Influence of sintering temperature on the electrochemical properties of P2-type Na0.67Mn0.7Ni0.2Mg0.1O2 cathodes for sodium-ion batteries

Sodium-ion batteries are thought to be ideal alternatives to Lithium-ion batteries due to their similar electro-chemical properties. However, several technique obstacles in cathode materials still impede the commercialized adoption of Sodium-ion batteries. Herein, the Mg-doping P2-type Na0.67Mn0.7Ni0.2Mg0.1O2 cathode materials were synthesized via a two-step process, including sol-gels and solid-state reaction method. This paper pays much attention to the optimal calcination temperature in the synthesis procedure and its effects are subsequently investigated. According to the results, under a series of calcination temperatures from 800 to 950 degrees C, Na0.67Mn0.7Ni0.2Mg0.1O2 cathode materials shows different particle sizes and crystalline structures, exhibiting varied electrochemical properties. Among them, samples calcinated at 900 degrees C display a high specific discharge capacity of 120.9 mAh g(-1), and a stable cycling performance of 67.2% retention at 1 C rate for 100 cycles. The results suggest that calcination temperature at approximately 900 degrees C could effectively promote the electro-chemical performance, which provides a good reference for the synthesis of cathode materials in sodium-ion batteries.