Enhanced Solar-Driven-Heating and Tough Hydrogel Electrolyte by Photothermal Effect and Hofmeister Effect.

Although plenty of progress and achievements are made on hydrogel electrolyte researches, the inherent inferior low-temperature performance of hydrogel electrolyte is still a severe challenge for wider application on the energy storage devices, due to the high content of water within hydrogel. Herein, an enhanced solar-driven-heating composite hydrogel electrolyte and a solar-driven-heating graphene based micro-supercapacitor are developed utilizing the photothermal conversion ability and self-initiation of MoS2 nanosheets and additional Hofmeister effect. The MoS2 composite hydrogel electrolyte not only improves the reliability of micro-supercapacitor owing to its splendid mechanical properties, but also endows the micro-supercapacitor with superior low-temperature electrochemical performance and broadens its operating environment to a much lower temperature (-56 °C), which should be attributed to the excellent ability in converting endless solar energy into required thermal energy. These efforts would construct a new application platform for solar energy conversion and present an efficient method to structure severe-cold resistant solid state energy storage devices for next-generation.