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 .Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 06/04/2026 has been entered.
Response to Amendment
The amendment filed on 06/04/2026 has been entered. Claims 1, 4-33, 53-66, and 68-74 are pending in the application. Claims 55-64 are withdrawn.
Applicant’s amendments to the claims have not introduced new matter and are supported in the specification in at least [00117] and [00149] of the instant specification.
Response to Arguments
Applicant’s arguments, see Pg. 10-11 filed 06/04/2026 with respect to claim 1, have been fully considered however are solely directed to the claim limitation “the first alkali metal salt comprises lithium and an alkali or alkali earth metal impurity selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, silicon chloride, iron chloride, nickel chloride, copper chloride, and any combination thereof” introduced in the amendment filed 06/04/2026, which postdates the final rejection mailed 02/04/2026.
Upon further search and consideration and as necessitated by the amendment, the 35 U.S.C. 103 rejection of 02/04/2026 is updated to be made under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Barker et al. (GB2464455A), with evidentiary support for claim 1 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173). Evidentiary reference Linneen supports that common lithium chloride sources contain metal impurities.
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 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, 4-14, 17-23, 26, 31, 33, and 53-54 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Barker et al. (GB2464455A), with evidentiary support for claim 1 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Note, the citations for Li and Chiga are from English-equivalent documents provided by the Examiner. The copies provided by Applicant only include an English abstract.
Regarding claim 1, Li teaches a method of preparing high-purity lithium sulfide comprising reacting lithium chloride (i.e. a first alkali metal salt) with sodium or potassium sulfohydrate (i.e. a first alkali metal hydrosulfide) in N-methyl pyrrolidone to produce a precipitate (i.e. second alkali metal salt precipitate) that is filtered off to provide a solution of lithium sulfide in N-methyl pyrrolidone that has its solvent removed prior to provide the high-purity lithium sulfide (i.e. a second sulfide) (Abstract; Claims 1, 4, 5; Pg. 2, par. 3-13; Pg. 2-3, Embodiment 1). N-methyl pyrrolidone is a polar solvent, as evidenced by Basma who teaches N-methyl pyrrolidone is a strongly polar solvent (Pg. 8963, left col.). While not indefinite, use of the word “optionally” in step (a) does not constitute a necessary aspect required by the claim and are not considered as required in the above rejection over Li. In particular, the phrase “a first sulfide” is not considered a required aspect of the claim.
The claim further requires “wherein the first alkali metal salt comprises lithium and an alkali or alkali earth metal impurity selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, silicon chloride, iron chloride, nickel chloride, copper chloride, and any combination thereof.” Li teaches the first alkali metal salt is lithium chloride (i.e. comprises lithium), however Li is silent regarding impurities in the lithium salt.
Chiga teaches a method of preparing lithium sulfide that comprises reacting sodium hydrosulfide and lithium chloride in an organic solvent, where the lithium chloride used in the reaction is not particularly limited and by-product lithium chloride can be used (Pg. 2, [0012]). Chiga teaches the reaction mixture include sodium hydroxide and sodium hydrosulfide and that the lithium chloride containing these sodium compounds can be reused to prepare lithium sulfide ([0014]; [0023]).
Chiga teaching a skilled artisan that the lithium chloride used is not particularly limited and can be by-product lithium chloride would necessarily teach a skilled artisan that lithium chloride sources such as technical/industrial grade lithium chloride could be used (i.e. the source is not particularly limited). A skilled artisan would further understand that these industrial or technical grade lithium chloride sources would contain metal impurities including sodium, magnesium, potassium, calcium, copper, iron, and nickel, as evidenced by Linneen (Abstract; Pg. 169, Table 1). Accordingly, a skilled artisan viewing the disclosure of Chiga would not be dissuaded from using lithium chloride sources containing impurities and such lithium chloride sources would contain one of the impurity metals required by the claim. Skilled artisans would also have an expectation of success in using available sources of lithium chloride to prepare sulfides with.
