DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
Status of Application
This is a final office action in response to Applicant's remarks and amendments filed on 11/17/2025. Claims 1, 2, and 7 are currently amended. Claims 3-9 are withdrawn. Claims 10-13 are new. Claims 1-2 and 10-13 are pending review in this action.
Applicant’s amendment to the specification and claims 1-2 have overcome the objections set forth in the previous Office Action.
The 35 U.S.C. 103 rejections in the previous Office Action are withdrawn.
New grounds of rejection necessitated by Applicant’s amendments are presented below.
Response to Arguments
Applicant's arguments filed 11/17/2025 have been fully considered but they are not persuasive.
Applicant argues that the combination of Sun and Zhao is improper because Sun teaches a single sintering step while Zhao teaches three sintering steps.
The Examiner respectfully disagrees, because Zhao teaches adding a coating agent and sintering to obtain a coated cathode material in order to reduce side reactions and stabilize the single-crystal material ([0025]).
Applicant argues that Sun and Zhao do not disclose “Step 3, balling milling the coated second material without jet milling to obtain the single-crystal cathode material” and the instant specification indicates that jet milling is employed in prior art to crush the sintered cathode material.
This argument is moot, because the rejection relies You to teach the new limitation of amended claim 1. However, the Examiner notes that neither Sun nor Zhao disclose the use of jet milling.
.
Claim Objections
Claims 10-13 are objected to because of the following informalities:
Claims 10-13 recite “The preparation method of claim 1,” but should recite “The preparing method of claim 1.”
Claim 12 recites “comprises,” but should recite “comprising” or “wherein the method comprises.”
Claim 13 recites “has an average particle size of is” but should recite “has an average particle size of.”
Appropriate correction is required.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2 and 10-13 are rejected under 35 U.S.C. 103 as being unpatentable over Sun (CN-101847722-A, the rejections below refer to the machine translation mailed 08/12/2025) in view of Zhao (WO 2022/207008 A1, English-language equivalent US 2023/0202866 A1 is cited below; previously cited) and You (CN-117747776-A, English-language equivalent US 2025/0300174 A1 is cited below).
Regarding claim 1, Sun discloses a preparing method for a single-crystal cathode material ([0012]), comprising:
Step 1, mixing and ball milling a lithium source with a nickel-cobalt-manganese polycrystalline precursor ([0016], [0019]) to form a mixture; and then performing a first sinter-treating to the mixture at a temperature of 650 to 950°C for 15-30 hrs (950 °C and 24 hours, [0033]) to obtain a first main material; and wherein the single-crystal cathode material contains particles of
LiaNixCoyMnzO2·cA (LiNi0.35Co0.3Mn0.35O2, [0034]), wherein 1≤a≤1.2 (a = 1), 0≤x≤1 (x = 0.35), 0≤y≤0.5 (y = 0.3), 0≤z≤0.5 (x = 0.35), and x+y+z＝1.
Sun does not disclose “Step 2, mixing and ball milling the first main material with source A and then performing a second sinter-treating to obtain a coated material at 650 °C to 950 °C for 5-15 hours; and Step 3, balling milling the coated second material without jet milling to obtain the single-crystal cathode material, wherein the source A forms a coating on a surface of the coated material and the source A is selected from oxides or carbonates of Nb, Sr, and W, and mixtures thereof” and wherein 0<c≤0.05.
Zhao teaches a preparing method for a single-crystal cathode material, comprising mixing a precursor material with source A ([0091]), and then performing a sinter-treating to obtain a coated material at 650 °C to 950 °C for 5-15 hours (overlapping ranges of 500-900 °C and 3-10 hours, [0090]; 780 °C for 6 hours in an example embodiment, [0170]); and crushing the coated material ([0170]), wherein the source A forms a coating on a surface of the coated material and the Source A is selected from oxides or carbonates of Nb and W or mixtures thereof (coating agent E [0087]), and wherein the coating is applied such that 0<c≤0.05 in the formula LiaNixCoyMnzO2·cA (overlapping range of 0≤c≤0.05 [0088]). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have modified the preparing method of Sun by adding Step 2, mixing the first main material with source A and then performing a second sinter-treating to obtain a coated material at 650 °C to 950 °C for 5-15 hours; and Step 3, crushing the coated second material to obtain the single-crystal cathode material, wherein the source A forms a coating on a surface of the coated material and the source A is selected from oxides or carbonates of Nb and W, and mixtures thereof and wherein 0<c≤0.05 because Zhao teaches that doing so stabilizes the structure of the material and reduces residual lithium on the surface of the material ([0025]).
