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 .
Response to Amendment
The amendment filed on 07/14/2026 does not place the application in condition for allowance.
The rejection of claims 1, 4, and 6-10 under U.S.C 103 is withdrawn.
New analysis follows.
Response to Arguments
Applicant's arguments filed 07/14/2026 have been fully considered but they are not fully persuasive.
Applicant argues the range of S-O based cyclic compound cited in Harada is 500 times broader than the claimed range and there are unexpected results leading to criticality of the claimed range. While the examiner agrees that the range of Harada is significantly broader than the claimed range, thereby overcoming the previous rejection of Harada, the data in the instant specification is not commensurate in scope with the claimed invention. To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). In particular, there are also only a very limited number of concentrations of the S-O based cyclic compounds included in the identified examples (0 ppm, 500 ppm and 5000 ppm) while a range of 400-600 ppm is claimed. The limited data set limits identification of the extent of the unexpected and superior results. For example, performance changes may be present inside or outside the claimed range and decreased performance may be present at 550 ppm or 1000 ppm on the upper end and 450 ppm or 100 ppm on the lower end. Without more data points, it is unknown where changes in the cycle performance data begin and end.
Applicant also argues Nakajima merely discloses mole ratios of the lithium salts and solvents and not weight percentages, however one of ordinary skill in the art would have recognized a mole ratio may be converted to the weight percentages and would inherently have overlapping ranges given the density and molecular weights of the materials used.
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.
Claims 1, 4, 6-10 are rejected under 35 U.S.C. 103 as being unpatentable over Youn et. al. (KR20190062969A, reference made to attached English translation), in view of Kawasoe (US20150229002A1) and further in view of Nakajima (JP2019046759, cited in IDS dated 11/30/23, reference made to English translation).
Regarding claims 1 and 4, Youn discloses a lithium-sulfur secondary battery comprising:
a positive electrode (i.e. slurry coated in Al foil), a negative electrode, a separator; and an electrolyte (¶ [0143]),
but does not disclose a specific example wherein the electrolyte contains a S-O-based cyclic compound, and the S-O-based cyclic compound is ethylene sulfite, 1,3-propane sultone, 1,3-propene sultone, ethylene sulfate, or a combination thereof.
Youn does disclose propene sultone may be chosen from a list of additives (¶ [0112]).
One of the ordinary skill in the art would recognize modifying the electrolyte by adding propene sultone would improve the high-temperature storage characteristics (¶ [0112]).
Therefore, it would have been obvious to one of ordinary skill in the art to have added the propene sultone to the electrolyte to improve high-temperature storage characteristics.
Youn also discloses wherein the electrolyte further contains a non-aqueous solvent comprises a non-fluorinated linear ether (ethylene glycol ethyl methyl ether) and a cyclic ether (methyltetrahydrofuran) (¶0143]) and a lithium salt (i.e. LiFSI) (¶ [0143]).
Youn does not disclose wherein the S—O-based cyclic compound is contained in the electrolyte in an amount of more than 400 ppm to 600 ppm based on the total weight of the electrolyte or wherein the non-aqueous solvent comprises a fluorinated linear ether in an amount of 60 wt. % to 95 wt. % based on the total weight of the non-aqueous solvent.
Kawasoe, related to lithium batteries, teaches a non-aqueous electrolyte which may contain additives including 1,3-propane sultone, 1,3-propene sultone, ethylene sulfite (¶ [0023]) in an amount of 500 ppm (example 7, 1, 3-propene sultone, Table 1, 0.05%mass).
One of ordinary skill in the art would have recognized even though the representative battery of Kawasoe is not a lithium sulfur battery, adding the propene sultone in the sulfur battery as taught by Youn in the amount taught by Kawasoe it would improve safety by reducing gas generation (¶ [0048]) and improve performance (¶ [0027]).
Therefore, it would have been obvious to one of ordinary skill in the art to add 500 ppm of propene sultone to the electrolyte of Youn to improve performance and safety.
Nakajima, related to a lithium-sulfur secondary battery, teaches fluorinated linear ethers 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(HFE) and 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoropropyl ether (TFEE) (¶[0079], Table 1, see examples 1-4) at 1:12 and 1:20 mole ratios of tetraethylene glycol dimethyl ether : fluorinated linear ether.
One of ordinary skill in the art would have recognized the fluorinated linear ether of Nakajima in the electrolyte solvent of Youn would provide increased capacity density (¶ [0014]) and the mole ratios of the ether solvents overlap with the claimed range of 60 wt.% -95 wt.% of fluorinated linear ether based on total weight of the non-aqueous solvent.
Therefore, it would have been obvious to one of ordinary skill in the art to have used the fluorinated linear ether of Nakajima in the electrolyte solvent of Youn to provide increased capacity density.
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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP §2144.05.
Regarding claim 6, modified Youn discloses a lithium-sulfur secondary battery according to claim 3, LiFSI (i.e. LiN(FSO2)2, ¶[0143]) as Experimental Example 1 and Youn further discloses LiSCN LiCl, LiBr, LiI, LiPF6, LiSbF6, LiAsF6, LiCF3SO3, LiCF3CO2, LiClO4, LiAlCl4, Li LiN (CF 3 SO 2) 3, LiN (FSO 2) 2, Lithium perchlorate as alternative lithium salt options.
Regarding claim 7, modified Youn discloses a lithium-sulfur secondary battery according to claim 1, wherein the positive electrode comprises a positive electrode active material layer, and the positive electrode active material layer has a porosity of 62% (¶ [0123]).
Regarding claim 8, modified Youn discloses a lithium-sulfur secondary battery according to claim 1, wherein the positive electrode has a loading amount of a positive electrode active material of 5.5 mAh/cm2 (¶ [0122]).
Regarding claim 9 and 10, modified Youn discloses a lithium-sulfur secondary battery according to claim 1, wherein the sulfur-carbon composite on the positive electrode comprises 70 wt. % of sulfur based on the total weight of the sulfur-carbon composite (¶0121]).
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 KAREN J. ARMSTRONG whose telephone number is (703)756-1243. The examiner can normally be reached Monday-Friday 10 am-6 pm EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jeffrey Barton can be reached at (571) 272-1307. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/K.J.A./Examiner, Art Unit 1726
/JEFFREY T BARTON/Supervisory Patent Examiner, Art Unit 1726 27 August 2026
Prosecution Insights