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 .
Status of Claims
Applicant’s amendment and arguments filed 10/09/2025 have been fully considered. Claim(s) 1, 27 is/are amended; claim(s) 5, 13, 19-21 remain withdrawn; and claim(s) 6-12 15-16 22-24 26, 38-77 is/are canceled. Examiner affirms that the original disclosure provides adequate support for the amendment.
Upon considering said amendment and arguments, the previous rejections under 35 U.S.C. 102 and 35 U.S.C. 103 set forth in the Office action mailed 04/09/2025 has/have been withdrawn. Applicant’s amendment necessitated the new grounds of rejection below.
Election/Restrictions
Examiner noted in the Office action filed 04/09/2025 that the restriction of Species 2A-2F was redrawn to correct the placement of claim 26 as being drawn to a non-elected Species 2B, being incorrectly grouped with Species 2A in the requirement for restriction filed 01/07/2025, and thus was not held final.
As the amendment filed 10/09/2025 cancels claim 26 and no remarks appear to have been filed traversing the restriction as redrawn in the previous Office action filed 04/09/2025, the election has been treated as an election without traverse and is therefore made final.
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.
Claim(s) 1-4, 14, 17-18, 25, 27-28, 36-37 is/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, cited in Office action filed 04/09/2025) in view of Manohar et al. (The Role of Sulfide Additives in Achieving Long Cycle Life Rechargeable Iron Electrodes in Alkaline Batteries; see copy provided with this office action).
Regarding claims 1, 2, 4, 27, Paulraj discloses a battery comprising a first electrode (“iron electrode”, pp. 4 ¶3). The first electrode material is formed of smaller CuSn-doped iron particles fused (i.e., sintered) together (Paulraj pp. 5 ¶ 1). As these smaller CuSn-doped iron particles undergo a step of sintering with each other to form the finished electrode material (i.e., are precursors to the finished material), they are broadly and reasonably interpreted as the sintered iron-bearing precursor (claims 1, 27).
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), Paulraj 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 (claims 1, 27). Such a modification would be made with a reasonable expectation of success, as Paulraj and Manohar both use the 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) (claims 1, 27). The first electrode comprises an additive including tin (pp. 3 ¶2) (claims 2, 4, 27), which has a low hydrogen evolution reaction (HER) activity (pp. 3 ¶1) and is noted as improving charging of the first electrode (pp. 2 ¶5) (claim 1).
Regarding claim 3, modified Paulraj discloses the battery of claim 2, wherein the additive comprises metallic or oxide forms of tin (Paulraj pp. 6 ¶1).
Regarding claims 14 and 17, modified Paulraj discloses the battery of claim 1, wherein the tin additive is in the first electrode in an amount of 2 wt% (Paulraj pp. 3 highlighted section 2), which falls within the claimed ranges of 0.1-20 wt% (claim 14) and 1-10 wt% (claim 17)
Regarding claims 18, 28, 36-37, modified Paulraj discloses the battery of claims 1 and 27 wherein the electrolyte comprises 6M KOH and 0.65M LiOH (Paulraj pp. 3 highlighted section 4) (claims 18, 37) and 0.002M Na2S (Manohar pp. A1866 col. 1 ¶1) (claim 18). The total hydroxide concentration (6.65M) is greater than 6M (claim 28), and the LiOH concentration (0.65M) is greater than 0.05M (claim 36)
Regarding claim 25, modified Paulraj discloses that the additive is in the form of an iron powder doped with the additive (Paulraj pp. 3 highlighted section 4), which is fully (i.e., at least partially) solid.
