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 .
Summary
Applicant’s arguments and claim amendments submitted June 24, 2026 have been entered into the file. Currently, claims 2 and 15-20 are cancelled and claims 1, 3, 5, and 8-10 are amended, resulting in claims 1 and 3-14 pending for examination.
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.
Claims 1, 3-12 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 2019/0013545 A1) in view of Guo (Guo, Y. et al. Directional LiFePO4 cathode structure by freeze tape casting to improve lithium ion diffusion kinetics. Journal of Power Sources. 506, 230052 (2021)), or in the alternative under Kim in view of Guo and Yi (US 2021/0151790 A1).
Regarding claims 1, 3, 7, 9, Kim teaches a method of manufacturing a hybrid bilayer-coated electrode, the method comprising:
providing a current collector (aluminum current collector, Kim Example 1) (instant claim 1)
forming a first layer on the current collector (first positive electrode slurry was applied on an aluminum current collector, Kim Example 1) (instant claim 1)
forming a second layer on top of the first layer by casting a slurry onto the first layer (second positive electrode slurry was applied on the first positive electrode mixture layer, Kim Example 1) (instant claim 1)
wherein the first layer is formed by coating a slurry-based composition on the current collector and subsequently calendering the slurry-based composition on the current collector (first positive electrode slurry was applied…then rolled, Kim Example 1) (instant claim 1)
wherein the slurry-based composition includes NMP (Kim Example 1 [80]) (instant claim 3)
wherein the electrode is a cathode (Kim Example 1) and the cathode includes LiNi0.6 Mn0.2 Co0.2O2 as an active material, a binder (PVdF), and a conductive additive (carbon black) (Kim Example 1) (instant claims 7 and 9)
Kim does not teach the second layer being formed onto the first layer by freeze casting.
Guo teaches that electrodes with higher tortuosity result in restricted lithium ion diffusion, which reduces electrode specific capacity (Guo pg. 2 left column paragraph 2). Guo further teaches the formation of a directional cathode structure using freeze casting (freeze tape casting) in order to improve lithium ion diffusion kinetics (Guo abstract) and that freeze casting results in cathodes with a vertically aligned microstructure and lower tortuosity (Guo pg. 2 right column paragraph 2). Guo also teaches the preparation of a cathode slurry (Guo Section 2.1).
Since Guo teaches that freeze casting can improve lithium ion diffusion kinetics it would have been obvious to modify the method of Kim to use freeze casting to form one of the layers in order to improve lithium ion diffusion. Overall, there are four options for the combination of layer formation methods:
first layer not freeze casted, second layer not freeze casted
first layer not freeze casted, second layer freeze casted
first layer freeze casted, second layer not freeze casted
first layer freeze casted, second layer freeze casted
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have selected one of these four combinations, including the option wherein the first layer is not freeze casted and the second layer is freeze casted, in order to obtain a method capable of producing a cathode with suitable performance according to the slurry composition being used and the desired battery application.
Alternatively, Yi teaches method of forming a cathode that comprises forming a first layer on a current collector and a second layer on top of the first layer (Yi Fig. 5). Yi further teaches that it is known to use different layer formation methods to form the first layer and the second layer, where one of the layers can be formed using freeze casting (Yi [41]) and the other layer can be formed using a method other than freeze casting (Yi [42]). It is noted that Yi describes the first layer as being formed using freeze casting instead of the second layer, as claimed. However, since Yi teaches that it is known to use different methods to form different layers of cathode, such as using freeze casting for one layer and a method other than freeze casting for another layer, Guo teaches that freeze casting has the benefits of improved lithium ion diffusion kinetics, as described above, and that there are only four combinations for the layer formation methods, as listed above, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have selected one of these four combinations, including the option wherein the first layer is not freeze casted and the second layer is freeze casted, in order to obtain a method capable of producing a cathode with suitable performance according to the slurry composition being used and the desired battery application.
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to use the freeze casting method taught by Guo to form the second layer of Kim in order to obtain the predictable solution of a method capable of producing a cathode with improved lithium ion diffusion and specific capacity.
Modified Kim further teaches the second layer being formed by depositing a coating of the slurry on the first layer (in modified method of Kim described above, the second layer is formed on the first layer using freeze casting), freezing the solvent after depositing the coating (directional freezing of solvent, Guo pg. 3 right column), and subsequently subliming the solvent (sublimed through freeze drying at -25°C under 1 Pa, Guo pg. 3 right column).
