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 1-4, 6-11, 13-14, 16-18, 20-21, 23, 27, and 38-39 are currently pending
Claims 1, 8, 11, 14, and 21 are amended
Claims 23, 27, and 38 have been previously withdrawn
New claim 39 has been added
Status of Amendments
The amendment filed 15 October 2025 has been fully considered, but does not place the application in condition for allowance.
This action has been made final.
Status of Objections and Rejections of the Office Action from 15 July 2025
The informality objections of claims 8, 11, and 14 have been withdrawn in view of Applicant’s amendment.
The 103 rejections over Yao in view of Wu have been withdrawn in view of Applicant’s amendment. However, a new grounds of rejection over Yao in view of Jiang and further in view of Wu has been set forth, as necessitated by applicant’s amendment.
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.
Claims 1-4, 6-11, 13-14, 16-18, 20-21, and 39 are rejected under 35 U.S.C. 103 as being unpatentable over Yao et al. (CN 112909329 A), hereinafter Yao, in view of Jiang et al. (US 20210242447 A1), hereinafter Jiang, further in view of Wu et al. (CN 109524599 A), hereinafter Wu.
Regarding claim 1, Yao teaches a method of making a solid-state electrolyte, the method comprising:
dissolving ethyl cellulose, in this case the binder (pg. 3, ¶ 5), in a nonpolar solvent (pg. 3 ¶ 4) (pg. 2, ¶ 6);
dispersing a sulfide solid electrolyte in the nonpolar solvent, in this case the sulfide electrolyte is mixed in with the solvent, binder, and a dispersant (pg. 2, ¶ 6);
casting the dispersion of the sulfide solid electrolyte in the nonpolar solvent to form a thin membrane, in this case uniformly dispersing the slurry on the surface of the electrode material (pg. 2, ¶ 7);
applying pressure to the membrane to form a thinner membrane, in this case forming to obtain the ultra-thin sulfide electrolyte layer, preferably comprising one or more of flat static pressure, isostatic pressing, rolling and punching (pg. 6, ¶ 4), which one of ordinary skill in the art would expect to form a thinner membrane than the initial dispersed slurry; and
heating the thin membrane to remove the nonpolar solvent, in this case orderly drying, thereby forming a solid-state electrolyte (pg. 2, ¶ 7).
Yao is silent as to the ethyl cellulose being a dispersant. However, Jiang teaches ethyl cellulose as being a dispersant and at least a portion of the polymer binder for a slurry [0034]. Further, Jiang teaches ethyl cellulose being used as the dispersant in combination with one or more other dispersants, like polyethylene glycol [0033].
Yao and Jiang are both considered to be equivalent to the claimed invention because they are in the same field of film slurry dispersion methods. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the ethyl cellulose of Yao to act as both a binder and a dispersant either in place of the polyethylene glycol or in combination with it, as taught by Jiang. The selection of a known material, in this case ethyl cellulose, based on its suitability for its intended use, in this case as a dispersant in substitution of or combination with polyethylene glycol in a film slurry, supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945).
Yao is further silent as to casting the dispersion of the sulfide solid electrolyte in the nonpolar solvent under vacuum filtration. However, Wu teaches a sulfide solid electrolyte preparation method comprising dispersing the slurry into a vacuum filtration device for vacuum filtration (pg. 3, ¶ 7). Wu further teaches drying and rolling the solid electrolyte diaphragm after vacuum filtration (pg. 3, ¶ 8) to bring the thickness of the diaphragm in embodiment A from 100 μm to 60 μm (pg. 3, ¶ 14-pg. 4, ¶ 1).
Yao and Wu are both considered to be analogous to the claimed invention because they are in the same field of sulfide solid electrolyte preparation methods. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the dispersion technique of Yao with the vacuum filtration dispersion technique of Wu. Simple substitution of one known method for another to obtain predictable results, in this case using vacuum filtration to form a thin sulfide solid electrolyte diaphragm, has been held to support a conclusion of obviousness. See MPEP 2143.I.B. Further, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the forming method of Yao to specifically form a thinner membrane, as taught by Wu. Doing so would have produced a flexible diaphragm sulfide solid electrolyte with high ionic conductivity (pg. 4, ¶ 1) as well as large mechanical strength and uniform thickness (abstract).
Regarding claim 2, modified Yao teaches the method of claim 1. Yao further teaches the nonpolar solvent being toluene (pg. 3, ¶ 4).
Regarding claim 3, modified Yao teaches the method of claim 1. Yao further teaches the sulfide solid electrolyte being Li6PS5Cl, in this case Li6PS5X where X is Cl, Br, or I (pg. 4, ¶ 13).
