DETAILED ACTION
Notice to Applicant
In the amendment dated 10/7/2025, the following has occurred: Claims 1 has been amended.
Claims 1-10 are pending and are examined herein. This is a Final Rejection.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-10 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 1 requires a solid electrolyte represented by formula (1):
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Claim 1 has been amended to require “a ratio of Sb and Ta in entire M2 is 40 mol % or more.” It is not clear what this limitation means or what its metes and bounds are. M2 has a subscript, y, that can vary between 0.010 and 1.50. Claim 1 has also been amended such that M2 is “at least one element selected from group consisting of Sb and Ta.”
The ambiguity is compounded by the fact that M1 is selected from Nb, Sb, Ta, and W, and M2 is not whatever M1 is, but the claimed ratio only refers to M2, leaving it somewhat open how to define M1 and M2. Does “a ratio of Sb and Ta” imply that M2 necessarily has both Sb and Ta and M1 therefore is only Nb and W? Why does the claim not say that? Does it mean something like “a ratio of Sb and/or Ta in M2”? but then what is the denominator or comparator in the ratio?
It is not clear what the “ratio of Sb and Ta” is. Ratio of the sum of Sb and Ta? with respect to what? Ratio of Sb to Ta? It is not clear how “in entire M2” is to be interpreted, since M2 can only be Sb and Ta. It is therefore unclear what “40 mol % or more” actually quantifies. The claim has been interpreted to require that Sb and Ta are 40 mol% or more of the M2 content in formula 1. The dependent claims are rejected for depending on claim 1.
Double Patenting
Claims 1-6 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-5 of copending Application No. 17/652,645. Although the claims at issue are not identical, they are not patentably distinct from each other because the ‘645 application is directed towards:
a stacked solid-state battery comprising a plurality of cells with facing electrode layers, with an overlapping LLZO composition, wherein Sb and Ta subscripts independently vary (claim 1)
a NASICON-type crystal second electrolyte that can be a phosphate compound (claims 3-4)
wherein the first and second electrolyte ratio varies from .1 to 9.0 (claim 5)
This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
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.
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.
Claims 1-10 are rejected under 35 U.S.C. 103 as being unpatentable over Hayashi (US 2013/0149593 to Hayashi et al.) in view of Yang (US 2021/0119245 to Yang et al.), in further view of Xiang (Xiang et al. “Dual regulation of Li+ migration of Li6.4La3Zr1.4M0.6O12 (M=Sb, Ta, Nb) by bottleneck size and bond length of M–O.” J. Am. Ceram. Soc. 2020; 103:2483-2490) and/or Hermann (US 2022/0158179 to Hermann et al.).
Regarding Claim 1, Hayashi teaches:
a stacked solid-state battery comprising a plurality of cells (Fig. 2, para 0061)
each of the cells including a cathode, solid electrolyte, and anode, the cathode/anode layers of adjacent cells are disposed to face each other (Fig. 2)
wherein the solid electrolyte comprises a NASICON structure, such as an LATP material (paras 0052-0053)
wherein the positive electrode layer comprises the solid electrolyte (¶ 0068) and wherein in at least one example the amount of the solid electrolyte in the positive electrode layers comprises 35 wt% (¶ 0085)
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Hayashi does not explicitly teach:
a doped LLZO material with two elements selected from Nb, Sb, Ta, and W, with one of those elements doped at a greater concentration than the other
Yang, however, from the same field of invention, regarding a solid electrolyte cell, teaches a solid electrolyte with better interfacial resistance (abstract), comprising two different inorganic solid electrolyte particle types selected from LATP and LLZO (para 0046). It would have been obvious to modify Hayashi to use a combination NASICON-LLZO material, like that taught in Yang, with the motivation to improve the total ion conductivity in a solid state cell.
Xiang also from the same field of invention, regarding LLZO materials, teaches that substituting Sb, Ta, and/or Nb for Zr improves ionic conductivity (abstract), and teaches substituting Zr with two or more of those elements, such as Ta0.3Sb0.3 and Nb0.3Ta0.3 (Table 1). Xiang is interpreted here as essentially teaching a substitutional range for the co-dopants ranging from 0.0 to 0.6, having only one example in the middle at 0.3/0.3. It was known in the art that the dopants were independently variable, as, for example, taught in Hermann, directed towards an LLZO doped solid electrolyte material. Hermann teaches garnet-like electrolyte of the form LiALaBM’CM’’DZrEOF wherein M’ and M’’ can be independently selected from W, Nb, Sb, and Ta (which substitute for Zr) and wherein C and D can independently vary between 0 and 2 (para 0046). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists (see MPEP 2144.05 [R-5]). It would have been obvious to one of ordinary skill in the art at the time the invention was made to select any portion of the disclosed ranges of Xiang and/or Hermann for the Zr dopants, including subscripts where the Ta/Sb/Nb are different, since Xiang and/or Hermann disclose substantially similar effects across the range, absent evidence that asymmetric co-doping of Zr with two of Nb, Sb, Ta, and W produces unexpected results.
