Performance characteristics of air-breathing anion-exchange membrane direct ethanol fuel cells

•An air-breathing AEM DEFC with Pt-free electrodes is designed and investigated.•Air-breathing AEM DEFC yields a peak power density of 38 mW cm−2 at room temperature.•The overshoot/undershoot behaviors of cell voltage are avoided in AEM DEFCs.•The cathode water flooding behavior occurs in the air-breathing AEM DEFC.

An air-breathing direct ethanol fuel cell (DEFC) with an anion-exchange membrane (AEM) and Pt-free electrodes is designed and investigated. Particular attention is paid to studying the performance characteristics of the air-breathing AEM DEFC. Experimental results reveal that this air-breathing AEM DEFC yields a peak power density as high as 38 mW cm−2 at room temperature, which is comparable to the conventional Pt-based proton exchange membrane direct methanol fuel cells (PEM DMFCs). The overshoot/undershoot behaviors of both the cell voltage and cell temperature are avoided in the air-breathing AEM DEFC due to the use of ethanol-tolerant cathode catalyst. It is also found that the cathode water flooding behavior occurs in this air-breathing AEM DEFC, thus lowering the cell performance.