Tuning the Electronic Structure of the Metal-Oxygen Group by Silicon Substitution in Lithium-Rich Manganese-Based Oxides for Superior Performance

Si-doped layered manganese-based lithium-rich oxides were used as cathodes for lithium-ion batteries. The silicon-doped electrode exhibits exceptional specific capacity as well as rate capability compared to those of the pristine sample. In particular, the modified cathode shows noticeable enhancement in thermal stability, wherein the heat release is reduced and the position of the exothermic peak increases by 60 degrees C. First-principles calculations suggest that Si atoms occupy sites of transition metals in Si-doped Li-rich materials, which gives rise to an appreciable downshift of the O 2p band relative to that of the pristine sample.