Development of Stable Bifunctional Air Electrodes for Zinc-Air Flow Batteries

Bifunctional air electrodes for the application in zinc-air flow batteries were manufactured in a scalable manufacturing process using precious metal-free oxide catalysts. During repeated charge/discharge cycling at 50 mA cm-2 and with synthetic air supply stable performances over more than 450 h and 200 cycles were achieved. The energy efficiency was 49% at start and 45% after 200 cycles. In addition, the pulse charging method with 150 mA cm-2 pulses was successfully applied on air electrodes.