Requirements for optimization of electrodes and electrolyte for the iron/chromium redox flow cell

Technical Report · Tue Sep 01 00:00:00 EDT 1981

DOI:https://doi.org/10.2172/5328915· OSTI ID:5328915

Jalan, V.; Stark, H.; Giner, J.

The iron/chromium redox flow cell has become an attractive system for bulk energy storage application. Earlier investigations at Giner, Inc. had established that the solubility and stability of aqueous acidic solution of Cr(II) and Cr(III) chlorides are sufficient for redox applications and had resulted in a number of findings which have enhanced the attractiveness of the Cr(III)/Cr(II) vs. Fe(III)/Fe(II) redox cell. The discovery of gold/lead combination electrocatalyst has proved to be the only system to date that provides a high activity for Cr(III)/CR(II) redox reaction and very high hydrogen overvoltage. A combination of gold and lead deposited on porous carbon felt structure provided a practical electrode for the Cr side for the redox flow cell. Improved catalyzation techniques were developed that included a pretreatment of carbon substrate and provided normalized carbon surface for uniform gold deposition. This permitted to efficiently use different batches of carbon felt materials which initially vary significantly in their physical and surface chemical properties, as well as their electrochemical behavior. Further modifications of gold impregnation technique (an alcohol assisted technique) gave to date the best performing electrodes. In addition to the liner sweep voltammetry, cyclic voltammetry has been used to determine the effects of different activation procedures on the Cr(III)/Cr(II) redox and H/sub 2/ evolution reactions. Attempts are made to identify the roles of carbon, gold and lead in the overall redox cycle. The behavior of the electrodes at both normal battery operating potentials and more extreme potentials is discussed with the implications for preparing efficient and stable electrodes for the energy storag battery.

• Research Organization: NASA Lewis Research Center, Cleveland, OH (United States); Giner, Inc., Waltham, MA (USA)
• DOE Contract Number: AI04-80AL12726
• OSTI ID: 5328915
• Report Number(s): DOE/NASA/0097-80/1; NASA-CR-165218; ON: DE82016122
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
ELECTROCATALYSTS
FABRICATION
PERFORMANCE TESTING
REDOX FUEL CELLS
OPTIMIZATION
CARBON
CATALYSIS
CATALYST SUPPORTS
CHROMIUM CHLORIDES
CHROMIUM IONS
DESIGN
ELECTRODES
ELECTROLYTES
ENERGY STORAGE SYSTEMS
GOLD
IMPURITIES
IRON IONS
LEAD
OVERVOLTAGE
REDOX REACTIONS
VOLTAMETRY
CATALYSTS
CHARGED PARTICLES
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CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM COMPOUNDS
DIRECT ENERGY CONVERTERS
ELECTROCHEMICAL CELLS
ELEMENTS
ENERGY SYSTEMS
FUEL CELLS
HALIDES
HALOGEN COMPOUNDS
IONS
METALS
NONMETALS
REGENERATIVE FUEL CELLS
TESTING
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
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300501 - Fuel Cells- Design & Development
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