A flexible self-healing Zn 3 V 2 O 7 (OH) 2 ·2H 2 O-based Zn-ion battery under continuous folding and twisting.

Engineering flexible and self-healing batteries is significant for wearable electronics. Here, we develop a flexible self-healing Zn-ion battery with a Zn 3 V 2 O 7 (OH) 2 ·2H 2 O cathode working with a polyvinyl alcohol hydrogel electrolyte. The battery achieves a high capacity and robust structure during switching and self-healing, and keeps a stable potential after cutting/healing several times. After being bent at 30°, 60°, 90°, 120° and 150°, the capacities remain stable, and the battery delivers 78.6 mA h g -1 when repeatedly folding at 90°, displaying the potential for various applications such as foldable cell phones.