Regarding Claim 2, Hayashi teaches:
wherein the solid electrolyte is contained in the solid electrolyte layer (Fig. 2, etc.)
Regarding Claims 3-4, Hayashi teaches:
use of LATP (paras 0052-0053)
See also Yang at paragraph 0046.
Regarding Claim 5, Hayashi does not teach:
a ratio for the two solid electrolytes
While Yang does not explicitly teach the relative mass% of the two solid electrolytes, it would have been obvious to one of ordinary skill in the art based on the whole disclosure of Yang that the two solid electrolytes each comprised a substantial fraction of the total. It would therefore have been obvious to provide such a substantial fraction, including fractions where they are more or less equal, absent any specific evidence to the contrary, since Yang appears to refer to them as equal components. For further evidence of ordinary skill in the art regarding the combination of LLZO and LATP see CN 110165236 to Guo et al., with English translation provided by the Office.
Regarding Claim 6, Hayashi teaches:
an internal current collecting layer between the adjacent cells (Fig. 2)
Regarding Claim 7, Hayashi teaches:
wherein the solid electrolyte as a whole comprises e.g. 35 wt% in the cathode (¶ 0080), and wherein the solid electrolyte can comprise two different solid electrolytes with a different composition may be used (¶ 0052)
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists (see MPEP 2144.05 [R-5]). Absent evidence of unexpected results for a specific ratio and composition of the first to second electrolyte, it would have been obvious to one of ordinary skill in the art to provide the electrolytes in conventional blends according to desired properties, such as a ratio of 1:1.
Regarding Claims 8-10, Hayashi teaches:
wherein the solid electrolyte is contained in the solid electrolyte layer (Fig. 2, etc.)
wherein the negative electrode comprises the first solid electrolyte (¶ 0069), at 35 wt % (¶ 0080)
wherein the solid electrolyte can comprise two different solid electrolytes with a different composition may be used (¶ 0052)
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists (see MPEP 2144.05 [R-5]). Absent evidence of unexpected results for a specific ratio and composition of the first to second electrolyte, it would have been obvious to one of ordinary skill in the art to provide the electrolytes in conventional blends according to desired properties, such as a ratio of 1:1.
Response to Arguments
Applicant’s arguments submitted 10/7/2025 have been considered but are not persuasive. Applicant conclusorily asserts that Xiang, relied upon for teaching Ta/Sb substitution of LLZO “does not describe M1 and M2 such that a ratio of Sb and Ta in entire M2 is 40 mol % or more.” It is not clear what Applicant is really saying here. Xiang is directed towards LLZO materials, with Zr and dopants of Sb/Ta/Nb (see p. 2485, Results and Discussion). For example, in some embodiments the dopant is all Ta/Sb, suggesting that M1 is Sb/Ta and M2 is Ta/Sb, whichever M1 is not. Insofar as “Sb and Ta in entire M2 is 40 mol % or more” means something else, it is not clear what that might be.
The Office points out that the logic of the rejection is such that Xiang and Hermann taken together appear to teach individually doping Ta/Sb/Nb/W in ranges between 0-2. It would have been obvious to dope those elements in LLZO in that range absent evidence of unexpected results.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Michael Dignan, whose telephone number is (571) 272-6425. The examiner can normally be reached from Monday to Friday between 10 AM and 6:30 PM. If any attempt to reach the examiner by telephone is unsuccessful, the examiner’s supervisor, Tiffany Legette, can be reached at (571)270-7078. Another resource that is available to applicants is the Patent Application Information Retrieval (PAIR). Information regarding the status of an application can be obtained from the (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAX. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, please feel free to contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). Applicants are invited to contact the Office to schedule an in-person interview to discuss and resolve the issues set forth in this Office Action. Although an interview is not required, the Office believes that an interview can be of use to resolve any issues related to a patent application in an efficient and prompt manner.
/MICHAEL L DIGNAN/Examiner, Art Unit 1723