Low-cost polyanion cathodes for sodium ion batteries: challenges, strategies, and progress

Abstract

As one of the most promising battery technologies for commercial applications after lithium-ion batteries, sodium-ion batteries have attracted extensive attention from researchers due to their abundant resources, high safety and wide operating temperature range. They have shown strong competitiveness in large-scale energy storage and some price-sensitive applications. However, the related technical research is not very mature. Among them, as a key component in determining the battery's performance, the choice of cathode materials is crucial. In this regard, the polyanionic cathode material has the characteristics of high working potential and good safety and becomes a promising candidate. However, the low electronic conductivity hinders its further development. Therefore, this review will focus on the modification measures of polyanionic cathode materials, including element doping, surface modification, mophology control, crystal plane design and phase engineering, pay attention to their improvement effect on the performance of active materials, and discuss the modification mechanism and the latest development trend. At the same time, the challenges in the commercialization of polyanionic cathode SIBs are pointed out. This review aims to provide potential modification ideas for researchers and promote the development of polyanion cathode materials for sodium ion batteries.