The charge compensation mechanism and structure stability study of Li2Mn15/16TM1/16O3 (TM=Cr, Mo, W)

Density functional theory (DFT) and ab initio molecular dynamics (AIMD) methods were used to study the charge compensation mechanism and structure stability of Li₂Mn_15/16TM_1/16O₃ (TM = Cr, Mo, W). The O loss and phase transition caused by Mn migration during the delithiation process were investigated. With the increasing of periodicity of the doped element, the charge provided by O is suppressed and O loss is inhibited. The charge providing ability of doping element as the oxidation center is weakened, and the function of activating Mn to provide charge is strengthened. The introduction of the doped elements is beneficial to the electrochemical performance, but it can induce unfavorable phase transitions. The established relationship between cathode material composition and electrochemical performance provides guidelines toward future material screen and design of lithium-ion batteries.