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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 9/16/2026 has been entered.
Response to Amendment
Examiner acknowledges amended Claims 1, 11, 14, and 15 and withdrawn Claims 6-9 in the response filed on 9/16/2026.
Response to Arguments
Applicant’s arguments with respect to Claims 1-5 and 10-20 have been considered but are moot in view of the new ground(s) of rejection.
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 1-5, 10-15, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over JP 2019029205 (“Wada et al.”) in view of CN 110429252 (“Guo et al.”).
For JP 2019029205 (“Wada et al.”), Examiner notes that Applicant provided an English translated document in the IDS 3/31/2023, and all citations will refer to said document. Examiner further notes that Applicant recognized US Pub. No. 20210313563 as the US counterpart for CN ‘252 in the IDS 8/11/2025, and all citations will refer to the US publication.
With regards to Claims 1-4 and 13, Wada et al. teaches a positive electrode comprising a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The positive electrode active material layer having a lower layer (first layer) region facing the positive electrode current collector and containing a first positive electrode active material (second positive electrode active material) and a first binder polymer, and an upper layer region (second layer) facing the lower layer region and containing a second positive electrode active material (first positive electrode active material) and a second binder polymer, wherein a Ni content of the second positive electrode active material is larger than a Ni content of the first positive electrode active material (Abstract, [0007], [0020], [0021], [0030], [0035], Table 1, and Example 13).
According to Applicant’s Specification, an intermixing region is formed by having a (wet) slurry for a lower layer containing the first positive electrode active material and a (wet) slurry for an upper layer containing the second positive electrode active material coated at the same time or continuously with a very short time interval and then dried (paragraph [0052] in Applicant’s published application). One of ordinary skill in the art would recognize that a wet slurry placed on top of another wet slurry, the interface between the two slurries is unlikely to remain perfectly distinct. Instead, a transition region can form at the interface where the slurry materials partially mix or intermingle.
In that regard, Wada et al. teaches its positive electrode active material layer is formed by coating two layers (upper and lower layers) at once with a double slot die and then drying. Moreover, the first positive electrode active material slurry may contain a second positive electrode active material, and the second positive electrode active material slurry may contain the first positive electrode active material [0035]. Based on the instant teachings, the Examiner deems that Wada et al. teaches an intermixing region in which the first positive electrode active material and the second positive electrode active material are mixed is present at a portion where the lower layer region is in contact with the upper layer region.
Wada et al.’s teaches its first positive electrode active material (second positive electrode active material) is Lia2Nib2Coc2Md2O2, where M=Mn, 0.9≤a2≤1.2, 0.1≤b2≤0.6, 0.1≤c2≤0.6, and 0.1≤d2≤0.55, and its second positive electrode active material (first positive electrode active material) is, for example, LiNi0.8Co0.1Mn0.1O2. Wada et al. further teaches the Ni content of the second positive electrode active material is 70-100 mol% based on a total transition metals of the second positive electrode active material (Abstract, [0007], [0020], [0021], [0030], [0035], Table 1, and Example 13).
Thus, Wada et al. teaches the Ni content of the first positive electrode active material is 10-60 mol% based on a total transition metals of the first positive electrode active material. Wada et al. further teaches that the Ni content of the second positive electrode active material is 70-100 mol% based on a total transition metals of the second positive electrode active material ([0007], [0020], [0021], and Table 1).
Wada et al. does not teach the Ni content of the first positive electrode active material is 65-70 mol% based on a total transition metals of the first positive electrode active material.
However, Guo et al. teaches a positive electrode comprising a lower layer region facing the positive electrode current collector and an upper layer region facing the lower layer region, wherein the lower layer region has a Ni content about 30 to about 80% and an upper layer region having a Ni content of about 50% to about 90% ([0043], [0044], [0077], [0078], and Example 27). It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have Wada et al.’s Ni content of the first positive electrode active material be 65-70 mol% based on a total transition metals of the first positive electrode active material in order to obtain a cathode with improved rate performance, cycle performance, and safety performance (Abstract).
With regards to Claims 5 and 19, Wada et al. teaches a weight ratio of the lower layer region to the upper layer region is within 20:80-80:20 (e.g. 30:70) ([0025] and Table 1).
