Prosecution Insights
Last updated: April 19, 2026
Application No. 18/050,322

ELECTROLYTE FORMULATIONS AND ADDITIVES FOR IRON ANODE ELECTROCHEMICAL SYSTEMS

Non-Final OA §102§103§DP
Filed
Oct 27, 2022
Examiner
CHOI, EVERETT TIMOTHY
Art Unit
1751
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Form Energy Inc.
OA Round
1 (Non-Final)
17%
Grant Probability
At Risk
1-2
OA Rounds
3y 7m
To Grant
-2%
With Interview

Examiner Intelligence

Grants only 17% of cases
17%
Career Allow Rate
2 granted / 12 resolved
-48.3% vs TC avg
Minimal -18% lift
Without
With
+-18.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
55 currently pending
Career history
67
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
59.4%
+19.4% vs TC avg
§102
25.5%
-14.5% vs TC avg
§112
10.8%
-29.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 12 resolved cases

Office Action

§102 §103 §DP
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 . Election/Restrictions Applicant’s election without traverse of Species 1, an additive comprising tin-based compounds, and Species 2A, a battery wherein the first electrode contains this additive in the reply filed on 01/06/2026 is acknowledged. Claim 2 has been cancelled. Claims 5, 6 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected member of Species 1 (antimony, indium additive compounds), there being no allowable generic or linking claim. Claims 14, 19 are likewise withdrawn as being drawn to a nonelected Species 2B, 2C, batteries where the additive is in the second electrode or electrolyte. Claims 1,3-4,10,13,15,18,20,23,25-28 and 31-32 are pending review in this Office action. Election was made without traverse in the reply filed on 01/06/2026. Claim Interpretation The term “direct reduced iron (DRI) or another sponge iron powder” is a product-by-process claim limitation, i.e., iron obtained by direct reduction. It is noted that product-by-process claims are not limited to the manipulations of the recited steps, only the structure implied by the steps (MPEP 2113 I). The claim term is interpreted as meaning a material comprising iron in a reduced form, such as iron metal Fe0, wustite (FeO), or a composite comprising iron metal and residual oxide phases. Support for this interpretation comes from paragraph [0036] of the instant specification. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1,3-4,10,13,15,18,20,23,25-28 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1,3-4,14,17-18,25,27,29 and 31 of copending Application No. 17/661,256 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Regarding claim(s) 1, 20, claims 1, 18, 27 of Reference claim a battery, comprising: a first electrode, comprising direct reduced iron (DRI) or another sponge iron powder (Ref. 1, “a sintered iron-bearing precursor”; see sec. Claim Interpretation above) (claims 1, 20) an electrolyte (claim 1) comprising a hydroxide (claim 20) (Ref 1, 18); and a second electrode (Ref 1) (claims 1, 20), wherein the first electrode or the electrolyte includes an additive containing an element that has a low hydrogen evolution reaction (HER) activity and/or improves a characteristic of the battery (claim 1) (Ref 1), said additive comprising at least one of tin, lead, indium, or antimony (Ref 27) (claim 20). Regarding claim(s) 3, 4, conflicting claims 3, 4 of Reference have corresponding limitations that are within the scope of the instant claims. Regarding claim(s) 10, conflicting claims 14, 17 of Reference have corresponding limitations that are within the scope of the instant claim. Regarding claim(s) 13, 23, 25-27, conflicting claims 18, 29, 31 of Reference have corresponding limitations that are within the scope of the instant claim. Regarding claim(s) 15, 28, conflicting claims 1, 27 of Reference have corresponding limitations that are within the scope of the instant claims. Regarding claim(s) 18, conflicting claims 25 of Reference have corresponding limitations that are within the scope of the instant claim. Claims 1,3-4,10,13,15,18,20,23,25-28, and 31 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1,16,73,80-82 and 84-85 of copending Application No. 19/001,934 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Regarding claim(s) 1, 20, claims 73, 80, 82, 84 of Reference claim a battery, comprising: a first electrode, comprising direct reduced iron (DRI) or another sponge iron powder (Ref. 73, “a first electrode comprising iron”; see sec. Claim Interpretation above) (claims 1, 20) an electrolyte (claim 1) comprising a hydroxide (claim 20) (Ref 73, 84); and a second electrode (Ref 73) (claims 1, 20), wherein the first electrode or the electrolyte includes an additive containing tin (Ref 73, 80, 82), which is recognized as having a low hydrogen evolution reaction (HER) activity and improving a characteristic of the battery (claim 1, 20) (see inst. spec. [0007]). Regarding claim(s) 3, 4, conflicting claims 73, 80-82 of Reference have corresponding limitations that are within the scope of the instant claims. Regarding claim(s) 10, conflicting claims 73, 80, 82 of Reference have corresponding limitations that are within the scope of the instant claim. Regarding claim(s) 13, 23, 25-27, conflicting claims 73, 84 of Reference have corresponding limitations that are within the scope of the instant claim. Regarding claim(s) 15, 28, conflicting claims 85 of Reference have corresponding limitations that are within the scope of the instant claims. Regarding claim(s) 18, conflicting claims 73, 80, 82 of Reference have corresponding limitations that are within the scope of the instant claim as the first electrode is at least partially a solid, and the additive is contained in the first electrode. Regarding claim(s) 31, conflicting claims 1, 16, 73 of Reference have corresponding limitations that are within the scope of the instant claim. Claim