Experimental Concerns of Current Collector Interference and Electrolyte Creep During Zinc-Air Battery Testing

Abstract

Evaluating the electrochemical performance of catalysts towards the oxygen reduction and evolution reactions in zinc-air batteries is a routine process often conducted using a two-electrode cell. At the air electrode, a current collector is necessary if a carbon paper-based gas diffusion layer (GDL) is employed. The catalytic properties of the current collector may interfere with the studied catalyst on the GDL if flaws in cell design allow electrolyte contact to be made with the current collector. At the zinc electrode, highly alkaline electrolytes (e.g., KOH), with high surface tension, can easily climb up the electrode and accumulate at the interface between the cell and the surrounding atmosphere. An oxygen concentration cell is then enabled by the deposited electrolyte and the zinc electrode is rapidly corroded until failure, prematurely ending a long-term cycling test.