DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 3/30/2026 has been entered.
Response to Amendment
This is a non-final office action in response to Applicant's remarks and amendments filed on 3/30/2026. Claims 1 and 5 are currently amended. Claims 2-4 and 7 are cancelled. Claims 1, 5-6 and 8-13 are pending review in this action.
The 35 U.S.C. 103 rejections in the previous Office Action are withdrawn.
New grounds of rejection necessitated by Applicant's amendments are presented below.
Response to Arguments
Applicant's arguments filed 3/30/2026 have been fully considered but they are not persuasive.
Applicant argues that Lee fails to teach or suggest the organic-substituted cyclic anhydrides represented by Chemical formulas 1 and 2, or that represented by Chemical Formula 3. However, the current rejection modifies Lee’s teaching of the cyclic anhydrides with well-known alternatives or species thereof by new references Burkhardt and Kim, where the cyclic anhydrides are known alternatives or species for forming a film on the anode surface in order to improve capacity retention characteristics or cycle characteristics of a lithium battery after high-temperature storage. For further details, please review the rejections below.
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, 5-6 and 8-13 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (KR2020016045A; refer to IDS filed 12/1/2022; machine translation on record) in view of Burkhardt (US20140302401A1) and Kim (US20100183926A1; refer to IDS filed 12/1/2022), and alternatively, further in view of Park (US20180248227A1; refer to IDS filed 12/1/2022).
Regarding Claim 1, Lee discloses an electrolyte solution for a lithium-sulfur secondary battery [pars. 0001-2,0008], comprising:
a lithium salt [pars. 0008,0029];
a non-aqueous solvent [pars. 0012-18,0026-27]; and
a cyclic anhydride compound (characteristic improving agents including carboxylic acid anhydrides such as succinic anhydride, maleic anhydride, etc.) [pars. 0036,0041-42].
Lee fails to explicitly disclose wherein the cyclic anhydride compound is represented by any one of Chemical Formula 1 to Chemical Formula 3.
That is, while Lee discloses unsubstituted configurations of anhydrides represented by Chemical Formulas 1 and 2 (carboxylic acid anhydrides such as succinic anhydride, maleic anhydride, etc.) for improving capacity retention or cycle characteristics after high-temperature storage [par. 0041], Lee fails to disclose organic R-substituted configurations, as claimed. However, Burkhardt, from the same field of endeavor, teaches electrolyte compositions for lithium secondary batteries comprising cyclic carboxylic acid anhydrides as film-forming chemical compounds which form a film on the anode in order to prevent side reactions between the anode and the electrolyte, thus improving cycling performance at high temperature [Burkhardt – Abstract; pars. 0005,0016-23,0056,0059]. In particular, Burkhardt teaches that suitable cyclic carboxylic acid anhydrides may be represented by Formula II, Formula I, or Formula IV, where R9-R12 may include H or C1 to C10 linear or branched alkyls [Burkhardt –par. 0059], which belong to the same functional family of Lee’s characteristic improving agents, and which read on, respectively, Chemical Formula 1, Chemical Formula 2, and Chemical Formula 3, as claimed. Particular examples of these cyclic carboxylic acid anhydrides include succinic anhydride, maleic anhydride, 2,3-dimethylmaleic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, 2,3-diphenylmaleic anhydride, and 3,4,5,6-Tetrahydrophthalic anhydride [Burkhardt – par. 0059]. Similarly, Kim, from the same field of endeavor, discloses an electrolyte compositions for lithium secondary batteries comprising anhydride components a film-forming compounds which form a film on the surface of the anode in order to improve storage characteristics at high temperature and prevent movement of lithium ions at low temperature [Kim – Abstract; pars. 0053,0055-57,0067-68]. Kim particularly teaches that the anhydride component may be represented by Formula (2) or Formula (3), wherein R10-R15 may each independently be hydrogen or C1 to C10 alkyl, including succinic anhydride, dimethyl succinic anhydride, [Kim – 0055-57], which belong to the same functional family of Lee’s characteristic improving agents, and which read on, respectively, Chemical Formula 1 and Chemical Formula 2, as claimed.
Therefore, before the effective filing date of the claimed invention, it would have been obvious for an ordinary skilled artisan to have modified the characteristic improving agents including carboxylic acid anhydrides of Lee to have comprised the alternative anhydrides of Burkhardt and/or Kim according to the claimed Chemical Formulas 1-3 as well-known substitutes for or species of succinic anhydride and maleic anhydrides for the purpose of improving capacity retention or cycle characteristics after high-temperature storage with a predictable expectation of success [MPEP § 2143].
