The combined effect of CaF2 coating and La-doping on electrochemical performance of layered lithium-rich cathode material

Highlights: • The combined effect of CaF₂ coating and La-doping, which could avoid the insufficient of single coating or single doping, is very helpful to improve the electrochemical performance of Li-rich oxide materials. • EDTA, as the nucleating agent, was decompose at 240 °C, which benefit for forming the pore at the primary particle. It is good for shorting the diffusion length of Li⁺. This work provides a new strategy for using the combined effect of coating-CaF₂ and La-doping to improve the electrochemical performance of lithium-rich layer material. Here, La-doping in metal transition(MT) layer is employed to block the migration channel of TM ions and stabilize the crystal structure, and coating-CaF₂ on the surface of lithium-rich layer oxide material is employed to retard the side reaction between active material and electrolyte. Benefiting from the combined effect of coating-CaF₂ and La-doping, CaF₂ coated Li_1.2Mn_0.52Ni_0.13Co_0.13La_0.02O₂ exhibits excellent cycling performance and voltage stability. CaF₂ coated Li_1.2Mn_0.52Ni_0.13Co_0.13La_0.02O₂ delivers the initial discharge capacity of 227.1 mAh g⁻¹ at 0.5 C. After 100 cycles, its retention of discharge capacity is 93.9%, and its voltage decay is only 0.203 V. This connecting mechanism of coating and doping, which can avoid the insufficient of single coating or single doping, is very helpful to develop effective strategies for the modification of Li-rich oxide materials.