Two-dimensional black phosphorus: Properties, fabrication and application for flexible supercapacitors

With the rapid development of flexible functional electronics (e.g., flexible display, electronic skin and intelligent wearable device), flexible supercapacitors (FSCs) have gained increasing concerns in the field of energy-storage devices. Benefiting from the unique structure and intrinsic excellent properties of two-dimensional material, in particular, two-dimensional black phosphorus (2D BP), the FSCs based on 2D BP have drawn a significant interest for practical applications. Herein, we have briefly reviewed the structures and properties of BP, illuminating its potential application for FSCs. The fabrication processes of BP in different dimensions including bulk BP, few-layer BP and BP quantum dots (BPQDs) are presented in detail. Moreover, the design strategies of BP-based FSCs including conventional sandwich-like structure, micro-in-plane configuration and other novel architectures are highlighted. Finally, the future challenges and development prospects of BP-based FSCs with high electrochemical performances are discussed. Based on the brief summary of the BP-based FSCs, this review is believed to inspire new research ideas for the exploration of BP-based FSCs with high electrochemical performances and excellent flexibility, so as to meet the latest requirements for the next-generation energy storage devices.