Prosecution Insights
Last updated: April 19, 2026
Application No. 19/350,727

ELECTROLYTE FOR A METAL-ION BATTERY CELL WITH HIGH-CAPACITY, MICRON-SCALE, VOLUME-CHANGING ANODE PARTICLES

Final Rejection §103
Filed
Oct 06, 2025
Examiner
AKRAM, IMRAN
Art Unit
1725
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Sila Nanotechnologies Inc.
OA Round
2 (Final)
64%
Grant Probability
Moderate
3-4
OA Rounds
3y 5m
To Grant
99%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
624 granted / 970 resolved
-0.7% vs TC avg
Strong +43% interview lift
Without
With
+43.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
37 currently pending
Career history
1007
Total Applications
across all art units

Statute-Specific Performance

§103
38.1%
-1.9% vs TC avg
§102
33.5%
-6.5% vs TC avg
§112
18.5%
-21.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 970 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 . Response to Arguments Applicant's arguments filed 3/4/26 have been fully considered but they are not persuasive. The art rejections still apply as presented previously. No amendment has been filed. Applicant only specifically address the rejection of claim 1 in the Remarks. The first two arguments (page 7) are directed to the deficiency Sakshaug in disclosing the feature of “a total open pore volume fraction of the porous Si-comprising anode electrode ranges from 5 vol. % to 35 vol. %.” Applicant asserts that the cited paragraph 179 pertains to the porous carbon scaffold prior to silicon deposition and that the disclosed particle pore volume is at the particle level and would not count as open porosity at the electrode level. The Examiner respectfully disagrees. The teaching of paragraph 179 pertains to the carbon scaffold before silicon deposition, it is true. However, Sakshaug is explicit in teaching what percentage of the porous scaffold would be filled with silicon (paragraph 310). Paragraph 310 states that the silicon embedded within the porous carbon scaffold can occupy anywhere from 5-100% of the total pore volume. This range encompasses the claimed 5-35 vol% of open (non-silicon embedded) porosity in the scaffold even after silicon deposition. Applicant further asserts on page 8 that Oka discloses utilizing a nitrile compound in the context of tungsten and that Sakshaug does not make use of tungsten in a meaningful way, thus the combination is inappropriate. The Examiner respectfully disagrees. The modification of Sakshaug by Oka is done by one ordinary skill in the art. If tungsten—an additive in Oka like the nitrile compound—is beneficial with the nitrile additive, then the tungsten could and would be added, as well. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1-6 and 13-22 are rejected under 35 U.S.C. 103 as being unpatentable over Sakshaug (US 2017/0170477 A1) in view of Oka (US 2017/0084916 A1). Regarding claim 1, Sakshaug discloses an apparatus comprising: a porous Si-comprising anode electrode (paragraph 3) with an areal capacity loading in a range of 2 mAh/cm2 to 10 mAh/cm2 (paragraph 509), and comprising: silicon-carbon (Si-C) nanocomposite anode particles, and a binder (paragraph 3); wherein: the Si-C nanocomposite anode particles: (a) exhibit an average particle size in a range of 4 microns to 14 microns (paragraph 188), (b) exhibit true density in a range from 1.2 g/cc to 2.0 g/cc (paragraphs 481-485), and (d) exhibit volume changes from 4 vol. % to 180 vol. % during one or more charge-discharge cycles of the Li-ion battery cell (paragraph 395), a total open pore volume fraction of the porous Si-comprising anode electrode ranges from 5 vol. % to 35 vol. % (paragraph 179), and a total weight fraction of the binder ranges from to 2 wt. % to 12 wt. % (paragraph 288); a porous cathode electrode comprising lithium cobalt oxide (LCO) cathode particles (paragraph 291); a separator electrically separating the porous Si-comprising anode electrode and the porous cathode electrode (paragraph 300); and an electrolyte ionically coupling the porous Si-comprising anode electrode and the porous cathode electrode and at least partially filling pores in the porous Si-comprising anode electrode, the cathode electrode and the separator (paragraph 300), wherein: the electrolyte comprises LiPF6 and an electrolyte solvent composition (paragraph 300), the electrolyte solvent composition comprises methyl butyrate (C5H10O2) and EC, DEC, and FEC (paragraph 300). The melting point of: methyl butyrate is -85°C to -95°C; ethylene carbonate 34°C to 38°C; diethyl carbonate is approximately -43°C; and fluoroethylene carbonate is 18°C to 