Claims 29-31, 33-35 are rejected under 35 U.S.C. 103 as being unpatentable over Paulraj in view of Manohar as applied to claim 27, further 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 claims 29-31, 33-35, modified Paulraj discloses the battery of claim 27 where an experimental embodiment has a total hydroxide concentration of 6.65 M (6M KOH, 0.65M LiOH, Paulraj pp. 3 highlighted section 4). While modified Paulraj does not appear necessarily limited to this concentration, and envisions considerations of improving the ionic conductivity of the battery (pp. 4 ¶4), modified Paulraj fails to disclose a battery having a total hydroxide concentration greater than 7M (claim 29) or between 7-11 M (claim 30), 7-10 M (claim 33), or 7.5-9.5 M (claim 34). Furthermore, while the electrolyte comprises greater than 0.05M LiOH, electrolyte also does not comprise greater than 6M KOH and NaOH (claim 31)
Weinrich, directed to a review of silicon-air and iron-air batteries (Weinrich, Abstract), teaches that KOH solutions between 5-8M have improved ionic conductivities and are thus commonly used for electrolytes in Fe-air batteries for this reason (pp. 14 ¶1). While Paulraj is not directed to a Fe-air battery specifically, Paulraj acknowledges both Ni-Fe and Fe-air battery chemistries as being similar battery applications such that a skilled artisan would still consider use of Weinrich’s teaching for use in modified Paulraj’s electrolyte (Paulraj pp. 12 ¶3).
As such, in seeking to provide sufficient ionic conductivity of modified Paulraj’s electrolyte, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to select a KOH concentration between 5-8M (a total hydroxide concentration being 5.65-8.65M OH) overlapping the recited ranges between 7-8.65M (claims 29, 30, 33) wherein the electrolyte includes KOH (claim 35), 7.5-8.65M hydroxide (claim 34), and 6-8M total KOH/NaOH (claim 31) such that one skilled in the art could have routinely selected within the overlap with the reasonable expectation of success, as Weinrich teaches a suitability of this hydroxide composition for the purpose of ionic conductivity and because this range is still appreciably close to the 6.65 M of Paulraj’s experimental embodiment.
Claim 32 is rejected under 35 U.S.C. 103 as being unpatentable over Paulraj in view of Manohar as applied to claim 30, further in view of Phillips et al. (US20090246623A1, cited in Office action filed 04/09/2025).
Regarding claim 32, modified Paulraj discloses the battery of claim 30 wherein the electrolyte comprises a molar concentration of KOH greater than that of LiOH (Paulraj pp. 3 ¶5), as LiOH is provided as an additive in smaller quantities for the purpose of improving iron dissolution as opposed to KOH, which is used as the primary component of the electrolyte (pp. 5 ¶2). While Paulraj does not appear incompatible with Na in the electrolyte, disclosing a suitability of adding Na2S as a sulfide source (pp. 2 ¶4), Paulraj fails to disclose the inclusion of NaOH in the electrolyte or indicate a molar concentration being less than that of KOH and greater than that of LiOH.
Phillips is directed to electrode and electrolyte compositions for a nickel-zinc secondary battery (Phillips, abstract) using an alkaline electrolyte solution (Phillips [0009]) related in scope to Paulraj which also uses an alkaline electrolyte (Paulraj pp. 12 ¶3). Phillips teaches NaOH, KOH, and LiOH as being suitable sources of alkalinity in an electrolyte having a similar range of 6-9M total hydroxide ([0010]).
As such, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to combine the use of KOH and NaOH in modified Paulraj’s electrolyte, with a reasonable expectation of success as Phillips teaches that both KOH and NaOH are equivalents for the same purpose as sources of alkalinity, i.e., hydroxide in the electrolyte (MPEP 2144.06 I).
Furthermore, as Paulraj appears to envision use of LiOH as an additive in a small concentration and not as a primary source of hydroxide in the alkaline electrolyte (pp. 5 ¶2), an ordinary skilled artisan would realistically consider only three possible molar concentrations of KOH, NaOH, and LiOH relative to each other, those being [KOH]>[NaOH]>[LiOH] as claimed in addition to [KOH]=[NaOH]>[LiOH] and [NaOH]>[KOH]>[LiOH]. As a person having ordinary skill in the art would necessarily select one of these options in order to produce modified Paulraj’s alkaline electrolyte with both a suitable hydroxide concentration and LiOH concentration, it would be obvious for one having ordinary skill in the art to routinely explore selecting hydroxides having relative molar concentrations of [KOH]>[NaOH]>[LiOH] in modified Paulraj’s electrolyte with a reasonable expectation of success.
Response to Arguments
Applicant’s arguments with respect to rejection of amended claims 1 and 27 under 35 U.S.C. 103 over Paulraj in view of Benson WO-2019133702-A1 (cited in previous Office action filed 04/09/2025) have been considered but are moot because the new ground of rejection as necessitated by amendment does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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.
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/E.C./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 1/12/2026