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
Applicant’s amendment and arguments filed 05/12/2026 have been fully considered. Claim(s) 1 is/are amended; claim(s) 6, 9-14 remain withdrawn. Examiner affirms that the original disclosure provides adequate support for the amendment.
Upon considering said amendment and arguments, the previous rejection(s) under 35 U.S.C. 103 over Cha (US20200335795A1) in view of Liu (CN107919459A) as set forth in the Office action mailed 02/12/2026 has/have been withdrawn.
Applicant’s amendment necessitated the new grounds of rejection below, which has necessitated a different interpretation of Cha and Liu as laid out in the rejections of record.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1 and 3-5 are rejected under 35 U.S.C. 103 as being unpatentable over Cha (US20200335795A1 cited in Office action filed 07/09/2025) in view of Liu CN107919459A (cited in IDS filed 04/15/2024, machine translation in 02/12/2026 Office action).
Regarding claim 1, Cha discloses a negative electrode (20) comprising:
a negative electrode current collector (1); and
a negative electrode active material layer (5, 3) comprising a first negative electrode active material layer (3) on at least one surface of the negative electrode current collector (1) and a second negative electrode active material layer (5) on the first negative electrode active material layer ([0026-0027], FIG. 1).
Cha discloses a suitability of impregnating the negative electrode (20) with an electrolyte comprising ethylene carbonate ([0091], [0077], [0123]), necessitating material compatibility of the first negative electrode active material layer with ethylene carbonate. Furthermore, Cha’s first negative electrode active material layer must have good adherence strength and ability to maintain the structural safety ([0034]). However, Cha does not expressly teach the use of ethylene carbonate provided in the first negative electrode active material layer to improve these characteristics as claimed in claim 1, reciting “wherein the first negative electrode active material layer comprises ethylene carbonate, wherein the ethylene carbonate is present in the first negative electrode active material layer in an amount of 2 wt% to 10 wt%”.
Liu (CN107919459A; see machine translation) is directed to a negative electrode wherein ethylene carbonate (EC) or propylene carbonate (PC) additives are provided in the negative electrode slurry at 2-8 parts relative to the weight of the electrode components excluding the solvent to inhibit cracking and peeling of the negative electrode during drying (Liu [0012-0014], [0005]). These considerations are pertinent to Cha’s disclosure (see Cha [0034]) where a skilled artisan would recognize cracking and peeling of the first negative electrode active material layer to be detrimental to the adhesion and structure of the layer. Furthermore, both Liu ([0012]) and Cha ([0103-0104]) employ the use of water-based negative electrode slurries, such that a skilled artisan would not be required to perform significant changes to Cha’s manufacturing procedure to provide EC or PC in a negative electrode slurry as taught by Liu.
Thus, in seeking to improve the adhesion and structural stability of Cha’s first negative electrode active material layer, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to provide an EC or PC additive in Cha’s first negative electrode active material layer through adding 2-8 parts EC/PC into the negative electrode slurry as taught by Liu in order to inhibit cracking and peeling of this layer.
Such a modification would be made with a reasonable expectation of success as Cha’s first negative electrode active material is materially compatible with EC/PC (Cha [0077]), and because both Liu and Cha utilize analogous water-based negative electrode active material slurries during manufacture.
It would likewise be obvious to select EC from the finite list of suitable additives taught by Liu (Liu [0014]), as Cha recognizes a suitability of EC being present in the negative electrode in the form of an infiltrated electrolyte component (Cha [0077]) and Liu teaches that EC in the slurry may remain as a residue in the electrode without impairing battery performance (Liu [0014]).
Thus, it would be obvious for one having ordinary skill in the art to provide Cha’s first negative electrode active material layer comprising ethylene carbonate, wherein the ethylene carbonate is present in the first negative electrode active material layer in an amount of 2 wt% to 8 wt% as according to Liu’s teaching, this range falling within and thus rendering obvious a portion of the range of 2 wt% to 10 wt% claimed in claim 1.
Furthermore, Cha only prioritizes ensuring the adherence strength and structural safety of the first layer of the two negative electrode active material layers, with the second layer instead prioritizing low resistance and improved battery characteristics (Cha [0034]). A skilled artisan would therefore only consider modifying Cha’s first negative electrode active material layer to provide the EC additive for purposes of inhibiting cracking and peeling as taught by Liu, thus leaving the second negative electrode active material layer which does not comprise ethylene carbonate as claimed in claim 1.
