Describes 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
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 25 January 2024 and 6 August 2025 were considered by the examiner.
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.
Claims 1 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over JP 2021128851 (JP’851) in view of JP2016072110 (JP’110).
Regarding claim 1, JP’851 discloses an energy storage device where part of the positive electrode (Fig. 4 40) is exposed creating a current collecting portion (Fig. 4 41) of the assembly. The active material layer of the electrode has a first edge portion (Fig. 4 42a) of the layer adjacent to the current collecting exposed area. This first region contains more lithium carbonate for increasing electric resistance compared to the second region (Fig.4 42b) adjacent to the first (¶0011). The electrode assembly is formed by winding a laminate with the positive electrode, negative electrode, and two separators (¶0022). The exposed current collecting substrate is located at one end in the width direction of the positive electrode (¶0023). The positive electrode material layer (Fig. 4 42) is formed of a mixture with components such as a conductive agent and binder (¶0041). The positive electrode active material is usually particles (¶0043).
While JP’851 discloses the wound electrode assembly with three separate regions with the first region adjacent to the exposed current region having higher reaction resistance it is silent of the active particles being different in the first and second regions.
Regarding dependent claim 2, JP’110 discloses a secondary battery with a flat wound electrode body including an elongated current collector (Fig. 1 22) with an active material layer (Fig. 1 14). The active material layers are made of different materials in the edge portion than the central portion allowing for the edge portions to be more easily crushed (¶0008). The resistance to crushing (or ease of crushing) of the negative electrode active material when pressure is applied can be controlled by the material, structure, particle size, shape, or the like of the negative electrode active material. Tap density is disclosed as an index of the ease of crushing of the negative electrode active material (¶0025). The ratio of the tap density of the first anode active material to the tap density of the second anode active material is preferably more than 1 and 2 or less (¶0031). The central portion and edge portion are recognized by difference in type, composition, or properties of the constituent components contained in the respective portions (¶0023). The specific surface area of the first anode active material (central portion 26) is described to be 2 m2/g or more and 4 m2/g or less (¶0027). The specific surface area of the second anode active material (edge portion 28) is preferably 1 m2/g or more and 3 m2/g or less (¶0032). Thus, the range of specific surface area is lower in the edge portion adjacent to the exposed current collector is less than the range of the central portion.
While JP ‘110 is silent in the specific disclosure of the BET specific surface area being smaller in the edge portion than the central portion it does teach the relationship between tap density and crushability of the material. It is obvious to one of ordinary skill in the art that if the tap density is defined to be larger in the second particle, corresponding to the edge region, than the first particle, corresponding to the central region, that the BET specific surface area would be smaller in the edge region than the central region (Additional Sources 1).
Thus, it would have been obvious to one skill in ordinary art to combine the three regions of the wound electrode with increased resistance in the second region taught in JP ‘851 with the combination of different active material particles in two regions having different resistances to crushing of JP’110 to meet the limitations of the invention in claims 1 and 2. One of ordinary skill in the art would have been motivated by the desire and expectation of combining prior art elements according to known methods to yield predictable results, including creating separate regions in the electrode assembly where the active material layer has one area with active particles that allow for increased resistance and easier to crush allowing for better longevity and durability of the electrode by having different active material particles in the compositive material.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over JP’851 in view of JP’110 as applied to claim 1 above, and further in view of U.S. Patent Publication Application 20120214063 (Morimoto et al.).
Regarding dependent claim 3, Morimoto et al. discloses a negative electrode for a lithium secondary battery where an electrode layer containing an active material, conductive assistant and binder is formed on the current collector (Abstract). The electrode layer (Fig. 1 12) is configured so that the concentration of the binder component decreases as distanced from the current collector (¶0053). That is, a current collector (Fig 1. 11) side of the electrode layer 12 is made of region that is dense in the rate of the binder component, and an electrolytic solution side is made a region that is sparse in the rate of the binder component. The region that is on the side of the electrolytic solution and sparse in the rate of the binder improves the permeability of the electrolytic solution, a conduction path of lithium ions can be secured, and an improvement in capacity owing to an increase in an electrode reaction area is expected. The region where the binder component is denser the flexibility and binding property are made higher, toughness and elastic property added, and the electrode layer is inhibited from peeling off the boundary between the current collector and the electrode layer (¶0054).
