Cycle performance improvement of NaCrO2 cathode by carbon coating for sodium ion batteries

The physical and electrochemical behaviors of the carbon-coated NaCrO2 electrodes for sodium-ion batteries are investigated for the first time. The discharge capacity of carbon-coated NaCrO2 after the 40th cycle remains 110 mAh g− 1. The carbon-coated NaCrO2 shows better performances in terms of the larger discharge capacity and improved cycle stability than naked NaCrO2. Our results have demonstrated the feasibility of the carbon-coating in improving the cyclic stability of electrode materials for sodium ion batteries.

► In this paper, we fabricated carbon-coated NaCrO2 composite by a solid-state reaction process. ► We examined the physical and electrochemical behaviors of the carbon-coated NaCrO2 electrodes with sodium. ► We found the discharge capacity of carbon-coated NaCrO2 of 110 mAh g− 1 after the 40th cycle. ► The carbon-coated NaCrO2 showed larger specific capacity and better cycle performance than those of the naked one. ► The carbon layer on the surface of NaCrO2 could effectively improve the cycling performance.