Prilling and Coating Strategy to Synthesize High-Performance Spherical NaNi0.4Fe0.2Mn0.4O2 Cathode Materials for Sodium Ion Batteries.

ABSTRACT

Low-cost sodium ion batteries are of great significance in large-scale energy storage applications. With its high energy density and simple synthesis process, layered transition-metal oxides have become one of the most likely sodium ion battery cathode materials to replace lithium ion batteries in the energy storage market. Here, we report a prilling and MoS2 coating strategy to prepare the spherical cathode material. The spherical micronano particles shorten the diffusion path of Na+, restrain the complexity phase transitions, and enhance the tap density of the materials. In addition, the MoS2 coating improves the electrical conductivity of the material and the structural stability of the cathode material in air. The initial specific discharge capacity is 148.4 mA h g-1 at 0.1 C, which can be maintained at 128.9 mA h g-1 after exposure to air for 10 days. This method dramatically improves the energy density and structural stability of the cathode material, which provides a new scheme for preparing high-performance sodium ion batteries.