Optimization of electrode characteristics for the Br2/H2 redox flow cell

Optimization of electrode characteristics for the Br2/H2 redox flow cell

TitleOptimization of electrode characteristics for the Br2/H2 redox flow cell
Publication TypeJournal Article
Year of Publication2015
AuthorsTucker, Michael C., Kyu-Taek Cho, Adam Z. Weber, Guangyu Lin, and Trung V. Nguyen
JournalJournal of Applied Electrochemistry
Volume45
Issue1
Pagination11 - 19
Date Published1/2015
ISSN0021-891X
Abstract

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.

DOI10.1007/s10800-014-0772-1