Two-dimensional graphene/quasi-two-dimensional graphene analogues for flexible supercapacitor in all-solid-state

Two-dimensional (2D) graphene/quasi-two-dimensional inorganic materials have been widely explored for construction of energy- related applications. Catering for rapid development of portable electronic devices, energy storage devices with ultra-thin and high flexibility are urgently needed. Very recently, planar supercapacitor with novel configurations has been rapidly developed as important energy storage devices. In this regard, the assembled thin film of 2D graphene and quasi-2D graphene analogues acted as the vital role for the planar configurations as well as the enhanced performances in the construction of planar energy storage device. This review summarized the construction concept of flexible supercapacitors in all-solid-state based on 2D graphene and quasi-2D graphene analogues. We also surveyed how to select quasi-2D graphene analogues with high electrochemical properties, and even how to use the synergic advantages of hybrid structure for further performance enhancement of planar supercapacitors. Recent progresses and possible future applications on planar supercapacitors were also reviewed and outlooked.