Cationic potential: An effective descriptor for rational design of layered oxides for sodium-ion batteries

Abstract

Sodium-ion batteries are very promising in large-scale energy storage. The exploration of Na layered oxides as cathode materials for Na ion batteries usually consumes much resource, while the performances of Na layered oxides are dominated by their crystal structures. Therefore, it is highly desired to predict the stacking mode of the target oxides in advance: whether O3-type with higher ordered structure and stability, or P2-type with more Na content. For this purpose density functional theory computations do not work. Very recently, Hu's group and international collaborators have proposed a cationic potential to provide a very timely, effective, and accurate criterion to predict the stacking mode of Na layered oxides (Science, 370 (2020) 708–711). Under the guidance of the cationic potential phase map, Na layered oxides could be rationally designed. Here we would like to highlight the progress that novel Na layered oxides could be obtained with the combination of large specific capacity, high power density and good cycling stability.