James J Graf

US Patent:

44488580, May 15, 1984

Filed:

Mar 17, 1983

Appl. No.:

6/476318

Inventors:

James E. Graf - Arcadia CA
John J. Rowlette - Monrovia CA

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

H01M 650

US Classification:

429 49

Abstract:

Batteries (50) containing oxidized, discharged metal electrodes such as an iron-air battery are charged by removing and storing electrolyte in a reservoir (98), pumping fluid reductant such as formalin (aqueous formaldehyde) from a storage tank (106) into the battery in contact with the surfaces of the electrodes. After sufficient iron hydroxide has been reduced to iron, the spent reductant is drained, the electrodes rinsed with water from rinse tank (102) and then the electrolyte in the reservoir (106) is returned to the battery. The battery can be slowly electrically charged when in overnight storage but can be quickly charged in about 10 minutes by the chemical procedure of the invention.