# US 10,374,261 B2 · High efficiency iron electrode and additives for use in rechargeable iron-based batteries > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,261 B2 - Document ID: US10374261B2 - Status: Granted - Kind: B2 - Application number: 15/358,291 - Filed: 2016-11-22 - Published: 2017-05-18 - Granted: 2019-08-06 - Earliest claimed: 2011-06-15 - Assignees: University of Southern California - Applicants: University of Southern California - Inventors: Sri R. Narayan; G. K. Surya Prakash; Robert Aniszfeld; Aswin Manohar; Souradip Malkhandi; Bo Yang - Web page: https://patentgrep.com/patent/US10374261B2 ## CPC - H01M 10/30: Nickel accumulators (H01M10/34 takes precedence) - H01M 4/12: of consumable metal or alloy electrodes (use of alloy compositions as active materials H01M4/38) - H01M 4/364: {as mixtures} - H01M 4/366: {as layered products} - H01M 4/38: of elements or alloys - H01M 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers - H01M 4/622: {being polymers} - H01M 10/26: Selection of materials as electrolytes - H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)} - H01M 12/065: {with plate-like electrodes or stacks of plate-like electrodes} - H01M 12/08: composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type - H01M 2004/021: {Physical characteristics, e.g. porosity, surface area} - H01M 2220/10: Batteries in stationary systems, e.g. emergency power source in plant - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract An iron electrode and a method of manufacturing an iron electrode for use in an iron-based rechargeable battery are disclosed. In one embodiment, the iron electrode includes carbonyl iron powder and one of a metal sulfide additive or metal oxide additive selected from the group of metals consisting of bismuth, lead, mercury, indium, gallium, and tin for suppressing hydrogen evolution at the iron electrode during charging of the iron-based rechargeable battery. An iron-air rechargeable battery including an iron electrode comprising carbonyl iron is also disclosed, as is an iron-air battery wherein at least one of the iron electrode and the electrolyte includes an organosulfur additive. ## Claims ### Claim 1 A nickel-iron rechargeable battery comprising a. an iron electrode comprising carbonyl iron, a polymeric binder and bismuth sulfide, wherein bismuth sulfide is present in an amount from 5 to 10 w/w % of the weight of the iron electrode; b. a nickel electrode spaced from the iron electrode; and c. an alkaline electrolyte in contact with the iron electrode and the nickel electrode. ### Claim 2 (depends on 1) The nickel-iron rechargeable battery of claim 1, wherein during cycling the battery the iron electrode comprises bismuth and iron sulfide. ### Claim 3 (depends on 1) The nickel-iron rechargeable battery of claim 1, wherein the polymeric binder is present in an amount from 5 to 30 w/w % of the weight of the iron electrode. ### Claim 4 (depends on 1) The nickel-iron rechargeable battery of claim 1, wherein the iron electrode is porous. ### Claim 5 (depends on 1) The nickel-iron rechargeable battery of claim 1, wherein the alkaline electrolyte comprises KOH. ### Claim 6 A nickel-iron rechargeable battery comprising a. an iron electrode comprising carbonyl iron, a polymeric binder, and a bismuth oxide additive; wherein the iron electrode is porous; b. a nickel electrode spaced from the iron electrode; and c. an alkaline electrolyte in contact with the iron electrode and the nickel electrode. ### Claim 7 (depends on 6) The nickel-iron rechargeable battery of claim 6, wherein during cycling of the battery the iron electrode comprises bismuth and iron sulfide. ### Claim 8 (depends on 6) The nickel-iron rechargeable battery of claim 6, wherein the polymeric binder is present in an amount from 5 to 30 w/w % of the weight of the iron electrode. ### Claim 9 (depends on 6) The nickel-iron rechargeable battery of claim 6, wherein the alkaline electrolyte comprises KOH. ### Claim 10 A nickel-iron rechargeable battery comprising a. an iron electrode comprising carbonyl iron, a polymeric binder and a bismuth oxide additive; wherein the iron electrode is porous; b. a nickel electrode spaced from the iron electrode; and c. an alkaline electrolyte in contact with the iron electrode and the nickel electrode. ### Claim 11 (depends on 10) The nickel-iron rechargeable battery of claim 10, wherein during cycling of the battery the iron electrode comprises bismuth. ### Claim 12 (depends on 10) The nickel-iron rechargeable battery of claim 10, wherein the polymeric binder is present in an amount from 5 to 30 w/w % polymeric binder. ### Claim 13 (depends on 10) The nickel-iron rechargeable battery of claim 10, wherein the alkaline electrolyte comprises KOH. ### Claim 14 A method for manufacturing an iron electrode for use in an iron-based rechargeable battery, the method comprising: a. combining carbonyl iron powder with a polymeric binder and a bismuth sulfide additive to create a mixture; wherein the bismuth sulfide additive is present in an amount from 5 to 10 w/w % of the weight of the mixture; and b. coating a metallic grid with the mixture. ### Claim 15 (depends on 14) The method of claim 14, wherein during cycling of the battery the iron electrode comprises bismuth and iron sulfide. ### Claim 16 (depends on 14) The method of claim 14 further comprising charging and discharging the formed electrode a plurality of times to allow the discharge capacity to increase to a stable value and the electrode to reach a lower hydrogen evolution rate. ### Claim 17 (depends on 14) The method of claim 14, wherein the mixture comprises 5 to 30 w/w % polymeric binder. ### Claim 18 (depends on 14) The method of claim 14, wherein the mixture further comprises 5 to 50 w/w % soluble additive. ### Claim 19 (depends on 14) The method of claim 14 further comprising the step of heating and applying pressure to the metallic grid.