One-pot construction of all-in-one flexible asymmetrical supercapacitors for extreme-condition applications

All-in-one flexible energy storage devices hold great application potential in the flexible and wearable electronics by virtue of unique configuration, however, still face severe challenges including complex fabrication steps, single variety of symmetrical supercapacitors and limited scenario applications. For the first time, we propose a facile one-pot approach to fabricate all-in-one flexible asymmetrical supercapacitors (AFASCs) through magnetic driving localization of magnetic FeOOH anode away from MnO2 cathode in the electrolyte containing ethylene vinyl alcohol copolymers toward multi-scenario applications. Distinctly different from the reported all-in-one approaches, this one-pot approach dramatically simplifies fabrication steps and especially extends more variety of electroactive materials for asymmetrical supercapacitors and even aqueous battery systems. A wellintegrated configuration without any interfaces forms in the FeOOH/MnO2 AFASCs with low interfacial resistance, high areal capacitance, good cyclic stability and remarkable energy density. Significantly, the FeOOH/ MnO2 AFASCs achieve superhigh capacitance retention not only in long-term bending and twisting deformations, but also under various extreme conditions including cutting, rolling, hammering, puncturing, sewing, soaking and washing in the water, as well as low temperature. Furthermore, the FeOOH/MnO2 AFASCs are demonstrated to power wearable smart bracelet, health monitoring, intelligent positioning system and running pod. Those findings can open up a new approach for one-pot construction of all-in-one flexible energy storage devices to meet future needs of flexible and wearable electronic devices under harsh working conditions.