Prosecution Insights
Last updated: April 19, 2026
Application No. 17/993,694

ELECTROLYTES FOR ELECTROCHEMICAL CELLS THAT CYCLE LITHIUM IONS

Final Rejection §103
Filed
Nov 23, 2022
Examiner
LEONG, JONATHAN G
Art Unit
1751
Tech Center
1700 — Chemical & Materials Engineering
Assignee
GM Global Technology Operations LLC
OA Round
2 (Final)
57%
Grant Probability
Moderate
3-4
OA Rounds
4y 0m
To Grant
74%
With Interview

Examiner Intelligence

Grants 57% of resolved cases
57%
Career Allow Rate
211 granted / 370 resolved
-8.0% vs TC avg
Strong +17% interview lift
Without
With
+16.9%
Interview Lift
resolved cases with interview
Typical timeline
4y 0m
Avg Prosecution
8 currently pending
Career history
378
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
52.2%
+12.2% vs TC avg
§102
26.6%
-13.4% vs TC avg
§112
16.8%
-23.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 370 resolved cases

Office Action

§103
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 . 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. Claim(s) 1-4 and 6-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (Stablizing Ni-Rich LiNi0.83Co0.12Mn0.05O2 with Cyclopentyl Isocyanate as a Novel Electrolyte Additive). Regarding claims 1-4 and 6, 13, and 15-17, Liu discloses an electrochemical cell that cycles lithium ions (Lithium-ion batteries, P12069/§Introduction/Para. 1; P12070/§Experimental Section/Paras. 1-4; P12076/§Conclusion) with sufficient specificity which also presents a prima facie case of obviousness for the same since Liu so strongly suggests a lithium ion battery possessing these limitations in combination based, at least, on the cited passages referred to within this rejection. Liu further discloses a first electrode comprising LiNi0.83Co0.12Mn0.05O2 (Abstract, P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed “a nickel-rich positive electroactive material comprising greater than or equal to about 80 mass % of nickel” of claim 1 and also within the scope of claim 13. Liu further discloses a second electrode comprising Si/C (P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed “silicon-based negative electroactive material” of claim 1, within the scope of “a composite electrode comprising the silicon-based negative electroactive material and a carbonaceous negative electroactive material” of claim 15, inherently, due to being DXA5, is within the scope of the claimed “greater than or equal to about 1 wt.% to less than or equal to about 50 wt.% of the silicon-based negative electroactive material and greater than or equal to about 50 wt.% to less than or equal to about 80 wt.% of the carbonaceous negative electroactive material” of claim 16, and within the scope of claim 17. Liu further discloses a separating layer disposed between the first electrode and the second electrode (Celgard 2400, P12070/§Experimental Section/Paras. 1-4); and an electrolyte in contact with at least one of the nickel-rich positive electroactive material in the first electrode and the silicon-based negative electroactive material in the second electrode (LiPF6, EC/EMC; P12070/§Experimental Section/Paras. 1-4), within the scope of claims 1, 4, and 6. Liu further discloses comprising 2 wt% of cyclopentyl isocyanate (§Experimental Section/Paras. 1-4; P12071/§Results and Discussion/C2/first full paragraph) and that other cyanate derivatives, such as ethyl isocyanate and hexamethylene diisocyanate, are known to provide good surface film-forming property to lithium-ion batteries (P12070/C1/first full paragraph). The examiner notes that the taught ethyl isocyanate is so compositionally close to the claimed methyl isocyanate that one having ordinary skill in the art would have found methyl isocyanate prima facie obvious to try in a mixture with cyclopentyl isocyanate and hexamethylene diisocyanate with a reasonable expectation that they would provide similar properties (MPEP 2144.09) while also ensuring good surface film-forming properties thus reading on claims 1-3. Because Liu contemplates using 2 wt% of cyclopentyl isocyanate as set forth above, it would have been obvious for one having ordinary skill in the art to have utilized a similar amount for the methyl isocyanate rendered obvious above which would be within the scope of the claimed “greater than or equal to about 1.5 wt.% to less than or equal to about 5 wt.% of an electrolyte additive” of claim 1, with a reasonable expectation of success in doing so. Regarding claims 7-8, Liu discloses all of the limitations as set forth above. Liu further discloses the solvent comprises a first solvent and a second solvent, the first solvent comprising ethylene carbonate (P12070/§Experimental Section/Paras. 1-4). Liu further discloses the second solvent comprises ethyl methyl carbonate (P12070/§Experimental Section/Paras. 