Stretchable fiber-shaped aqueous aluminum ion batteries

The emerging wearable electronics have significantly motivated the development of fiber-shaped batteries with excellent electrochemical performance, safety, and flexibility. Aluminum (Al) ion batteries are potential candidates due to their high natural abundance, three-electron-redox behavior, and low cost. However, the integration of Al ion battery into wearable electronics remains unexplored. Herein, a stretchable fiber-shaped aqueous Al ion battery is reported, which involves manganese hexacyanoferrate cathode, graphene oxide decorated MoO3 anode, and hydrogel electrolyte. The resulting fiber-shaped battery exhibits good stretching properties and cycling stability (91.6% over 100 cycles at 1 A cm(-3)). Moreover, by employing a rocking-chair energy storage mechanism, the fiber-shaped battery offers a high specific capacity of 42 mAh cm(-3) at 0.5 A cm(-3), corresponding to a high specific energy of 30.6 mWh cm(-3). As a demonstration, the fiber-based Al ion batteries are integrated into wearable textiles to power LED light, demonstrating the feasibility in stretchable and wearable electronics.