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 .
Status of Claims
Claims 1, 5, 7, 10 are amended.
Claim 6 is cancelled.
Claims 12-14 are new.
Response to Amendment
Applicant’s amendments filed on 12/17/2025 have been entered.
Claim objections have been withdrawn in view of the amendments.
Claim rejections under 35 USC 103 from previous Office Action have been withdrawn in view of the arguments and amendment.
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 (i.e., changing from AIA to pre-AIA ) 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.
Claim(s) 1, 4, 5, 7-10, 13 are rejected under 35 U.S.C. 103 as being unpatentable over Naruhashi et al (JP 2016216312A; machine translation) as evidenced by Cammack et al (“Reaction intermediates”, Cammack, R. Attwood, T. K. Campbell, P. N. Parish, J. H. Smith, A. D. Stirling, J. L. Vella, F.. (2006). Oxford Dictionary of Biochemistry and Molecular Biology (2nd Edition). Oxford University Press. Retrieved from https://app.knovel.com/hotlink/toc/id:kpODBMBE01/oxford-dictionary-biochemistry/oxford-dictionary-biochemistry)..
Regarding Claim 1 and Claim 9,
Naruhashi teaches a method for producing lithium sulfide, comprising a step of calcining a raw material mixture containing lithium sulfate (a raw material containing lithium and sulfur elements) and a reducing agent (Paragraph 0009). The reducing agent is selected from carbon materials such as organic sugars, polyhydric alcohols, and carbon black, carbon fiber etc (Paragraphs 0018-0021). Naruhashi teaches the use of inert gas in the firing step such as nitrogen, argon, helium or hydrogen (Paragraph 0029; reducing gas). The calcining step has a temperature of 750 to 1000 C. This range contains the claimed range of 830 C to 930 C (which is claimed in the second step). Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to choose temperature range from Naruhashi that is within the claimed range in order to suppress the formation of a different phase and efficiently obtain lithium sulfide (Paragraph 0029).
The claimed invention states a first step of reducing a raw material containing lithium (Li) and sulfur (S) elements, using a reductant containing a carbon (C) element, thereby obtaining an intermediate; and a second step of reducing the intermediate using a reducing gas, thereby obtaining lithium sulfide, wherein the second step is performed at a temperature in a range of 830 C to 930 C. Per Cammack, the definition of “reaction intermediates” is a transient chemical species formed directly or indirectly from the reactants of a chemical reaction, and that further reacts to give the reaction products. Furthermore, the instant specification also states that the first step and second step are performed simultaneously when a reducing atmosphere is used as the atmosphere for the reduction reaction (Paragraph 0020).
Naruhashi has the same reactants (lithium-sulfur compound, and reductant), and it also has the same calcining/heat treatment temperature and atmosphere (inert gas such as nitrogen, argon, helium, hydrogen). Hydrogen is an inert reducing gas atmosphere. Hence, Naruhashi reaction would also produce an intermediate, and result in a two step reaction as claimed in instant invention.
Claim 9 is a product-by-process claim that claims the lithium sulfide product made with method described above using the teachings of Naruhashi.
Regarding Claim 4,
Naruhashi teaches the use of an inert gas atmosphere such as nitrogen, argon, helium, or hydrogen (Paragraph 0029). Nitrogen, argon are non-reducing inert gases akin to the inert gases in instant specification in Paragraph 0020.
Regarding Claim 5,
Naruhashi teaches the use of a temperature in the calcining step from 700 to 1000 C. This range includes the claimed range of 700-850 C. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use the claimed temperature in order to suppress the formation of a different phase and efficiently obtain lithium sulfide (Paragraph 0029).
Regarding Claims 7-8,
Naruhashi teaches a method for producing lithium sulfide, comprising a step of calcining a raw material mixture containing lithium sulfate (a raw material containing lithium and sulfur elements) and a reducing agent (Paragraph 0009). The reducing agent is selected from carbon materials such as organic sugars, polyhydric alcohols, and carbon black, carbon fiber etc (Paragraphs 0018-0021). Naruhashi teaches the use of an inert gas atmosphere such as nitrogen, argon, helium, or hydrogen (Paragraph 0029). The calcining step has a temperature of 750 to 1000 C. This range contains the claimed range of 830 to 870 C, and 840 C to 860 C. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to choose temperature range from Naruhashi that is within the claimed range in order to suppress the formation of a different phase and efficiently obtain lithium sulfide (Paragraph 0029).
Regarding Claim 10, and Claim 13,
Naruhashi teaches a method for producing an inorganic solid electrolyte comprising lithium sulfide obtained by specific method described in Naruhashi, and reacting that with phosphorus sulfide and lithium iodide (Paragraph 0044). The phosphorus sulfide can be phosphorus pentasulfide as seen in formulas shown in Paragraph 0045 i.e. P2S5. Lithium iodide is a lithium halide. The process consists of mechanical milling and mixing the above compounds, and then heating and melting the resulting mixture in an inert gas atmosphere (Paragraph 0047). This is akin to firing the raw material composition.
The method of producing lithium sulfide per Naruhashi is also akin to the claimed invention. Naruhashi teaches a method for producing lithium sulfide, comprising a step of calcining a raw material mixture containing lithium sulfate (a raw material containing lithium and sulfur elements) and a reducing agent (Paragraph 0009). The reducing agent is selected from carbon materials such as organic sugars, polyhydric alcohols, and carbon black, carbon fiber etc (Paragraphs 0018-0021). Naruhashi teaches the use of inert gas in the firing step such as nitrogen, argon, helium or hydrogen (Paragraph 0029). The calcining step has a temperature of 750 to 1000 C. This range contains the claimed range of 830 C to 930 C (which is claimed in the second step). Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to choose temperature range from Naruhashi that is within the claimed range in order to suppress the formation of a different phase and efficiently obtain lithium sulfide (Paragraph 0029).
