DETAILED ACTION
This Office Action is responsive to the February 5th, 2026 arguments and remarks (“Remarks”).
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 11/17/2025 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Response to Amendment
In response to the amendments received on February 5th, 2026:
Claims 1-5 and 8-20 are pending in the current application. Claim 1 is amended. Claims 6 and 7 were previously cancelled. Claims 15-20 were previously withdrawn.
Claim 1 is amended to describe that adding the complexing agent decomposes the sulfide-based solid electrolyte.
No new matter has been introduced. Support for the amended limitations is found in the applicant’s disclosure including the originally filed specification (para. 49-52).
The new grounds of rejection are necessitated by amendment.
Status of Claims
Claims 1-5 and 8-14 stand rejected under 35 U.S.C. 103 as described below:
Claims 1-4 and 8-14 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (C.N. Pat. No. 110661051 A) as further evidenced by Lain (U.S. Pat. No. 6447669 B1), and in view of Liang et al. (Liang, Chengdu et al. “Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium Sulfur Batteries.” U.S. Department of Energy, May 2012, https://www.energy.gov/sites/prod/files/2014/03/f10/es105_liang_2012_p.pdf).
The rejections are withdrawn based on the amendment to Claim 1.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (C.N. Pat. No. 110661051 A) as further evidenced by Lain (U.S. Pat. No. 6447669 B1), and in view of Liang et al. (Liang, Chengdu et al. “Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium Sulfur Batteries.” U.S. Department of Energy, May 2012, https://www.energy.gov/sites/prod/files/2014/03/f10/es105_liang_2012_p.pdf) as applied to Claim 1 above, and further in view of Lain (U.S. Pat. No. 6447669 B1). The rejections are withdrawn based on the amendment to Claim 1.
The new grounds of rejection are necessitated by amendment.
Cited Prior Art
Previously Cited Liu et al. (C.N. Pat. No. 110661051 A) (“Liu et al.”)
Previously Cited Lain (U.S. Pat. No. 6447669 B1) (“Lain”)
Previously Cited Liang et al. (Liang, Chengdu et al. “Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium Sulfur Batteries.” U.S. Department of Energy, May 2012, https://www.energy.gov/sites/prod/files/2014/03/f10/es105_liang_2012_p.pdf) (“Liang et al.”)
Yoon et al. (U.S. Pat. No. 20190198916 A1) (“Yoon et al.”)
Response to Arguments
Applicant’s arguments filed February 5th, 2026 have been fully considered but they are not persuasive as further described below:
Applicant presents arguments to Claim 1 as amended. Applicant argues that prior art references Liu and Liang fail to suggest that adding the complexing agent decomposes the sulfide-based electrolyte as amended (see pg. 6 of the “Remarks”); applicant argues that the addition of elemental sulfur as taught by Liu functions to further complex the electrolyte rather than to decompose the electrolyte. Additionally, applicant states that Liang does not cure the deficiencies of Liu nor suggest the amended limitations.
As restated by the applicant (see pg. 5 of the “Remarks”), the Office cites Liang to teach a novel electrolyte additive such as P2S5 in which forms complexes with Li2S and can facilitate the dissolution of lithium sulfide/polysulfides of ether based electrolytes (Liang, pg. 11). Further, the function of the P₂S₅ additive as taught by Liang et al. aligns with the function of the elemental sulfur of Liu et al. as Liu et al. teaches that the elemental sulfur is used to promote dissolution in a suitable solvent to form a lithium polysulfide electrolyte in which can be separated and recovered (Liu et al., para. 32-33). Further, one of ordinary skill in the art would find the teachings of Liang et al. useful in providing an alternative suitable complexing agent to the elemental sulfur of Liu et al. "Applying a known technique to a known device (method or product) ready for improvement to yield predictable results is likely to be obvious.” See KSR International Co. v. Teleflex Inc., 550 U.S. __,__, 82 USPQ2d 1385, 1395 – 97 (2007) (see MPEP § 2143, D.). In this case, adding a complexing agent to an electrolyte for recovery/separation purposes is known as shown by Liu and Liang. Further, "The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)" (MPEP 2144.07). It would be obvious to select P2S5 as a complexing agent for an electrolyte as Liang teaches its capabilities of promoting effective dissolution and recovery (Liang, pg. 11).
