Effect of calcination temperature on the structure and electrochemical performance of single crystal Li-rich materials

Single crystal cathode materials have better cycling stability than the polycrystalline ones, since they own smaller specific surface area and better mechanical strength, thus suffering from reduced contact with electrolyte and suppressed generation of cracks during long-term cycling. Consequently, in this work, the single crystal Li-rich materials were synthesized using a molten salt method towards solving the problem of fast capacity decline. We investigated the role of calcination temperature on the structure and performance of synthesized Li-rich materials, and found out that higher temperature is beneficial to the particle growth and structural stability, but it also leads to lattice shrinkage and increased Li2MnO3 phase, which deteriorated the electrochemical performance. Therefore, the calcination temperature is one of the most important parameters in the synthesis of single crystal lithium rich materials, and it is necessary to determine the optimal calcination temperature to achieve a balance between capacity and cycle stability.