Optimization of electrode characteristics for the Br-2/H-2 redox flow cell

Journal Article · Fri Oct 17 00:00:00 EDT 2014 · Journal of Applied Electrochemistry

DOI:https://doi.org/10.1007/s10800-014-0772-1· OSTI ID:1210990

Tucker, MC; Cho, KT; Weber, AZ; Lin, GY; Nguyen, TV

The Br-2/H-2 redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (-) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (-) catalyst layer on the membrane instead of on the carbon paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm(-2) and a peak power density of 1.4 W cm(-2). Maximum energy efficiency of 79 % is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br- reversibly adsorbs at the Pt (-) electrode for potentials exceeding a critical value, and the extent of Br- coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.

• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• DOE Contract Number: DE-AR0000262
• OSTI ID: 1210990
• Journal Information: Journal of Applied Electrochemistry, Vol. 45, Issue 1; ISSN 0021-891X
• Country of Publication: United States
• Language: English