Prosecution Insights
Last updated: April 19, 2026
Application No. 18/709,529

BATTERY SEPARATORS AND METHODS FOR TESTING THE SAME

Non-Final OA §102
Filed
May 13, 2024
Examiner
HOQUE, FARHANA AKHTER
Art Unit
2858
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Celgard LLC
OA Round
1 (Non-Final)
86%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
97%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
737 granted / 859 resolved
+17.8% vs TC avg
Moderate +11% lift
Without
With
+11.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
21 currently pending
Career history
880
Total Applications
across all art units

Statute-Specific Performance

§101
2.1%
-37.9% vs TC avg
§103
46.8%
+6.8% vs TC avg
§102
42.2%
+2.2% vs TC avg
§112
5.3%
-34.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 859 resolved cases

Office Action

§102
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 § 102 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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claims 1-49 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Hasegawa et al. (U.S. 2018/0316049 A1). With respect to claim 23, Hasegawa discloses a complex method of testing battery separator performance (evaluating battery separator performance in stacked battery structures by measuring short-circuit resistance and electrical resistance behavior across separator layers (see abstract, para 0002-0005, 0045-0052, Figs. 1-3), comprising one or more of the following: measuring the ionic conduction of the separator; measuring the wettability of the separator under vacuum; measuring the wettability of the separator while being squeezed; and, measuring internal short resistance (ISR) of the separator (measuring internal short-circuit resistance to evaluate separator integrity and performance in stacked batteries; abstract, para 0003, 0048-0052). With respect to claim 24, Hasegawa discloses the method of claim 23, wherein the ionic conduction of the separator is measured (measures electrical resistance across separator layers, such resistance measurements necessarily depend on ionic conduction through the separator material, para 0045-0052). With respect to claim 25, Hasegawa discloses the method of claim 23, wherein the wettability of the separator is measured under vacuum (involves controlled pressure environments to ensure proper electrolyte penetration, which includes vacuum or reduced-pressure conditions used to assess wettability). With respect to claim 26, Hasegawa discloses the method of claim 23, wherein the ISR of the separator is measured (measures short-circuit resistance and contact resistance to detect internal shorts in stacked batteries; abstract 0003, 0048-0052). With respect to claim 27, Hasegawa discloses the method of claim 26, wherein the ISR of the separator is measured in an x-direction of the separator (measuring resistance across layered battery structures along defined structural axes measured along a particular direction of the stack). With respect to claim 28, Hasegawa discloses the method of claim 26, wherein the ISR of the separator is measured in the y-direction of the separator (Hasegawa layered structured inherently supports direction-specific resistance measurements, including measurements along a y-direction of the separator). With respect to claim 29, Hasegawa et al. discloses the method of claim 26, wherein the ISR of the separator is measured in the z-direction (Hasegawa measures resistance through thickness of stacked battery layers, i.e. normal to the separator surface (see Figs. 1-3). This thickness measurement corresponds to the z-direction of the separator layer battery structure). With respect to claim 30, Hasegawa et al. discloses the method of claim 26, wherein a squeeze electrode demo is used when testing the ISR of the separator, and the squeeze electrode demo is selected from the following: cathode-material layer/separator/cathode-material layer (para 0045-0052; various electrode materials and current collectors (e.g. cathode material layers, anode material layers, metal foils and conductive structures); anode-material layer/separator/anode-material layer; anode-material layer/separator/cathode-material layer; Cu-foil/separator/aluminum-foil; Al-foil/separator/Cu-foil; Cu-foil/separator/Cu-foil; Cu-mesh/separator/Cu mesh; Al-mesh/separator/Al meshCu particles/separator/Cu particles; and Al- particles/separator/Al particles. With respect to claim 31, Hasegawa discloses the method of claim 23, wherein the wettability of the separator is measured while being squeezed (the separator is squeezed between electrode layers during evaluation; i.e. being compressed and the electrolyte behavior and separator performance are therefore evaluated during compression while the separator is under compressive force while being squeezed). With respect to claim 32, Hasegawa discloses the method of claim 23, wherein the ionic conduction is measured, the wettability under vacuum is measured, and the internal short resistance is measured (measures short-circuit resistance and contact resistance to detect internal shorts in stacked batteries; abstract 0003, 0048-0052). With respect to claim 33, Hasegawa discloses the method of claim 23, wherein the battery separator is a porous polymeric Battery separator (para 0163, lines 1-15). With respect to claim 34, Hasegawa discloses the method of claim 33, wherein the battery separator is a porous polyolefin Battery separator (para 0045-0052; various electrode materials and current collectors (e.g. cathode material layers, anode material layers, metal foils and conductive structures). With respect to claim 35, Hasegawa discloses the method of claim 33, wherein the battery separator is made by a dry-process (para 0144, lines 1-15). With respect to claim 36, Hasegawa discloses the method of claim 35, wherein the battery separator is made by a dry-process that utilizes particles to form pores (para 0144, lines 1-15). With respect to claim 37, Hasegawa discloses the method of claim 35, wherein the battery separator is made by a dry-process that does not utilize particles to form pores (para 0144, lines 1-15). With respect to claim 38, Hasegawa discloses the method of claim 33, wherein the battery separator is made by a wet-process (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144). With respect to claim 39, Hasegawa discloses an ideal separator comprising one or more of the following properties: low electrical resistance (ER)/σᵢ approaching infinity; σₑ approaching zero when the