Advantageously, using lithium chloride that possesses byproducts, including sodium hydrosulfide, allows for a more efficient process and makes it possible to perform continuous production of the lithium sulfide by reusing by-produced lithium chloride starting materials directly ([0012]; [0023]; [0028]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use byproduct containing lithium chloride, where the byproducts include sodium salts such as sodium hydroxide and sodium hydrosulfide, in the process of Li in order to make the process more efficient by reusing lithium chloride byproduct material and in order to achieve a continuous production process, as taught by Chiga.
Regarding claims 4-9, Li teaches the high-purity lithium sulfide product has a purity of greater than 99%, with less than 0.1% lithium sulfite impurities and less than 0.5% lithium sulphate impurities (Pg. 2, par. 14). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). In the instant case, the range taught by Li (greater than 99% pure lithium sulfide) overlaps with the claimed ranges ((Claim 4) at least 90% free of alkali metal or alkali earth metal impurities; (Claim 5 at least 95% free of alkali metal or alkali earth metal impurities; (Claim 6; at least 98% free of alkali metal or alkali earth metal impurities; (Claim 7) at least 99% free of alkali metal or alkali earth metal impurities; (Claim 8) at least 99.5% free of alkali metal or alkali earth metal impurities; (Claim 9) at least 99.9% free of alkali metal or alkali earth metal impurities). Therefore, the range in Li renders obvious the claimed ranges.
Regarding claims 10-11, Li teaches the solvent is removed via vacuum to provide dry lithium sulfide product (Pg. 2, par. 13-15; Embodiment 1). Li teaches the lithium sulfide powder is 99% pure and that greater than 98% of the N-methyl pyrrolidone solvent is reclaimed (Pg. 2, par. 15).
Regarding claims 12-13, Li teaches the lithium sulfide powder is 99% pure and that greater than 98% of the N-methyl pyrrolidone solvent is reclaimed (Pg. 2, par. 15). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). In the instant case, the range taught by Li (greater than 98% of the N-methyl pyrrolidone solvent is reclaimed) overlaps with the claimed ranges ((Claim 12) over 99% by weight of the polar solvent is removed; (Claim 13) over 80% by weight of the polar solvent is removed). Therefore, the range in Li renders obvious the claimed ranges.
Regarding claim 14, Li teaches the solvent is removed via vacuum to provide dry lithium sulfide product (Pg. 2, par. 13-15; Embodiment 1).
Regarding claims 17-20, Li teaches the high-purity lithium sulfide product has a purity of greater than 99%, with less than 0.1% lithium sulfite impurities and less than 0.5% lithium sulphate impurities (Pg. 2, par. 14). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). In the instant case, the range taught by Li (greater than 99% pure lithium sulfide) overlaps with the claimed ranges ((Claim 17) at least 95% pure by weight; (Claim 18) at least 98% pure by weight; (Claim 19) at least 99% pure by weight; (Claim 20) at least 99.5% pure by weight). Therefore, the range in Li renders obvious the claimed ranges.
Regarding claim 21, Li teaches the solution obtained following filtration includes lithium hydrogen sulfide (i.e. sulfur lithium hydride) that can be decomposed via heat treatment to provide lithium sulfide (Abstract; Pg. 2, par. 8-10).
Regarding claims 22-23, Li teaches the decomposition of the sulfur lithium hydride (i.e. LiHS) only produces hydrogen sulfide in route to provide lithium sulfide as a solid (Pg. 2, par. 7-11).
Regarding claim 26, Li teaches the alkali metal salt precipitated is separated by filtration (Pg. 2, par. 4).
Regarding claim 31, Li teaches the reaction of lithium chloride and sodium sulfhydrate provides lithium sulfide and a sodium chloride precipitate, that is filtered (Pg.2-3, Embodiment 1; Abstract).