Regarding claim 3, modified Cha discloses the negative electrode of claim 1. Liu further teaches optimizing a weight percentage of EC within a range of 2-8 wt% relative to the other negative electrode layer components excluding the solvent ([0012]) where increasing the presence of EC (see Examples 1-2 and Comparative Example 1, [0049], [0045], [0064]) has a corresponding reduction on the cracking, peeling, and curling observed when drying the negative electrode ([0077-0080], FIGs. 1a-1c, 2a-2c), this range closely encompassing claim 3’s range of 3-6 wt% EC present in the first negative electrode active material layer.
Thus, in seeking to suitably reduce cracking, peeling, and curling of modified Cha’s negative electrode by a suitable amount, one having ordinary skill in the art would have selected an amount of EC in the first negative electrode active material layer within the encompassed claimed range of 3-6 wt% with a reasonable expectation of success (MPEP 2144.05 I).
Furthermore, it would be known to an ordinary skilled artisan that EC itself is not an active material, and increasing the proportion of EC necessarily decreases the amount of active material in the negative electrode. As an illustrative example, Liu provides Comparative Example 1 having 95.2 parts graphite active material and 0 parts EC (Liu [0062-0064]), Example 1 with 92.82 parts graphite and 2.5 parts EC ([0039-0039]), and Example 2 with 90.44 parts graphite and 5 parts EC ([0044-0045]). While increasing the EC content alleviates electrode curling and cracking ([0078-0080], FIGs. 2(a)-2(c)), the additional EC reduces the amount of active material in Example 2 compared with Example 1 and the comparative example.
Thus, a skilled artisan would need to balance the EC proportion in modified Cha’s first negative electrode active material between at least 2 wt% to sufficiently reduce the peeling and cracking, and less than 8% to avoid reducing the content of negative electrode active material and the energy density, this range encompassing the range of 3-6% claimed in claim 3 such that it would be obvious for one having ordinary skill in the art to utilize the claimed encompassed range through routine optimization with respect to Liu’s teaching (MPEP 2144.05 II).
Regarding claims 4, 5, modified Cha discloses the negative electrode of claim 1. Cha further discloses an experimental example wherein a loading amount of the first negative electrode active material is 7.5 mg/cm2, and a loading amount of the second negative electrode active material is 7.5 mg/cm2 (Cha [0105]). Correspondingly, a loading amount of the first negative electrode active material is 187.5 mg/25cm2, thus rendering obvious or disclosing with sufficient specificity the selection of this loading amount within the range of 50-400 mg/25cm2 claimed in claim 4.
A total loading amount of the negative electrode active material layer is also (187.5+187.5) mg/25cm2 = 357 mg/cm2, thus rendering obvious or disclosing with sufficient specificity the selection of this loading amount within the range of 50-600 mg/25cm2 as claimed in claim 5.
Response to Arguments
Examiner acknowledges the declaration under 37 CFR 1.132 filed 10/09/2025. However, upon consideration, the declaration filed 10/09/2025 has not been found to overcome the rejection of claims 1 and 3-5 under 35 U.S.C. 103 over Cha in view of Liu as applied above.
Applicant’s arguments filed 05/12/2026 have been considered but have not been found persuasive for the reasons addressed below:
Applicant asserts A), there would have been no reason to modify Cha by additionally including EC in order to improve the electrolyte wettability of the first active material layer. Applicant cites claim 1 and [0006], [0020], and [0027-0028] of Cha in support, which recite the use of a comparatively greater proportion of first binder in the first active material layer to improve adhesion of the current collector (Remarks pp. 6-7)
While this argument has been considered, it has not been found persuasive as neither Liu nor Cha are relied upon to recognize potential improvements of including EC in the first active material layer to improve the electrolyte wettability. Recognition of the improved electrolyte wettability as latent property present but not recognized in the prior art does not form a basis for patentability (MPEP 2145 II).
Furthermore, the cited improvements to electrolyte wettability as supported by exemplary embodiments of the instant specification (see inst. spec. ¶[0070-0093]) are not supported over the entire range of negative electrode materials and structures encompassed by the claims.
For example, the amended claims fail to limit the negative electrode to a specific type of negative electrode active material, whereas the experimental examples appear to use artificial graphite particles exclusively as the negative electrode active material ([0073-0074]). As written, the scope of the claims would include the structure of a sheet of lithium metal as an active material coated with an EC film as a first negative electrode active material layer; the cited effects of improved electrolyte impregnation (Remarks pp. 12 ¶2) would not apply to this electrode which has no porosity (being a sheet of lithium metal) and does not allow for any electrolyte impregnation into the layer. It is also unclear whether different types of negative electrode active material (e.g., natural graphite, silicon) having different properties would provide the same unexpected results to electrolyte impregnation, capacity retention rate, and electrode resistance resulting from a range of 2-10 wt% EC.
