Prosecution Insights
Last updated: April 19, 2026
Application No. 18/449,019

AIR ELECTRODE/SEPARATOR ASSEMBLY AND METAL-AIR SECONDARY BATTERY

Non-Final OA §103§112
Filed
Aug 14, 2023
Examiner
LIANG, JACKIE
Art Unit
1726
Tech Center
1700 — Chemical & Materials Engineering
Assignee
NGK Insulators Ltd.
OA Round
1 (Non-Final)
Grant Probability
Favorable
1-2
OA Rounds
3y 2m
To Grant

Examiner Intelligence

Grants only 0% of cases
0%
Career Allow Rate
0 granted / 0 resolved
-65.0% vs TC avg
Minimal +0% lift
Without
With
+0.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
16 currently pending
Career history
16
Total Applications
across all art units

Statute-Specific Performance

§103
48.8%
+8.8% vs TC avg
§102
23.3%
-16.7% vs TC avg
§112
20.9%
-19.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 0 resolved cases

Office Action

§103 §112
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. Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b ) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the appl icant regards as his invention. Claims 2-4 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 2 recites the limitation “a humidity conditioning material” in line 4. It is unclear whether the “humidity conditioning material” in line 4 refers to the “humidity conditioning material” in lines 3-4 of claim 1, which claim 2 depends upon, or a different “humidity conditioning material”. Claims 3 and 4 are similarly rejected due to their dependence on claim 2. 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, 5, 7, 10, 12, 13, and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Koda et al. (JP 2007157445 A, translation provided by applicant) in view of Kitoh et al. (US 2017/0077476 A1) and Mizuno (US 2013/0143132 A1) . Regarding claim 1, Koda et al. discloses a n air electrode/separator assembly (see Koda et al. Annotated Fig. 1 below) , comprising: a separator (paragraph 0008 and Fig. 1, separator 8) , a catalyst layer (paragraph 0027 and Fig. 1, positive electrode catalyst layer 4) comprising a catalyst for an air electrode, an electron conductive material, a binder (paragraph 0019, positive electrode catalyst layer formed from a mixture including an oxygen reduction catalyst, a binder, and a conductive material), and a humidity conditioning material (paragraph 0013, highly hygroscopic polymer that is carboxymethyl cellulose) , and covering one side of the separator (Fig. 1) , and a gas diffusion electrode provided on the catalyst layer on a side opposite to the hydroxide ion conductive separator (paragraph 0028 and Fig. 1, diffusion paper 6 on a side on positive electrode catalyst layer 4 opposite to separator 8) . Koda et al. does not disclose that the separator is a hydroxide ion conductive separator, n or that the catalyst layer further comprises a hydroxide ion conductive material . Kitoh et al. discloses a hydroxide ion conductive separator (paragraphs 0052 and 0056-57, separator is a hydroxide ion conductive separator that is a composite body containing a porous body and a layered double hydroxide). Koda et al. and Kitoh et al. are considered to be analogous to the claimed invention because they are in the same field of metal-air batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator assembly of Koda et al. with the teachings of Kitoh et al., and one of ordinary skill in the art would have a reasonable expectation of success in doing so. Doing so would allow for efficient migration of hydroxide ions between the positive and negative electrodes, resulting in charge/discharge reactions between the electrodes (Kitoh et al. paragraph 0052). Modified Koda does not disclose that the catalyst layer further comprises a hydroxide ion conductive material. Mizuno discloses a catalyst layer comprising a hydroxide ion conductive material (paragraph 0010, air electrode catalyst contains a layered double hydroxide). As evidenced by Kitoh et al. above, layered double hydroxides are hydroxide ion conductive. Mizuno is considered to be analogous to the claimed invention because it is in the same field of metal-air batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator assembly of modified Koda with the teachings of Mizuno, and one of ordinary skill in the art would have a reasonable expectation of success in doing so. Doing so would improve the amount of reduced oxygen and demonstrate high discharge capacity in the air electrode catalyst (Mizuno paragraph 0017). Koda et al. Annotated Fig. 1 Regarding claim 5, modified Koda discloses the limitations of claim 1. Koda et al. further discloses wherein the humidity conditioning material comprises a water