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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 07/16/2026 has been entered.
Information Disclosure Statement
The multiple information disclosure statements filed 07/16/2026 are accompanied with the appropriate IDS size fee assertion under 37 CFR 1.17(v)(3) and have been considered by the Examiner.
Election/Restrictions
Claims 27-37, which have been amended to claim a first electrode comprising an additive including at least one of lead (Species 1C) or antimony (Species 1B) are withdrawn based on the election without traverse (03/07/2025) of Species 1A (a tin additive) in response to the restriction mailed 01/07/2025
Status of Claims
Applicant’s amendment and arguments filed 07/16/2026 have been fully considered. Claim(s) 1 and 27 is/are amended; claim(s) 27-37 are withdrawn (see above); and claim(s) 2-5 and 19-21 has/have been canceled. Examiner affirms that the original disclosure provides adequate support for the amendment.
Upon considering said amendment and arguments, the previous rejection(s) under 35 U.S.C. 103 set forth in the Office action mailed 01/16/2026 has/have been withdrawn.
New grounds of rejection are presented hereinbelow.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 14, 17, 18 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Paulraj et al. (Electrochemical Performance and in Operando Charge Efficiency Measurements of Cu/Sn-Doped Nano Iron Electrodes; copy with 04/09/2025 Office action) in view of Manohar et al. (The Role of Sulfide Additives in Achieving Long Cycle Life Rechargeable Iron Electrodes in Alkaline Batteries; copy with 01/16/2026 Office action) and Narayan et al. (US-20150086884-A1, cited in IDS filed 07/16/2026):
Regarding claim 1, Paulraj discloses a battery comprising a first electrode (“iron electrode”, pp. 4 ¶3) comprising a sintered iron-bearing precursor (“doped nano iron powder’) (p. 3 ¶4).
Paulraj further discloses the addition of sulfur to the first electrode as Bi2S3 to depassivate the electrode (pp. 2 ¶4, pp. 7 ¶2), which would be recognized by the skilled artisan as providing sulfides into the electrolyte from release of S--2- during discharge (evidenced by Manohar pp. A1866 col. 2 ¶3), but does not explicitly indicate a proportion of sulfide in the electrolyte as being between 0.001M and 0.5M.
Manohar, directed to a similar battery comprising an iron electrode provided with Bi--2S3 for the same purpose of inhibiting passivation (Manohar, abstract, pp. A1867 col. 2 ¶1), observes the depletion of sulfide ions during battery operation by oxidation at a counter electrode, causing a capacity loss (pp. A1866 col. 2 ¶5, FIG. 1A). The sulfide loss and capacity degradation may be prevented by providing a concentration of 2 mM (0.002M) sulfide in the electrolyte using Na2S (pp. A1866 col. 1 ¶1).
Thus, in seeking to ensure depassiviation of Paulraj’s first electrode during battery operation and prevent capacity loss, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to provide Paulraj’s electrolyte with a sulfide in a concentration of 0.002M sulfide as taught by Manohar, thus falling within claim 1’s range. Such a modification would be made with a reasonable expectation of success, as Paulraj and Manohar both use sulfides for same purposes of electrode depassiviation, and Manohar teaches applicability of 0.002M sulfide in the electrolyte for an analogous battery chemistry to Paulraj comprising an iron-containing first electrode with Bi2S3.
Modified Paulraj further discloses a second electrode (“counter electrode”) in electrochemical communication with the first electrode via the electrolyte (Paulraj pp. 4 ¶3) as claimed in claim 1.
Paulraj discloses the use of tin as a dopant in the first electrode to inhibit the hydrogen evolution reaction (HER) kinetics (Paulraj p. 12 ¶2), but fails to further disclose the use of tin as one of the additive species in the group of claim 1, being sodium stannate trihydrate (Na2SnO3- 3H20), potassium stannate trihydrate (K2SnO3-3H20), cylindrite (Pb3Sn4FeSb2S14), copper iron tin sulfide (Cu2FeSnS4), lead-tin alloys (60/40 Sn/Pb solder, 63/37 Sn/Pb solder, Terne I alloy: 10-20% Sn, balance Pb), zinc-tin alloys (Terne II alloy: 10-20% Sn, balance Zn), or tin sulfide (SnS or SnS2).
However, tin sulfide is recognized in the art to perform the same HER reaction function; Narayan, a battery with an analogous first electrode formed by sintering an iron-bearing precursor (Narayan, abstract, [0008]) teaches the use of tin sulfide for the same purposes as a HER-reducing additive by sintering tin sulfide in the iron-bearing precursor of the first electrode ([0068], [0071]).
