Preparation and electrochemical properties of Co doped core-shell cathode material on a lithium iron phosphate surface

A core-shell structured lithium iron phosphate (LFP) with LFP as the core and LiCo_xFe_1−xPO₄ as the shell was prepared using the solvothermal method. The doped Co broadened the diffusion channel of Li⁺ in the [010] direction. Combined with the interface migration model, this core-shell structure was found to enhance the diffusion of Li⁺. The doped Co facilitated the formation of CoP, thereby improving the electronic conductivity of LFP. In addition, Co on the surface inhibited the corrosion of electrolytes during the cycle and protected the olivine structure of LFP. This core-shell structure cathode material possesses good interface stability and cycle stability during the cycle process. Electrochemical tests found the Co-doped core-shell structure to improve conductivity and exhibit excellent cycle performance and rate performance and it maintained 165.1mAh g⁻¹ 300 cycles at 0.1 C.