Prosecution Insights
Last updated: April 19, 2026
Application No. 17/519,960

Electrolytes for Low Temperature Applications

Final Rejection §103
Filed
Nov 05, 2021
Examiner
MELFI, OLIVIA MASON
Art Unit
1729
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Nanyang Technological University
OA Round
4 (Final)
71%
Grant Probability
Favorable
5-6
OA Rounds
2y 10m
To Grant
99%
With Interview

Examiner Intelligence

Grants 71% — above average
71%
Career Allow Rate
22 granted / 31 resolved
+6.0% vs TC avg
Strong +34% interview lift
Without
With
+34.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
38 currently pending
Career history
69
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
64.3%
+24.3% vs TC avg
§102
13.1%
-26.9% vs TC avg
§112
21.2%
-18.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 31 resolved cases

Office Action

§103
DETAILED ACTION This Office Action is responsive to the October 29th, 2025 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 October 29th, 2025: Claims 1-2, 9-10, 13-18, and 20 are pending in the current application. Claims 1, 13-14, and 16 have been amended. Claims 3-8, 11-12, and 19 have been cancelled. Response to Arguments Applicant’s arguments filed with the Remarks on October 29th, 2025 with respect to claims 1-2, 9-10, 13-18, and 20 are acknowledged, however, Applicant’s arguments are not persuasive. Applicant’s argument that unexpected results occur when an electrolyte comprises more than 4 solvents is not persuasive. Applicant highlights in their Remarks that the prior art of record, Smart, only discloses three or four solvent electrolyte mixtures and not any examples comprising more than four solvents – such as claimed. And that the examples of Smart are closer to the commercial examples as described in the instant disclosure. While the instant disclosure does show an improvement in specific capacity retention between C3 and 6-mix at temperatures below 0oC (Table 9), there are not examples with 4 or 5 electrolyte solvents to prove the exact point of criticality in the number of solvents present. It is unclear as to whether 5 solvents would achieve the desired results. Also, in Table 6 the 4 mix and 6 mix electrolytes have the same ionic conductivity at -60oC and the same activation energy (as seen in Table 7). Which invalidates the criticality argument of more than 4 solvents. Additionally, Applicant argues a criticality of the volume percent (vol%) in conjunction with the use of more than 4 solvents. However, the examples provided in the instant disclosure fail to include an electrolyte comprising more than 4 solvents with volume percentages that fall outside of the claimed range. And, therefore, there is no proof of the criticality of having a specific vol% range in an electrolyte solution with more than 4 solvents. In conclusion, Applicant’s arguments are not persuasive. Any modifications to the rejection are as necessitated by the amendment. Claim Interpretation The limitation “about” as seen in at least 6 of Claim 1 is interpreted to be within + or – 5 volume%, as defined in paragraph [0043] of Applicant’s own PG Publication. Prior Art Abe US PG Publication 2018/0277900 (“Abe”) Previously cited Smart US Patent 6,492,064 (“Smart”) 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 1-2, 13-18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Abe US PG Publication 2018/0277900. Regarding Claims 1 and 20, Abe discloses an electrolyte for a lithium secondary battery (electrochemical cell) ([0015], entire disclosure dependent upon) comprising: Solvent A being ethylene carbonate (EC) ([0017], [0040]); Solvent Group B comprising propylene carbonate (PC) and other organic solvents including diethyl carbonate (DEC), methyl ethyl carbonate (MEC), and ethyl propionate ([0040], [0065]) and two other chain esters selected from a group including ethyl acetate (EA) and methyl propionate (MP) ([0070]-[0071]) (which meets the claim limitation of at least four other organic solvents selected from the group consisting of ethyl methyl carbonate, diethyl carbonate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, or propyl butyrate); wherein Solvent A is present in the electrolyte in an amount between 5 and 25% by volume (which encompasses the claimed range of at least about 10 vol% to about 20 vol%)1 ([0036]); wherein propylene carbonate in Solvent Group B is present in the electrolyte in an amount between 5 and 25% by volume (which encompasses the claimed range of at least about 10 vol% to about 20 vol%)1 ([0036]); wherein dimethyl carbonate in Solvent Group B is present in the electrolyte in an amount between 20 and 30% by volume (which overlaps the claimed range of at least about 10 vol% to about 20 vol%)1 ([0036]); wherein methyl ethyl carbonate in Solvent Group B is present in the electrolyte in an amount between 20 and 40% by volume (which overlaps the claimed range of at least about 10 vol% to about 20 vol%)1 ([0036]); wherein ethyl acetate in Solvent Group B is present in the electrolyte in an amount between 10 and 20% by volume (which overlaps the claimed range of at least about 10 vol% to about 20 vol%)1 ([0070], [0082]); and wherein methyl propionate in Solvent Group B is present in the electrolyte in an amount between 10 and 20% by volume (which overlaps the claimed range of at least about 10 vol% to about 20 vol%)1 ([0070], [0082]), and fluoroethylene carbonate (FEC) in an amount between 0.3% and 10% by volume (which encompasses the claimed range of about 0.5 vol% to about 5 vol%)1 ([0055]-[0060]), and wherein the electrolyte has a freezing point of -50oC or lower (which encompasses the claimed range of about -100oC or lower)1 ([0096]). 