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 .
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged. Applicant has complied with all of the conditions for receiving the benefit of an earlier filing date under 35 U.S.C. 119(e).
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDSs) submitted on 05/24/2023, 08/09/2024, 10/01/2024, and 10/15/2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Drawings
The drawings received on 05/24/2023 were reviewed and are acceptable.
Specification
The specification filed on 05/24/2023 was reviewed and is acceptable.
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.
Claim(s) 1-3, 5, 8-14, and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 2015/0010819 A1; hereinafter “Lee”) in view of Oh et al. (US 2016/0013476 A1; hereinafter “Oh”) and Kim et al. (US 2018/0323423 A1; hereinafter “Kim”).
Regarding claims 1 and 14, Lee discloses a positive electrode active material for a lithium secondary battery, and related method of preparing said material (Title) comprising:
at least one secondary particle (secondary particles, Abstract) comprising an agglomerate of primary macro particles (primary particles, Abstract),
wherein an average particle size (D50) of the primary macro particle is 1 mm or more (2 to 3 mm, Abstract), an average particle size (D50) of the secondary particle is from 3 to 15 mm (5 to 8 mm, Abstract),
a specific surface area of the positive electrode active material before applying a pressure to an electrode comprising the positive electrode active material is from 0.2 to 1.2 m2/g (0.366 m2/g, Table 4, Example 1, [0188]), and
a BET change of the positive electrode active material before/after the applying a pressure to the electrode comprising the positive electrode active material is 70% or less (0.532/0.366=1.45, which is equivalent to ~45% “BET change”, Table 4, Example 1, [0188]).
However, Lee does not disclose that all or part of the secondary particle or the primary macro particle is coated with a lithium boron oxide, nor specifically rolling the electrode wherein a rolling condition of the electrode is a condition that a porosity of the electrode is at from 15% to 30%.
Oh teaches a cathode active material for lithium secondary batteries (Title). Oh teaches that impurities can remain present on the surface of a cathode active material due to conventional fabrication processes, and that such impurities may affect aging characteristics and cause swelling by reacting with electrolytes ([0006]). Accordingly, Oh teaches a method of preparing a cathode active material which easily transforms lithium impurities present in a lithium transition metal oxide into a structurally stable lithium boron oxide by performing a heat treatment near the melting point of a boron-containing compound ([0019]). Oh teaches that the heat treatment results in a coating layer of lithium boron oxide formed on a typically used lithium transition metal oxide cathode active material ([0045-0051]). Oh further teaches that such process and coating increases the capacity retention ratio of the battery and exhibits excellent output characteristics due to the decrease in the resistance increase rate ([0115-0116]).
Lee and Oh are analogous prior art to the current invention because they are concerned with the same field of endeavor, namely positive electrode active materials for lithium secondary batteries.
Before the effective filing date of the current invention, it would have been obvious to one having ordinary skill in the art to utilize the lithium boron oxide coating method of Oh during the production of the positive electrode active material of Lee with the reasonable expectation that doing so would increase the capacity retention ratio of the battery and provide excellent output characteristics, as suggested by Oh.
Accordingly, the skilled artisan would find it obvious that modified Lee discloses that all or part of the secondary particle or the primary macro particle is coated with a lithium boron oxide (Oh: [0045-0051]).
Kim teaches a method for producing a positive electrode for a secondary battery (Title). Kim teaches in efforts to produce secondary batteries with various performances, e.g. high capacity, high output, long service life, and high-speed charging, it is important to consider how much active material may be filled to produce a high-capacity battery, but that when excessive rolling is used to increase the packing density, disconnection of an electrode occurs or crack formation of the active material increases ([0005-0006]). Accordingly, Kim teaches a method of rolling an electrode two times or less under certain conditions ([0044-0045]). Kim teaches that such rolling should produce a positive electrode active material layer having a porosity after rolling of most preferably 23 to 24%, and an elongation of the positive electrode current collector should be 1% or less ([0042]).
Kim is analogous prior art to the current invention because they are concerned with the same field of endeavor, namely positive electrodes for lithium secondary batteries.
Before the effective filing date of the current invention, it would have been obvious to one having ordinary skill in the art to utilize the rolling process of Kim to produce the positive electrode of modified Lee with the reasonable expectation that doing so would prevent disconnection of the electrode and prevent crack formation of the positive electrode active material, as suggested by Kim.
Accordingly, the skilled artisan would find it obvious that modified Lee discloses rolling of the electrode (Kim: [0044]), and wherein a rolling condition of the electrode is a condition that a porosity of the electrode is at from 15% to 30% (Kim: 23-24%, [0042], which falls within the recited range).
Regarding specifically the method for preparing the recited positive electrode active material, modified Lee further discloses:
(S1) synthesizing a precursor comprising nickel, cobalt, and manganese through a coprecipitation reaction (Lee: [0077-0078]);
(S2) mixing the precursor comprising the nickel, the cobalt, and the manganese with a lithium raw material and doping elements (Lee: [0070, 0084, 0087]) and performing thermal treatment to prepare a nickel-based lithium transition metal oxide (Lee: [0070]);
(S3) mixing the nickel-based lithium transition metal oxide with a boron compound (Oh: [0032]) and performing thermal treatment to coat a surface of the nickel-based lithium transition metal oxide with a lithium boron oxide (Oh: 0035-0036]).
