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 .
Election/Restrictions
Applicant's election with traverse of Species A2 and Species B1 in the reply filed on 08/04/2026 is acknowledged.
However, applicant presents no arguments regarding why the restriction is not proper. The examiner notes species restrictions are based on the instant specification and not the claims alone. See MPEP 806.04(e).
The requirement is still deemed proper and is therefore made FINAL.
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 1-2, 11, 13-14, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN110660957B, see US PG Pub US 20210119196 A1 for citations) over Yachi et al. (US20210143427A1).
Regarding claims 1-2 and 13-14, Li discloses an electric apparatus (i.e. device, [0179]) comprising an electrochemical apparatus ([0165]), the electrochemical apparatus comprising a positive electrode ([0165]), wherein the positive electrode comprises a current collector ([0058]. Fig. 10, 10), a conductive layer (i.e. conductive primer layer, [0129], Fig. 10, 11), and an active substance layer (i.e. electrode active material layer, [0058], Fig. 10, 12);
the conductive layer is disposed between the current collector and the active substance layer (i.e. conductive primer layer…is disposed between current collector and electrode active material layer, [0058]).
Li further discloses wherein the conductive layer comprises a conductive material ([0129]) which is at least one of a conductive carbon material and metal material layer ([0131]). Furthermore, while Li discloses wherein the conductive carbon material is selected from at least one of zero-, one-, two-, and three-dimensional conductive carbons ([0132]), Li does not explicitly disclose the conductive layer comprising secondary particles formed from primary particles of the conductive agent or that the D50 of the secondary particles satisfies 0.1 µm ≤ D50 ≤ 0.4 µm.
Yachi teaches a carbon fiber aggregate for an electrode mixture layer for a non-aqueous electrolyte secondary battery ([0001]). Yachi further teaches the carbon fiber aggregates can form long-distance conductive paths ([0008]). Yachi further teaches the carbon fiber aggregates include carbon fibers (i.e. secondary particles formed from primary particles of a conductive agent, [0045]) where the average fiber diameter of the carbon fiber aggregate is 10 to 900 nm ([0048]), or 0.01 µm 0.90 µm, which encompasses the claimed range of 0.1 µm ≤ D50 ≤ 0.4 µm, as claimed in claims 1 and 13. Yachi further teaches the average fiber diameter refers to a volumetric average value measured with the use of a particle size distribution meter for image analysis (i.e. D50 based on volumetric analysis, [0042]).
Yachi further teaches carbon fiber aggregates of less than 10 nm in average fiber diameter are very low in bulk density and inferior in handling ability, while carbon fiber aggregates greater than 900 nm in average fiber diameter are likely to have gaps produced between fibers in electrode mixture layers ([0048]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected and optimized within the claimed range for the D50 of the carbon fiber aggregates, to achieve the desired balance between handling ability and gaps between fibers in the conductive layer, as taught by Yachi (MPEP 2144.01 II).
While Li does not explicitly disclose a D90 of the secondary particles satisfying 0.2 µm ≤ D90 ≤ 0.6 µm , a skilled artisan would recognize that Yachi’s carbon fiber aggregates, in possessing an average fiber diameter (i.e. D50), also necessarily and inherently possess a D90 and in wanting to optimize D50 would further desire to optimize D90 to maximize the effects of the average diameter.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have arrived at the claimed range for D90 by way of routine optimization, in order to achieve the desired balance between handling ability and gaps between fibers in the conductive layer, as taught by Yachi (2144.05 I).
Regarding claims 11 and 20, modified Li discloses all limitations as set forth above.
Modified Li further discloses the single-sided thickness H of the conductive primer layer (i.e. the conductive layer) is preferably 0.1 to 5 µm (Li, [0146]), which encompasses the claimed range of 0.3 – 1.0 µm.
Li further suggests that if the thickness is too low, the conductive layer cannot effectively improve the conductivity of the electrode plates, while if the thickness is too high, it will reduce the weight energy density of the battery ([0146]).
Therefore, it would have been obvious to one of ordinary skill of the art, before the effective filing date of the claimed invention, to have selected and optimized within the overlapping portion of the ranges, in order to achieve the desired balance between conductivity of the electrode and weight energy density of the battery, as suggested by Li (MPEP 2144.05 II).
Claims 3-10 and 15-19 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN110660957B, see US PG Pub US 20210119196 A1 for citations) and Yachi et al. (US20210143427A1), as applied to claim 1 above, and further in view of Porcher et al. (US20200343542A1).
Regarding claims 3, 5-6, 15, and 17, modified Li discloses all limitations as set forth above.
