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 .
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 .
Status of Claims
Claims 1 and 6 have been amended.
Claims 3 and 4 have been canceled.
Claims 10 and 11 have been added.
Status of Amendment
The amendment filed on August 15th, 2025 has been fully considered but does not place the application in condition for allowance.
Status of Objections and Rejections Pending since the Office Action of May 19th, 2025
The provisional double patenting rejections of claims 1, 3, 7, 8, and 9 have been withdrawn in view of the Applicant's amendment.
The 112(b) rejection of claim 4 is moot because claim 4 is cancelled.
The 103 rejections of claims 1-9 are withdrawn in view of the Applicant's amendment.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on June 11th, 2025 was filed after the mailing date of the non-final rejection on May 19th, 2025. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim is 6 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 6 recites the term "the primary particles" in the last line of the claim. There is insufficient antecedent basis for this limitation in the claim. For the sake of this Office Action, the term “primary particles” will refer to particles that may or may not be part of an aggregated mass.
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.
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.
Claims 1, 2, and 5-11 are rejected under 35 U.S.C. 103 as being unpatentable over Du (US 2020/0006767 A1) and further in view of Suhara (US 7,381,498 B2) and Kuroda (US 2021/0083286 A1).
Regarding claim 1, Du teaches a positive electrode comprised of a current collector and a positive electrode mixture layer containing positive electrode active material disposed on the surface of the current collector (abstract). The positive electrode active material layer includes a first and a second sublayer, which correspond to the claimed “regions” (abstract). Both the first and second sublayer are wholly comprised of the first and second positive active materials since the electrode is formed by sequentially applying the corresponding electrode slurries to a positive current collector [0046]. Both of these layers have the same thickness in order to enhance mechanical strength [0035].
Du teaches possible compositions of the positive active material of the first sublayer [0013] and the positive active material of the second sublayer [0026]. However, Du is silent on the quantitative compressive strength of these two layers. Kuroda and Suhara are analogous art to Du because all teach secondary batteries. Kuroda teaches a positive active material with the composition of Du’s first sub-layer (Kuroda, abstract) and Suhara teaches a composite oxide as a positive active material layer with the composition of Du’s second sub-layer (Suhara, abstract).
Kuroda teaches the usage of “single particles” in their positive active material layer (abstract). Although Kuroda’s disclosure teaches the usage of these particles in combination with other positive active material particles, Kuroda also teaches that these single particles “do not have grain boundaries within the particles and are less prone to particle breakage. This results in less likelihood of generation of a new surface due to particle breakage. This means that possible decomposition reactions with the electrolyte on the new surface are less likely to occur” [0019]. With all of these benefits, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to use these particles by themselves in an active material layer. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to use the “single particles” taught by Kuroda in the first sub-layer of Du to achieve all of the benefits listed above.
Furthermore, these particles have a compressive strength that is 120 MPa or more and 400 MPa or less (Kuroda, [0035]), overlapping with the claimed range of 250 MPa to 400 MPa. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP 2144.05 (I).
Suhara provides an example of their composite powder that comprises of two granular powders that individually have compression strengths of 87.6 MPa and 25.3 MPa with a mass mixing ratio of 75:25 of the first to second powder (Suhara, column 9, lines 22-42). Taking a weighted average of those compression strengths results in a value of 72 MPa, which is less than 150 MPa.
Lastly, with respect to both Kuroda and Suhara, “[t]he selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945).” See MPEP 2144.07.
Henceforth, the positive electrode that has a first sublayer using the single particles taught by Kuroda (corresponding to the applicant’s first region and first positive electrode active material, respectively) and a second sublayer using the active material taught by Suhara (corresponding to the applicant’s second region and second positive electrode active material, respectively) will be referred to as “modified Du.”
Regarding claims 2 and 10, modified Du’s second positive active material may have a compression strength of 72 MPa which is less than ¾ of 200 MPa, a value near the low end of the range of compression strengths of modified Du’s first positive active material (75% of 200 is 150). The difference between the two compression strengths (200 – 72 = 128) is 128 MPa, which lies within the range recited within claim 10.
Regarding claims 5 and 11, modified Du teaches that the outer layer, the first sublayer/region, may have “high mechanical strength” and have a “certain protective effect on the structural stability” of the second sub-layer which is “conducive to the improvement and processing performance of the positive electrode plate” (Du, [0009] and [0010]). Therefore, when manufacturing a positive electrode active material layer with two sub-layers or regions, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to use a first positive active material with a greater compression strength (modified Du’s first positive active material) in the layer further away from the current collector in order to protect the second positive active material (modified Du’s second positive active material) in the layer closer to the current collector (as required by claim 5).
