Prosecution Insights
Last updated: April 19, 2026
Application No. 17/998,357

LITHIUM ION SECONDARY BATTERY AND SEPARATION MEMBRANE

Non-Final OA §103
Filed
Nov 10, 2022
Examiner
CULLEN, SEAN P
Art Unit
1725
Tech Center
1700 — Chemical & Materials Engineering
Assignee
LG Energy Solution, Ltd.
OA Round
3 (Non-Final)
69%
Grant Probability
Favorable
3-4
OA Rounds
3y 5m
To Grant
98%
With Interview

Examiner Intelligence

Grants 69% — above average
69%
Career Allow Rate
841 granted / 1222 resolved
+3.8% vs TC avg
Strong +29% interview lift
Without
With
+29.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
49 currently pending
Career history
1271
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
35.5%
-4.5% vs TC avg
§102
21.8%
-18.2% vs TC avg
§112
37.1%
-2.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1222 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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 02 December 2025 has been entered. Status of Claims and Other Notes Claims 1–10 are pending. 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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. The paragraph numbers cited in this Office Action in reference to the instant application are referring to the paragraph numbering of the PG-Pub of the instant application. See US 2023/0178850 A1. Specification Applicants' amendments have overcome the objections to the specification. Claim Rejections - 35 USC § 103 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 1–10 are rejected under 35 U.S.C. 103 as being unpatentable over Chang et al. (US 2019/0214685 A1, hereinafter Chang) in view of Nishijima et al. (US 6,534,214 B1, hereinafter Nishijima). Regarding claim 1, Chang discloses a lithium ion secondary battery (FIG. 2B, [0044]) comprising: a positive electrode mixture layer (15, [0033]); a negative electrode mixture layer (12', [0044]), and a separation membrane (13, 16, 17, 20) located between the positive electrode mixture layer (15) and the negative electrode mixture layer (12', [0047]), wherein the positive electrode mixture layer (15) comprises a positive electrode active material, a first lithium salt, and a first solvent (see cathode, [0033]), wherein the negative electrode mixture layer (12') comprises a negative electrode active material (12a), a second lithium salt (12b), and a second solvent (12b) different from the first solvent (FIG. 3, [0072]), and wherein the separation membrane (13, 16, 17, 20) comprises at least one resin selected from the group consisting of a resin comprising, as a monomer unit, at least one monomer having a (meth)acryloyl group , and a resin comprising, as a monomer unit, at least one olefin comprising fluorine ([0039], [0051], [0059], [0135], [0146]). Chang does not explicitly disclose: a second solvent that is different in composition from the first solvent, wherein the positive electrode mixture layer does not contain the second solvent and the negative electrode mixture layer does not contain the first solvent. Nishijima discloses a lithium ion secondary battery (50) comprising a positive electrode mixture layer (3) comprises a positive electrode active material, a first lithium salt, and a first solvent (TABLE 1, C13/L28–37), a negative electrode mixture layer (6) comprises a negative electrode active material, a second lithium salt, and a second solvent that is different in composition from the first solvent (TABLE 1, C13/L28–37), wherein the positive electrode mixture layer does not contain the second solvent and the negative electrode mixture layer does not contain the first solvent (TABLE 1, C13/L28–37) to enhance battery performance and cycle life characteristics (TABLE 1, C13/L20–27). Chang and Nishijima are analogous because they are directed to lithium ion secondary batteries. Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention to make the lithium ion secondary battery of Chang with the first and second solvents of Nishijima to enhance battery performance and cycle life characteristics. Regarding claim 2, Chang discloses all the claim limitations as set forth above and further discloses a lithium ion secondary battery: wherein the separation membrane (13, 16, 17, 20) further comprises a porous body (16, [0055]), and wherein the at least one resin is retained in the porous body (16, [0059]). Regarding claim 3, Chang discloses all the claim limitations as set forth above and further discloses a lithium ion secondary battery: wherein the porous body (16) is made of a polymer (FIG. 3, [0055]). Regarding claim 4, Chang discloses all the claim limitations as set forth above and further discloses a lithium ion secondary battery: wherein the separation membrane (13, 16, 17, 20) further comprises inorganic oxide particles (13) retained in the porous body (16, [0060]). Regarding claim 5, Chang discloses all the claim limitations as set forth above and further discloses a lithium ion secondary battery: wherein the separation membrane (13, 16, 17, 20) further comprises a third lithium salt (20) and a third