Spherical Li1.26Fe0.22Mn0.52O2 cathode material assembled by molten salt – Spray granulation method and improved cycling performance for Li-ion batteries

Abstract

Due to the abundant reserves of Fe and Mn, the Fe–Mn based cathode material have attracted much attention as electrode materials for next generation lithium ion batteries. In order to keep the high activity and improve the stability of the nanoparticles, the spherical Li1.26Fe0.22Mn0.52O2 is assembled by spray granulation method with nano-precursor prepared by molten salt method. The granulated spheres have a higher specific discharge capacity 197 ​mAh g−1 at 0.2C than that of nanoparticles obtained by simple molten salt method. The granulated spheres also exhibit a distinctly improved cycle stability and rate performance. Moreover, the tap density of granulated spheres increases and their specific surface area decreases obviously, indicating that the primary particles contact closely and particle's contact area with electrolyte reduces. Therefore, particle granulation avails to balance material's activity and stability. In addition, the micron-spherical particles are beneficial to make electrode fabrication easier and increase the specific energy density of batteries.