Modified Li further discloses wherein the binder in the conductive primary layer may be a mixture of the acrylic based/acrylate-based water-dispersible binder (i.e. second additive) and another binder (i.e. first additive) (Li, [0145]). Li further teaches that in the conductive primer layer (i.e. conductive layer), the water dispersible binder (i.e. second additive) is more conducive to reducing the DCR (internal DC resistance) and it is preferable to use an acrylic based/acrylate-based binder such as at least one of polyacrylic acid, sodium polyacrylate, sodium methacrylate etc. (Li, [0254]; [0143]). Furthermore, modified Li discloses the another binder (i.e. first additive) may be selected from one of styrene butadiene rubber, oil dispersible polyvinylidene fluoride, sodium carboxymethyl cellulose, etc. (Li, [0145]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date from the effective filing date of the claimed invention, to have selected sodium polyacrylate as the first additive (i.e. polycarboxylic salt), and carboxymethyl cellulose (i.e. a cellulose ether) as the second additive, with reasonable expectation of success in achieving a successful conductive layer.
Assuming, arguendo, that applicant is able to convincingly argue that Li does not disclose sodium polyacrylate and carboxymethyl cellulose (CMC) with sufficient specificity, the claim limitations would, nonetheless, still be obvious for the following reasons.
Porcher teaches an electrode for a lithium storage battery including a battery comprising a mixture of two polymers: the first polymer being a first polyacrylate or one of its derivatives, the second polymer being a second polyacrylate or a carboxymethyl cellulose ([0028]). Porcher further teaches the polyacrylate derivative is a polymer or copolymer having a base forming at least 50% acrylate function where R corresponds to a cation such as lithium, sodium or ammonium ([0085]- [088]) in its dissociated form.
Porcher further teaches that PAA (polyacrylate), and CMC are both polymers with relatively high Young’s Modulus and sufficient elasticity ([0022]) and performances, in terms of coulombic efficiency are better with PAA ([0023]). Furthermore, Porcher includes a working example in which PAA is dissociated with NaOH, thus forming sodium polyacrylate ([0139]; [0085]- [0088]). Sodium polyacrylate satisfies claimed structure unit A, as claimed in claim 5.
Therefore, it would have been further obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected sodium polyacrylate and CMC from the list provided by Li, as these are not only common binder materials in the art, but also for the benefit of sufficient elasticity and columbic efficiency, as taught by Porcher.
The selection of sodium polyacrylate and CMC satisfy claims 2, 5-6, 15, and 17.
Regarding claim 4 and 16, modified Li discloses all limitations as set forth above.
Modified Li teaches the conductive layer comprising carboxymethyl cellulose as the first additive and sodium polyacrylate as the second additive, as rendered obvious above.
Porcher further discloses a polymer binder is characterized by their chain length by molecular weight, MW (i.e. weight-average molecular weight, [0017]- [0020]). Furthermore, Porcher teaches the molecular weight of the CMC is advantageously comprised between 650,000 g/mol and 4,000,000 g/mol and even more advantageously between 650,000 g/mol and 1,500,000 g/mol, which is 6.5 x 105 to 1.5 x 106 ([0101]), which overlaps with the claimed range of 4x105 to 8x105 for a weight-average molecular weight of the first additive.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected within the overlapping portion of the ranges for the weight-average molecular weight of CMC, with reasonable expectation that such a selection would result in a successful conductive layer.
Regarding claims 7 and 18, modified Li discloses all limitations as set forth above.
Modified Li discloses a conductive carbon material (Li, [0132]) wherein the conductive carbon material is carbon fiber aggregates (Yachi, [0045]), as rendered obvious above. Thus, modified Li satisfies claims 7 and 18.
Regarding claims 8 and 19, modified Li discloses all limitations as set forth above.
Modified Li discloses a conductive layer comprising a first additive of carboxymethyl cellulose and a second additive of sodium polyacrylate, as rendered obvious above.
Modified Li further discloses wherein based on the total weight of the conductive primer layer, the conductive material by weight is 10% to 99%, more preferably 20% to 80% (Li, [0130]), which fully encompasses the claimed mass percentage of the conductive agent of 40-75%. Furthermore, the percentage of the binder is 1% to 90% by weight, more preferably 20 to 80%, and even more preferably 20-50% (Li, [0129]). Li further teaches that the percentages help to improve the conductivity of the electrode plate and the bonding force between the current collector and the electrode active material layer.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected within the overlapping portion of the ranges for the mass percent of the conductive agent with reasonable expectation of achieving a conductive layer with sufficient conductivity and adhesion.
Modified Li further discloses that the acrylic based/acrylate-based binder (i.e. second additive of sodium polyacrylate) is 50wt% to 100 wt% of the binder in the conductive primer layer (Li, [0145]), suggesting that modified Li desires equal amounts or majority of the first additive in the binder, with the binder comprising the first and second additive (Li, [0145], Porcher, [0028]). However, modified Li does not explicitly disclose mass percentages of the first and second additives.
