2D and 3D Halide Perovskite‐Based Supercapacitors

Abstract Metal halide perovskites (MHPs) are extremely promising materials for energy storage applications. Among them, two‐dimensional (2D) halide perovskites attract much attention for supercapacitor applications because of exciting properties such as electronic confinement, structural flexibility, attractive performance and stability. On the other hand, owing to its low exciton binding energy and long‐range carrier transport nature, three‐dimensional (3D) halide perovskites have been employed as one of the most promising supercapacitor materials. These materials have become one of the highly promising mixed electronic‐ionic material for efficient energy storage devices. 2D and 3D MHPs have distinctive physicochemical and electrochemical characteristics, and capacity to create hetero‐structures to strengthen their electrochemical capabilities. Thus, it is important to understand synthesis, properties and various electrochemical aspects of MHPs and their super‐capacitive behaviors. This review article focuses on the extensive overview of the recent developments of MHPs which have demonstrated exciting possibilities as supercapacitor materials but relatively less explored till now. Our review article comprises of synthesis processes, opto‐electronic properties, mechanism, supercapacitor performances, challenges and opportunities in brief. This review thus thoroughly discusses the importance and intriguing aspect of 2D and 3D halide perovskites as supercapacitor materials for their futuristic energy storage applications.