Two‐Dimensional Layered BiOX (X=Cl, Br) Compounds as Anode Materials for Lithium‐Ion Batteries

Many layered structure nanomaterials have been suggested as promising electrode materials for lithium‐ion batteries. Ternary layered compounds, BiOX (X=Cl, Br) are usually used as photocatalysts for energy generation and environmental protection. However, there has not been a report of BiOX as electrode materials for lithium‐ion batteries to this point. In this study, two‐dimensional BiOX nanosheets are synthesized using a hydrothermal method, and electrochemical measurements show that layered BiOX can display remarkable electrochemical performance for use as an anode in lithium‐ion batteries. Capacities of approximately 254 and 230 mAh g −1 are maintained after 15 cycles at a current density of 500 mA g −1 for BiOCl and BiOBr, respectively. The electrochemical properties are much better than that of BiOI (137 mAh g −1 ). Study of the mechanism reveals that Li 3 OX (X=Cl, Br) and Li 3 Bi are formed after the lithium ions become embedded in the layered BiOX.