absorbent resin (paragraph 0036, carboxymethyl cellulose used as a highly hygroscopic polymer) . Regarding claim 7, modified Koda discloses the limitations of claim 5. Koda et al. further discloses wherein the water absorbent resin is at least one selected from the group consisting of a polyacrylamide resin, potassium polyacrylate, a polyvinyl alcohol resin, and a cellulose resin (paragraph 0036, carboxymethyl cellulose used as a highly hygroscopic polymer) . Regarding claim 10, modified Koda discloses the limitations of claim 1. Modified Koda further discloses wherein the hydroxide ion conductive material in the catalyst layer is a layered double hydroxide (LDH) ( Mizuno paragraph 0010, catalyst contains layered double hydroxide ) . Regarding claim 12, modified Koda discloses the limitations of claim 1. Modified Koda further discloses wherein the hydroxide ion conductive separator is a layered double hydroxide (LDH) separator ( Kitoh et al. paragraph s 0056 -57 , separator is a composite body containing a porous body and a layered double hydroxide) . Regarding claim 13, modified Koda discloses the limitations of claim 12. Modified Koda further discloses wherein the LDH separator is composited with a porous substrate ( Kitoh et al. paragraph s 0056 -57 , separator is a composite body containing a porous body and a layered double hydroxide) . Regarding claim 15, modified Koda discloses the limitations of claim 1. Koda et al. further discloses a metal-air secondary battery (paragraph 0008, air battery) comprising the air electrode/separator assembly according to claim 1 (paragraph 0008 and see Koda et al. Annotated Fig. 1 above, air electrode/separator assembly) , a metal negative electrode (paragraphs 0008 and 0021, negative electrode with active material that is preferably zinc) , and an electrolyte, wherein the electrolyte is separated from the catalyst layer by the hydroxide ion conductive separator interposed therebetween (paragraph 0003, separator interposed between air electrode and gelled negative electrode containing an alkaline electrolyte) . Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Koda et al. (JP 2007157445 A, translation provided by applicant) in view of Kitoh et al. (US 2017/0077476 A1) and Mizuno (US 2013/0143132 A1) as applied to claim 1 above, and further in view of Yajima et al. (US 2008/0014491 A1) . Regarding claim 2, modified Koda discloses the limitations of claim 1. Modified Koda does not disclose wherein the air electrode/separator assembly further comprises a humidity conditioning portion at an outer circumferential portion of the catalyst layer, the humidity conditioning portion comprising a humidity conditioning material. Yajima et al. discloses wherein the air electrode/separator assembly further comprises a humidity conditioning portion at an outer circumferential portion of the catalyst layer (paragraph 0044 and Fig. 1, water-diffusing portion 2a covering the periphery of cathode catalyst layer 2) , the humidity conditioning portion comprising a humidity conditioning material (paragraph 0063, water-diffusing portion 2a formed from a porous material having water absorbing ability) . Although Yajima et al. is in the field of fuel cells rather than the field of metal-air batteries, it is considered to be analogous art because it is reasonably pertinent to the problem faced by the inventor in controlling water produced in a reaction. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the humidity conditioning material of modified Koda with the teachings of Yajima et al. according to known methods to yield the predictable result of water absorption, and one of ordinary skill in the art would have a reasonable expectation of success in doing so (see MPEP §2143(I)(A)). Regarding claim 3, modified Koda discloses the limitations of claim 2. Modified Koda further discloses wherein the humidity conditioning portion is provided at an outer circumferential portion of the catalyst layer other than the top edge thereof (Yajima et al. paragraph 0044 and Fig. 1, water-diffusing portion 2a covering the periphery of cathode catalyst layer 2) . With regard to the limitation “ wherein the air electrode/separator assembly is arranged vertically ,” modified Koda discloses wherein the air electrode/separator assembly is arranged horizontally (Koda et al. Fig. 1, air electrode/separator assembly layers are stacked horizontally), c hanging the orientation of the air electrode current collector would not modify the operation of the air electrode/separator assembly. Arranging the assembly vertically amounts to rearrangement of parts of the air