With regards to Claim 10, Wada et al. teaches a lithium secondary battery comprising the positive electrode (Abstract and [0007]).
With regards to Claims 11 and 12, Wada et al. teaches each of the first binder polymer and the second binder polymer includes polyvinylidene fluoride, wherein a weight percentage of the first binder polymer in the lower layer region is 1 wt%, wherein a weight percentage of the second binder polymer in the upper layer region is 1 wt%, and therefore a weight percentage of a combined wight of the first binder polymer and the second binder polymer based on a total weight of the positive electrode material layer is within the range of 1-3 wt% [0079].
With regards to Claim 14, Wada et al.’s teaches its second positive electrode active material (first positive electrode active material) is Lia1Nib1Coc1Md1O2, where M=Mn and Al, 0.9≤a1≤1.2, 0.7≤b1≤0.9, 0.05≤c1≤0.15, and 0.05≤d1≤0.15 [0020]. Examiner notes that product claims with numerical ranges which overlap prior art ranges were held to have been obvious under 35 USC 103. In re Wertheim 191 USPQ 90 (CCPA 1976); In re Malagari 182 USPQ 549 (CCPA 1974); In re Fields 134 USPQ 242 (CCPA 1962); In re Nehrenberg 126 USPQ 383 (CCPA 1960). Also see MPEP 2144.05.
With regards to Claim 15, Wada et la. teaches the first positive electrode active material has an average particle diameter, D50, of 4 μm, and wherein the second positive electrode active material has a D50 of 12 μm ([0026] and [0049]).
Claims 16-18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over JP 2019029205 (“Wada et al.”) in view of CN 110429252 (“Guo et al.”) as applied to Claim 1 above, and further in view of US Pub. No. 20190013545 (“Kim et al.”).
With regards to Claims 16-18, Wada et al. teaches the positive electrode active material layer as set forth above.
Wada et al. does not teach the thicknesses of the positive electrode active material layer, the lower layer region, and the upper layer region as claimed.
However, Kim et al. teaches a positive electrode active material layer comprising a lower layer region having a thickness of 15 to 40 μm and an upper layer region having a thickness of 30 to 80 μm, and therefore a total thickness of its positive electrode active material layer is 45 to 120 μm (Fig. 4 and [0052]). It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to optimize the thicknesses of Wada et al.’s lower layer region and upper layer region as claimed in order to achieve desirable performance characteristics [0007].
With regards to Claim 20, Wada et al. does not teach the porosity of its positive electrode active material layer.
However, Kim et al. teaches its lower layer region having a porosity of 18 to 34% and its upper layer region having a porosity of 20 to 40%. Thus, the porosity of its positive electrode active material layer overlaps with the claimed porosity range of 20-40%. It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have a porosity of Wada et al.’s positive electrode active material layer be 20-40% in order to achieve desirable performance as disclosed in paragraph [0007].
Conclusion
The prior art made of record and not relied upon is considered pertinent to Applicant's disclosure.
US Pub. No. 20180301740 (“Min et al.”) teaches a positive electrode (E) comprising a positive electrode current collector (10) and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The positive electrode active material layer having a lower layer region (20) facing the positive electrode current collector and containing a first positive electrode active material and a first binder polymer, and an upper layer region (30) facing the lower layer region and containing a second positive electrode active material and a second binder polymer, wherein a Ni content of the second positive electrode active material is larger than a Ni content of the first positive electrode active material (Abstract, Fig. 1, [0017], [0029], [0043]-[0048], [0075], [0077], and [0081]).
Min et al. further teaches its active material is Li1+x[NiaCobMnc]1-xO2, wherein -0.2≤x≤0.2, 0.5≤a≤0.98, 0.01≤b0.4, and 0.01≤c≤0.4. Examples of the active material may be Li[Ni0.6Co0.2Mn0.2]O2, Li[Ni0.8Co0.1Mn0.1]O2, or the like, but is not limited thereto [0045]. Min et al. teaches that two active material slurries are applied on a current conductor, dried at 130°C, and then rolled to manufacture the positive electrode active material layer [0081].
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/LC/
Lisa Chau
Art Unit 1785
/Holly Rickman/Primary Examiner, Art Unit 1785
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