Regarding claim 33, Li teaches the first alkali metal hydrosulfide is sodium sulfhydrate (Abstract; Claim 1 and 5), which is synonymous with NaHS.
Regarding claim 53, Li teaches the desired product from the method is high-purity lithium sulfide (Abstract; Claim 1). It would be obvious to a skilled artisan to include the desired product (Li2S) as a starting material as it would necessarily provide the desired product (Li2S).
Regarding claim 54, Li teaches the reaction of lithium chloride and sodium sulfhydrate provides lithium sulfide (Li2S) and a sodium chloride precipitate, that is filtered (Pg.2-3, Embodiment 1; Abstract).
Claims 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024) and further in view of Sugawara et al. (JP2016207354A English), with evidentiary support for claim 1 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Regarding claims 15-16, modified Li teaches the process of claim 1 and the claims further require “adding a sulfur source to increase the purity of the second sulfide,” and “wherein the sulfur source comprises one or more of elemental sulfur and H2S,” to which Li and Chiga are silent.
Sugawara teaches a process for preparing a sulfide solid electrolyte that includes preparing lithium sulfide (Abstract; Pg. 2, par. 7). Sugawara teaches that an additional treatment can be performed with hydrogen sulfide gas (i.e. H2S) in order to improve the purity of the lithium sulfide (Pg. 4, par. 1). Advantageously, performing treatment with hydrogen sulfide improves the purity of the lithium sulfide and can convert other lithium containing impurities present in the sample into lithium sulfide (Pg. 4, par. 1; Pg. 8, Production Example 1).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use a sulfur source such as hydrogen sulfide to further treat the lithium sulfide material to improve the purity of the lithium sulfide in the process of Li in order to improve the purity of the lithium sulfide by converting other lithium salts into lithium sulfide, as taught by Sugawara.
Claims 24-25 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024) and further in view of Yanagi et al. (US20180183096A1), with evidentiary support for claim 1 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Regarding claims 24-25, modified Li teaches the method of claim 1 and the claim further requires “further comprising adding an anti-solvent compound to the supernatant” and “wherein the anti-solvent comprises a hydrocarbon-based solvent, a non-polar solvent, or a combination thereof,” to which Li and Chiga are silent.
Yanagi teaches a method for preparing Li2S, where the raw materials, including LiHS and other lithium salts, are dissolved in good solvent that serves to dissolve the Li2S prior to adding a poor solvent in which the Li2S particles have low solubility in order to precipitate the solid ([0057]-[0059]). Yanagi teaches the poor solvent is a hydrocarbon solvent, with dodecane and tridecane as exemplary solvents ([0059]). Advantageously, the poor solvent not only allows precipitation of the target product, but provides the process an advantage of fast heat conduction and affords easy collection of the product ([0059]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to add a poor solvent to the supernatant, such as dodecane and/or tridecane, in the process of Li in order to precipitate the target product while providing a fast heat conduction and affording easy collection of the product, as taught by Yanagi.
Claims 27, 29-30, and 32 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024) and further in view of Yang et al. (CN112551491A English; cited in IDS dated 07/05/2023), with evidentiary support for claim 1 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Note, the citations Yang below are from the English equivalent provided by the Examiner. The copy provided by Applicant only included an English abstract.
Regarding claims 27 and 29, modified Li teaches the process of claim 1 and the claims further require the polar solvent is “substantially anhydrous” and “comprises at least one alcohol selected from the group consisting of ethanol, 1-propanol, 1-butanol, and mixtures thereof,” to which Li and Chiga are silent.
