Prosecution Insights
Last updated: October 25, 2026
Application No. 18/903,490

SILICON PARTICLES FOR BATTERY ELECTRODES

Final Rejection §103
Filed
Oct 01, 2024
Priority
Jan 18, 2010 — provisional 61/295,993 +9 more
Examiner
NGUYEN, KHANH TUAN
Art Unit
1761
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Enevate Corporation
OA Round
3 (Final)
74%
Grant Probability
Favorable
4-5
OA Rounds
7m
Est. Remaining
93%
With Interview

Examiner Intelligence

Grants 74% — above average
74%
Career Allowance Rate
807 granted / 1083 resolved
+9.5% vs TC avg
Strong +19% interview lift
Without
With
+18.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
26 currently pending
Career history
1121
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
47.6%
+7.6% vs TC avg
§102
24.4%
-15.6% vs TC avg
§112
19.3%
-20.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1083 resolved cases

Office Action

§103
DETAILED ACTION Final 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 claims filed on 09/02/2026 is entered and acknowledged by the Examiner. The 09/02/2026 claims are the same as the amendment claims filed on 02/03/2026. These two set of claims have been amended from the original claims filed on 10/01/2024; therefore, they necessitated new grounds of rejection set forth below. The rejection of claims 1-25 under 35 U.S.C. 103 as being unpatentable over JP'213 (JP 4610213 B2) in view of Wegener (US 2019/0305366 A1) is withdrawn in view of Applicant’s remark. (New Grounds of Rejection) 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 1-25 are rejected under 35 U.S.C. 103 as being unpatentable over JP'213 (JP 4610213 B2) in view of US 2006/0166098 A1 (hereinafter Tabuchi). JP’213 is relied upon as set forth in the Office action filed on 11/05/2025. With respect to claims 1-6 and 12-18, JP'213 disclose a negative electrode for a lithium secondary battery including active material particles containing silicon and/or a silicon alloy and a method of forming the same (See unlabeled page 2, Tech-Problem section) JP'213 exemplify the negative electrode (battery electrode) comprises 81.8 parts by weight of silicon powder having an average particle diameter of 3 µm to form a negative mixture slurry with 8.6 wt% of N-methylpyrrolidone solution containing 18.2 parts by weight of polyimide binder (See Experiment 1, unlabeled page 9). The solid content, i.e., 81.8 parts by weight of silicon powder and 18.2 parts by weight of polyimide binder, in the mixture slurry is 91.4 wt% (total solid wt% minus 8.6 wt% NMP solution). Of the 91.4 wt% of solid, only 81.8% of the solid weight is silicon particles based on total 100 parts by weight of silicon particles and polyimide binder. This equates to about 89.5 wt% of silicon particles and is less than 90 wt% as required in claims 1 and 12-13. The mixing of silicon particles in the negative mixture slurry would distribute the silicon particles throughout the negative mixture slurry (active material layer precursor) as recited in claims 1 and 13. The negative mixture slurry is applied to one side of a current collector (top surface of current collector) and heated to form a mixture layer (active material layer) on the current collector surface as recited in claims 1 and 13 (See Experiment 1, unlabeled page 9). It should be noted that a current collector has a layer structure and is known to have a top surface and a bottom surface as recited in claims 1 and 13. JP'213 failed to disclose the silicon particles having (BET) average surface area per unit mass of less than 4 m²/g as recited in claims 1-6 and 13-18. Tabuchi discloses a negative active electrode material comprises a composite particle (C) containing 10-70 wt% of silicon particle (A) and coated with 3-60 wt% of carbon powder ((B), an electronic conductive additive) useful as for non-aqueous electrolyte secondary battery having excellent in charge/discharge cycle performance and has a high energy density (See [0009], [0013], [0035], [0036], [0045], [0053], [0060], [0068], and [0086]). Tabuchi discloses that the silicon particle having D50 diameter (average particle size) of 5 um (See [0107]). Tabuchi discloses that the silicon particle with BET specific surface area of 1.0-10.0 m²/g to achieve satisfactory cycle performance (See [0042] and [0100]). When the BET specific surface area is less than 1.0 m.sup.2/g, the current density per surface area of the active material during charge/discharge becomes large; therefore, Li is deposited on the negative electrode and consequently the cycle performance deteriorates (See [0100]). On the other hand, when it exceeds 10 m.sup.2/g, the reaction area with the electrolyte solution during charge becomes large and the decomposition of the electrolyte solution is made to proceed, so that the cycle performance deteriorates and the discharge capacity deteriorates; thus, it is preferable to employ the BET specific surface area of not larger than 10 m.sup.2/g (See [0100]). Tabuchi also exemplify the silicon particle having BET specific surface area of 1.0 m²/g ([0100]). Tabuchi discloses The BET specific surface area suggested by Tabuchi is covering the claimed BET surface area of claims 1-6 and 13-18. