DETAILED 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 .
2. The Applicant's amendments filed on November 25, 2025, were received. Claims 1, 16, 17, 19, 21-23 and 33 have been amended. Claim 41 has been cancelled. None of the Claims have been withdrawn from consideration or added as new. Therefore, Claims 1-40 are pending in this office action.
3. The text of those sections of Title 35, U.S.C. code not included in this action can be found in the prior Office Action issued on September 16, 2025.
Information Disclosure Statement
4. Information disclosure statement (IDS), submitted November 19, 2025, has been received and considered by the examiner.
Claim Rejections - 35 USC § 112
5. The rejection of Claims 17,19 and 21-23 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, has been overcome based on the amendments to the Claims and the arguments presented on page 6 of the Remarks dated November 25, 2025.
6. The rejection of Claim 41 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, has been overcome based on the cancellation of the Claim and the arguments presented on page 7 of the Remarks dated November 25, 2025.
Claim Rejections - 35 USC § 102
7. The rejection of Claims 1-5, 7-8, 12-15, 20, 24, 27-28, 30-34, 37-38 and 40-41 under 35 U.S.C. 102(a)(1) as being anticipated by Li et al. (CN 103552990A), has been overcome based on the amendments to the Claims and the arguments presented on page 7 of the Remarks dated November 25, 2025.
Claim Rejections - 35 USC § 103
8. The rejection of Claims 6, 9-10 and 16-19 under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A), as applied to Claims 1-5, 7-8, 12-15, 20, 24, 27-28, 30-34, 37-38 and 40-41 above, and in further view of Lisenker et al. (US 2021/0253424 A1), has been overcome based on the amendments to the Claims and the arguments presented on pages 7-8 of the Remarks dated November 25, 2025.
9. The rejection of Claims 11, 21-23, 25-26, 29, 35-36 and 39 under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A), as applied to Claims 1-5, 7-8, 12-15, 20, 24, 27-28, 30-34, 37-38 and 40-41 above, has been overcome based on the amendments to the Claims and the arguments presented on pages 7-8 of the Remarks dated November 25, 2025.
10. Claims 1-5, 7-8, 11-15 and 20-40 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A) in view of Yang et al. (CN112551491A).
With regard to Claim 1, Li et al. disclose a method for producing lithium sulfide comprising: reacting LiCI and a first alkali metal hydrosulfide, in a solvent comprising one or more polar solvent to produce a mixture comprising Li2S and an alkali metal salt (paragraphs 0007-0008). Li et al. do not specifically disclose a first sulfide comprising one or more of Na₂S, K₂S, and (NH4)₂S.
Yang et al. disclose a method of preparing lithium sulfide comprising reacting a lithium source and a sulfur compound under an inert atmosphere, where the sulfur compound is selected from anhydrous sodium sulfide (See Claim 2; Abstract). Advantageously, the method of Yang et al. employing the sodium sulfide sulfur source has a high purity of lithium sulfide produced and does not involve high temperature and high pressure (paragraphs 0003-0004). Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to modify the method of producing lithium sulfide of Li et al. to include the use of sodium sulfide as the first sulfide in the process of Li et al. in order to provide high purity lithium sulfide that does not involve high temperature or high pressures to obtain the product, as taught by Yang et al..
With regard to Claim 2, Li et al. further disclose separating a supernatant comprising the Li2S (paragraphs 0014-0018, 0024-0025).
With regard to Claim 3, Li et al. further disclose removing the solvent from the Li2S, the alkali metal salt, or both the Li2S and the alkali metal salt (paragraphs 0014- 0018, 0024-0025).
With regard to Claim 4, Li et al. disclose wherein the removing the solvent comprises evaporating the solvent to produce a powder (paragraphs 0024-0026,0030).
With regard to Claim 5, Li et al. disclose wherein the removing the solvent comprises vacuum drying, or a combination thereof (paragraph 0026).
With regard to Claim 7, Li et al. disclose wherein the first alkali metal hydrosulfide comprises NaHS, KHS, or a combination thereof (paragraph 0013).
With regard to Claim 8, Li et al. disclose wherein the first alkali metal hydrosulfide comprises NaHS (paragraph 0013).
With regard to Claim 11, Li et al. do not specifically disclose wherein the LiCI comprises 900 ppm to about 1100 ppm H2O content. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to use the LiCI comprises 900 ppm to about 1100 ppm H2O content in the method of Li et al., since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 12, Yang et al. disclose wherein the first sulfide is substantially anhydrous (See Claim 2; Abstract).
With regard to Claims 13-14, Yang et al. do not specifically disclose wherein the first sulfide comprises about 100 ppm to about 1500 ppm H2O content, more specifically, wherein the first sulfide comprises about 900 ppm to about 1100 ppm H2O content. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to use a first sulfide comprising about 100 ppm to about 1500 ppm H2O content, more specifically, the first sulfide comprising about 900 ppm to about 1100 ppm H2O content in the method of Li et al. and Yang et al., since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 15, Li et al. disclose wherein the mixture and the supernatant comprises a second alkali metal hydrosulfide, such as sodium hydrosulfide dihydrate (paragraph 0028).
