Ampere-hour-scale zinc-air pouch cells

Abstract

All-solid-state zinc-air pouch cells promise high energy-to-cost ratios with inherent safety; however, finding earth-abundant high power/energy cathodes and super-ionic electrolytes remains a fundamental challenge. Here we present realistic zinc-air pouch cells designed by the (101)-facet copper phosphosulfide [CPS(101)] as a cathode as well as anti-freezing chitosan-biocellulosics as super-ionic conductor electrolytes. The proposed CPS(101) exhibits trifunctional activity and stability (>30,000 cycles) towards reversible oxygen reactions and hydrogen evolution reactions, outperforming commercial Pt/C and RuO2. Furthermore, hydroxide super-ion conductors utilizing polymerized chitosan-biocellulosics reveal exceptional conductivity (86.7 mS cm(-1) at 25 degrees C) with high mechanical/chemical robustness. High cell-level energy densities of 460 Wh kg(cell)(-1)/1,389 Wh l(-1) are normally measured in pouch cells (1 Ah) with a cycle lifespan of 6,000/1,100 cycles at 25 mA cm(-2) for 20/70% depths of discharge, and the highest densities we could achieve were 523 Wh kg(cell)(-1)/1,609 Wh l(-1). Flexible pouch cells operate well at rates of 5-200 mA cm(-2) over a broad temperature range of -20 to 80 degrees C. Zinc-air batteries are viewed as a sustainable storage technology, but their commercialization requires a genuine performance leap forwards from the laboratory scale. Here the authors report a cell-level design and demonstrate an ampere-hour pouch cell with exceptionally high energy density and cycle lifespan.