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, Abe teaches the instantly claimed electrolyte according to Claim 1, and Abe discloses wherein Solvent Group B comprises at least 4 other organic solvents (which meets the claimed limitation of four, five, six, seven, or eight) ([0015], [0017], [0070]-[0071]). Regarding Claim 13, Abe teaches the instantly claimed electrolyte according to Claim 1, and Abe discloses wherein the electrolyte further comprises vinylene carbonate and lithium salt (which meets the claim limitation of one or more additives selected from the group consisting of non-halogenated cyclic carbonate, non-halogenated linear carbonate, vinylene carbonate, and lithium salt) ([0043]-[0048], [0055]-[0056]). Regarding Claim 14, Abe teaches the instantly claimed electrolyte according to Claim 1, and Abe discloses wherein the electrolyte further comprises between 0.07% and 7% by volume (which encompasses the claimed range of about 0.5 vol% to about 5 vol%)1 of an unsaturated cyclic carbonate (which meets the claim limitation of non-halogenated cyclic carbonate, non-halogenated linear carbonate, unsaturated cyclic carbonate, and/or unsaturated linear carbonate) ([0057]-[0058]). Regarding Claim 15, Abe teaches the instantly claimed electrolyte according to Claim 1, and Abe discloses wherein the electrolyte comprises a lithium salt in a concentration between 0.8 M and 1.5 M (which falls within and therefore anticipates the claimed range of about 0.5 M to about 3 M) ([0043]-[0046]). Regarding Claim 16, Abe teaches the instantly claimed electrolyte according to Claim 15, and Abe discloses wherein the lithium salt is selected from the group consisting of lithium hexafluorophosphate, lithium bis(oxalate)borate, and lithium difluorooxolato borate (which meets the claim limitation of lithium hexafluorophosphate, lithium bis(oxalate)borate, lithium difluorooxolato borate, lithium hexafluoroarsenate (V), lithium bis(trifluoromethansulfonyl)imide, lithium bis(perfluoroethanesulfonyl)imide, lithium tetrafluoroborate, lithium perchlorate, lithium trifluoromethanesulfonate, lithium tris(trifluoromethansulfonyl)methide, or any combinations or mixtures thereof) ([0043]-[0045]). Regarding Claim 17, Abe teaches the instantly claimed electrolyte according to Claim 1, and Abe discloses wherein Solvent A and Solvent Group B of the electrolyte can comprise: ethylene carbonate (EC) ([0040]), propylene carbonate (PC) ([0040]), diethyl carbonate (DEC) ([0065]), methyl ethyl carbonate (MEC) ([0062]-[0063]), ethyl propionate ([0040]), and ethyl acetate ([0076]). Regarding Claim 18, Abe teaches the instantly claimed electrolyte according to Claim 1, and Abe discloses wherein the electrolyte can comprise: ethylene carbonate (EC) ([0040]), propylene carbonate (PC) ([0040]), diethyl carbonate (DEC) ([0065]), methyl ethyl carbonate (MEC) ([0062]-[0063]), ethyl propionate ([0040]), ethyl acetate ([0076]); fluoroethylene carbonate (FEC) in an amount between 0.3% and 10% by volume (which encompasses the claimed range of about 0.5 vol% to about 5 vol%)1 ([0055]-[0060]); and between 0.8 and 1.5 M (which falls within and therefore anticipates the claimed range of about 0.5 M to about 3 M) LiPF6 ([0043]-[0046]). Claims 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over Abe US PG Publication 2018/0277900, as applied to Claim 1, further in view of Smart US Patent 6,492,064. Regarding Claims 9-10, Abe teaches the instantly claimed electrolyte according to Claim 1. Abe fails to disclose wherein the organic solvents in Solvent Group B are in equivolume ratio to each other and Solvent A. However, Smart discloses an organic solvent system for electrolytes (Col. 2, Lines 25-40 and 60-65). Smart teaches the use of multiple organic solvents with an electrolyte, including ethylene carbonate and propylene carbonate, wherein the solvents are added in equal volume amounts (Col. 6 lines 12-25 and Col. 2, lines 60-65 and Col. 7 lines 36-45 and Col. 8 lines 15-30) in order to improve low temperature conductivity and increase compatibility of the electrolyte (Col. 5 lines 1-4). 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 Abe such that the organic solvents in Solvent Group B are in equivolume ratio to each other and to Solvent A in order to improve low temperature conductivity and increase compatibility of the electrolyte, as taught by Abe. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to OLIVIA MASON RUGGIERO whose telephone number is (703)756-4652. The examiner can normally be reached Monday-Thursday, 7am-6pm 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, Ula Ruddock can be reached on (571)272-1481. 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. /O.M.R./Examiner, Art Unit 1729 /ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729
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Prosecution Timeline

Nov 05, 2021
Application Filed
Aug 15, 2024
Non-Final Rejection — §103
Nov 19, 2024
Response Filed
Feb 06, 2025
Final Rejection — §103
May 12, 2025
Request for Continued Examination
May 13, 2025
Response after Non-Final Action
Jul 25, 2025
Non-Final Rejection — §103
Oct 29, 2025
Response Filed
Jan 21, 2026
Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
71%
Grant Probability
99%
With Interview (+34.2%)
2y 10m
Median Time to Grant
High
PTA Risk
Based on 31 resolved cases by this examiner. Grant probability derived from career allow rate.

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