Yang teaches a method of preparing lithium sulfide comprising reacting a lithium source and a sulfur compound under an inert atmosphere with at least one of anhydrous methanol, ethanol, propanol, isopropanol, butanol, and tert-butanol that have been treated with activated molecular sieves (Abstract; Claim 1 and 5; Pg. 3, par. 19). Advantageously, the method of Yang, including application of anhydrous polar alcoholic solvents, provides a method that provides high purity lithium sulfide in a reproducible fashion that does not involve high temperature or high pressures to obtain the product (Pg. 4, par. 3-4).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use an anhydrous poor solvent such as at least one of anhydrous methanol, ethanol, propanol, isopropanol, butanol, and tert-butanol, in the process of Li in order to provide high purity lithium sulfide in a reproducible fashion that does not involve high temperature or high pressures to obtain the product, as taught by Yang.
Regarding claim 30, modified Li teaches the method of claim 1, where Li teaches the first alkali metal salt is lithium chloride and the first alkali metal hydrosulfide is sodium hydrosulfide (Abstract; Claims 1 and 5).
The claim further requires the first sulfide is present and that “the first sulfide comprises Na2S,” to which Li and Chiga are silent.
Yang teaches 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 (Claim 2; Abstract). Advantageously, the method of Yang employing the sodium sulfide sulfur source has a high purity of lithium sulfide produced and does not involve high temperature and high pressure (Pg. 4, par. 3-4).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use sodium sulfide as the first sulfide in the process of Li 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.
Regarding claim 32, modified Li teaches the method of claim 1, where Li teaches the first alkali metal salt is lithium chloride and the first alkali metal hydrosulfide is sodium hydrosulfide (Abstract; Claims 1 and 5).
The claim further requires the optional first sulfide is present and that “the optional first sulfide is selected from the group consisting of K2S, Na2S, (NH4)2S, and mixtures thereof,” to which Li and Chiga are silent.
Yang teaches 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 (Na2S) (Claim 2; Abstract). Advantageously, the method of Yang employing the sodium sulfide sulfur source has a high purity of lithium sulfide produced and does not involve high temperature and high pressure (Pg. 4, par. 3-4).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use sodium sulfide as the first sulfide in the process of Li 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.
Claim 28 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024) and further in view of Senga et al. (US20180162730A1; cited in IDS dated 04/14/2025), with evidentiary support for claim 1 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Regarding claim 28, modified Li teaches the method of claim 1 and the claim further requires “the first alkali metal hydrosulfide is substantially anhydrous,” to which Li and Chiga are silent.
Senga teaches a method of preparing a solid electrolyte comprising lithium sulfide that includes heating a mixture comprising lithium hydrosulfide and lithium halide in the presence of hydrogen sulfide (Abstract; [0044]). Senga teaches the hydrogen sulfide supplied to the reaction aids to suppress the formation of lithium hydroxide through hydrolysis and subsequently allow the lithium hydrosulfide an lithium halide to productively react to obtain the target sulfur-containing complex more efficiently ([0078]-[0080]). Additionally, Senga teaches the reaction should be kept free of water because hydrate salts of halides, represented by the formula Li3OX where X represents a halogen element, worsen battery performance ([0037]-[0040]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use provide anhydrous hydrosulfide salts in the process of Li in order to suppress hydrate salt formation during the reaction that worsen battery performance and simultaneously allow for productive reaction of the hydrosulfide and halide salts to provide the desired sulfide product, as taught by Senga.
Claim 65 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024), with evidentiary support for claim 65 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173)..
Regarding claim 65, the term “water-reactive alkali metal sulfide” in the preamble and step (b) and (c) is interpreted as referring to lithium sulfide. The term “water-reactive alkali metal sulfide” is not given a special definition in the instant specification and the term is not interpreted to require additional structure outside of referring to lithium sulfide of a high purity, as interpreted from the instant invention, including par. [0004]-[0006] of the instant specification. See MPEP 2111.02.
Li teaches a method of producing high-purity lithium sulfide (Abstract), meeting the limitation of “water-reactive alkali metal sulfide”.
