A silver–bismuth bimetallic functionalized negative electrode for iron–chromium flow batteries

The sluggish redox kinetics of chromium ions at the negative electrode have hindered the development of iron-chromium redox flow batteries. A silver-bismuth bimetallic composite-modified electrode was fabricated <i>via</i> electrodeposition to address this limitation. The modified electrode significantly enhanced the reversibility and electrochemical activity of the Cr³⁺/Cr²⁺ redox reaction. Single-cell performance evaluation demonstrated that the modified electrode achieved coulombic, voltage, and energy efficiencies of 95.09%, 82.26%, and 78.22% at 40 mA cm^-2, respectively. The energy efficiency is increased by 17% compared to conventional graphite felt electrodes.