Bi@C Nanoplates Derived from (BiO)2CO3 as an Enhanced Electrode Material for Lithium/Sodium‐Ion Batteries

Abstract Two‐dimensional (2D) carbon coated bismuth nanoplates (Bi@C) were prepared by a self‐template and subsequent thermal treatment process utilizing 2D (BiO) 2 CO 3 nanosheets as starting material. The 2D nanoplates provide feasible pathways for electrons and ions while the outer carbon‐coated layer efficiently prohibited the agglomeration of Bi and accommodated the huge volume change of Bi during the charging/discharging process. The as‐obtained Bi@C nanoplates maintain a capacity higher than 420 mAh g −1 after 150 cycles as an anode of lithium ion batteries (LIBs). For sodium ion batteries (SIBs), a capacity of approximately 200 mAh g −1 over 200 cycles was achieved by the Bi@C electrode. The as‐obtained 2D Bi@C nanoplates solves the problem of low conductivity and a large volume change of Bi when applied as an anode of secondary batteries, offering a simple, low‐cost, and eco‐friendly method for fabricating bismuth‐carbon composite electrodes with excellent electrochemical performance in LIBs and SIBs.