Prosecution Insights
Last updated: April 19, 2026
Application No. 18/991,739

SEPARATOR AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

Final Rejection §103
Filed
Dec 23, 2024
Examiner
MARTIN, ANGELA J
Art Unit
1727
Tech Center
1700 — Chemical & Materials Engineering
Assignee
SK Ie Technology Co. Ltd.
OA Round
3 (Final)
68%
Grant Probability
Favorable
4-5
OA Rounds
4y 1m
To Grant
35%
With Interview

Examiner Intelligence

Grants 68% — above average
68%
Career Allow Rate
586 granted / 868 resolved
+2.5% vs TC avg
Minimal -32% lift
Without
With
+-32.4%
Interview Lift
resolved cases with interview
Typical timeline
4y 1m
Avg Prosecution
81 currently pending
Career history
949
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
64.1%
+24.1% vs TC avg
§102
26.0%
-14.0% vs TC avg
§112
7.9%
-32.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 868 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 . The Applicant has amended independent claim 1 and dependent claims 5, 7-9, 12; and canceled claims 4, 10, 13. The pending claims are claims 1-3, 5-9, 11, 12, 14. 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. Claim Rejections - 35 USC § 103 4. 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. 5. Claim(s) 1-3, 5-9, 11, 12, 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al., KR 20230106504. Regarding clam 1, Lee et al., teaches a separator (0001; 0010) comprising: a porous substrate (0010); and an inorganic particle layer (0003; 0010) including a binder (0030) and inorganic particles (0030) disposed on at least one surface of the porous substrate (0010), wherein the inorganic particles (0010) include first inorganic particles having an average particle diameter of 0.001 to 20 um (0017), wherein binder includes an acryl-based binder (0076; 0213) and an acrylamide-based water-soluble binder (0078), wherein the separator has heat shrinkage rates in the machine direction and in the transverse direction of 5% or less as measured after being allowed to stand at 150°C for 60 minutes (0024), and wherein the separator has a ΔGurley permeability of 100 sec/100 cc or less as calculated by the following Equation 1: Equation 1 ΔGurley permeability (40 sec/100 cc or less (0085); ; 40 sec/100 cc or less; 0085) = Pm – Ps, wherein Pm is a gas permeability of the separator (0116), and Ps is a gas permeability of the porous substrate (0026; 0040; 0057); wherein the inorganic particles include first inorganic particles having an average particle diameter (D50) of 0.01 to 10 um (0109), wherein the binder includes acryl-based binder (0076), acrylamide-based polymers (0078). Lee et al., does not teach wherein the inorganic particle layer has a packing density of 1.2 g/m2·μm or more. However, Lee teaches similar materials in the separator, such as a porous substrate and inorganic particle layer including a binder, and A prima facie case of obviousness may be made when chemical compounds have very close structural similarities and similar utilities. "An obviousness rejection based on similarity in chemical structure and function entails the motivation of one skilled in the art to make a claimed compound, in the expectation that compounds similar in structure will have similar properties." In re Payne, 606 F.2d 303, 313, 203 USPQ 245, 254 (CCPA 1979). See In re Papesch, 315 F.2d 381, 137 USPQ 43 (CCPA 1963). Lee et al., does not teach wherein a ratio of a breakdown voltage (kV) of the separator to an overall average thickness (μm) of the separator is 0.15 kV/μm or more, and wherein the separator has a peak in a range of 1070 cm-1 to 1082 cm-1 in a spectrum by Fourier transform infrared spectroscopy (FT-IR). However, “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.). Regarding clam 2, Lee et al., teaches wherein the inorganic particles include any one or two or more selected from the group consisting of metal oxides (0015; 0106; 0137), metal nitrides (0015; 0106), and metal carbides (0015; 0106). Regarding clam 3, Lee et al., teaches wherein the inorganic particles have an average particle diameter (D50) of 0.001 to 20 um (0017; 0109) or 0.01 to 10 um (0109). Regarding clam 5, Lee et al., does not teach wherein the inorganic particles further include second inorganic particles having a larger average particle diameter (D50) than the first inorganic particles. Lee et al., teaches the “size of the inorganic particles is not limited as long as the purpose of the present invention is achieved, and specifically, the size of the inorganic particles, i.e., the average diameter, may be 0.001 to 20 um, specifically, 0.01 to 10 um”. (0109). Therefore, “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.). Regarding clam 6, Lee et al., does not teach wherein the second inorganic particles are included at 50 wt% or less based on the total weight of the first inorganic particles and the second inorganic particles. However, “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.). Regarding clam 7, Lee et al., teaches wherein the acryl-based binder (0076; 0078) is an acryl-based particulate binder (0078; 0101). Regarding clam 8, Lee et al., does not teach wherein the acryl-based particulate binder has a glass transition temperature of -60°C to 0°C, however, Lee et al., teaches that the glass transition temperature is not limited to a claimed range (0079). Regarding clam 9, Lee et al., teaches wherein the acrylamide-based water-soluble binder (0078) has a glass transition temperature of 100°C to 200°C (0079). Regarding clam 11, Lee et al., teaches wherein the binder is included at 0.1 parts by weight to 20 parts by weight with respect to 100 parts by weight of the inorganic particles (0018); or 0.1 to 10 parts by weight (0132). Regarding clam 12, Lee et al., does not teach wherein a weight ratio between the acrylamide-based water-soluble binder and the acryl-based particulate binder is 1:1 to 1:10. However, “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.). Regarding clam 14, Lee et al., teaches lithium secondary battery comprising the separator of claim 1 (0135; 0137-0138; 0191). Response to Arguments 6. Applicant's arguments filed 1/21/2026 have been fully considered but they are not persuasive. The Applicant argues that “there is no rationale to modify Lee to arrive at the present invention…The examples in Lee, in practice, do not use organic binders. As such, Lee teaches away from the present invention.” However, Lee et al., teaches “In a separation membrane according to one embodiment, the inorganic particle layer may further include an organic binder.” (0030)… “The separator of a conventional secondary battery includes an inorganic particle layer adhered by an organic binder on a porous substrate to ensure the stability of the battery.” (0069). Applicant argues that “Lee is completely silent regarding the packing density of the inorganic particle layer.” However, Lee teaches similar materials in the separator, such as a porous substrate and inorganic particle layer including a binder, and A prima facie case of obviousness may be made when chemical compounds have very close structural similarities and similar utilities. "An obviousness rejection based on similarity in chemical structure and function entails the motivation of one skilled in the art to make a claimed compound, in the expectation that compounds similar in structure will have similar properties." In re Payne, 606 F.2d 303, 313, 203 USPQ 245, 254 (CCPA 1979). See In re Papesch, 315 F.2d 381, 137 USPQ 43 (CCPA 1963). Conclusion 7. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANGELA J MARTIN whose telephone number is (571)272-1288. The examiner can normally be reached 7am-4pm. 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, Barbara Gilliam can be reached at 571-272-1330. 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. ANGELA J. MARTIN Examiner Art Unit 1727 /ANGELA J MARTIN/Examiner, Art Unit 1727
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Prosecution Timeline