Li teaches a method of preparing high-purity lithium sulfide comprising reacting lithium chloride (i.e. a first alkali metal salt) with sodium or potassium sulfohydrate (i.e. a first alkali metal hydrosulfide) in N-methyl pyrrolidone to produce a precipitate (i.e. second alkali metal salt precipitate) that is filtered off to provide a solution of lithium sulfide in N-methyl pyrrolidone that has its solvent removed prior to provide the high-purity lithium sulfide (i.e. a second sulfide) (Abstract; Claims 1, 4, 5; Pg. 2, par. 3-13; Pg. 2-3, Embodiment 1). N-methyl pyrrolidone is a polar solvent, as evidenced by Basma who teaches N-methyl pyrrolidone is a strongly polar solvent (Pg. 8963, left col.).
The claim further requires “wherein the first alkali metal salt comprises lithium and an alkali or alkali earth metal impurity selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, silicon chloride, iron chloride, nickel chloride, copper chloride, and any combination thereof.” Li teaches the first alkali metal salt is lithium chloride (i.e. comprises lithium), however Li is silent regarding impurities in the lithium salt.
Chiga teaches a method of preparing lithium sulfide that comprises reacting sodium hydrosulfide and lithium chloride in an organic solvent, where the lithium chloride used in the reaction is not particular limited and by-product lithium chloride can be used (Pg. 2, [0012]). Chiga teaches the reaction mixture include sodium hydroxide and sodium hydrosulfide and that the lithium chloride containing these sodium compounds can be reused to prepare lithium sulfide ([0014]; [0023]).
Chiga teaching a skilled artisan that the lithium chloride used is not particularly limited and can be by-product lithium chloride would necessarily teach a skilled artisan that lithium chloride sources such as technical/industrial grade lithium chloride could be used (i.e. the source is not particularly limited). A skilled artisan would further understand that these industrial or technical grade lithium chloride sources would contain metal impurities including sodium, magnesium, potassium, calcium, copper, iron, and nickel, as evidenced by Linneen (Abstract; Pg. 169, Table 1). Accordingly, a skilled artisan viewing the disclosure of Chiga would not be dissuaded from using lithium chloride sources containing impurities and such lithium chloride sources would contain one of the impurity metals required by the claim.
Advantageously, using lithium chloride that possesses byproducts, including sodium hydrosulfide, allows for a more efficient process and makes it possible to perform continuous production of the lithium sulfide by reusing by-produced lithium chloride starting materials directly ([0012]; [0023]; [0028]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use byproduct containing lithium chloride, where the byproducts include sodium salts such as sodium hydroxide and sodium hydrosulfide in the process of Li in order to make the process more efficient by reusing lithium chloride byproduct material and in order to achieve a continuous production process, as taught by Chiga.
The claim further requires “a first sulfide” is reacted with the first alkali metal salt and first alkali metal hydrosulfide, to which Li and Chiga are silent.
Yang teaches 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 (Na2S) (Claim 2; Abstract).
Advantageously, the method of Yang employing sodium sulfide (Na2S) as a sulfur source has a high purity of lithium sulfide produced and does not involve high temperature and high pressure (Pg. 4, par. 3-4).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use sodium sulfide as the first sulfide in the process of Li 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.
Claims 66 and 68-72 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024), with evidentiary support for claim 66 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Regarding claim 66, Li teaches a method of preparing high-purity lithium sulfide comprising reacting lithium chloride (i.e. a first alkali metal salt) with sodium or potassium sulfohydrate (i.e. a first alkali metal hydrosulfide) in N-methyl pyrrolidone prior to removing the solvent to provide the high-purity lithium sulfide (i.e. a second sulfide) (Abstract; Claims 1, 4, 5; Pg. 2, par. 3-13; Pg. 2-3, Embodiment 1). N-methyl pyrrolidone is a polar solvent, as evidenced by Basma who teaches N-methyl pyrrolidone is a strongly polar solvent (Pg. 8963, left col.).
