Structure Stabilization in Layered Transition Metal Oxide Positive Electrodes for Sodium Ion Batteries

Sodium-ion batteries (SIBs) have stepped into the spotlight as a promising alternative to lithium-ion batteries (LIBs) for large-scale energy storage systems. However, the stability and performance of sodium ion battery electrode materials are lacking compared to their lithium counterparts as a consequence of the larger size of the Na⁺ ion compared to Li⁺. The layered transition metal oxide (LTMO) positive electrodes have attracted extensive attention for SIBs due to its favorable electrochemical performance. However, they suffer from complex and irreversible phase transitions during cycling, which leads to the chemomechanically-induced structural degradation and rapid capacity decay, limiting its practical applications. In this talk, we will discuss our recent progress in stabilizing LTMO structures during cycling and the origin of the phase interface’s influence on the Na⁺ storage and transport properties. <i>In situ</i>/operando spectroscopic techniques used in our work to track the phase transitions will also be discussed.