solvent (20, [0040]). Regarding claim 6, Chang discloses a separation membrane (13, 16, 17, 20) comprising: at least one resin selected from the group consisting of a resin comprising, as a monomer unit, at least one monomer having a (meth)acryloyl group, and a resin comprising, as a monomer unit, at least one olefin comprising fluorine ([0039], [0051], [0059], [0135], [0146]), wherein the separation membrane (13, 16, 17, 20) is for being disposed between a positive electrode mixture layer (15) and a negative electrode mixture layer (12') in a lithium ion secondary battery (FIG. 2B, [0047]), and wherein the lithium ion secondary battery comprises t the positive electrode mixture layer (15) comprising a positive electrode active material, a first lithium salt, and a first solvent (see cathode, [0033]); and the negative electrode mixture layer (12') comprising a negative electrode active material (12a), a second lithium salt (12b), and a second solvent (12b) different from the first solvent (FIG. 3, [0072]). Chang does not explicitly disclose: a second solvent that is different in composition from the first solvent, wherein the positive electrode mixture layer does not contain the second solvent and the negative electrode mixture layer does not contain the first solvent. Nishijima discloses a lithium ion secondary battery (50) comprising a positive electrode mixture layer (3) comprises a positive electrode active material, a first lithium salt, and a first solvent (TABLE 1, C13/L28–37), a negative electrode mixture layer (6) comprises a negative electrode active material, a second lithium salt, and a second solvent that is different in composition from the first solvent (TABLE 1, C13/L28–37), wherein the positive electrode mixture layer does not contain the second solvent and the negative electrode mixture layer does not contain the first solvent (TABLE 1, C13/L28–37) to enhance battery performance and cycle life characteristics (TABLE 1, C13/L20–27). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention to make the lithium ion secondary battery of Chang with the first and second solvents of Nishijima to enhance battery performance and cycle life characteristics. Regarding claim 7, Chang discloses all the claim limitations as set forth above and further discloses a separation membrane, further comprising: a porous body (16, [0055]), and wherein the at least one resin is retained in the porous body (16, [0059]). Regarding claim 8, Chang discloses all the claim limitations as set forth above and further discloses a separation membrane: wherein the porous body (16) is made of a polymer (FIG. 3, [0055]). Regarding claim 9, Chang discloses all the claim limitations as set forth above and further discloses a separation membrane, further comprising: inorganic oxide particles (13) retained in the porous body (16, [0060]). Regarding claim 10, Chang discloses all the claim limitations as set forth above and further discloses a separation membrane, further comprising: a third lithium salt (20) and a third solvent (20, [0040]). Response to Arguments Applicant’s arguments with respect to claims 1–10 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Lin discloses a lithium ion secondary battery (100) comprising a positive electrode mixture layer (108) comprises a positive electrode active material, a first lithium salt, and a first solvent (see cathode electrolyte formulations, [0033]), a negative electrode mixture layer (106) comprises a negative electrode active material, a second lithium salt, and a second solvent that is different in composition from the first solvent (see anode active materials, [0034]), wherein the positive electrode mixture layer does not contain the second solvent (see anode active materials, [0034]) and the negative electrode mixture layer does not contain the first solvent (see cathode electrolyte formulations, [0033]) to enhance battery performance and cycle life characteristics (see electrolytic solution, [0027]). Any inquiry concerning this communication or earlier communications from the examiner should be directed to Sean P Cullen, Ph.D. whose telephone number is (571)270-1251. The examiner can normally be reached Monday to Thursday 6:00 am to 4:00 pm CT, Friday 6:00 am to 12:00 pm CT. 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 A 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. /Sean P Cullen, Ph.D./Primary Examiner, Art Unit 1725
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Prosecution Timeline

Nov 10, 2022
Application Filed
May 23, 2025
Non-Final Rejection — §103
Aug 27, 2025
Response Filed
Sep 09, 2025
Final Rejection — §103
Dec 02, 2025
Request for Continued Examination
Dec 03, 2025
Response after Non-Final Action
Jan 30, 2026
Non-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
69%
Grant Probability
98%
With Interview (+29.1%)
3y 5m
Median Time to Grant
High
PTA Risk
Based on 1222 resolved cases by this examiner. Grant probability derived from career allow rate.

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