The claim further requires “wherein the first alkali metal salt comprises lithium and an alkali or alkali earth metal impurity selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, silicon chloride, iron chloride, nickel chloride, copper chloride, and any combination thereof.” Li teaches the first alkali metal salt is lithium chloride (i.e. comprises lithium), however Li is silent regarding impurities in the lithium salt.
Chiga teaches a method of preparing lithium sulfide that comprises reacting sodium hydrosulfide and lithium chloride in an organic solvent, where the lithium chloride used in the reaction is not particular limited and by-product lithium chloride can be used (Pg. 2, [0012]). Chiga teaches the reaction mixture include sodium hydroxide and sodium hydrosulfide and that the lithium chloride containing these sodium compounds can be reused to prepare lithium sulfide ([0014]; [0023]).
Chiga teaching a skilled artisan that the lithium chloride used is not particularly limited and can be by-product lithium chloride would necessarily teach a skilled artisan that lithium chloride sources such as technical/industrial grade lithium chloride could be used (i.e. the source is not particularly limited). A skilled artisan would further understand that these industrial or technical grade lithium chloride sources would contain metal impurities including sodium, magnesium, potassium, calcium, copper, iron, and nickel, as evidenced by Linneen (Abstract; Pg. 169, Table 1). Accordingly, a skilled artisan viewing the disclosure of Chiga would not be dissuaded from using lithium chloride sources containing impurities and such lithium chloride sources would contain one of the impurity metals required by the claim.
Advantageously, using lithium chloride that possesses byproducts, including sodium hydrosulfide, allows for a more efficient process and makes it possible to perform continuous production of the lithium sulfide by reusing by-produced lithium chloride starting materials directly ([0012]; [0023]; [0028]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use byproduct containing lithium chloride, where the byproducts include sodium salts such as sodium hydroxide and sodium hydrosulfide in the process of Li in order to make the process more efficient by reusing lithium chloride byproduct material and in order to achieve a continuous production process, as taught by Chiga.
Regarding claims 68-72, Li teaches the high-purity lithium sulfide product has a purity of greater than 99%, with less than 0.1% lithium sulfite impurities and less than 0.5% lithium sulphate impurities (Pg. 2, par. 14). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. MPEP 2144.05 (I). In the instant case, the range taught by Li (greater than 99% pure lithium sulfide) overlaps with the claimed ranges ((Claim 68) at least 90% free of alkali metal or alkali earth metal impurities; (Claim 69 at least 95% free of alkali metal or alkali earth metal impurities; (Claim 70; at least 98% free of alkali metal or alkali earth metal impurities; (Claim 71) at least 99% free of alkali metal or alkali earth metal impurities; (Claim 72) at least 99.5% free of alkali metal or alkali earth metal impurities). Therefore, the range in Li renders obvious the claimed ranges.
Claim 73 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024), with evidentiary support for claim 73 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Regarding claim 73, Li teaches a method of preparing high-purity lithium sulfide comprising reacting lithium chloride (i.e. a first alkali metal salt) with sodium or potassium sulfohydrate (i.e. a first alkali metal hydrosulfide) in N-methyl pyrrolidone to produce a precipitate (i.e. second alkali metal salt precipitate) that is filtered off to provide a solution of lithium sulfide in N-methyl pyrrolidone that has its solvent removed prior to provide the high-purity lithium sulfide (i.e. a second sulfide) (Abstract; Claims 1, 4, 5; Pg. 2, par. 3-13; Pg. 2-3, Embodiment 1). N-methyl pyrrolidone is a polar solvent, as evidenced by Basma who teaches N-methyl pyrrolidone is a strongly polar solvent (Pg. 8963, left col.). While not indefinite, use of the word “optionally” in step (b) does not constitute necessary aspects required by the claim and are not considered as required in the above rejection over Li. In particular, the phrase “removing one or more alkaline earth metal sulfide from the mixture” is not considered a required aspect of the claim.