1-4), and that the first and second solvents are in a weight ratio of 3:7 (P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed volume ratio of “about 3:7” of claim 8 or, at least, close enough that the skilled artisan would have considered the properties to be substantially the same. Liu further indicates that dimethyl carbonate was a known alternative solvent (P12071/§Results and Discussion/Table 1). Even though Liu does not happen to utilize DMC in a specific embodiment, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to have utilized DMC as an alternative or in addition to EMC in the claimed volume ratio with a reasonable expectation that such would successfully function as an electrolyte solvent. Regarding claims 9-12, Liu discloses all of the limitations as set forth above. Liu further teaches that it is known in the art to add vinylene carbonate and/or fluoroethylene carbonate as additives to the electrolyte in order to enhance the stability of the SEI layer as well as improve battery performance (P12070/first paragraph). Thus, while Liu does not disclose adding vinylene carbonate and/or fluoroethylene carbonate as additive solvents in a particular embodiment, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to have done so in additive amounts, in order to enhance the stability of the SEI layer as well as improve battery performance as taught by Liu, thus rendering obvious claims 9-12 since the claimed range amounts are considered by one having ordinary skill in the art to be closely encompassed by Liu’s teaching that these are “additives” such that the skilled artisan would have had a reasonable expectation of success in choosing the encompassed portion of the ranges. Regarding claim 14, Liu discloses all of the limitations as set forth above wherein the nickel-rich positive electroactive material is represented by LiNi0.83Co0.12Mn0.05O2 (Abstract, P12070/§Experimental Section/Paras. 1-4). Liu further teaches that it is known that both LiNixCoyMn1-x-yO2 and LiNixCoyAl1-x-yO2 where x ≥ 0.8 are cathode active materials having high achievable capacity (P12069/§Introduction/Para. 2). While Liu’s disclosed LiNi0.83Co0.12Mn0.05O2 differs from the claim as it doesn’t explicitly include Alz, where 0.01 ≤ z ≤ 0.08, the addition/doping of such amount of Al would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, with the reasonable expectation of successfully arriving at a cathode active material having high achievable capacity. Regarding claim 18, Liu discloses an electrochemical cell that cycles lithium ions (Lithium-ion batteries, P12069/§Introduction/Para. 1; P12070/§Experimental Section/Paras. 1-4; P12076/§Conclusion) with sufficient specificity which also presents a prima facie case of obviousness for the same since Liu so strongly suggests a lithium ion battery possessing these limitations in combination based, at least, on the cited passages referred to within this rejection. Liu further discloses a first electrode comprising LiNi0.83Co0.12Mn0.05O2 (Abstract, P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed “a nickel-rich positive electroactive material comprising greater than or equal to about 80 mass % of nickel” of claim 18 since it necessarily and inherently possesses some porosity allowing for electrolyte to intermingle therein. Liu further discloses a second electrode comprising Si/C (P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed “silicon-based negative electroactive material” of claim 18 since it necessarily and inherently possesses some porosity allowing for electrolyte to intermingle therein. Liu further discloses a separating layer disposed between the first porous electrode and the second porous electrode (Celgard 2400, P12070/§Experimental Section/Paras. 1-4); wherein the electrolyte comprises a lithium-containing salt selected from LiPF6, a first solvent comprising EC, a second solvent comprising EMC, and that the first and second solvents are in a weight ratio of 3:7 (P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed volume ratio of “about 3:7” or, at least, close enough that the skilled artisan would have considered the properties to be substantially the same. Liu further indicates that dimethyl carbonate was a known alternative solvent (P12071/§Results and Discussion/Table 1). Even though Liu does not happen to utilize DMC in a specific embodiment, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to have utilized DMC as an alternative or in addition to EMC in the claimed volume ratio with a reasonable expectation that such would successfully function as an electrolyte solvent. Liu further discloses comprising 2 wt% of cyclopentyl isocyanate (§Experimental Section/Paras. 1-4; P12071/§Results and Discussion/C2/first full paragraph) and that other cyanate derivatives, such as ethyl isocyanate and hexamethylene diisocyanate, are known to provide good surface film-forming property to lithium-ion batteries (P12070/C1/first full paragraph). The examiner notes that the taught ethyl isocyanate is so compositionally close to the claimed methyl isocyanate that one having ordinary skill in the art would have found methyl isocyanate prima facie obvious to try by itself or in a mixture with cyclopentyl isocyanate and hexamethylene diisocyanate with a reasonable expectation that they would provide similar properties (MPEP 2144.09) while also ensuring good surface film-forming properties thus reading on claims 18. Because Liu contemplates using 2 wt% of cyclopentyl isocyanate as set forth above, it would have been obvious for one having ordinary skill in the art to have utilized a similar amount for the methyl isocyanate rendered obvious above which would be within the scope of the claimed “greater than or equal to about 1.5 wt.