Hybrid Halide Perovskite‐Based Electrochemical Supercapacitors: Recent Progress and Perspective

Hybrid halide perovskites have become highly popular mixed electronic−ionic material over the past decade due to a wide range of applications in flexible optoelectronics especially for energy conversion and light‐emitting devices. While ion migration in these materials is the main cause of device instability under heat and light, this property can make them ideal for energy storage applications such as Li‐ion batteries, photorechargeable batteries, and supercapacitors. Herein, progress so far in the field of perovskite material‐based electrochemical supercapacitors is summarized, unraveling charge storage mechanisms in these types of devices, as well as important perspectives for future development of the field. In these types of materials, the total charge/energy storage can be modulated by the induced field due to ion migration inside the bulk perovskite film. The electronic−ionic coupling in metal halide perovskite materials is crucial for the charge storage mechanism in perovskite‐based energy storage devices. A general strategy is proposed to prepare the porous perovskite electrode from the powder of perovskite single crystals for high‐performance perovskite supercapacitors. The modified power law equation for perovskite‐based energy storage devices is proposed. In the end, the possibility of photorechargeable perovskite‐based energy storage devices is also discussed.