The claim further requires “wherein the first alkali metal salt comprises lithium and an alkali or alkali earth metal impurity selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, silicon chloride, iron chloride, nickel chloride, copper chloride, and any combination thereof.” Li teaches the first alkali metal salt is lithium chloride (i.e. comprises lithium), however Li is silent regarding impurities in the lithium salt.
Chiga teaches a method of preparing lithium sulfide that comprises reacting sodium hydrosulfide and lithium chloride in an organic solvent, where the lithium chloride used in the reaction is not particular limited and by-product lithium chloride can be used (Pg. 2, [0012]). Chiga teaches the reaction mixture include sodium hydroxide and sodium hydrosulfide and that the lithium chloride containing these sodium compounds can be reused to prepare lithium sulfide ([0014]; [0023]).
Chiga teaching a skilled artisan that the lithium chloride used is not particularly limited and can be by-product lithium chloride would necessarily teach a skilled artisan that lithium chloride sources such as technical/industrial grade lithium chloride could be used (i.e. the source is not particularly limited). A skilled artisan would further understand that these industrial or technical grade lithium chloride sources would contain metal impurities including sodium, magnesium, potassium, calcium, copper, iron, and nickel, as evidenced by Linneen (Abstract; Pg. 169, Table 1). Accordingly, a skilled artisan viewing the disclosure of Chiga would not be dissuaded from using lithium chloride sources containing impurities and such lithium chloride sources would contain one of the impurity metals required by the claim.
Advantageously, using lithium chloride that possesses byproducts, including sodium hydrosulfide, allows for a more efficient process and makes it possible to perform continuous production of the lithium sulfide by reusing by-produced lithium chloride starting materials directly ([0012]; [0023]; [0028]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use byproduct containing lithium chloride, where the byproducts include sodium salts such as sodium hydroxide and sodium hydrosulfide in the process of Li in order to make the process more efficient by reusing lithium chloride byproduct material and in order to achieve a continuous production process, as taught by Chiga.
Claim 74 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN103552990A English; cited in IDS dated 11/07/2024) in view of Wolden et al. (US20210261411A1; cited in IDS dated 07/05/2023) and Chiga et al. (JP3872846B2 English; cited in IDS dated 10/01/2024), with evidentiary support for claim 74 provided by Basma et al. (J. Phys. Chem. B 2018, 122, 8963−8971) and Linneen et al. (Sep. and Pur. Tech. 2019, 214, 168-173).
Regarding claim 74, Li teaches a method of preparing high-purity lithium sulfide comprising reacting lithium chloride (i.e. a first alkali metal salt) with sodium or potassium sulfohydrate (i.e. a first alkali metal hydrosulfide) in N-methyl pyrrolidone to produce a precipitate (i.e. second alkali metal salt precipitate) that is filtered off to provide a solution of lithium sulfide in N-methyl pyrrolidone that has its solvent removed prior to provide the high-purity lithium sulfide (i.e. a second sulfide) (Abstract; Claims 1, 4, 5; Pg. 2, par. 3-13; Pg. 2-3, Embodiment 1). N-methyl pyrrolidone is a polar solvent, as evidenced by Basma who teaches N-methyl pyrrolidone is a strongly polar solvent (Pg. 8963, left col.). While not indefinite, use of the word “optionally” in step (a) does not constitute necessary aspects required by the claim and are not considered as required in the above rejection over Li. In particular, the phrase “a first sulfide” is not considered a required aspect of the claim.
The claim further requires a “third sulfide” is produced in step (a), to which Li only describes lithium sulfide is obtained as a product.