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to formula a negative electrode material (battery electrode) comprises of silicon particles of JP'213 where the silicon particles having a BET specific surface area of at least than 1 m²/g in order to improved cycle performance and discharge capacity as suggested by Tabuchi (See [0100] of Tabuchi). The burden is upon the applicant to prove otherwise. In re Fitzgerald, 205 USPQ 594. Regarding claims 7-10 and 19-20, JP'213 discloses that the active material particles (silicon particles) having a preferred average particle diameter size (median particle size) of 10 µm or less (See connecting unlabeled pages 4-5). JP'213 discloses a good charge/discharge characteristics and uniformity of the charge/discharge reaction distribution in the electrode is improved with small average particle diameter and a narrow particle size distribution (See unlabeled page 5). Regarding claim 12, JP'213 discloses that the active material can contain 50 wt% or less of conductive powder total of the active material particles (silicon particles) (See 6th paragraph of unlabeled page 6). In other words, the amount of silicon particles as active material particles is 50 wt% or more. The lower limit of the silicon active material particles in the negative electrode material overlaps with the instant claimed amount of silicon in the active material layer. Regarding claims 21 and 24, JP'213 discloses that the active material comprises silicon particles dispersed in a binder such as polyimide that is heat treated at 600°C or less to sinter the binder (See unlabeled page 3, 2nd paragraph and at bottom of unlabeled page 6). Wegner discloses a polymer carbon precursor is carbonized at temperature of 400-1,400°C (See [0052] and [0070]). The heat treatment of polymer binder at 600°C or less, suggested by JP'213, would carbonize and cure the polymer binder and provide silicon particles distributed throughout the carbonized polymer binder. Regarding claims 22 and 25, JP'213 discloses that the silicon particles could be surface coated (See bottom of unlabeled page 4). Wegener discloses silicon particles are surface coated with carbonized carbon (See [0018] and [0032]). Regarding claim 23, JP'213 discloses that the average particle diameter of the silicon particles (active material articles) are preferably 10 um or less (See unlabeled page 4, last paragraph). Wegener discloses that the silicon particle having d50 diameter (average particle size) of 1-15 um (See [0041]). The claimed median particle size of the silicon particles overlaps with the claimed ranges. In view of the foregoing, the above claims have failed to patentably distinguish over the applied art. 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 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. Response to Arguments Applicant’s arguments with respect to the claim(s) above have been considered but are moot because the new ground of rejection. 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 KHANH TUAN NGUYEN whose telephone number is (571)272-8082. The examiner can normally be reached M-F 9:00 AM to 5:00 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, Angela Brown-Pettigrew can be reached at (571) 272-2817. 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. /KHANH T NGUYEN/Primary Examiner, Art Unit 1761
Read full office action

Prosecution Timeline

Oct 01, 2024
Application Filed
Nov 05, 2025
Non-Final Rejection mailed — §103
Feb 03, 2026
Response Filed
Jun 03, 2026
Final Rejection mailed — §103
Sep 02, 2026
Response after Non-Final Action
Sep 18, 2026
Final Rejection mailed — §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

4-5
Expected OA Rounds
74%
Grant Probability
93%
With Interview (+18.7%)
2y 8m (~7m remaining)
Median Time to Grant
High
PTA Risk
Based on 1083 resolved cases by this examiner. Grant probability derived from career allowance rate.

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