Lee further discloses wherein the non-aqueous solvent comprises a linear ether (e.g, dimethoxymethane) and a cyclic ether (e.g., such as dimethyl isosorbide, or dioxolane) [Lee – pars. 0012-16,0027-28,0058,0066]. Alternatively, Park, from the same field of endeavor, teaches an electrolyte composition for lithium sulfur batteries comprising a non-aqueous solvent system including a linear ether and a cyclic ether at a volumetric ratio of 5:95 to 95:5 in order to target effects of suppressing gas generation during battery operation, and thus, reduce a swelling phenomenon of battery, resulting in excellent stability during battery operation [Park – pars. 0022,0031,0036]. Therefore, before the effective filing date of the claimed invention, it would have been obvious for an ordinary skilled artisan to have modified the non-aqueous solvent of Lee to have particularly included a co-solvent system comprising a linear ether and a cyclic ether at a volumetric ratio of 5:95 to 95:5 in order to target effects of suppressing gas generation during battery operation, and thus, reduce a swelling phenomenon of battery, resulting in excellent stability during battery operation, without undue experimentation and with a reasonable expectation of success.
Regarding Claim 5, Lee, as modified by Burkhardt, teaches wherein the cyclic anhydride compound includes 2,3-dimethylmaleic anhydride, which reads on the claimed Chemical Formula 1-3 [Burkhardt – par. 0059].
Regarding Claim 6, Lee discloses wherein the lithium salt is at least one selected from the group consisting of LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiB(Ph)4, LiC4BO8, LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, LiSO3CH3, LiSO3CF3, LiSCN, LiC(CF3SO2)3, LiN(CF3SO2)2, LiN(C2F5SO2)2, LiN(SO2F)2 and lithium lower aliphatic carboxylate [Lee – par. 0029].
Regarding Claim 8, modified Lee discloses wherein the linear ether is selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, dibutyl ether, diisobutyl ether, ethylmethyl ether, ethylpropyl ether, ethyl tert-butyl ether, dimethoxymethane, trimethoxymethane, dimethoxyethane, diethoxyethane, dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, tetra-ethylene glycol dimethyl ether, ethylene glycol divinylether, diethylene glycol divinylether, triethylene glycol divinylether, dipropylene glycol dimethyl ether, butylene glycol ether, diethylene glycol ethylmethyl ether, diethylene glycol isopropylmethyl ether, diethylene glycol butylmethyl ether, diethylene glycol tert-butylethyl ether, and ethylene glycol ethylmethyl ether [Lee - pars. 0027,0058,0066; Park – 0029,0031,0035].
Regarding Claim 9, modified Lee discloses wherein the cyclic ether is selected from the group consisting of dioxolane, methyldioxolane, dimethyldioxolane, vinyldioxolane, methoxydioxolane, ethylmethyldioxolane, oxane, dioxane, trioxane, tetrahydrofuran, methyl tetrahydrofuran, dimethyl tetrahydrofuran, dimethoxy tetrahydrofuran, ethoxy tetrahydrofuran, dihydropyran, tetrahydropyran, furan and 2-methylfuran [Lee – pars. 0027,0066; Park – par. 0034].
Regarding Claim 10, modified Lee discloses wherein the content of the cyclic anhydride compound is 0.01 to 5 weight% relative to the total weight of the electrolyte solution [Lee – par. 0041-42], which overlaps the claimed range, establishing a prima facie case of obviousness [MPEP 2144.05(I)].
Regarding Claim 11, Lee discloses the electrolyte solution further comprising a nitric acid-based compound [par. 0032].
Regarding Claim 12, Lee discloses wherein the nitric acid-based compound is at least one selected from the group consisting of lithium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imidazolium nitrate, and pyridinium nitrate [par. 0033].
Regarding Claim 13, modified Lee discloses a lithium-sulfur secondary battery, comprising the electrolyte solution of claim 1; a positive electrode; a negative electrode; and a separator [Lee – par. 0043].
Conclusion
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HAROON S. SHEIKH
Primary Examiner
Art Unit 1751
/Haroon S. Sheikh/ Primary Examiner, Art Unit 1751
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