Construction and electrochemical performance of NaCrO2@Cr2O3 cathode material for sodium-ion batteries
(1. College of Materials and Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China)
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: The electrochemical performance of layered O3-type NaCrO2 cathode material is significantly affected by the side reactions between NaCrO2 and electrolyte during sodium storage. A uniform Cr2O3 coating layer was in situ constructed on the surface of NaCrO2 by controlling the excess ratio of sodium source. The structure, morphology, valence and electrochemical performance of the Cr2O3-coated NaCrO2 were characterized. The results indicate that the Cr2O3 coating layer does not alter the crystal structure and morphology of NaCrO2, but effectively suppresses the side reactions between NaCrO2 and electrolyte, and improves the surface/interfacial stability of NaCrO2 material. The Cr2O3-coated NaCrO2 exhibits improved electrochemical performance with a capacity retention of 66.4% after 500 cycles at 10C.
Key words: NaCrO2; Cr2O3; sodium-ion battery; cathode material; electrochemical performance