Regarding claims 4 and 6, modified Yao teaches the method of claim 1. Yao further teaches the solid-state electrolyte having a thickness of 1-50 µm (pg. 6, ¶ 7) which overlaps with the claimed 20-50 µm. Embodiment 1 of Yao further teaches an ultra-thin sulfide electrolyte layer with a thickness of 20 µm (pg. 7, ¶ 5). If the prior art discloses a point within the claimed range, the range is considered obvious. UCB, Inc. v. Actavis Labs. UT, Inc., 65 F.4th 679, 687, 2023 USPQ2d 448 (Fed. Cir. 2023).
Regarding claims 7-11, 13-14, and 17-20, modified Yao teaches the method of claim 1. Yao further teaches the solid-state electrolyte having a conductivity of 10-5 to 5*10-2 S/cm, or 0.01 to 50 mS/cm (pg. 6, ¶ 7), which overlaps with the claimed range of 0.75 to 5 mS/cm, as required by claims 10 and 11. Embodiment 1 of Yao further teaches an ultra-thin sulfide electrolyte layer having a conductivity of 4.4*10-3 S/cm, or 4.4 mS/cm (pg. 7, ¶ 5). Yao is silent as to the temperature at which the conductivity was measured. Yao is further silent as to the resistance of the solid-state electrolyte, as required by claims 7-9, the ion conductivity of the solid-state electrolyte, as required by claims 13-14, the porosity of the solid-state electrolyte, as required by claims 17-18, the homogeneous distribution of chlorine, sulfur, and phosphorus throughout the solid-state electrolyte, as required by claim 20, and the continued ion conductance of the solid-state electrolyte allowed by the ethyl cellulose, as required by claim 21.
However, modified Yao teaches a substantially identical process to the claimed invention. Modified Yao teaches the method of claim 1 with Yao further teaching the identical materials (pg. 3, ¶ 4 and pg. 4, ¶ 13), thickness (pg. 6, ¶ 7 and pg. 7, ¶ 5), and weight percent of specific materials (pg. 5, ¶ 9 and pg. 9, ¶ 6). Therefore, one of ordinary skill in the art would expect the product produced by the taught method to have the inherent values claimed in claims 7-11, 13-14, and 17-20. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). Further, "Products of identical chemical composition can not have mutually exclusive properties." In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
Regarding claim 16, modified Yao teaches the method of claim 1. Yao further teaches the bonding agent being from about 0.5% to 30% of the total mass of the mixture (pg. 5, ¶ 9). This overlaps with the claimed range of 1 to 5 wt%. Embodiment 6 further teaches 5% of the total mass of the mixture being ethyl cellulose (pg. 9, ¶ 6). If the prior art discloses a point within the claimed range, the range is considered obvious. UCB, Inc. v. Actavis Labs. UT, Inc., 65 F.4th 679, 687, 2023 USPQ2d 448 (Fed. Cir. 2023).
Regarding claim 39, modified Yao teaches the method of claim 1. Yao further teaches the elements of the sulfide solid electrolyte being homogenously distributed from the dispersing of the sulfide solid electrolyte in the nonpolar solvent. In this case, the slurry components, including the sulfide solid electrolyte, are taught to be mixed uniformly to obtain the electrolyte slurry (pg. 3, ¶ 8).
Response to Arguments
Applicant's arguments filed 15 October 2025 have been fully considered but they are not persuasive.
Applicant argues that the combination of Yao and Wu does not teach the combination of vacuum filtration and applying pressure to the membrane to form a thinner membrane. Examiner respectfully disagrees for the reasons outlined above. Yao teaches dispersing the slurry followed by a type of forming comprising one or more of flat static pressure, isostatic pressing, rolling and punching, which one of ordinary skill in the art would expect to form a thinner membrane. Wu teaches vacuum filtration followed by drying and rolling which is shown to decrease the thickness of the membrane in embodiment A. Therefore, the combination of the vacuum filtration of Wu, as a known alternate dispersion method, followed by the forming method of Yao or the substitution of the vacuum filtration and rolling method of Wu in place of the dispersion and forming technique of Yao would read on the new limitation.
Applicant’s arguments with respect to the ethyl cellulose of 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
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 DUSTIN KENWOOD VAN KIRK whose telephone number is (703)756-4717. The examiner can normally be reached Monday-Friday 9am-5pm EST.
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/DUSTIN VAN KIRK/Examiner, Art Unit 1722
/NIKI BAKHTIARI/Supervisory Patent Examiner, Art Unit 1722
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