electrode/separator assembly , which would have been a matter of design choice to one having ordinary skill in the art. See In re Japikse , 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) (see MPEP § 2144.04(VI)(C)). Regarding claim 4, modified Koda discloses the limitations of claim 2. Modified Koda further discloses wherein the air electrode/separator assembly is arranged horizontally (Koda et al. Fig. 1, air electrode/separator assembly layers are stacked horizontally), and wherein the humidity conditioning portion is provided over an entire circumferential portion of the catalyst layer (Yajima et al. paragraph 0044 and Fig. 1, water-diffusing portion 2a covering the periphery of cathode catalyst layer 2) . Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Koda et al. (JP 2007157445 A, translation provided by applicant) in view of Kitoh et al. (US 2017/0077476 A1) and Mizuno (US 2013/0143132 A1) as applied to claim 5 above, and further in view of Shiraishi (JP 2005174765 A, translation provided by applicant). Regarding claim 6, modified Koda discloses the limitations of claim 1. Modified Koda does not disclose wherein the humidity conditioning material further comprises a silica gel. Shiraishi discloses wherein the humidity conditioning material further comprises a silica gel (paragraph 0020, silica gel used as a water absorbing material) . Although Shira i shi is in the field of fuel cells rather than the field of metal-air batteries , it is considered to be analogous art because it is reasonably pertinent to the problem faced by the inventor in controlling water produced in a reaction. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the humidity conditioning material of modified Koda with the teachings of Shiraishi according to known methods to yield the predictable result of water absorption, and one of ordinary skill in the art would have a reasonable expectation of success in doing so (see MPEP §2143(I)(A)) . In addition, d oing so would result in a high water absorbing effect (Shira i shi paragraph 0020). Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Koda et al. (JP 2007157445 A, translation provided by applicant) in view of Kitoh et al. (US 2017/0077476 A1) and Mizuno (US 2013/0143132 A1) as applied to claim 1 above, and further in view of Hattori et al. (US 2017/0141445 A1). Regarding claim 8, modified Koda discloses the limitations of claim 1. Modified Koda does not disclose wherein the catalyst layer comprises 0.001 to 15% by volume of the humidity conditioning material in terms of solid content, relative to 100% by volume of solid content of the catalyst layer. Hattori et al. discloses an organic binder that may be carboxymethyl cellulose that is present in the air electrode at an amount less than or equal to 10 volume % (paragraphs 0033-0034). Hattori et al. is considered to be analogous to the claimed invention because it is in the same field of metal-air batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator assembly of modified Koda with the teachings of Hattori et al., according to known methods to yield the predictable result of controlling water absorption in the catalyst layer, and one of ordinary skill in the art would have a reasonable expectation of success in doing so (see MPEP §2143(I)(A)). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See In re Wertheim , 541 F.2d 257, 191 USPQ 90 (CCPA 1976) (see MPEP § 2144.05(I)). Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Koda et al. (JP 2007157445 A, translation provided by applicant) in view of Kitoh et al. (US 2017/0077476 A1) and Mizuno (US 2013/0143132 A1) as applied to claim 1 above, and further in view of Yoshida et al. (US 2013/0302705 A1). Regarding claim 9, modified Koda discloses the limitations of claim 1. Modified Koda does not disclose wherein the catalyst layer comprises a two-layer structure composed of a catalyst layer for charge adjacent to the hydroxide ion conductive separator and a catalyst layer for discharge adjacent to the gas diffusion electrode. Yoshida et al. discloses wherein the catalyst layer comprises a two-layer structure composed of a catalyst layer for charge adjacent to the hydroxide ion conductive separator (paragraphs 0097-0099 and Fig. 1, amphoteric catalyst layer 4 adjacent to anion exchange membrane 3 with oxygen generation ability for charging) and a catalyst layer for discharge adjacent to the gas diffusion electrode (paragraphs 0 102- 0 104 and Fig. 1, oxygen reduction catalyst layer 5 adjacent to gaseous diffusion layer 9 with oxygen reduction ability for discharging) . Yoshida et al. is considered to be analogous to the claimed invention because it is in the same field of metal-air batteries . It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator assembly of modified Koda with the teachings of Yoshida et al. , and one of ordinary skill in the art would have a reasonable expectation of success in doing so. Doing so would result in a battery with one-cell structure capable of discharging and charging with desirable repeating efficiency and excellent discharge output (Yoshida et al. paragraph s 0011 and 0 112 ). Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Koda et al. (JP 2007157445 A, translation provided by applicant) in view of Kitoh et al. (US 2017/0077476 A1) and Mizuno (US 2013/0143132 A1) as applied to claim 1 above, and further in view of Yamamura et al. (US 2017/0012334 A1). Regarding claim 11, modified Koda discloses the limitations of claim 1. Modified Koda does not disclose wherein the catalyst layer comprises 10 to 60% by volume of the hydroxide ion conductive material relative to 100% by volume of solid content of the catalyst layer. Yamamura et al. discloses the amount of the hydroxide-ion-conductive material contained in the air electrode layer is preferably 10 to 80 vol % relative to the total amount of the air electrode catalyst, electron-conductive material, and hydroxide-ion-conductive material (paragraph 0027). Yamamura et al. is considered to be analogous to the claimed invention because it is in the same field of metal-air batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator assembly of modified Koda with the teachings of Yamamura et al., according to known methods to yield the predictable result of controlling hydroxide ion permeability in the catalyst layer, and one of ordinary skill in the art would have a reasonable expectation of success in doing so (see MPEP §2143(I)(A)). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See In re Wertheim , 541 F.2d 257, 191 USPQ 90 (CCPA 1976) (see MPEP § 2144.05(I)). Claim 1 4 is rejected under 35 U.S.C. 103 as being unpatentable over Koda et al. (JP 2007157445 A, translation provided by applicant) in view of Kitoh et al. (US 2017/0077476 A1) and Mizuno (US 2013/0143132 A1) as applied to claim 1 above, and further in view of Kotani et al. (US 2014/0106240 A1). Regarding claim 14, modified Koda discloses the limitations of claim 1. Koda et al. discloses an air electrode current collector (paragraph 0029 and Fig. 1, positive electrode current collector 5 on the same side of diffusion paper 6 as positive electrode catalyst layer 4 ), but does not disclose the air electrode current collector on the gas diffusion electrode on a side opposite to the catalyst layer. Kotani et al. discloses an air electrode current collector on the gas diffusion electrode on a side opposite to the catalyst layer (paragraphs 0045-0046 and 0049 and Fig. 1, catalyst layer 4, gas diffusion layer 5, and current collector 6) . Kotani et al. is considered to be analogous to the claimed invention because it is in the same field of metal-air batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator assembly of modified Koda with the teachings of Kotani et al. , and one of ordinary skill in the art would have a reasonable expectation of success in doing so. Changing the placement of the air electrode current collector would not modify the operation of the air electrode/separator assembly. Relocation of the air electrode current collector to a side opposite to the catalyst layer amounts to rearrangement of parts of the air electrode/separator assembly , which would have been a matter of design choice to one having ordinary skill in the art. See In re Japikse , 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) (see MPEP § 2144.04(VI)(C)). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to FILLIN "Examiner name" \* MERGEFORMAT Jackie Liang whose telephone number is FILLIN "Phone number" \* MERGEFORMAT (571)-272-0880 . The examiner can normally be reached FILLIN "Work Schedule?" \* MERGEFORMAT M-F 8:30AM - 4:30PM . 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, FILLIN "SPE Name?" \* MERGEFORMAT Jeffrey T. Barton can be reached at FILLIN "SPE Phone?" \* MERGEFORMAT (571)-272-1307 . 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. /J.L./ Examiner, Art Unit 1726 /TAMIR AYAD/ Primary Examiner, Art Unit 1726
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Prosecution Timeline

Aug 14, 2023
Application Filed
Mar 16, 2026
Non-Final Rejection — §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
Grant Probability
3y 2m
Median Time to Grant
Low
PTA Risk
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