Porcher teaches a similar binder comprising polyacrylate (dissociated with NaOH to form sodium polyacrylate, [0085-0088]), and CMC ([0099]). Porcher further teaches that PAA (polyacrylate), and CMC are both polymers with relatively high Young’s Modulus and sufficient elasticity ([0022]) and performances, in terms of coulombic efficiency, are better with PAA ([0023]). Furthermore, Porcher teaches that the macromolecules of PAA, when dissociated, adopt a conformation that is more unfolded, causing the electrode ink to be more viscous and present a more marked shear thinning behavior which is beneficial for electrochemical performances ([0093]). Porcher further teaches that inks with a first polyacrylate as well as a second polymer, which a second polyacrylate of different molecular weight or CMC, present improved rheological properties compared with inks only containing a single polyacrylate and are therefore easier to deposit by coating and allow greater incorporation of PAA in the ink, resulting in electrodes with better electrochemical properties ([0104]).
Thus, Porcher suggests a greater amount of PAA than CMC in the binder, similar to modified Li, to improve electrochemical properties ([0023]; [0104]), which is further exhibited by Inks D-H (Table of [0157]). Nevertheless, an amount of CMC or a second PAA is still desired to allow the incorporation of PAA in the ink and attain easier coating ([0104]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, in addition to optimizing the amount of conductive material in the conductive layer, to have arrived at the claimed ranges for the mass percentage of the first and second additives through optimizing the amounts of PAA with the amounts of CMC in the binder in order to achieve the desired balance between easier coating, and the incorporation of PAA and its resulting improved electrochemical properties, as suggested by Porcher and desired by Li.
Regarding claim 9, modified Li discloses all limitations as set forth above.
Modified Li discloses a conductive layer comprising a first additive of carboxymethyl cellulose and a second additive of sodium polyacrylate, as rendered obvious above.
Modified Li further discloses that the acrylic based/acrylate-based water dispersible binder (i.e. second additive of sodium polyacrylate) is 50wt% to 100 wt% of the binder in the conductive primer layer (Li, [0145]).
As the binder composition is only the acrylic based/acrylate-based binder (i.e. sodium polyacrylate) and the another binder (i.e. CMC) (Li, [0145], Porcher, [0028]), the remaining weight of the binder is CMC. Thus, the ratio of the first additive to the second additive, as disclosed by Li, is 0:1 to 1:1, which encompasses the claimed ratio of 1:4 - 1:5.
Thus, modified Li satisfies claim 9.
Regarding claim 10, modified Li discloses all limitations as set forth above.
The examiner notes the limitation “wherein the preparation of the conductive layer comprises the following steps…” is a product-by-process limitation (See MPEP 2113). The implied structure is simply the electrochemical apparatus of claim 3, as the active material and conductive layer were dried to obtain the positive electrode plate (see [0093] of the instant specification), and the conductive layer slurry is an intermediate, where the limitations regarding the first and second solid contents (i.e. first solid content is 13-30% and second solid content is greater than or equal to 3%) further limit the intermediate.
Thus, modified Li satisfies claim 10.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN110660957B, see US PG Pub US 20210119196 A1 for citations) and Yachi et al. (US20210143427A1), as applied to claim 1 above, and further in view of Song et al. (KR20170021487).
Regarding claim 12, modified Li discloses all limitations as set forth above.
Modified Li discloses the conductive primer layer to be disposed between the current collector and the electrode active material layer (Li, [0009]) but does not explicitly disclose coverage of the conductive primer layer (i.e. conductive layer) to be 60% - 100%.
Song teaches a similar positive electrode comprising a conductive adhesive layer (i.e. conductive layer) applied on one or both sides of the current collector ([0018]).
Furthermore, Song teaches the coating layer of the conductive adhesive layer may be applied with a coating area of 5% to 95% based on the total area of the collector, which overlaps with the claimed coverage of the conductive layer is 60-100%. Song teaches that when the coated area of the conductive adhesive layer is less than 5% based on the total area of the current collector, the area where the positive electrode mixture is adhered and fixed to the current collector is too small, and separation of the positive electrode mixture from the current collector cannot be prevented ([0030]). Conversely, if the coating is 95% or more, it is difficult to exert the effect of minimizing the deterioration of the electrical conductivity due to the addition of the conductive adhesive layer because the area where the positive electrode material is directly adhered on the current collector is small ([0030]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected and optimized within the overlapping portion of the ranges, in order to achieve the desired balance between adhesion between the conductive layer and positive electrode material layer, and electrical conductivity (MPEP 2144.05 II).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ESTHER J TAN whose telephone number is (571)272-3479. The examiner can normally be reached M-F 7:30 AM-4:00 PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Leong can be reached at (571)270-1292. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/E.J.T./Examiner, Art Unit 1751
/Haroon S. Sheikh/Primary Examiner, Art Unit 1751
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