Wolden teaches a method of making anhydrous metal sulfide nanocrystals that comprises mixing a first sulfide salt (Abstract; [0013]), comprising Na2S, K2S, Rb2S, Cs2S, Fr2S, (NH4)2S, P2S5, NiS, and combinations thereof ([0017]), with a first lithium salt selected from the group consisting of lithium carbonate (Li2CO3), lithium sulfate (Li2SO4), lithium sulfite (Li2SO3), lithium amide (LiNH2), lithium nitride (LiN3), lithium nitrate (LiNO3), lithium phosphate (Li3PO4), and combinations thereof ([0018]), to provide Li2S (i.e. a second sulfide) and/or other metal or metalloid sulfides (MSn) (i.e. a third sulfide), where MSn is selected from the group consisting Cr2S3 , MnS, ReS2 , FeS2 , RuS2 , OsS2 , CoS2 , RhS2 , IrS3 , NiS2 , PdS, PtS, HfS2 , NbS2 , TaS2 , GeS2 , SiS2 , TiS2 , SnS2 , MoS2 , ZrS2 , CdS, ZnS, VS2 , WS2 , Al2S3 , CaS, and MgS ([0019]-[0023]). Advantageously, the method provides Li2S that is easily separated and recovered from the reaction mixture, including the other metal sulfides formed when allowing for sufficient time to form M2X product salts ([0010]-[0013]; [0020]-[0021]; [0038]). Additionally, the process of Wolden allows low cost lithium salts to be used as raw materials while still providing lithium sulfide with the proper morphology and crystal size to be suitable for use in battery applications ([0010]-[0012]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to produce additional metal or metalloid sulfides in the process of Li as the other metal sulfide formed can be easily separated from the Li2S product while allowing the Li2S particles to maintain morphology and particle size distributions that are suitable for battery use applications, as taught by Wolden.
The claim further requires ““wherein the first alkali metal salt comprises lithium and an alkali or alkali earth metal impurity selected from the group consisting of sodium salts, magnesium salts, potassium salts, calcium salts, or a combination thereof.” Li teaches the first alkali metal salt is lithium chloride (i.e. comprises lithium), however Li and Wolden are silent regarding impurities in the lithium salt.
Chiga teaches a method of preparing lithium sulfide that comprises reacting sodium hydrosulfide and lithium chloride in an organic solvent, where the lithium chloride used in the reaction is not particular limited and by-product lithium chloride can be used (Pg. 2, [0012]). Chiga teaches the reaction mixture include sodium hydroxide and sodium hydrosulfide and that the lithium chloride containing these sodium compounds can be reused to prepare lithium sulfide ([0014]; [0023]).
Chiga teaching a skilled artisan that the lithium chloride used is not particularly limited and can be by-product lithium chloride would necessarily teach a skilled artisan that lithium chloride sources such as technical/industrial grade lithium chloride could be used (i.e. the source is not particularly limited). A skilled artisan would further understand that these industrial or technical grade lithium chloride sources would contain metal impurities including sodium, magnesium, potassium, calcium, copper, iron, and nickel, as evidenced by Linneen (Abstract; Pg. 169, Table 1). Accordingly, a skilled artisan viewing the disclosure of Chiga would not be dissuaded from using lithium chloride sources containing impurities and such lithium chloride sources would contain one of the impurity metals required by the claim.
Advantageously, using lithium chloride that possesses byproducts, including sodium hydrosulfide, allows for a more efficient process and makes it possible to perform continuous production of the lithium sulfide by reusing by-produced lithium chloride starting materials directly ([0012]; [0023]; [0028]).
Thus, prior to the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to use byproduct containing lithium chloride, where the byproducts include sodium salts such as sodium hydroxide and sodium hydrosulfide in the process of Li in order to make the process more efficient by reusing lithium chloride byproduct material and in order to achieve a continuous production process, as taught by Chiga.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Barker et al. (GB2464455A); Barker teaches a method of preparing sulfides that contain lithium and transition metals, where the synthesis includes an alkali salt including a mineralizing agent such as sodium chloride (Abstract; Pg. 7, lines 12-26).
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/JORDAN W TAYLOR/Examiner, Art Unit 1738
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