Similarly, the types and weights of binder and conductive material in the experimental examples’ negative electrodes ([0073-0074]) are not positively recited in claim 1, and it is unclear whether the same unexpected results would occur at the same range with different types or amounts of binders and conductive materials.
Furthermore, the scope of claim 1 as presented does not necessitate the use of the claimed negative electrode with a liquid electrolyte. Currently, the scope of claim 1 encompasses a negative electrode employed in an all-solid-state battery which lacks a liquid electrolyte and thus lacks any benefits from improved electrolyte wettability (MPEP 716.02 d).
Applicant asserts B), one of ordinary skill in the art would not have applied the negative electrode manufacturing method of Liu to the negative electrode of Cha, as such application would be contrary to the objective of Liu. Liu is directed to preventing cracking and bead defects occurring during drying through use of EC as an additive to lower the surface tension (Liu [0011], [0028]) (Remarks pp. 7-8). In comparison, Cha, which uses a multilayer negative electrode active material structure, is asserted by Applicant to be prone to coating crack formation and interfacial stress during manufacturing as different layers inevitably have different drying rates and shrinkage behavior. Applying Liu’s teaching to Cha’s negative electrode structure disregards the objective and underlying principle of Liu (Remarks p. 8).
While this argument has been considered, it has not been found persuasive. Applicant alleges that Cha’s two layers have different drying rates and shrinkage behavior and are thus subject to increased shrinkage stress, this cited as a fundamental difference in operation between Cha and Liu (Remarks p. 8). However, Cha’s manufacturing process involves applying and drying a first negative electrode active material layer prior to applying the second negative electrode active material layer ([0062]). Thus, the cited differences in drying speed would not apply when the second negative electrode active material layer is applied to an already dried first negative electrode active material.
Applicant identifies difficulty in improving the first negative electrode active material layer’s electrolyte wettability, which is solved through the addition of solid EC in the first negative electrode active material. The second negative electrode active material layer is formed closer to the electrolyte and has no need to improve the electrolyte wettability; rather, by not including ethylene carbonate in the second negative electrode active material layer, the ratio of negative electrode active material is increased and the energy density is improved (Remarks pp 8-9, inst. spec. ¶[0039]). Applicant asserts that the applied references do not contemplate these effects or the advantages resulting from Applicant’s claimed negative electrode structure (Remarks pp. 9).
While this argument has been considered, it has not been found persuasive; Cha and Liu do not necessarily need to identify or recognize Applicant’s identified effects to electrolyte wetting and energy density for a skilled artisan to consider providing Cha‘s first negative electrode active material layer containing EC and a second negative electrode active material layer omitting EC; see rejection of claim 1 under Cha and Liu in this Office action (MPEP 2145 II).
Moreover, Applicant’s disclosure does not provide comparative examples which isolate poorer performance or reduced energy density to the inclusion of EC in the second layer to provide evidence supporting these asserted advantages (MPEP 716.02(d) II)
Applicant asserts C), there would have been no motivation to apply the EC addition to only the preparation of the first active material layer while excluding it from the second active material layer. Specifically, Liu discloses only the preparation of a single-layer negative electrode, there is no motivation to apply Liu’s teaching to only the first negative electrode active material layer specifically. An ordinary skilled artisan would be motivated, if anything, to add EC to both negative electrode active material layers (Remarks p. 9).
While this argument has been considered, it has not been found persuasive; Cha and Liu do not necessarily need to identify or recognize Applicant’s identified effects to electrolyte wetting and energy density for a skilled artisan to consider modification to provide Cha with a first negative electrode active material layer containing EC and a second negative electrode active material layer omitting EC; see discussion of rejection of claim 1 under Cha and Liu in this Office action (MPEP 2145 II).
Specifically, Cha only prioritizes ensuring the adherence strength and structural safety of the first layer of the two negative electrode active material layers, with the second layer instead prioritizing low resistance and improved battery characteristics (Cha [0034]). As Liu does not attribute any specific improvements to resistance or battery characteristics from EC, a skilled artisan would have no reason to improve the peeling and cracking characteristics of Cha’s second negative electrode active material layer through the addition of EC, even when motivation exists to improve these characteristics in Cha’s first negative electrode active material layer through providing EC.
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.
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/E.C./Examiner, Art Unit 1751
/Haroon S. Sheikh/Primary Examiner, Art Unit 1751
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