An Intrinsically Stretchable and Compressible Zn-Air Battery
Stretchability and compressibility are highly practical for next-generation rechargeable metal-air batteries. However, the stretchable and compressible metal-air batteries have never been reported. There are two reasons: on one hand, the conventional polyvinyl alcohol-based electrolytes are neither very stretchable nor compressible; on the other hand, most previously used catalysts are powders which have the inherent defect of easily falling off especially when high strains are applied. Herein, we fabricated an intrinsically highly stretchable and compressible Zn-air battery (ZAB) with decline of nearly 40 times compared to RuO2 in cost of catalyst. The assembled battery consists of a highly stretchable and compressible sodium polyacrylate (PANa) hydrogel electrolyte, and a thin Au bifunctional catalyst macro foil which can well maintain geometric integrity during the whole large stretch and compression. Consequently, the ZAB is intrinsically stretched to 300% strain and compressed to 85% strain with well retained charge/discharge performances.