Improvement of Cycling Stability of Cathode Materials and Industrialization Process for Sodium-ion Batteries

Compared with traditional lithium-ion batteries, sodium-ion batteries are an ideal alternative due to their cost advantages and sustainable resource supply. At present, the cathode materials for sodium-ion batteries mainly include transition metal oxides, polyanionic compounds and Prussian blue analogues. However, irreversible phase conversion, Jahn-Teller effect and interface instability of cathode materials seriously affect the cycling stability of sodium-ion batteries. In this paper, the research progress and industrialization process of strategies for improving cyclic stability of cathode materials for sodium-ion batteries are systematically introduced. Firstly, the structure as well as advantages and disadvantages of cathode materials is analyzed in detail, and the structural stability, cost and cycling performance are compared. Secondly, the latest research progress of structure optimization and chemical element doping strategies in improving the cycling stability of cathode materials is elaborated in detail, and the interaction between structural stability, electronic conductivity, ion intercalation/deintercalation of cathode materials and electrochemical performance is revealed. Then, the development process and industrialization progress sodium-ion batteries are summarized. Finally, the significant problems that still need to be addressed for cathode materials and systems for sodium-ion batteries are sorted out and their future developments are prospected, aiming propel the steady and healthy development of sodium-ion battery industry.