Claim 11 has very similar limitations to claim 5. The difference in patentability lies within the claimed ranges. Claim 5 implicitly states that “the positive electrode mixture layer contains a first positive electrode active material having a compressive strength of 200 MPa or more and 400 MPa or less, and a second positive electrode active material having a compressive strength of 150 MPa or less”. Claim 11 only requires that the first positive active material have a compressive strength that is less than 400 MPa and that the second positive active material have a compressive strength that is smaller than the first positive active material’s strength. Therefore, the rationale for rejection of claim 5 also suffices as a rationale for rejection of claim 11.
Regarding claim 6, modified Du’s first positive active material is composed of single particles that have a diameter of 0.5 µm or more (Kuroda, [0067]) and modified Du’s second positive active material is composed of aggregated primary particles that range from 0.5 – 7 µm (Suhara, column 5, lines 29-31). Both of these ranges overlap with the claimed range of “500 nm or less.” In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP 2144.05 (I).
Regarding claims 7 and 8, Du’s method of manufacturing the double layered positive electrode involves sequentially applying and drying electrode slurries onto a current collector. First, the slurry comprised of the second positive active material will be applied and dried, and then the slurry comprised of the first positive active material will be applied and dried (Du, [0046]). Therefore, the weight percent of active material in each region/layer will correspond to the weight percent of active material in the slurry. Modified Du’s second positive electrode active material slurry may be 88% active material by weight (Suhara, column 9, lines 45-75), which is greater than 50%. As mentioned above, the positive active material of Kuroda’s disclosure is not solely comprised of the single particles used for modified Du’s first positive active material. However, the process of making said active material involves creating a slurry that consists of lithium metal composite oxide powder and pure water. That slurry is then subjected to a process of “dehydration, separation and drying at 105 °C” [0189]. Since water evaporates at temperatures greater than 100 °C and one of ordinary skill in the art would not expect a finished active material of a battery to be largely comprised of unevaporated water or solid metal-hydroxide byproducts, it would be reasonable to expect that the amount of active material created is much greater than 50%.
Regarding claim 9, modified Du teaches a secondary battery with a positive electrode, a separator, a negative electrode facing the positive electrode and the separator interposed in between, and a liquid electrolyte (Du, abstract, [0042]).
Response to Arguments
Applicant's arguments filed August 15th, 2025 have been fully considered but they are not persuasive. On pages 10 and 11, the Applicant argues that “since Suhara merely teaches the positive electrode mixture layer having a single-layer structure, Suhara does not take into account the appropriate range of the compressive strength of positive active materials for [the] two-region structure recited in claim 1”. The Examiner respectfully disagrees. The fact that Suhara (US 7,381,498 B2) does not consider or discuss a two-layered system would not prevent nor discourage a person of ordinary skill in the art to combine the technical concepts and advantages taught by Suhara with concepts disclosed by other inventors.
The Applicant also argues that since Du teaches that “the conventional ternary positive electrode material (in form of agglomerated secondary particles) has problems of the low compressive strength and crushing”. Therefore, one of ordinary skill in the art “would not have been prompted to replace the positive electrode active materials having monocrystalline or quasi-monocrystalline of Du” with Hiratsuka’s or Suhara’s positive active material. The Examiner agrees, based on that reasoning, that Hiratsuka cannot be used as the first positive active material of Du because it comprises agglomerated particles.
The Examiner, however, respectfully points out that Du also teaches “when the first positive electrode active material in the first sub-layer…has a monocrystalline or quasi-monocrystalline structure, the problems of the low compressive strength and crushing of the conventional ternary positive electrode material (in form of agglomerated secondary particles) can be effectively alleviated [0021]. Therefore, as long as the first sub-layer has the monocrystalline or quasi-monocrystalline structure, the second sub-layer may comprise an active material comprised of agglomerated particles, i.e., Suhara’s positive active material.
Applicant’s arguments with respect to Hiratsuka (US 2017/0226790 A1) are considered moot because the rejection set forth above does not rely on Hiratsuka.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN K BLACKWELL-RUDASILL whose telephone number is (571)270-0563. The examiner can normally be reached Monday - Friday 9:00 a.m. - 5:00 p.m.
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/R.B.R./Examiner, Art Unit 1722
/ANCA EOFF/Primary Examiner, Art Unit 1722