Bi₂Se₃@C Rod-like Architecture with Outstanding Electrochemical Properties in Lithium/Potassium-Ion Batteries

Lithium-ion batteries (LIBs) and potassium-ion batteries (KIBs) have broad application prospects in the fields of small/medium-sized electronic products and large-scale energy storage. However, the fast and low reversible capacity decay, poor rate capacity, and slow charge storage kinetics severely affect their large-scale applications. In this work, a Bi2Se3@C rod-like architecture was synthesized through an in situ selenization method using metal–organic frameworks as the precursor. The micro/nanoporous carbon structure not only offers a stable matrix to ensure electrode integrity but also absorbs a large amount of Bi2Se3 changes during repeated lithiation/potassization processes. In addition, the porous structure frame prevents the agglomeration of Bi2Se3 nanoparticles with larger surface energy and shortens the diffusion path of ion transport, thereby improving the rate performance. Therefore, Bi2Se3@C shows outstanding lithium/potassium storage properties when applied in lithium/potassium-ion batteries. The study of the electrochemical reaction mechanism shows that partial rhombohedral Bi2Se3 transformed into orthorhombic Bi2Se3 after cycling. Pseudocapacitance contribution promotes the enhancement of the specific capacity and rate properties of the Bi2Se3@C electrode. The excellent electrochemical performance of the Bi2Se3@C micro/nanostructure shows that it has promising potential as lithium/potassium-ion battery anode materials.