Effect of cell design on the durability of secondary zinc-air batteries

Secondary zinc-air batteries (ZAB) are promising sustainable energy storage systems, but their practical implementation has been hindered by a focus on materials, electrode/electrolyte design and formulations that do not translate into an efficient energy storage device. The prevailing cell design features an oversized zinc anode and an unbalanced electrolyte. As a result, the depth of discharge (DoD) of the zinc anode is typically low (<10%) and the durability of tests usually is limited to 500 h. This study focuses on evaluating the electrochemical impact of different cell designs for zinc-air batteries (ZABs) and highlights the critical role of positioning an electrolyte reservoir in close proximity to the zinc anode where a lifetime of up to 4000 h have been obtained. Our tests also involve high utilization of the zinc anode, ranging from 17.5% to 70.0% of the depth of discharge (DoD), equivalent to 136–546 mAh/g_Zn.