It would have been obvious to one of ordinary skill in the art to have incorporated the regions of binder concentration in the active material layer being higher towards the end of the exposed current with the electrode sheet of JP’851 in view of JP’110. One of ordinary skill in the art would have been motivated by the desire and expectation of combining prior art elements according to known ways to achieve predictable results. This would include incorporating the binder concentration increase in the region adjacent to the exposed current collector to improve the toughness and flexibility while increasing the electrode reaction area of the third region with the different active particles of the compositive material as discussed above.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over JP’851 in view of JP’110 as applied to claim 1 and 2 above, and further in view of U.S. Patent Publication Application 2019/0296335 A1 (Yao).
Regarding claim 4, Yao discloses an electrochemical cell having a multilayered electrode with a first layer adjacent to the current collector and a second layer intermediate to the first layer and the separator (¶0069). The first layer includes at least one active material, and the second layer includes at least one active material and at least one non-active material disclosed to be a ceramic material (¶0070). The first and second active material particles are not limited to being the same or different from each other (¶0100). The inclusion of the non-active particles in the second layer, those that have greater hardness, creates a higher resistance to compression (¶0039). When the multilayer electrode undergoes the calendaring process this increased resistance creates a first layer that has a lower porosity near the current collector (¶0062). This increased porosity near the separator can counteract a natural electrolyte-concentration gradient field (¶0063).
Yao is silent in the specific disclosure of the mass fraction of the active material particles in the first and second layers. However, one of ordinary skill in the art could reasonably understand that the inclusion of the non-active ceramic particles to the second layer, allowing for a higher pore volume fraction, would result in a smaller mass fraction of the active material particles compared to the first layer adjacent to the current collector.
Thus, it would have been obvious to one skill in ordinary art to combine the three regions of the wound electrode with increased resistance in the second region taught in JP ‘110 with the combination of the multilayer structure of Yao particularly in the secondary region of the electrode to meet the limitations in claim 4. One of ordinary skill in the art would have been motivated by the desire and expectation of combining prior art elements according to known methods to yield predictable results. By creating a secondary layer with increased porosity compared to the layer closer to the current collector and place it within the secondary region of the electrode as to further improve upon the reaction resistance of claim 4 by counteracting the natural electrolyte-concentration gradient field.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over JP’851 in view of JP’110 as applied to claim 1 and 2 above, and further in view of U.S. Patent Application Publication 2012/0258343 A1 (Takahata et al.).
Regarding dependent claim 5, Takahata et al. discloses a lithium secondary battery with a negative electrode sheet where in the wound electrode body the content of the binder of the outer active material layer on the outer circumference side is smaller than the inner negative material layer on the inner circumference side of the electrode collector (Abstract). It is disclosed that decreasing the content of the binder of the outer mixture layer increases the surface area of the active material participating in the reaction and increases the reactivity of outer mixture layer (¶0058).
It would have been obvious to one of ordinary skill in the art to have incorporated the decrease in the binder content in the outer layer of Takahata et al. with the electrode sheet of JP’851 in view of JP’110. One of ordinary skill in the art would have been motivated by the desire and expectation of combining prior art elements according to known ways to achieve predictable results. This would include incorporating the binder content variation of the outer layer to increase the reactivity of the outer layer compared to the inner layer to create greater reaction resistance in the inner layer with the strip electrode discussed above.
Additional Sources
Characterization of Porous Solids and Powders: Surface Area, Pore Size and Density by S. Lowell (pages 2,18,331 in particular)
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/D.E.H./Examiner, Art Unit 1784
/HUMERA N. SHEIKH/Supervisory Patent Examiner, Art Unit 1784
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