With regard to Claim 20, Li et al. disclose wherein the first alkali metal hydrosulfide is substantially anhydrous (paragraph 0013).
With regard to Claims 21-23, Li et al. do not specifically disclose wherein the ratio of masses of the first alkali metal hydrosulfide and the water incorporated therein is greater than 2:1; wherein the ratio of masses of the first alkali metal hydrosulfide and the water incorporated therein is greater than 3:1; and, wherein the ratio of masses of the first alkali metal hydrosulfide and the water incorporated therein is greater than 4:1. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to use the first alkali metal hydrosulfide and water as a polar solvent, and include a ratio of masses of the first alkali metal hydrosulfide and the water incorporated therein greater than 2:1; greater than 3:1; and, greater than 4:1 since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 24, Li et al. disclose wherein the produced alkali metal salt inherently comprises LiCI, which is filtered out (paragraph 0025).
With regard to Claim 25, Li et al. disclose LiCI being filtered out of the mixed solution (paragraph 0025), but do not specifically disclose wherein the mixture comprises ≥5% LiCI by mass. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to have the mixture comprises ≥5% LiCI by mass, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 26, Li et al. disclose LiCI being filtered out of the mixed solution (paragraph 0025), but do not specifically disclose wherein the mixture comprises ≥10% LiCI by mass. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to have the mixture comprises ≥10% LiCI by mass, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 27, Li et al. disclose wherein the mixture comprises >99% Li2S (paragraph 0034), which meets the claimed limitation of at least 95% Li2S and LiCI by mass, collectively.
With regard to Claim 28, Li et al. disclose wherein the mixture comprises >99% Li2S (paragraph 0034), which meets the claimed limitation of at least 98% Li2S and LiCI by mass, collectively.
With regard to Claim 29, Li et al. disclose a yield of >99% Li2S (paragraph 0034), but do not specifically disclose wherein Li2S + LiCI are produced at ≥ 95% purity, individually. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to include Li2S + LiCI produced at ≥ 95% purity, individually, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 30, Li et al. disclose >99% Li2S (paragraph 0034), which meets the claimed limitation of Li2S + LiCI are produced at ≥ 98% yield, collectively.
With regard to Claim 31, Li et al. disclose a solid-state electrolyte comprising Li2S produced by the method of claim 1 (paragraph 0004).
With regard to Claim 32, Li et al. disclose a solid-state electrolyte comprising LiCI produced by the method of claim 1 (paragraph 0004).
With regard to Claim 33, Li et al. disclose a method for producing lithium sulfide comprising: reacting LiX, in the form of LiCI, and a first alkali metal hydrosulfide, in a solvent comprising one or more polar solvent to produce a mixture comprising Li2S and an alkali metal salt, while X is halogen (paragraphs 0007-0008). Li et al. do not specifically disclose a first sulfide comprising one or more of Na₂S, K₂S, and (NH₄)₂S.
Yang et al. disclose a method of preparing lithium sulfide comprising reacting a lithium source and a sulfur compound under an inert atmosphere, where the sulfur compound is selected from anhydrous sodium sulfide (See Claim 2; Abstract). Advantageously, the method of Yang et al. employing the sodium sulfide sulfur source has a high purity of lithium sulfide produced and does not involve high temperature and high pressure (paragraphs 0003-0004). Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to modify the method of producing lithium sulfide of Li et al. to include the use of sodium sulfide as the first sulfide in the process of Li et al. in order to provide high purity lithium sulfide that does not involve high temperature or high pressures to obtain the product, as taught by Yang et al..
With regard to Claim 34, Li et al. disclose wherein the produced alkali metal salt comprises LiX, or LiCI (paragraphs 0007-0008).
With regard to Claim 35, Li et al. disclose LiCI being filtered out of the mixed solution (paragraph 0025), but do not specifically disclose wherein the mixture comprises ≥5% LiCI by mass. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to have the mixture comprises ≥5% LiCI by mass, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 36, Li et al. disclose LiCI being filtered out of the mixed solution (paragraph 0025), but do not specifically disclose wherein the mixture comprises ≥10% LiCI by mass. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to have the mixture comprises ≥10% LiCI by mass, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 37, Li et al. disclose wherein the mixture comprises >99% Li2S (paragraph 0034), which meets the claimed limitation of at least 95% Li2S and LiX by mass, collectively.
With regard to Claim 38, Li et al. disclose wherein the mixture comprises >99% Li2S (paragraph 0034), which meets the claimed limitation of at least 98% Li2S and LiX by mass, collectively.