As applicant points to Reaction 4 disclosed in the specification (para. 51-52), the decomposition of the solid electrolyte is solely based on the presence of a solid electrolyte material such as Li6PS5Br. In this case, Li6PS5Br is a known sulfide based solid electrolyte for a lithium secondary battery in which comprises a high ionic conductivity providing improved battery performance as evidenced by Yoon et al. (para. 52). Li6PS5Br is encompassed by the claimed broad genus of “sulfide-based solid electrolytes.” As the sulfide based solid electrolyte can comprise a compound such as Li6PS5Br as further evidenced by Yoon et al. in which the method for separation and recovery is suggested by the prior art, the recited step “wherein adding the complexing agent decomposes the sulfide-based solid electrolyte” is considered a “whereby clause” and is the result of a process step positively recited. “The court noted that a "whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited." Id. (quoting Minton V. Nat'l Ass'n of Securities Dealers, Inc., 336 F.3d 1373, 1381, 67 USPQ2d 1614, 1620 (Fed. Cir. 2003))" (see MPEP 2111.04.I.). Therefore, applicant’s arguments are deemed unpersuasive.
All changes made to the rejection are necessitated by 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 and 8-14 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (C.N. Pat. No. 110661051 A) as further evidenced by Lain (U.S. Pat. No. 6447669 B1), and in view of Liang et al. (Liang, Chengdu et al. “Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium Sulfur Batteries.” U.S. Department of Energy, May 2012, https://www.energy.gov/sites/prod/files/2014/03/f10/es105_liang_2012_p.pdf) as further evidenced by Yoon et al. (U.S. Pat. No. 20190198916 A1).
Regarding Claim 1, Liu et al. teaches a recycling method for separating and recovering materials from a solid-state battery (electrochemical cell) (para. 45-47). The solvent and solid-state electrochemical cell were stirred to form a homogeneous mixture wherein the materials of the solid-state electrochemical cell include a sulfide-based solid-state electrolyte (step (a)) (para. 54). Liu et al. teaches adding elemental sulfur (functionally equivalent to a complexing agent as it is used to transform Li3PS4 to Li3PS7) in which can be added to the electrochemical cell and solvent (para. 54) (in a container as further evidenced by Lain as described below). One of ordinary skill in the art would be motivated to perform the method provided by Liu et al. to provide a solid battery recycling method comprising simple separation steps and mild reaction conditions in which can efficiently separate sulfide electrolytes and electrode materials without generating highly toxic and highly corrosive H2S gas (para. 47).
Although Liu et al. is silent to the presence of a container and the order of adding the solvent (before or after introducing the electrochemical cells to the container), it is obvious to one of ordinary skill in the art that the mixture is held in a container to contain the solvent and promote effective mixing in which the solvent can be added to the electrochemical cells in the container; this concept is further evident by Lain in which teaches a method for separating and recovering materials from a lithium-ion cell (electrochemical cell) comprising directly situating the electrochemical cells in a container in which a solvent is added (para. 2-4 of “Description”). The electrochemical cell and the solvent is stirred (in a container as evidenced above) providing mechanical energy and promoting dissolution of the sulfide electrolyte (first materials) (para. 35-36)) of the solid-state electrochemical cell (step (b)) (para. 47, 54). The solution (solvent and dissolved first materials) is separated from the positive and negative electrode material (remaining materials) of the soli-state electrochemical cell (step (c)) (para. 54). The dissolved sulfide solid electrolyte (first materials) are subject to rotary evaporation and drying for recovery (step (d)) (para 54).
It is well known in the art to repeat process steps using the same or different solvents in electrochemical cell recovery methods to ensure complete separation of materials and improve recovery yields as further evident by Lain in which teaches repeating steps (comparable to those claimed) of a battery recovery process with a different solvent to recover remaining materials (para. 5 of “Description”). The use of a known technique to improve similar devices (methods or products) in the same way is likely to be obvious. See KSR International Co. v. Teleflex Inc., 550 U.S. 417, 82 USPQ2d 1385, 1395 - 97 (2007) (see MPEP § 2143, C). In this case, it would be obvious to one of ordinary skill in the art to repeat steps (a), (b), (c), and (d) of Liu et al. with one or more same or different solvents or mixtures (known method of enhancement) to achieve predictable results (higher yield, further recovery of materials of the electrochemical cell such as the sulfide-based solid-state electrolyte) (step (e)).