Objections Claim 23 contains minor grammatical errors, reciting inter alia “concentration…in the electrolyte is greater than about 7 M or greater”. Suggested amendments for this limitation include “greater than about 7M” or “about 7 M or greater”. Claims 5, 6, 14, 19, which were withdrawn without traverse in response to the restriction filed 08/19/2025, are objected to for failing to accurately depict the changes made in most recent set of claims filed 01/06/2026. Currently, the statuses of these claims are indicated as being (Original) or (Previously presented) and should be indicated as (Withdrawn); see MPEP 714 I. C. Claim Rejections - 35 USC § 102 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 1,3-4,10,13,15,18,20,25-28 and 31-32 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Paulraj et al. (Electrochemical Performance and in Operando Charge Efficiency Measurements of Cu/Sn-Doped Nano Iron Electrodes, cited with copy in 10-27-2022 IDS) Regarding claim(s) 1, 3, 20, Paulraj discloses a battery, comprising: a first electrode (“iron electrode), comprising direct reduced iron (DRI) or another sponge iron powder (“nano iron powder” P3/¶1-2; see sec. Claim Interpretation) (claims 1, 20) an electrolyte (claim 1) comprising a hydroxide (claim 20) (P3/¶5); and a second electrode (“counter electrode”, P4/¶3) (claims 1, 20), wherein the first electrode includes an additive containing an element (tin) (claims 3, 20) that has a low hydrogen evolution reaction (HER) activity (P3/¶1) and assists in improving a characteristic of the battery (conductivity, iron electrode operational stability) (P5/¶1) (claim 1). Regarding claim(s) 4, 18, Paulraj discloses the battery of claim 3 wherein the additive comprises metallic tin and tin oxide (SnO2) (P6/¶1) (claim 4). These forms are fully (i.e., at least partially) solid (claim 18). Regarding claim(s) 10, Paulraj discloses the battery of claim 1 wherein the additive (Sn) is in the first electrode in an amount from 2 wt% to 4 wt% (Samples 1, 2, P3/¶2), within the claimed range of 0.1-40 wt% of the first electrode. Regarding claim(s) 13, Paulraj discloses the battery of claim 1, wherein the electrolyte comprises potassium hydroxide (KOH) and lithium hydroxide (LiOH) (P3/¶5) Regarding claim(s) 15, 28, Paulraj discloses the battery of claim 1 and claim 20. Paulraj forms the first electrode with bismuth sulfide (P3/¶4). As the first electrode is in contact with the electrolyte solution during assembly and charge/discharge, at least some amount of sulfide initially provided in the first electrode would inherently end up dissolved in (i.e., included in) the electrolyte (claims 15, 28) Regarding claim(s) 25-27, Paulraj discloses the battery of claim 20, wherein the electrolyte includes KOH (claim 25) and 0.65M LiOH (≥0.05M LiOH, claim 26) (P3/¶5), where the mixture of KOH and LiOH is within the group of claim 27. Regarding claim(s) 31, 32, Paulraj discloses the battery of claim 1, wherein experimental examples of the first electrode have discharge capacities ranging from 378-602 mAh/g (P7 Table 3) (>300 mAh/g, claim 31) and discharge potentials ranging from 0.9-0.93 V (P7/¶2) (>0.75V, claim 32). 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. Claim(s) 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Paulraj as applied to claim 20 in view of Weinrich et al. (Silicon and Iron as Resource-Efficient Anode Materials for Ambient-Temperature Metal-Air Batteries: A Review; see copy provided with this office action) Regarding claim(s) 23, Paulraj discloses the battery of claim 20. Paulraj uses an experimental hydroxide concentration of 6.65M to form the alkaline electrolyte (6M KOH, 0.65M LiOH, P3/¶5); while not appearing necessarily limited to this concentration, Paulraj fails to disclose a battery wherein the total concentration of hydroxide in the electrolyte is about 7 M or greater. Weinrich, discussing related silicon-air and iron-air batteries (Weinrich, Abstract), teaches that KOH solutions between 5-8M have improved ionic conductivities and are commonly used as electrolytes in iron-air batteries for this reason (Weinrich P14/¶1). As such, in seeking to optimize the ionic conductivity in modified Paulraj’s electrolyte according to Weinrich’s teaching, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to optimize a KOH concentration between 5-8M (a total hydroxide concentration being 5.65-8.65M OH), and consequently utilize a range of total hydroxide concentration overlapping with a portion of the claimed range between 7-8.65M (≥7M, claim 23) through routine optimization. Such an optimization would be made with a reasonable expectation of success as a range of 7-8.65M is still appreciably close to the 6.65 M of Paulraj’s experimental embodiment (MPEP 2144.05 II). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to EVERETT T CHOI whose telephone number is (703)756-1331. The examiner can normally be reached Monday-Friday 11:00-8:00. 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, Jonathan G Leong can be reached on (571) 270 1292. 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. /E.C./Examiner, Art Unit 1751 /JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 3/10/2026
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Prosecution Timeline

Oct 27, 2022
Application Filed
Mar 10, 2026
Non-Final Rejection — §102, §103, §DP (current)

Precedent Cases

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2y 5m to grant Granted Aug 05, 2025
Study what changed to get past this examiner. Based on 2 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
17%
Grant Probability
-2%
With Interview (-18.2%)
3y 7m
Median Time to Grant
Low
PTA Risk
Based on 12 resolved cases by this examiner. Grant probability derived from career allow rate.

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