US 11,929,528 B2
Apparatus and method for determining state of charge in a redox flow battery via limiting currents
Evan R. King, Quincy, MA (US); Kean Duffey, Brighton, MA (US); Adam Morris-Cohen, Maynard, MA (US); John Goeltz, Carmel, CA (US); and Steven Y. Reece, Cambridge, MA (US)
Assigned to Lockheed Martin Energy, LLC, Bethesda, MD (US)
Filed by Lockheed Martin Energy, LLC, Bethesda, MD (US)
Filed on Aug. 19, 2020, as Appl. No. 16/997,403.
Application 16/997,403 is a division of application No. 15/033,607, granted, now 10,833,340, previously published as PCT/US2014/063290, filed on Oct. 31, 2014.
Claims priority of provisional application 61/898,635, filed on Nov. 1, 2013.
Prior Publication US 2020/0381751 A1, Dec. 3, 2020
Int. Cl. H01M 8/04186 (2016.01); H01M 4/96 (2006.01); H01M 8/04082 (2016.01); H01M 8/0444 (2016.01); H01M 8/04791 (2016.01); H01M 8/18 (2006.01); H01M 8/20 (2006.01); H01M 8/22 (2006.01)
CPC H01M 8/04194 (2013.01) [H01M 4/96 (2013.01); H01M 8/04201 (2013.01); H01M 8/0444 (2013.01); H01M 8/04791 (2013.01); H01M 8/188 (2013.01); H01M 8/20 (2013.01); H01M 8/222 (2013.01); Y02E 60/50 (2013.01)] 40 Claims
OG exemplary drawing
 
1. A method of determining the ratio of the oxidized and reduced forms of a redox couple in solution, said method comprising:
(a) contacting a first stationary working electrode and a first counter electrode to the solution;
(b) contacting a second stationary working electrode and a second counter electrode to the solution;
(c) applying a first potential at the first stationary working electrode relative to the first counter electrode and measuring a first constant current for the first stationary working electrode; and
(d) applying a second potential at the second stationary working electrode relative to the second counter electrode and measuring a second constant current for the second stationary working electrode;
wherein the first and second constant currents have opposite signs; and
wherein the ratio of the absolute values of the first and second constant currents reflects the ratio of the oxidized and reduced forms of the redox couple in solution.