23°C. Sakshaug discloses the use of nitrile compounds (paragraph 126) but not as an additive composition to the electrolyte solvent. Oka—in an invention for a non-aqueous electrolyte secondary battery—discloses the use of nitrile as an additive in the electrolyte to form good coatings with both electronic conductivity and ion permeability on the surfaces of the lithium transition metal oxide particles; this further increases the effect of enhancing regenerative characteristics (paragraph 33). It would have been obvious to one having ordinary skill in the art at the time of invention to utilize nitrile compounds—known to Sakshaug—in the electrolyte of Sakshaug to improve electronic conductivity and ion permeability, enhancing regenerative characteristics as suggested by Oka. Regarding claim 2, Sakshaug discloses that the Si-C nanocomposite anode particles exhibit specific a capacity of 150 to over 3500 mAh/g (paragraph 304). Regarding claim 3, Sakshaug discloses that Si-C nanocomposite anode particles exhibit specific surface area below 15 m2/g (paragraph 337). Regarding claims 4-6, Sakshaug discloses that the electrolyte comprises at least one lithium salt in addition to LiPF6, including lithium fluoride and lithium sulfate (paragraph 290). Regarding claims 13 and 14, Sakshaug discloses that the electrolyte comprises vinylene carbonate, fluoroethylene carbonate (FEC), ethylene carbonate (EC), and/or propylene carbonate (PC) (paragraph 8). Regarding claims 15 and 16, Sakshaug discloses that the electrolyte comprises EC:DEC+10% FEC (paragraph 507). Regarding claims 17-19, Oka discloses that the nitrile compound is adiponitrile (paragraph 35) in the amount of 0.1 mass percent to 10 mass percent and more with respect to the mass of the nonaqueous electrolyte (paragraph 37). Regarding claim 20, Sakshaug discloses a total open pore volume fraction of the porous Si-comprising anode electrode ranges from 5 vol. % to 25 vol. % (paragraph 179), Regarding claims 21 and 22, Sakshaug discloses an areal capacity loading over 2.3 mAh/cm2 (paragraph 509). Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Sakshaug and Oka as applied to claim 4 above, and further in view of Park (US 2013/0029230 A1). Neither Sakshaug nor Oka discloses the use of LiFSI. Park—in an invention for a non-aqueous electrolyte secondary battery—discloses the use of LiFSI as a lithium salt low lattice energy and high dissociation degree such that the lithium salt is excellent in ion conductivity and has good thermal stability and oxidation resistance (paragraph 46). It would have been obvious to one having ordinary skill in the art at the time of invention to utilize LiFSI as a lithium salt in Sakshaug for its excellent ion conductivity and good thermal stability and oxidation resistance as suggested by Park. Claim 8-12 are rejected under 35 U.S.C. 103 as being unpatentable over Sakshaug and Oka as applied to claim 4 above, and further in view of Jeon (US 2011/0111305 A1). Neither Sakshaug nor Oka discloses the use of ethyl propionate and propyl propionate. Jeon—in an invention for a non-aqueous electrolyte secondary battery—discloses the use of a mixture of ethylene carbonate (EC) and propylene carbonate (PC) and (b) ethyl propionate are mixed at a volume ratio (a:b) in the range from 10:90 to 70:30 (paragraph 15) and propyl propionate (paragraph 24) since a propionate-based ester has a low freezing point and a high boiling point and exhibits excellent low-temperature characteristics (paragraph 21). It would have been obvious to one having ordinary skill in the art at the time of invention to utilize ethyl propionate and propyl propionate as the low-melting point solvent since it exhibits excellent low-temperature characteristics as suggested by Jeon. 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 IMRAN AKRAM whose telephone number is (571)270-3241. The examiner can normally be reached M-F 9a-5p. 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, Basia Ridley can be reached at 571-272-1453. 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. /IMRAN AKRAM/Primary Examiner, Art Unit 1725
Read full office action

Prosecution Timeline

Oct 06, 2025
Application Filed
Dec 11, 2025
Non-Final Rejection — §103
Mar 04, 2026
Response Filed
Mar 23, 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

3-4
Expected OA Rounds
64%
Grant Probability
99%
With Interview (+43.1%)
3y 5m
Median Time to Grant
Moderate
PTA Risk
Based on 970 resolved cases by this examiner. Grant probability derived from career allow rate.

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