallite size of the primary macroparticles is 150 nm or more.
Hiratsuka ‘934 teaches a lithium-nickel transition metal oxide (see [0026]) wherein the average crystallite size is 150 to 300 nm. When the average crystallite size is within this range, the ion conductivity of the composite oxide can be improved (see [0050]).
In view of Hiratsuka ‘934, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to modify the positive electrode active material of the combination of Hiratsuka and Oh to include wherein the average crystallite size is 150 to 300 nm, because it helps to improve the ion conductivity of the composite oxide. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP §2144.05(I).
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Hiratsuka and Oh as applied to claim 1 above, and further in view of Kim et al. (EP 3764438 A1, hereinafter “Kim”; listed in the IDS filed 12 May 2025).
Regarding claim 6, the combination of Hiratsuka and Oh is silent to wherein the microparticles are present in an amount of 10 to 100 parts by weight based on 100 parts by weight of the macroparticles.
Kim teaches a first positive active material and a second positive active material wherein the second positive electrode active material may be a secondary particle formed by agglomerating primary particles (see [0050]). The first positive electrode active material is a large particle and a second positive active electrode active material is a small particle (see [0023]). Kim teaches that the first positive electrode active material and the second positive electrode active material may be mixed at a weight ratio of 60:40 to 85:15. When the active materials are included in the above described ranges, the thermal stability of the active material may be enhanced, the destruction of the structure of the positive electrode active material and the deterioration of the cycle characteristics may be prevented, and the output and capacity characteristics of the batter may be further enhance (see [0051]).
In view of Kim’s teachings, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to modify the positive electrode active material of the combination of Hiratsuka and Oh to include wherein the microparticles are present at a weight ratio of 60:40 to 85:15, because the thermal stability of the active material may be enhanced, the destruction of the structure of the positive electrode active material and the deterioration of the cycle characteristics may be prevented, and the output and capacity characteristics of the batter may be further enhanced. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP §2144.05(I).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Hiratsuka and Oh as applied to claim 1 above, and further in view of Kawakami et al. (US 2017/0352864; hereinafter “Kawakami”).
Regarding claim 7, the combination of Hiratsuka and Oh is silent to wherein the carbon material coating layer is present in an amount of 0.05 to 10 parts by weight based on 100 parts by weight of the primary macroparticles.
Kawakami teaches coating of a lithium-manganese complex oxide with a coating layer, which contains carbon. Since carbon has high conductivity, the particle coated with carbon in the electrode of the storage battery can reduce the resistance of the electrode, for example (see [0186]). Therefore, the carbon material coating is a result effective variable.
In view of Kawakami’s teachings, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to modify the positive electrode active material of the combination of Hiratsuka and Oh to include wherein the carbon material coating layer is present in an amount of 0.05 to 10 parts by weight based on 100 parts by weight of the primary macroparticles, because discovering the optimum amount of the carbon material coating layer to provide for the optimal reduction in the resistance of the electrode, would have been nothing more than routine optimization. See MPEP §2144.05(II).
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-12 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
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/S.S.H/Examiner, Art Unit 1735 2 October 2026
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735
