DETAILED ACTION
This Office Action is responsive to the February 17th, 2026 arguments and remarks (“Remarks”).
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 .
Response to Amendments
In response to the amendments received in the Remarks on February 17th, 2026:
Claims 1-4 and 6-12 are pending in the current application. Claim 1 has been amended. Claim 5 has been cancelled.
Response to Arguments
Applicant’s arguments filed with the Remarks on February 17th, 2026 with respect to Claims 1-4 and 6-12 are acknowledged, however, Applicant’s arguments are not persuasive.
Applicant’s argument that the prior art fails to disclose an electrolyte comprising a first solvent comprising a benzene-based compound and a second solvent comprising 1,3-dioxolane is not persuasive.
As stated in the Non-Final Rejection mailed on November 17th, 2025, Hwang discloses an electrolyte prepared by mixing at least two solvents ([0014]) wherein the first solvent is selected from a group including benzene ([0024]) and the second solvent is selected from a group including 1,3-dioxolane ([0025]). While there are no specific examples in Hwang that disclose a binary solvent system solely comprising benzene and 1,3-dioxolane, the claim limitations are currently written do not exclude other organic solvents from being present in the electrolyte (the claim limitation solely requires the presence of the first solvent and the second solvent). Further, it would have been obvious to a person having ordinary skill in the art to try each and every possible combination as disclosed by Hwang, including a mixture of benzene as the first solvent and 1,3-dioxolane as the second solvent.
While Hwang does disclose volume ratios based on a solvent system comprising more than 2 solvents, the volume ratio between the first solvent and the second solvent are still relevant regardless of the other solvents present. A person having ordinary skill in the art would recognize that the first solvent and the second solvent of Hwang would still have a 1:1 ratio regardless of whether the combination of the first and second solvents account for 100% of the total electrolyte volume or 1% of the total electrolyte volume.
Therefore, this argument is not persuasive and the rejection of record is maintained.
Applicant’s argument that unexpected results occur when an electrolyte comprises a benzene-based compound and 1,3-dioxolane in a volume ratio of 1:0.5 to 1:4 is not persuasive.
Applicant’s argument that an electrolyte comprising a first solvent comprising a benzene-based compound and a second solvent of 1,3-dioxolane in a volume ratio 1:0.5 to 1:4 exhibits improved ionic conductivity is not persuasive. Example 5 has a volume ratio of 1:0.33 (which falls outside of the claimed range) and Comparative Example 1 does not comprise a benzene-based compound (i.e. volume ratio of 0:1 which falls outside of the claimed range) and both of these examples have a higher ionic conductivity (Example 5: 3.67 mS/cm and Comparative Example 1 11.4 mS/cm) than Example 3 (3.07 mS/cm) which has a volume ratio of 1:1 (which falls within the claimed range).
Applicant’s argument that an electrolyte comprising a first solvent comprising a benzene-based compound and a second solvent of 1,3-dioxolane in a volume ratio 1:0.5 to 1:4 exhibits improved capacity retention rate at 100 cycles is not persuasive.
While Comparative Example 1 (volume ratio 0:1 which falls outside of the claimed range) has a lower capacity retention rate than Examples 1-4 and 6 (which have volume ratios that fall within the claimed range), Table 2 merely shows that an electrolyte comprising a first solvent comprising a benzene-based compound exhibits improved capacity retention rate. There is no comparative example that comprises a first solvent comprising a benzene-based compound and a second solvent of 1,3-dioxolane while having a volume ratio that falls outside of the claimed range. And, therefore, there is no evidence that the instant application has unexpected results over the electrolyte of Hwang that comprises benzene and 1,3-dioxolane in a volume ratio of 1:0.67 to 1:10 (which overlaps the claimed range).
Therefore, this argument is not persuasive and the rejection of record is maintained.
Any modifications to the rejection are as necessitated by the amendment.
Prior Art
Previously cited Hwang US PG Publication 2002/0045101 (“Hwang”)
Previously cited Scrosati US PG Publication 2014/0127575 (“Scrosati”)
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
Claims 1-3 and 6-12 are rejected under 35 U.S.C. 103 as being unpatentable over Hwang US PG Publication 2002/0045101.
Regarding Claim 1, Hwang discloses an electrolyte for a lithium-sulfur battery (Abstract, entire disclosure dependent upon) comprising:
an electrolyte salt ([0017]) comprising lithium (such as lithium perchlorate LiClO4, , lithium tetrafluoroborate LiBF4, lithium hexafluorophosphate LiPF6, lithium trifluoro sulfonate LiCF3SO3, lithium hexafluoroarsenate LiAsF6, or lithium trifluoromethane sulfonyl imide LiN(CF3SO2)2) (which meets the claim limitation of a lithium salt) ([0035]); and
a solvent ([0014], [0017]),
wherein the solvent includes a first solvent comprising a benzene based compound (such as benzene) and a second solvent comprising 1,3-dioxolane ([0014], [0017], [0024]-[0025]),
and Hwang discloses the use of between 5% and 30% by volume of the first solvent ([0030]) and 20% and 50% by volume of the second solvent ([0031]). Therefore, the skilled artisan would recognize that Hwang discloses a volume ratio of the first solvent and the second solvent is 1:0.67 to 1:10 (which overlaps the claimed range of 1:0.5 to 1:4)1.
The skilled artisan would recognize that the solvent of Hwang is a non-aqueous organic solvent, as evidenced by Applicant’s own PG Publication paragraphs [0018]-[0019].