You teaches a preparing method for a single-crystal cathode material ([0040]), comprising:
Step 1, mixing and ball milling ([0070]) a lithium source ([0067]) with a nickel-cobalt-manganese precursor ([0064]) to form a mixture ([0054); and then performing a first sinter-treating to the mixture to obtain a first main material ([0054]);
Step 2, mixing and ball milling ([0070]) the first main material (product of the primary sintering, [0062]) with source A (coating agent, [0062]) and then performing a second sinter-treating (secondary sintering, [0062]) to obtain a coated material at 650 °C to 950 °C (overlapping range of 300 °C to 900 °C, [0076]) for 5-15 hours (overlapping range of 6-24 hours, [0077]); and
Step 3, balling milling the coated second material without jet milling to obtain the single-crystal cathode material (shaping by ball milling, [0078]),
wherein the source A (coating agent) forms a coating on a surface of the coated material and the source A is selected from oxides of Nb, Sr, and W, and mixtures thereof ([0062]).
A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to modify the method of Sun in view of Zhao by using ball milling in Step 2 and ball milling without jet milling in Step 3, wherein the source A is selected from an oxide of Nb, Sr, and W, and mixtures thereof, because You teaches that using ball milling to mix and crush ([0070],[0078]) and using Sr as a coating agent ([0062]) are known methods of preparing a single-crystal cathode material.
Regarding claim 2, Sun in view of Zhao and You teaches wherein a mass ratio of the first main material to the source A is 1.0: (0.002-0.01) (You: overlapping range of 1.0:(0-0.1), [0074]).
Regarding claim 10, Sun in view of Zhao and You teaches wherein the source A is selected from oxides of Nb, carbonates of Nb, and mixtures thereof (Zhao: [0088], You: [0062]).
Regarding claim 11, Sun in view of Zhao and You teaches wherein the source A is selected from oxides of Sr (You: [0062]).
Regarding claim 12, Sun in view of Zhao and You teaches wherein the method comprises no sinter-treating in addition to the first sinter-treating and the second sinter-treating (Sun teaches a single sinter-treating corresponding to the first sinter-treating, Zhao teaches the second sinter-treating to apply the coating, see rejection of claim 1).
Regarding claim 13, Sun in view of Zhao and You teaches wherein the single-crystal cathode material has an average particle size of is 2-6 µm (Sun: overlapping range of 5-10 µm, [0033]).
Sun in view of Zhao and You does not disclose wherein the single-crystal cathode material has a specific surface area of 0.5-1.5 m2/g, and a total free lithium in the single-crystal cathode material of less than 1500 ppm by mass.
However, because the preparing method of Sun in view of Zhao and You is substantially identical to that of the claimed invention (see claim 1), it is the Office’s position that the single-crystal cathode material has a specific surface area of 0.5-1.5 m2/g, and a total free lithium in the single-crystal cathode material of less than 1500 ppm by mass.
Alternatively, You teaches that the specific surface area of single-crystal cathode material can be controlled ([0030]). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have optimized the specific surface area of the material formed by the preparing method of Sun in view of Zhao and You, including to a range corresponding to “0.5-1.5 m2/g,” because You teaches that increasing the median particle size D50 of the material decreases the specific surface area of the material and improves cycling stability ([0029]), but also causes decreased capacity and rate performance ([0034]).
Zhao that a coated single-crystal cathode material has less total free lithium on its surface ([0025]). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have minimized the total free lithium in the single-crystal cathode material formed by the preparing method of Sun in view of Zhao and You because Zhao teaches that reducing the total free lithium in the single-crystal cathode material reduces undesirable side reactions ([0025]).
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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/C.C.D./Examiner, Art Unit 1723 /TIFFANY LEGETTE/Supervisory Patent Examiner, Art Unit 1723