Electrochemical performance and application of lithium-rich cathode material under normal voltage

TAN Yajun; FENG Mingyan; WANG Zhengwei

doi:10.19996/j.cnki.ChinBatlnd.2025.03.006

Abstract：Under atmospheric pressure conditions(voltage range 2.7 to 4.2 V),research on the electrochemical performance of lithium-rich cathode materials has shown significant advantages.In 1 C rate charge-discharge cycle tests conducted at room temperature,the material's capacity remained largely stable,with a capacity retention rate of 103.4%after 2 500 cycles(compared to around 90%after 200 cycles in the 2.7 to 4.3 V voltage range).The continuous increase in discharge capacity during the early stages of cycling and the refined X-ray diffraction(XRD)results indicate that Li2MnO3 undergoes slow decomposition under atmospheric pressure and plays a lithium-supplementing role during charging and discharging.Further,the composite material consisting of lithium-rich materials and lithium manganate was assembled into batteries at different mass ratios as active cathode materials.Experimental results show that in the composite system with 50%mass fraction of lithium-rich material,the battery retains its capacity almost unchanged after 500 charge-discharge cycles at 1 C rate at room temperature;even after 400 charge-discharge cycles at 1 C rate in a 45℃high-temperature environment,the capacity retention rate remains as high as 94.3%.The lithium-supplementing effect of the lithium-rich material effectively mitigates the substantial capacity decay of lithium manganate in the initial cycles,enhancing the performance of lithium manganate by over 20%,while also increasing the energy density of the battery system.