Enhanced Electrochemical Performance of Mesocarbon-Microbeads-Based Anodes through Air Oxidation for Sodium-Ion Batteries

Air oxidation is introduced as a simple and feasible method of modification for mesocarbon microbeads (MCMBs), which improves the electrochemical performance of MCMBs as anodes for sodium-ion batteries (SIBs). Optimal oxidation conditions are explored. Green MCMBs, initially oxidized at 360 degrees C then carbonized (OC-MCMB360), exhibit a high reversible capacity up to 286mAhg(-1) at a current density of 25mAg(-1). In addition, the OC-MCMB360 sample also presents an excellent rate performance with 79mAhg(-1) at a current density of 3.2Ag(-1) and a considerable reversible capacity of 166mAhg(-1) after 100 cycles at 100mAg(-1). The larger interlayer spacing and increased defect sites caused by oxidation contribute to the enhanced electrochemical performance of oxidized MCMBs in SIBs.