It would therefore be obvious for one having ordinary skill in the art to provide the tin (i.e., Paulraj’s HER-mitigation additive) in the form of tin sulfide in modified Palulraj’s sintered first electrode for the same purpose of mitigating the HER reaction kinetics in the electrode as taught by Narayan, thus reading on the use of tin sulfide in the group of claim 1, with a reasonable expectation of success since it does not alter the intrinsic function the tin additive in modified Paulraj’s first electrode of mitigating the HER reaction (MPEP 2144.06 II).
Regarding claims 14, 17, modified Paulraj discloses the battery of claim 1. Paulraj’s tin additive is in the first electrode in an amount of 2 wt% (Paulraj pp. 3 highlighted section 2); Narayan uses a similar 2-8 wt% composition of tin sulfide (Narayan [0068]). It would therefore be obvious to provide the tin sulfide additive in modified Paulraj’s first electrode in an amount of 2 wt% as exemplified by Paulraj with a tin additive, and as suggested by Narayan’s additive range with a reasonable expectation of success, which falls within claim 14’s range of 0.1-20 wt% and claim 17’s range of 1-10 wt%.
Regarding claim 18, modified Paulraj discloses the battery of claim 1 wherein the electrolyte comprises 6M KOH and 0.65M LiOH (Paulraj pp. 3 highlighted section 4) and 0.002M Na2S (Manohar pp. A1866 col. 1 ¶1) as claimed in claim 18.
Regarding claim 25, modified Paulraj discloses that the additive is in the form of tin sulfide sintered in the first electrode (Paulraj pp. 3 highlighted section 4, Narayan [0068]), which is fully (i.e., at least partially) solid.
Claims 1, 14, 17, 18 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Narayan (US-20150086884-A1, cited in IDS filed 07/16/2026):
Regarding claim 1, Narayan discloses a battery (“nickel-iron battery”, [0064]), comprising:
a first electrode (“iron electrode”) comprising a sintered iron-bearing precursor (“electrode-forming blend”) ([0070]);
an electrolyte comprising a sulfide (“sodium sulfide”) at a concentration of 3 g/L ([0110]), i.e., 0.038 M, which falls within the claimed concentration range of 0.001 M and 0.5 M;
a second electrode (“nickel electrode”) in electrochemical communication with the first electrode via the electrolyte ([0064]).
The first electrode (“iron electrode”) further includes bismuth oxide, sodium bismuth oxide, bismuth sulfide, copper sulfide, nickel sulfide, zinc sulfide, lead sulfide, mercury sulfide, indium sulfide, gallium sulfide, tin sulfide, or iron sulfide additives to reduce discharge passivation and inhibit the hydrogen evolution reaction ([0068]). While Narayan fails to disclose with sufficient specificity an additive from the recited group, given Narayan’s finite list of additives overlaps with the recited list of additives with respect to tin sulfide (SnS or SnS2), it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to explore the selection of at least tin sulfide (SnS or SnS2) as claimed in claim 1 in order to reduce discharge passivation and inhibit the HER reaction under Narayan’s teaching, with a reasonable expectation of success (MPEP 2144.07).
Regarding claims 14 and 17, modified Narayan discloses the battery of claim 1, wherein the additive is in the first electrode in an amount of 1 to 10 wt % of the first electrode ([0068]), which falls within claim 14’s range of 0.1-20 wt% and matches claim 17’s range of 1-10 wt%.
Regarding claim 18, modified Narayan discloses the battery of claim 1, wherein the electrolyte comprises lithium hydroxide and potassium hydroxide ([0067]), as claimed in claim 18 wherein sodium hydroxide and sodium sulfide are recited optionally.
Regarding claim 25, modified Narayan discloses the battery of claim 1, wherein the additive is in the form of tin sulfide sintered in the first electrode (Narayan [0068]) which is fully (i.e., at least partially) solid.
Response to Arguments
Applicant’s arguments with respect to the rejection of amended claim 1 under the previously cited combination of Paulraj in view of Manohar (remarks p. 6-7) have been considered but are moot because the arguments are drawn to the amendment of claim 1 to limit the additive to the tin-based additives recited in the group of claim 1, which has necessitated new grounds of rejection over Paulraj and Manohar in view of Narayan et al. (US20150086884A1) as discussed above, and alternatively under Narayan; see the corresponding rejections of claim 1 (i.e., p. 4, p. 6 of this Office action).
Additionally, Applicant’s arguments that the combination of Paulraj in view of Manohar fails to teach or disclose an additive including at least one of lead or antimony as recited in amended claim 27 (Remarks p. 7-8) have been considered but are moot because amended claim 27 and dependent claims 28-37 have been withdrawn; see §Election/Restrictions above.
Conclusion
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/E.C./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 9/23/2026
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