With regard to Claim 39, Li et al. disclose a yield of >99% Li2S (paragraph 0034), but do not specifically disclose wherein Li2S + LiX are produced at ≥ 95% purity, individually. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to include Li2S + LiX produced at ≥ 95% purity, individually, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05.
With regard to Claim 40, Li et al. disclose >99% Li2S (paragraph 0034), which meets the claimed limitation of Li2S + LiX are produced at ≥ 98% yield, collectively.
11. Claims 6, 9-10 and 16-19 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A) in view of Yang et al. (CN112551491A), as applied to Claims 1-5, 7-8, 11-15 and 20-40 above, and in further view of Lisenker et al. (US 2021/0253424 A1).
With regard to Claim 6, Li et al. and Yang et al. disclose the method in paragraph 10 above, including a polar solvent of N-methylpyrrolidone (paragraph 0010), but do not specifically disclose wherein the polar solvent comprises ethanol, 1- propanol, 1- butanol, or a combination thereof.
Lisenker et al. disclose a process for producing a metal sulfide including dissolving a substantially anhydrous alkali metal salt and a substantially anhydrous sulfide compound in a substantially anhydrous polar solvent, wherein the polar solvent comprises ethanol, 1-propanol, 1-butanol, or a combination thereof (paragraphs 0012- 0013). Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to modify the method of Li et al. and Yang et al. to include a polar solvent comprising ethanol, 1-propanol, 1-butanol, or a combination thereof, because Lisenker et al. teach that these materials provide sufficient differential solubility for a high solubility alkali metal sulfide and a low solubility by-product ad does not participate in deleterious side reactions (paragraph 0013).
With regard to Claims 9 and 10, Li et al. and Yang et al. disclose the method in paragraph 10 above, including LiCI, but do not specifically disclose wherein the LiCI is substantially anhydrous; and, wherein the LiCI comprises 100 ppm to about 1500 ppm H2O content.
Lisenker et al. disclose a process for producing a metal sulfide including dissolving a substantially anhydrous alkali metal salt and a substantially anhydrous sulfide compound in a substantially anhydrous polar solvent, wherein the alkali metal salt is substantially anhydrous, with a water content most preferably less than 200 ppm (paragraph 0012). Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to modify the method of Li et al. and Yang et al. to include LiCI being substantially anhydrous; and, wherein the LiCI comprises 100 ppm to about 1500 ppm H2O content, because Lisenker et al. teach that the degree of hydration may impact hydrolyzation, add complexity to precipitation and separating steps and reduce resultant alkali metal sulfide purity (paragraph 0012).
With regard to Claims 16-17, Li et al. and Yang et al. disclose the method in paragraph 10 above, but do not specifically disclose further introducing an anti-solvent to the supernatant, wherein the anti-solvent comprises a hydrocarbon-based solvent, a non-polar solvent, or a combination thereof.
Lisenker et al. disclose a process for producing a metal sulfide including dissolving a substantially anhydrous alkali metal salt and a substantially anhydrous sulfide compound in a substantially anhydrous polar solvent, and, additionally adding a desired amount of an anti-solvent such as heptane or other aprotic chain hydrocarbons (paragraphs 0012-0013, 0017). Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to modify the method of Li et al. and Yang et al. to further include introducing an anti-solvent to the supernatant, wherein the anti-solvent comprises a hydrocarbon-based solvent, a non-polar solvent, or a combination thereof, because Lisenker et al. teach that these materials drive additional precipitation of the low-solubility by-product (paragraph 0017).
With regard to Claims 18-19, Li et al. and Yang et al. disclose the method in paragraph 10 above, but do not specifically disclose further adding a sulfur source, wherein the sulfur source comprises one or more of elemental sulfur and H2S (paragraph 0016).
Lisenker et al. disclose a process for producing a metal sulfide including dissolving a substantially anhydrous alkali metal salt and a substantially anhydrous sulfide compound in a substantially anhydrous polar solvent, and, additionally adding a sulfur source in the form of H2S or solid elemental sulfur. Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to modify the method of Li et al. and Yang et al. to further include adding a sulfur source, wherein the sulfur source comprises one or more of elemental sulfur and H2S, because Lisenker et al. teach that these materials further improve the purity of the desired alkali metal sulfide (paragraph 0016).
Response to Arguments
12. Applicant’s arguments, see pages 6-8, filed November 25, 2025, with respect to the rejection(s) of Claims 1-5, 7-8, 12-15, 20, 24, 27-28, 30-34, 37-38 and 40-41 under 35 U.S.C. 102(a)(1) as being anticipated by Li et al. (CN 103552990A), have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Yang et al. (CN112551491A).
Conclusion
13. 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.
14. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KARIE O APICELLA whose telephone number is (571)272-8614. The examiner can normally be reached Monday thru Friday; 8:00AM to 5:00PM EST.
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/KARIE O'NEILL APICELLA/Primary Examiner, Art Unit 1725