% to less than or equal to about 5 wt.% of an electrolyte additive” of claim 18, with a reasonable expectation of success in doing so. Regarding claim 19, Liu discloses all of the limitations as set forth above. Liu further teaches that it is known in the art to add vinylene carbonate and/or fluoroethylene carbonate as additives to the electrolyte in order to enhance the stability of the SEI layer as well as improve battery performance (P12070/first paragraph). Thus, while Liu does not disclose adding vinylene carbonate and/or fluoroethylene carbonate as additive solvents in a particular embodiment, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to have done so in additive amounts, in order to enhance the stability of the SEI layer as well as improve battery performance as taught by Liu. Claim(s) 5 and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (Stablizing Ni-Rich LiNi0.83Co0.12Mn0.05O2 with Cyclopentyl Isocyanate as a Novel Electrolyte Additive), as applied to claims 1 and 15 above, and further in view of Lee et al. (A bi-functional lithium difluoro(oxalate)borate additive for lithium cobalt oxide/lithium nickel manganese cobalt oxide cathodes and silicon/graphite anodes in lithium-ion batteries at elevated temperatures). Regarding claim 5, Liu discloses all of the limitations as set forth above wherein Liu disclosed the lithium-containing salt comprises a second lithium-containing salt selected from LiPF6 (P12070/§Experimental Section/Paras. 1-4), but does not explicitly disclose a first lithium-containing salt comprises lithium difluoro(oxalate)borate. Lee teaches in similar batteries (Abstract) that lithium difluoro(oxalate)borate as an additive enhances the electrochemical performance of batteries containing NMC cathodes and high-capacity Si-C anodes (Abstract). It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to have added lithium difluoro(oxalate)borate as a first lithium-containing salt in the electrochemical cell of Liu in order to enhance the electrochemical performance of the batteries as taught by Lee. Regarding claim 16, Liu discloses all of the limitations as set forth above. Assuming, arguendo, that applicant is somehow able to persuasively prove that the DXA5 of Liu is not within the scope of the claimed “greater than or equal to about 1 wt.% to less than or equal to about 50 wt.% of the silicon-based negative electroactive material and greater than or equal to about 50 wt.% to less than or equal to about 80 wt.% of the carbonaceous negative electroactive material”, such a limitation would have still been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention since Lee already recognized that an Si-C anode material having a high-capacity had a 7.5 : 92.5 Si:C ratio (P2/§2.1; Abstract), thus providing the skilled artisan with a reasonable expectation of success in utilizing such as the Si-C material of Liu. Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (Stablizing Ni-Rich LiNi0.83Co0.12Mn0.05O2 with Cyclopentyl Isocyanate as a Novel Electrolyte Additive), as applied to claims 1 and 15 above, and further in view of Lee et al. (A bi-functional lithium difluoro(oxalate)borate additive for lithium cobalt oxide/lithium nickel manganese cobalt oxide cathodes and silicon/graphite anodes in lithium-ion batteries at elevated temperatures). Regarding claim 20, Liu discloses an electrochemical cell that cycles lithium ions (Lithium-ion batteries, P12069/§Introduction/Para. 1; P12070/§Experimental Section/Paras. 1-4; P12076/§Conclusion) with sufficient specificity which also presents a prima facie case of obviousness for the same since Liu so strongly suggests a lithium ion battery possessing these limitations in combination based, at least, on the cited passages referred to within this rejection.. Liu further discloses an electrolyte comprising a first lithium-containing salt selected from LiPF6 (P12070/§Experimental Section/Paras. 1-4), but does not explicitly disclose a second lithium-containing salt comprises lithium difluoro(oxalate)borate. Lee teaches in similar batteries (Abstract) that lithium difluoro(oxalate)borate as an additive enhances the electrochemical performance of batteries containing NMC cathodes and high-capacity Si-C anodes (Abstract). It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to have added lithium difluoro(oxalate)borate as a second lithium-containing salt in the electrochemical cell of Liu in order to enhance the electrochemical performance of the batteries as taught by Lee. Liu further discloses a first solvent comprising EC, a second solvent comprising EMC, and that the first and second solvents are in a weight ratio of 3:7 (P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed volume ratio of “about 3:7” or, at least, close enough that the skilled artisan would have considered the properties to be substantially the same. Liu further indicates that dimethyl carbonate was a known alternative solvent (P12071/§Results and Discussion/Table 1). Even though Liu does not happen to utilize DMC in a specific embodiment, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to have utilized DMC as an alternative or in addition to EMC in the claimed volume ratio with a reasonable expectation that such would successfully function as an electrolyte solvent. Liu further discloses comprising 2 wt% of cyclopentyl isocyanate (§Experimental Section/Paras. 