1 In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976).
Regarding Claim 2, Hwang teaches the instantly claimed electrolyte according to Claim 1, and Hwang discloses wherein the benzene-based compound comprises benzene (which meets the claim limitation of at least one selected from the group consisting of benzene, 1,4-difluorobenzene, 1,3,5-trifluorobenzene, 1,2,4,5-tetrafluorobenzene, and hexafluorobenzene) ([0024]).
Regarding Claim 3, Hwang teaches the instantly claimed electrolyte according to Claim 2, and Hwang discloses wherein the benzene-based compound comprises benzene ([0024]).
Regarding Claim 6, Hwang teaches the instantly claimed electrolyte according to Claim 1, and Hwang discloses wherein the lithium salt comprises at least one selected from the group consisting of lithium perchlorate LiClO4, lithium tetrafluoroborate LiBF4, lithium hexafluorophosphate LiPF6, lithium trifluoro sulfonate LiCF3SO3, lithium hexafluoroarsenate LiAsF6, and lithium trifluoromethane sulfonyl imide LiN(CF3SO2)2 (which meets the claim limitation of LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3CO2, LiC4BO8, LiAsF6, LiSbF6, LiAlCl4, LiSO3CH3, LiSO3CF3, LiSCN, LiC(CF3SO2)3, LiN(CF3SO2)2, LiN(C2F5SO2)2, LiN(SO2F)2, lithium chloroborate, lithium lower aliphatic carboxylic acid having 4 or less carbon atoms, lithium tetraphenyl borate, and lithium imide) ([0035]).
Regarding Claims 7-8, Hwang teaches the instantly claimed electrolyte according to Claim 1, and Hwang discloses wherein the concentration of the electrolyte salt is between 0.5M and 2.0M ([0035]), specifically 1M of LiSO3CF3 ([0044]) – or 1 mole of LiSO3CF3 per 1 liter of solvent. The skilled artisan would recognize that the greatest molar ratio between the second solvent and the lithium salt occurs when the solvent comprises 100% 1,3-dioxolane. Given a density of 1.06 g/mL of 1,3-dioxolane, this solution comprises 1,060 g of 1,3-dioxolane. And given a molar mass of 74.08 g/mol, there are 14.31 mol of 1,3-dioxolane present.
Therefore, Hwang discloses wherein a molar ratio of the second solvent and the lithium solvent is less than 14.31:1 (which encompasses the claimed ranges of 4:1 or more and 4.5:1 to 8:1)1.
Regarding Claim 9, Hwang teaches the instantly claimed electrolyte according to Claim 1, and Hwang discloses a lithium-sulfur battery (Abstract), comprising:
a positive electrode comprising a positive electrode active material ([0040]-[0041]);
a negative electrode comprising a negative electrode active material ([0039]-[0040]);
and the electrolyte according to Claim 1 (Abstract).
Regarding Claim 10, Hwang teaches the instantly lithium sulfur battery according to Claim 9, and Hwang discloses wherein the positive electrode active material comprises at least one selected from the group consisting of sulfur element (elemental sulfur) and sulfur compounds (such as Li2Sn (n≥1), an organic sulfur compound, and a carbon-sulfur polymer of (C2Sx)n where x=2.5 to 50 and n≥2) ([0041]).
Regarding Claim 11, Hwang teaches the instantly claimed lithium sulfur battery according to Claim 9, and Hwang discloses wherein the positive electrode active material comprises at least one selected from the group consisting of Li2Sn (n≥1), an organic sulfur compound, and a carbon-sulfur polymer of (C2Sx)n where x=2.5 to 50 and n≥2 (which meets the claim limitation of inorganic sulfur, Li2Sn (n≥1), a disulfide compound, an organic sulfur compound, and a carbon-sulfur polymer of (C2Sn)x (x=2.5 to 50 and n≥2) ([0041]).
Regarding Claim 12, Hwang teaches the instantly claimed lithium sulfur battery according to Claim 9, and Hwang discloses wherein the negative electrode active material comprises at least one selected from the group consisting of lithium metal and lithium containing alloy ([0039]).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Hwang US PG Publication 2002/0045101, as applied to Claim 2, further in view of Scrosati US PG Publication 2014/0127575.
Regarding Claim 4, Hwang teaches the instantly claimed electrolyte according to Claim 2. Hwang fails to disclose wherein the benzene-based compound comprises 1,4-difluorobenzene.2
However, Scrosati discloses an electrolyte for a lithium-sulfur battery ([0010], entire disclosure dependent upon) comprising: a lithium salt ([0044]), and a non-aqueous organic solvent ([0044], [0058]), and wherein the non-aqueous organic solvent includes a first solvent comprising a benzene-based compound ([0044], [0054]-[0057]) and a second solvent comprising 1,3-dioxolane ([0044]-[0048], [0051]).
Scrosati teaches the use of a benzene-based compound including 1,4-difluorobenzene as an electrolyte solvent to effectively transfer ions during an electrochemical reaction of the battery ([0050]-[0057]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the electrolyte of Hwang such that the benzene-based compound comprises 1,4-dilfuorobenzene in order to effectively transfer ions during an electrochemical reaction of the battery, as taught by Scrosati.
2 The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395 – 97 (2007) (see MPEP § 2143, B.).
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 extension fee 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 date of this final action.
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/O.M.R./Examiner, Art Unit 1729
/ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729