Dec 23, 2024
Application Filed
May 17, 2025
Non-Final Rejection — §103
Sep 04, 2025
Applicant Interview (Telephonic)
Sep 04, 2025
Examiner Interview Summary
Sep 18, 2025
Response Filed
Oct 22, 2025
Non-Final Rejection — §103
Jan 21, 2026
Response Filed
Feb 23, 2026
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12597613
NEGATIVE ELECTRODE COMPOSITION, NEGATIVE ELECTRODE SLURRY, NEGATIVE ELECTRODE PLATE, AND SECONDARY BATTERY AND ELECTRICAL DEVICE CONTAINING SAME
2y 5m to grant Granted Apr 07, 2026
Patent 12592429
HEAT EXHANGER AND BATTERY SYSTEM INCLUDING SAME
2y 5m to grant Granted Mar 31, 2026
Patent 12586866
High-Strength Separator
2y 5m to grant Granted Mar 24, 2026
Patent 12562370
Electrode for Lithium Secondary Battery, Method of Preparing the Same and Lithium Secondary Battery Including the Same
2y 5m to grant Granted Feb 24, 2026
Patent 12548862
ELECTRODE ASSEMBLY AND BATTERY
2y 5m to grant Granted Feb 10, 2026
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
68%
Grant Probability
35%
With Interview (-32.4%)
4y 1m
Median Time to Grant
High
PTA Risk
Based on 868 resolved cases by this examiner. Grant probability derived from career allow rate.

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