Research Progress on Manganese-Based Poly-Anion Cathode Materials for Sodium-Ion Batteries

Poly-anionic compounds (PACs) have emerged as one of the most promising cathode materials for sodium-ion batteries due to their stability, safety, and suitable working voltage. Manganese-based materials, with manganese as the transition metal element, have high cost-effectiveness and strong high-voltage capacity. They are also safe and environmentally friendly. This paper systematically reviews the research progress of manganese-based poly-anionic materials for sodium-ion batteries through literature research, focusing on the working principle of sodium-ion batteries and the structure and electrochemical performance about six common types of manganese-based poly-anionic materials. The research finds that manganese-based PACs show good application prospects due to their three-dimensional stable framework, high voltage and high energy density potential brought by the double-electron reaction. However, they generally have poor electronic conductivity, some materials have actual specific capacities lower than theoretical values, and low ion diffusion efficiency at low temperatures. Ion doping and structural optimization can effectively improve these deficiencies. In addition, this review discusses the important role of technologies such as artificial intelligence in promoting the sustainable development of sodium-ion batteries in the future.