Solid Electrolyte Li_1.4Al_0.4Ti_1.6(PO₄)₃ as for the Lithium-Rich Manganese-Based Cathode Material Coating Li_1.2Ni_0.13Co_0.13Mn_0.54O₂

Abstract

Li1.2Ni0.13Co0.13Mn0.54O2 (L2MO) material coated with Li1.3Al0.3Ti1.7(PO4)3(LATP) was synthesized by sol-gel method. The coating amount was 0%, 0.5%, 1%, 1.5%, 2%. It is found that LATP coating improves the cycle stability of the material. After 200 cycles at 0.6 C rate, the cycle retention rate of the uncoated sample is 72.7%, while the retention rate of sample with 1% coating amount reaches 85%. LATP coating improves the rate performance of the material. The sample with 1% coating amount has the best rate performance, and the discharge specific capacity is 71.5 mAh/g at 10 C rate, while the discharge specific capacity of the sample without coating is 60.1 mAh/g. LATP coating alleviates the side reaction between the material surface and the electrolyte. As a solid electrolyte, it promotes the transmission of Li+ and reduces the charge transfer impedance of the material. The thermal stability of these materials was tested by DSC. The results show that LATP coating could improve the thermal stability of the material in charged state.