Regarding claim 2, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses that the BET change of the positive electrode active material before/after the rolling of the electrode comprising the positive electrode active material is 50% or less (Lee: ~45% “BET change”, Table 4, Example 1, [0188]).
Regarding claim 3, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses that a specific surface area of the positive electrode active material after the rolling is 1.5 m2/g or less (Lee: 0.532 m2/g, Table 4, Example 1, [0188])
Regarding claim 5, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses that an average particle size (D50) of the primary macro particle is 2 mm or more (Lee: 2 to 3 mm, Abstract), and
a ratio of the average particle size (D50) of the primary macro particle/an average crystal size of the primary macro particle is 2 or more (Lee: see [0054] which describes the material as having a hexagonal crystal structure with an a-axis length of 2.867 to 2.868 Å and a c-axis length of 14.228 to 14.229 Å, which gives a low end approximation of the recited ratio being 7140 with respect to the a-axis length or 1408 with respect to the c-axis length for a 2 mm diameter particle, either of which fall well within the recited range of 2 or more).
Regarding claim 8, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses that a ratio of the average particle size (D50) of the secondary particle/the average particle size (D50) of the primary macro particle is 2 to 4 times (Lee: 5 to 8 mm/2 to 3 mm = 2.5 at the low end and 2.67 at the high end, which falls within the recited range).
Regarding claims 9 and 10, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses that the positive electrode active material comprises a nickel-based lithium transition metal oxide (Lee: [0061]), specifically Li1.05Ni0.5Co0.2Mn0.3O2 (Lee: [0067]), which falls within the recited formula where a = 0.05, x = 0.2, y = 0.3, w = 0, and M1 is Mn.
Regarding claim 11, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses that a boron content of the lithium boron oxide is 0.05 to 1 wt% based on the total weight of the positive electrode active materiel (Oh: [0042]), and thus does not explicitly disclose a range of 0.05 to 0.2 mass%.
However, before the effective filing date of the current invention, it would have been obvious to one having ordinary skill in the art to routinely select the overlapping portions of the disclosed ranges (0.05 to 1 wt% appears to significantly overlap with 0.05 to 0.2 mass%) because selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05 (I)).
Regarding claims 12 and 13, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses a positive electrode (Lee: cathode, Title) and a lithium secondary battery (Lee: Title) comprising the recited positive electrode active material (as noted above).
Regarding claim 16, modified Lee discloses all of the claim limitations as set forth above.
Modified Lee further discloses that the boron compound is H3BO3 (Oh: H3BO3, [0030]).
Allowable Subject Matter
Claim(s) 4, 6-7, 15, and/or 17 is/are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
The present invention is related to, inter alia, a positive electrode active material, and related method of preparing said material, comprising:
(claim 4) a ratio of particles of less than 1 mm is less than 5%;
(claim 6) the primary macro particle is separated from the secondary particle during rolling;
(claim 7) an average crystal size of the primary macro particle is 150 nm or more;
(claim 15) the treatment to prepare the nickel-based lithium transition metal oxide is performed at 800 to 900 °C; and
(claim 17) synthesizing the precursor is performed in a pH7 to pH 10 condition.
Lee et al. (US 2015/0010819 A1; hereinafter “Lee”) is considered to be the closest relevant prior art to dependent claims 4, 6-7, and 15. Lee in view of Oh and Kim discloses most of the claim limitations as set forth above.
However, Lee does not disclose, teach, fairly suggest, nor render obvious the above noted limitations. To the contrary, Lee explicitly discloses desiring primary particle sizes of 2 to 3 mm (Abstract), intentionally agglomerating primary particles into secondary particles ([0037]), and crystal sizes in the Angstrom range ([0054]), all of which serve to stabilize the cathode slurry and increase the mixture density of the cathode ([0036]). Lee further explicitly discloses that the heat treatment for the nickel-based lithium transition metal oxide is performed between 1000 °C to 1050 °C ([0070]). Lee teaches that such methods produce a battery which has reduced gas generation at high voltages and making the battery more reliable and safer ([0036]).
Accordingly, there does not appear to be any reasonable basis for the skilled artisan to abandon the teachings of Lee and be directed towards the above noted limitations because doing so would reasonably appear to lead to a battery which is less reliable and less safe.
Jung et al. (US 2012/0231351 A1) is considered to be the closest relevant prior art to dependent claim 17. Jung et al. discloses producing a nickel cobalt manganese oxide precursor via coprecipitation, wherein coprecipitation happens at a pH of 11 at a reaction temperature of about 40 °C ([0070]).
Accordingly, there does not appear to be any reasonable basis for the skilled artisan to be directed towards a pH of 7 to 10 because such a range does not appear to produce coprecipitation of the precursor, as suggested by Jung et al.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Choi et al. (US 2020/0365875 A1) discloses a negative electrode active material; and
Min et al. (US 2020/0388839 A1) discloses a cathode active material.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAMES M ERWIN whose telephone number is (571)272-3101. The examiner can normally be reached Monday-Friday: 6am-3pm PDT.
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/JAMES M ERWIN/Primary Examiner, Art Unit 1725 01/27/2026