Highly\nConductive Supramolecular Salt Gel Electrolyte\nfor Flexible Supercapacitors

Conductive\ngels have greatly facilitated the development of flexible\nenergy storage devices, including supercapacitors, batteries, and\ntriboelectric nanogenerators. However, it is challenging for gel electrolytes\nto tackle the trade-off issues between mechanical properties and conductivity.\nHerein, a strategy of all inorganic salt-driven supramolecular networks\nis presented to construct gel electrolytes with high conductivity\nand reliable mechanical performance for flexible supercapacitors.\nThe salt gel is successfully fabricated by combining a salt supramolecular\nnetwork constructed by NH<sub>4</sub>Mo<sub>7</sub>O<sub>24</sub>·4H<sub>2</sub>O and FeCl<sub>3</sub>·6H<sub>2</sub>O and a polymer\nnetwork of poly(vinyl alcohol). The inorganic salt supramolecular\nnetwork serves as a rigid self-supporting framework in the hydrogel\nsystem for improving the mechanical properties and providing abundant\nactive sites for accelerating ion transport. Furthermore, the salt\ngel-enabled supercapacitors are equipped and exhibit a high specific\ncapacitance (199.4 mF cm<sup>–2</sup>) and excellent energy\ndensity (27.69 μWh cm<sup>–2</sup>). Moreover, the flexible\nsupercapacitors not only present remarkable cyclic stability after\n3000 charging/discharging cycles but also exhibit good electrochemical\nstability even under severe deformation conditions. The strategy of\nsalt-gel-driven flexible supercapacitors would provide fresh thinking\nfor the development of advanced flexible energy storage fields.