3D hierarchical self-supporting Bi₂Se₃-based anode for high-performance lithium/sodium-ion batteries

Bi₂Se₃ is a promising material for anodes in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its abundance, easy preparation, and high capacity. However, its practical application is hindered by low conductivity and significant volume variation during cycling, leading to poor rate capability and cycling stability. Herein, a novel composite consisting of Bi₂Se₃ nanoplates deposited on carbon cloth (CC) and encapsulated by reduced graphene oxide (rGO) has been designed and synthesized. The composite structure combines the advantages of the Bi₂Se₃ nanoplates, CC substrate, and rGO encapsulation, leading to enhanced electrochemical properties. The physical vapor deposition of Bi₂Se₃ nanoplates onto CC ensures a high loading of active material, while the rGO encapsulation provides a conductive and stable framework for the composite. This synergistic design allows for improved electron and ion transport, as well as efficient accommodation of the volume changes during cycling. In LIBs, the composite demonstrates a high reversible capacity of 467.5 mAh/g at 0.1 A/g after 120 cycles. Moreover, it displays an outstanding rate capability, delivering a capacity of 398.6 mAh/g at 5.0 A/g. Similarly, in SIBs, the composite maintains a reversible capacity of 375.3 mAh/g at 0.1 A/g over 100 cycles and exhibits a high-rate capacity of 286.3 mAh/g at 5.0 A/g. This work represents a significant step forward in addressing the challenges associated with Bi₂Se₃ as an anode material, paving the way for the development of high-performance LIBs and SIBs.