Recent Progress on CoP as Anodes for Metal-Ion Batteries

With the rapid development of portable electronic devices and electric vehicles, metal-ion batteries, especially lithium/sodium/potassium-ion batteries (LIBs/SIBs/PIBs), have become a research hotspot because of their high energy density and cycle stability. The battery system primarily comprises three key components: negative electrode material, positive electrode material, electrolyte, and diaphragm. The selection of the negative electrode material will directly impact the battery's energy density. Among many anode materials, CoP has received widespread attention for its high theoretical capacity (894mAh g^-1). However, cobalt phosphide faces challenges related to electrochemical instability, which stems from its poor intrinsic conductivity and substantial volume expansion during charge/discharge cycling. This article reviews the progress of CoP as an anode material for metal-ion batteries over the past decade. It discusses its electrochemical performance in LIBs/SIBs/PIBs, including specific capacity, cycling stability, and rate performance. In addition, the article discusses the synthesis methods and structural regulation of CoP, as well as the strategies to improve its electrochemical performance by constructing heterostructures and compositing with carbonaceous materials. Finally, the article points out the challenges in the current research and the future development direction, to provide theoretical guidance and experimental reference for the practical application of CoP in metal-ion batteries.