Further, “the selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. lnterchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)” (see MPEP § 2144.07); it is within the scope of one of ordinary skill in the art to select a solvent in which would appropriately dissolve the material desired to be recovered whether the solvent is the same or different. Therefore, all claim limitations are met.
Liu et al. does not teach the complexing agent selected from the group consisting of P2S5, P4S8, P4S9, Sb2S5 and mixtures thereof.
Liang et al. teaches P2S5 as a novel electrolyte additive in which forms complexes with Li2Sx and facilitates the dissolution of lithium sulfide/polysulfides in ether based electrolytes (pg. 11). Therefore, one of ordinary skill in the art would consider the P2S5 electrolyte additive to be functionally equivalent to a complexing agent based on its ability to form complexes with lithium sulfide as described by Liang et al.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the complexing agent of Liu et al. to include P2S5 as taught by Liang et al. to promote dissolution of the lithium sulfide/polysulfide complex. Although the teachings of Liang et al. are not directed to a recovery method of an electrochemical cell, both Liu et al. and Liang et al. teach an additive (complexing agent) for a solid state electrolyte. Further, the function of the P2S5 additive as taught by Liang et al. aligns with the function of the elemental sulfur of Liu et al. as Liu et al. teaches that the elemental sulfur is used to promote dissolution in a suitable solvent to form a lithium polysulfide electrolyte in which can be separated and recovered (Liu et al., para. 32-33). Further, one of ordinary skill in the art would find the teachings of Liang et al. useful in providing an alternative suitable complexing agent to the elemental sulfur of Liu et al.
As applicant points to Reaction 4 disclosed in the specification (para. 51-52), the decomposition of the solid electrolyte is solely based on the presence of a sulfide based solid electrolyte material such as Li6PS5Br. In this case, Li6PS5Br is a known sulfide based solid electrolyte for a lithium secondary battery in which comprises a high ionic conductivity providing improved battery performance as evidenced by Yoon et al. (para. 52). Li6PS5Br is encompassed by the claimed broad genus of “sulfide-based solid electrolytes.” As the sulfide based solid electrolyte can comprise a compound such as Li6PS5Br as further evidenced by Yoon et al. in which the method for separation and recovery is suggested by the prior art, the recited step “wherein adding the complexing agent decomposes the sulfide-based solid electrolyte” is considered a “whereby clause” and is the result of a process step positively recited. “The court noted that a "whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited." Id. (quoting Minton V. Nat'l Ass'n of Securities Dealers, Inc., 336 F.3d 1373, 1381, 67 USPQ2d 1614, 1620 (Fed. Cir. 2003))" (see MPEP 2111.04.I.). Therefore, applicant’s arguments are deemed unpersuasive.
Regarding Claim 2, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the materials of the electrochemical cell can include electrode metals (para. 36), active materials (para. 35-36), and conductive agents (additives) (para. 37). Therefore, all claim limitations are met. One of ordinary skill in the art would be motivated to perform the method provided by Liu et al. to provide a solid battery recycling method comprising simple separation steps and mild reaction conditions in which can efficiently separate sulfide electrolytes and electrode materials without generating highly toxic and highly corrosive H2S gas (para. 47).
Regarding Claim 3, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the materials of the electrochemical cell can include lithium metal, cathode active materials, aluminum metal, and conductive agents such as carbon black (carbon additives) (para. 36-37). Therefore, all claim limitations are met. One of ordinary skill in the art would be motivated to perform the method provided by Liu et al. to provide a solid battery recycling method comprising simple separation steps and mild reaction conditions in which can efficiently separate sulfide electrolytes and electrode materials without generating highly toxic and highly corrosive H2S gas (para. 47).
Regarding Claim 4, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the solid phase materials (remaining materials) of the solid-state electrochemical cell are washed with pyridine (additional solvent) (para. 54). The purpose of the washing step can be to remove residual materials as further evident by Lain in which teaches an electrochemical cell recovery method comprising a step of washing remaining materials with water (additional solvent) to remove residual materials (para. 6 of “Description”). One of ordinary skill in the art would be motivated to perform the method provided by Liu et al. to provide a solid battery recycling method comprising simple separation steps and mild reaction conditions in which can efficiently separate sulfide electrolytes and electrode materials without generating highly toxic and highly corrosive H2S gas (para. 47).