The claimed invention states a first step of reducing a raw material containing lithium (Li) and sulfur (S) elements, using a reductant containing a carbon (C) element, thereby obtaining an intermediate; and a second step of reducing the intermediate using a reducing gas, thereby obtaining lithium sulfide, wherein the second step is performed at a temperature in a range of 830 C to 930 C. Per Cammack, the definition of “reaction intermediates” is a transient chemical species formed directly or indirectly from the reactants of a chemical reaction, and that further reacts to give the reaction products. Naruhashi has the same reactants (lithium-sulfur compound, and reductant), and it also has the same calcining/heat treatment temperature and atmosphere (inert gas such as nitrogen, argon, helium, hydrogen). Hence, Naruhashi reaction would also produce an intermediate, and result in a two step reaction as claimed in instant invention.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Naruhashi as evidenced by Cammack, and further in view of Kambara et al (US 20140302382 A1).
Naruhashi teaches the solid electrolyte formed using the same raw materials, and process of making, but does not specifically teach that the solid electrolyte contains a crystalline phase with an argyrodite type crystal structure.
However, Kambara teaches a method to make solid electrolyte that has a crystalline phase (Paragraph 0181). Kambara also refers to the crystallized solid electrolyte as a glass ceramic (Paragraph 0181). This type of material is considered to have an argyrodite structure. Also, per MPEP 2112.01 II., products of identical chemical composition can not have mutually exclusive properties. Hence, the solid electrolyte of Kambara has a crystalline phase, and argyrodite structure as claimed.
Claim 2, 3, 12, 14 are rejected under 35 U.S.C. 103 as being unpatentable over Naruhashi as evidenced by Cammack, in view of Kikuchi et al (US 20230135532 A1; effective filing date 03/17/2020).
Regarding Claim 2 and Claim 3,
Naruhashi teaches the two step reaction of claimed invention that occurs in an inert atmosphere of hydrogen which is a reducing gas. Naruhashi has the same reactants (lithium-sulfur compound, and reductant), and it also has the same calcining/heat treatment temperature and atmosphere (inert gas such as nitrogen, argon, helium, hydrogen). Hydrogen is an inert reducing gas atmosphere. Naruhashi teaches the use of X-ray diffraction to measure the peaks related to the products of the lithium sulfide process such that the peaks are measured at the 2θ corresponding to lithium sulfate, lithium sulfide and lithium carbonate. Since, the reactions, and method related to heat treatment and inert atmosphere in Naruhashi is the same as the claimed invention, it is expected that the intensity of the resulting products using XRD is the same as the claimed invention. See MPEP 2112.01, that states when the claimed and prior art products are produced by identical or substantially identical processes, a prima facie case of obviousness has been established.
Furthermore, in Kikuchi Figure 4 (annotated below), X-ray diffraction is used to measure the unreacted residue, and in the product peaks of raw material lithium sulfate (which is the claimed IA) do not appear. The XRD graph also shows that in the region of the peak for lithium carbonate (which is the claimed IC) there is no discernable peak formed. This means that the product has negligible amounts of lithium carbonate. Kikuchi has similarity in lithium sulfide production process as explained in more detail in rejection of Claims 12, 14 below. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention that the XRD peak intensities of resulting products in the combined method of Naruhashi and Kikuchi are in the same ratio as the claimed invention in order to produce lithium sulfide with high ionic conductivity (Paragraph 0013).
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Regarding Claim 12,
Naruhashi teaches the two step reaction of claimed invention that occurs in an inert atmosphere of hydrogen which is a reducing gas. Naruhashi teaches the use of argon and nitrogen as inert gases used in the heating step, but does not specifically teach that the first step is performed in an inert gas atmosphere which is non-reducing.
However, Kikuchi teaches a method for producing lithium sulfide in which a first reaction step takes place between lithium sulfate, and reducing agent such as carbon (Paragraph 0021, 0024). Kikuchi also teaches that an inert gas atmosphere of argon or nitrogen is used in the furnace for this reaction step (Paragraph 0029). These are non-reducing inert gases per the ones used in the instant specification. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to combine the teachings of Naruhashi and Kikuchi to use the non-reducing atmosphere for reacting lithium sulfate and carbon in order to produce lithium sulfide with high ionic conductivity (Paragraph 0013).
Regarding Claim 14,
Naruhashi teaches the method steps of claim 10, and the use of inert gas atmosphere in the calcining step, but does not specifically teach that the first step is performed in a non-reducing inert gas atmosphere.
However, Kikuchi teaches a method for producing lithium sulfide in which a first reaction step takes place between lithium sulfate, and reducing agent such as carbon (Paragraph 0021, 0024). Kikuchi also teaches that an inert gas atmosphere of argon or nitrogen is used in the furnace for this reaction step (Paragraph 0029). These are non-reducing inert gases per the ones used in the instant specification. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to combine the teachings of Naruhashi and Kikuchi to use the non-reducing atmosphere for reacting lithium sulfate and carbon in order to produce lithium sulfide with high ionic conductivity (Paragraph 0013).
References of Interest
Barker et al (US 20110200878 A1)
Response to Arguments
Applicant’s arguments, see Page 8, filed 12/5/2025, with respect to Claim 6 (as seen in previous claim set) have been fully considered and are persuasive. The 35 USC 103 rejection from previous action has been withdrawn. Examiner agrees that the combination of Miyashita and Tamura teach away from the claimed temperature limitation. Thus, upon second review, examiner has issued a new non-final action.
Conclusion
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/SUHANI JITENDRA PATEL/Examiner, Art Unit 1783
/MARIA V EWALD/Supervisory Patent Examiner, Art Unit 1783