separator is dry or wet with electrolyte; low or no volume (higher Wh/I); low or no weight (high Wh/kg); anti-compression (z-performance, wet); super strong (XYZ direction strength for processing when dry and wet) (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144) all temperature stability (mechanical, electrical, and electro-chemical when wet and dry); and ability to apply infinite force when measuring ISR. With respect to claim 40, Hasegawa discloses the separator of claim 39, wherein the separator is a dry-process separator formed with the use of particles (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144). With respect to claim 41, Hasegawa discloses the separator of claim 39, wherein the separator is a dry-process separator formed without the use of particles (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144). With respect to claim 42, Hasegawa discloses the separator of claim 39, wherein the separator is a wet process separator (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144). With respect to claim 43, Hasegawa discloses a complex method of testing battery separator performance, comprising one or more of the following: measuring the ionic conduction of the separator; measuring the wettability of the separator under vacuum; measuring the wettability of the separator being squeezed (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144) measuring tension strength using a puncture strength test; and, measuring internal short resistance (ISR) of the separator. With respect to claim 44, Hasegawa discloses a complex method of testing battery separator performance, comprising two or more of the following: measuring the ionic conduction of the separator; measuring the wettability of the separator under vacuum; measuring the wettability of the separator being squeezed; measuring tension strength using a puncture strength test; and, measuring internal short resistance (ISR) of the separator (measuring internal short-circuit resistance to evaluate separator integrity and performance in stacked batteries; abstract, para 0003, 0048-0052). With respect to claim 45, Hasegawa discloses a complex method of testing battery separator performance, comprising three or more of the following: measuring the ionic conduction of the separator; measuring the wettability of the separator under vacuum; measuring the wettability of the separator being squeezed; measuring tension strength using a puncture strength test; and, measuring internal short resistance (ISR) of the separator (measuring internal short-circuit resistance to evaluate separator integrity and performance in stacked batteries; abstract, para 0003, 0048-0052). With respect to claim 46, Hasegawa discloses a complex method of testing battery separator performance, comprising four or more of the following: measuring the ionic conduction of the separator; measuring the wettability of the separator under vacuum (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144); measuring the wettability of the separator being squeezed; measuring tension strength using a puncture strength test; and, measuring internal short resistance (ISR) of the separator (measuring internal short-circuit resistance to evaluate separator integrity and performance in stacked batteries; abstract, para 0003, 0048-0052). With respect to claim 47, Hasegawa discloses a battery separator comprising two or more of the following properties: low electrical resistance (ER)/σi approaching infinity; σₑ approaching zero when the separator is dry or wet with electrolyte; low or no volume (higher Wh/I); low or no weight (high Wh/kg); anti-compression (z-performance, when wet); super strong (XYZ direction strength for processing when dry and wet) (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144); all temperature stability (mechanical, electrical, and electro-chemical when wet and dry); and ability to apply infinite force when measuring ISR. With respect to claim 48, Hasegawa discloses a battery separator comprising three or more of the following properties: low electrical resistance (ER)/σi approaching infinity; σₑ approaching zero when the separator is dry or wet with electrolyte; low or no volume (higher Wh/I); low or no weight (high Wh/kg); anti-compression (z-performance, when wet); super strong (XYZ direction strength for processing when dry and wet) (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144); all temperature stability (mechanical, electrical, and electro-chemical when wet and dry); and ability to apply infinite force when measuring ISR. With respect to claim 49, Hasegawa discloses a battery separator comprising four or more of the following properties: low electrical resistance (ER)/σi approaching infinity; σₑ approaching zero when the separator is dry or wet with electrolyte; low or no volume (higher Wh/I); low or no weight (high Wh/kg); anti-compression (z-performance, when wet); super strong (XYZ direction strength for processing when dry and wet); all temperature stability (mechanical, electrical, and electro-chemical when wet and dry) (the wet process is considered here as a paste was produced by mixing N-methylpyrrolidone (NMP) with a conductive material (furnace black, average primary particle size of 66 nm, manufactured by Tokai Carbon Co., Ltd.) and PVDF (KF polymer L#9130, manufactured by Kureha Corp.) so as to be conductive material:PVDF=20:80 in the volume ratio. An Al foil (15 μm thickness, 1N30 manufactured by UACJ Corp.) was coated with the obtained paste so as the thickness after drying to be 10 μm, dried in a drying furnace, and a coating layer was formed; para 0144); and ability to apply infinite force when measuring ISR. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to FARHANA AKHTER HOQUE whose telephone number is (571)270-7543. The examiner can normally be reached Monday-Friday, 7:30am-4:00pm. 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, Eman A Alkafawi can be reached at 571-272-4448. 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. /FARHANA A HOQUE/Primary Examiner, Art Unit 2858
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Prosecution Timeline

May 13, 2024
Application Filed
Feb 07, 2026
Non-Final Rejection — §102 (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

1-2
Expected OA Rounds
86%
Grant Probability
97%
With Interview (+11.2%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 859 resolved cases by this examiner. Grant probability derived from career allow rate.

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