Regarding Claim 8, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the solid electrolyte comprising Li2S-P2S5 (equivalent to a P2S5-Li2S complex) in which is dissolved in the organic solvent forming one of the dissolved materials (para. 32-33, 47).
Regarding Claim 9, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the solvent can include a hydrocarbon organic solvent (hydrocarbon-based solvent) (para. 41). “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. lnterchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)” (see MPEP § 2144.07). One of ordinary skill in the art would be motivated to select a hydrocarbon organic solvent to provide a suitable solvent to dissolve the electrolyte with the electrode material being insoluble within (para. 41).
Regarding Claim 10, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the solvent can include xylene (xylene-based solvent) (para. 41). “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. lnterchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)” (see MPEP § 2144.07). One of ordinary skill in the art would be motivated to select xylene to provide a suitable solvent to dissolve the electrolyte with the electrode material being insoluble within (para. 41).
Regarding Claim 11, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the solvent can include NMP (a polar solvent). “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. lnterchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)” (see MPEP § 2144.07). One of ordinary skill in the art would be motivated to select NMP to provide a suitable solvent to dissolve the electrolyte with the electrode material being insoluble within (para. 41). As applied to Claim 1, it would be obvious to one of ordinary skill in the art to repeat recovery steps (step (a), (b), (c), and (d)) with an appropriate solvent to recover remaining materials. One of ordinary skill in the art would be motivated to repeat process steps to ensure complete separation of dissolved materials and promote further dissolution.
Regarding Claim 12, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. Liu et al. teaches the solvent can include nitrile organic solvents (nitrile-based solvent) (para. 22). “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. lnterchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)” (see MPEP § 2144.07). One of ordinary skill in the art would be motivated to select a nitrile-based solvent to provide a suitable solvent to dissolve the electrolyte with the electrode material being insoluble within (para. 41). As applied to Claim 1, it would be obvious to one of ordinary skill in the art to repeat recovery steps (step (a), (b), (c), and (d)) with an appropriate solvent to recover remaining materials as further evidenced by Lain above. One of ordinary skill in the art would be motivated to repeat process steps to ensure complete separation of dissolved materials and promote further dissolution.
Regarding Claim 13, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 12 above. Liu et al. teaches the nitrile-based solvent can include acetonitrile (para. 41). “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. lnterchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)” (see MPEP § 2144.07). One of ordinary skill in the art would be motivated to select a nitrile organic solvent to provide a suitable solvent to dissolve the electrolyte with the electrode material being insoluble within (para. 41).
Regarding Claim 14, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above. As applied to Claim 1, Liu et al. teaches the method of providing energy is stirring in which is equivalent to physically agitating the soli-state electrochemical cell and the solvent (para. 54) in which can be performed in a container as evidenced by Lain above. One of ordinary skill in the art would be motivated to perform the method provided by Liu et al. to provide a solid battery recycling method comprising simple separation steps and mild reaction conditions in which can efficiently separate sulfide electrolytes and electrode materials without generating highly toxic and highly corrosive H2S gas (para. 47).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (C.N. Pat. No. 110661051 A) as further evidenced by Lain (U.S. Pat. No. 6447669 B1), and in view of Liang et al. (Liang, Chengdu et al. “Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium Sulfur Batteries.” U.S. Department of Energy, May 2012, https://www.energy.gov/sites/prod/files/2014/03/f10/es105_liang_2012_p.pdf) as further evidenced by Yoon et al. (U.S. Pat. No. 20190198916 A1) as applied to Claim 1 above, and further in view of Lain (U.S. Pat. No. 6447669 B1).
Regarding Claim 5, Liu et al. is modified by Liang et al. teaching all claim limitations as applied Claim 1 above.
Liu et al does not teach separating by density segregation.
Lain teaches a method for separating and recovering materials from a lithium-ion cell (electrochemical cell) comprising separating materials based on their density (density segregation) (para. 7 of “Background”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the solid-state electrochemical cell recovery method of Liu et al. to include separation by density segregation as taught by Lain. One of ordinary skill would be motivated to perform the described modification to provide an effective method of recovering remaining materials such as the current collectors of the electrochemical cell (para. 7 of “Background). Further, Lain teaches a process for treating lithium cells and cell components in which materials can be recovered safely and reused (para. 1 of “Background”).
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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/C.R.D./Examiner, Art Unit 1729
/ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729