Abstract
The charge/discharge characteristics of an undivided redox flow battery, using porous electrodes and chromium-EDTA electrolyte are discussed. The results indicate that a high current efficiency can be achieved using this system with single pass, flow through electrodes. With 0.2 M electrolytes and a charging current density of 30 mA cm−2, 100% current efficiency was achieved with 48% conversion of Cr(III) to Cr(II). However, the overall energy efficiency of charge/discharge of this redox flow battery was less than 7%. The results suggest that this poor efficiency was associated with the slow kinetics and consequently large overpotential of the Cr(V)-EDTA/Cr(III)-EDTA redox couple.
ACKNOWLEDGMENTS
The authors would like to thank Dr. R. A. W. Dryfe, Dr. Kyu Cheol Namkung and Dr. N. Carpenter for helpful discussions during the course of this project. Authors also wish to acknowledge the EPSRC and the University of Malaya for the financial and technical support of this programme.
Notes
*Present Address: Energy Storage and Research, Ford Motor Company, MI 48120, USA.