Recent Advances in Alkali Metal‐Ion Hybrid Supercapacitors

Abstract An alkali metal‐ion hybrid supercapacitor is composed of a battery‐type electrode and a capacitor‐type one, with alkali metal ions transporting in the bulk of the whole device. In brief, batteries and supercapacitors are systematically combined in alkali metal‐ion hybrid supercapacitors accompanying with the fusion of both merits and exceptional performances. Such hybrid devices can deliver both high energy and power density, as well as long cycle life. In this review, the energy storage mechanisms, electrode materials and electrolytes are summarized for alkali metal‐ion hybrid supercapacitors, focusing on recent advances, current problems and future perspectives.