1-4; P12071/§Results and Discussion/C2/first full paragraph) and that other cyanate derivatives, such as ethyl isocyanate and hexamethylene diisocyanate, are known to provide good surface film-forming property to lithium-ion batteries (P12070/C1/first full paragraph). The examiner notes that the taught ethyl isocyanate is so compositionally close to the claimed methyl isocyanate that one having ordinary skill in the art would have found methyl isocyanate prima facie obvious to try by itself or in a mixture with cyclopentyl isocyanate and hexamethylene diisocyanate with a reasonable expectation that they would provide similar properties (MPEP 2144.09) while also ensuring good surface film-forming properties thus reading on claims 18. Because Liu contemplates using 2 wt% of cyclopentyl isocyanate as set forth above, it would have been obvious for one having ordinary skill in the art to have utilized a similar amount for the methyl isocyanate rendered obvious above which would be within the scope of the claimed “greater than or equal to about 1.5 wt.% to less than or equal to about 5 wt.% of an electrolyte additive” of claim 18, with a reasonable expectation of success in doing so. Liu further discloses a first electrode comprising LiNi0.83Co0.12Mn0.05O2 (Abstract, P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed “a nickel-rich positive electroactive material comprising greater than or equal to about 80 mass % of nickel” of claim 18 since it necessarily and inherently possesses some porosity allowing for electrolyte to intermingle therein. Liu further discloses a second electrode comprising Si/C (P12070/§Experimental Section/Paras. 1-4) which is within the scope of the claimed “silicon-based negative electroactive material selected from the group consisting of Si, SiOx (where x ≤ 2), and combinations thereof” since it necessarily and inherently possesses some porosity allowing for electrolyte to intermingle therein. Liu further discloses a separating layer disposed between the first porous electrode and the second porous electrode (Celgard 2400, P12070/§Experimental Section/Paras. 1-4). Response to Arguments Applicant's arguments filed 8/21/2025 have been fully considered but they are not persuasive. The Applicant argues that the cited prior art of record (Liu and Lee) is silent with regard to the claimed electrolyte additive in each of the independent claims. The Examiner respectfully submits that while neither Liu nor Lee explicitly disclose the particular claimed electrolyte additive, e.g. methyl isocyanate, because Liu teaches the broader family of “cyanate derivatives” such as ethyl isocyanate, are known to provide good surface film-forming property to lithium-ion batteries (P12070/C1/first full paragraph), a prima facie case of obviousness is met (see above rejections). The examiner notes that the taught ethyl isocyanate is so compositionally close to the claimed methyl isocyanate that one having ordinary skill in the art would have found methyl isocyanate prima facie obvious to try with a reasonable expectation that it would provide similar properties (MPEP 2144.09) while also ensuring good surface film-forming properties. 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 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 JONATHAN G LEONG whose telephone number is (571)270-1292. The examiner can normally be reached M-Th, 8am-5pm ET. 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, Srilakshmi Kumar can be reached at 5712727769. 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. /JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 2/18/2026
Read full office action

Prosecution Timeline

Nov 23, 2022
Application Filed
May 22, 2025
Non-Final Rejection — §103
Jul 16, 2025
Interview Requested
Aug 11, 2025
Applicant Interview (Telephonic)
Aug 11, 2025
Examiner Interview Summary
Aug 21, 2025
Response Filed
Feb 18, 2026
Final Rejection — §103
Mar 31, 2026
Interview Requested
Apr 09, 2026
Applicant Interview (Telephonic)
Apr 09, 2026
Examiner Interview Summary

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

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Prosecution Projections

3-4
Expected OA Rounds
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Grant Probability
74%
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4y 0m
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