Regarding claim 4, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claim 1, as described above. Modified Kim further teaches the second layer being formed by depositing a coating of the slurry on the first layer (in modified method of Kim described above, the second layer is formed on the first layer using freeze casting), freezing the solvent after depositing the coating (directional freezing of solvent, Guo pg. 3 right column), and subsequently subliming the solvent via controlling the ambient temperature and/or pressure (sublimed through freeze drying at -25°C under 1 Pa, Guo pg. 3 right column).
In order to perform the freeze casting using the method of Guo, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to form the second layer slurry of Kim to contain water solvent, as taught by Guo (Guo Section 2.1), and adjust the binder used in order to use a binder that is soluble in water (CMC, Guo Section 2.1).
Regarding claims 5 and 6, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claims 1 and 4, as described above. Modified Kim further teaches the solvent being water (Guo Section 2.1, deionized water).
Regarding claim 8, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claims 1 and 7, as described above. Claim 8 does not affirmatively require an anode. Therefore, modified Kim reads on claim 8, as the claim does not further limit the species taught by modified Kim.
Regarding claim 10, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claim 1, as described above. Kim further teaches the porosity of the first layer being within the claimed range of 15% to 50% (18% to 34%, Kim [59]).
Regarding claim 11, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claim 1, as described above. Kim is silent to the tortuosity of the first layer. However, since Guo teaches that freeze casting lowers tortuosity and the modified method of Kim uses freeze casting to form the second layer, there is a reasonable basis to conclude that the second layer having a tortuosity less than that of the first layer would obviously flow from the modified method of Kim.
Regarding claim 12, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claim 1, as described above. Kim and Guo do not explicitly teach tortuosity values. However, Guo teaches that it is desirable to have low tortuosity, as described above. Fig. 1 of Guo depicts pores formed using the freeze casting method that are vertically aligned and straight, thus depicting a tortuosity close to or approximately 1. Additionally, Yi teaches that it is known and suitable for the tortuosity to be 1 when using a freeze casting method to form a layer (Yi [41], claim 19). Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to tune the freeze casting method in modified Kim obtain a method capable of fabricating cathodes with low tortuosity, including values in the range of 1 to 3, in order to obtain cathodes with improved lithium ion diffusion.
Regarding claim 14, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claim 1, as described above. Modified Kim further teaches the step of forming the second layer being performed using a freeze tape caster (Guo Fig. 2a).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, as applied to claim 1 above, and in further view of Markevich (Markevich, E. et al. Improved Performance of Li Metal LiNi0.8Co0.1Mn0.1O2 Cells with High Loading Cathodes and Small Amounts of Electrolyte Solutions Containing Fluorinated Carbonates at 30 °C-55°C. Journal of the Electrochemical Society. 167, 7, 070509 (2020)).
Regarding claim 13, Kim in view of Guo, or in the alternative Kim in view of Guo and Yi, teaches all features of claim 1, as described above. Kim, Guo, and Yi are silent to areal loading (mAh/cm2). Kim teaches the cathode comprising NCM (Kim Example 1).
Markevich teaches a cathode comprising NCM that has an areal capacity of 3.4 mAh/cm2 (Markevich Experimental – Materials Section). Since Markevich teaches that an areal capacity of 3.4 mAh/cm2 is suitable, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to tune the method of Kim in view of Guo to obtain electrodes with an areal loading of 3.4 mAh/cm2 in order to fabricate electrodes with suitable performance for use in batteries.
Response to Arguments
Response – Specification Objections
The objections to the specification due language of the abstract are overcome by applicant’s amendments to the specification in the response received on June 24, 2026. The objections to the specification are withdrawn.
Response – Claim Objections
The objections to claims 3, 5, 8, and 9 due to informalities are overcome by applicant’s amendments to claims 3, 5, 8, and 9 in the response received on June 24, 2026. The objections to claims 3, 5, 8, and 9 are withdrawn.
Response – Claim Rejections 35 USC § 112
The rejections of claims 9 and 10 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 are overcome by applicant’s amendments to claims 9 and 10 in the response received June 24, 2026. These rejections to claims 9 and 10 are withdrawn.
Response – Claim Rejections 35 USC § 102 and 103
The rejections of claims 1, 6-8, and 14 under 35 U.S.C. 102(a)(1) as being anticipated by Yi (US 2021/0151790 A1) are overcome by applicant’s amendments to claim 1 in the response received June 24, 2026. These rejections of 1, 6-8, and 14 are withdrawn.
Applicant’s arguments with respect to claim 1 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
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Albano (US 2020/0373552 A1): appears to disclose low tortuosity electrodes formed using freeze casting (abstract, Example 1).
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/J.S.C./Examiner, Art Unit 1789
/MARLA D MCCONNELL/Supervisory Patent Examiner, Art Unit 1789
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