Over-lithiated NCM through Li5FeO4 for high energy silicon-based lithium-ion batteries

Abstract

Si/C composite material is a promising anode material for next-generation lithium-ion batteries due to its high capacity. However, it also exhibits significant initial capacity loss in a full cell due to the unstable SEI. To compensate for the loss of Li inventory, a pre-lithiation reagent, Li₅FeO₄ (LFO), is incorporated into the LiNi_0.85Co_0.12Mn_0.03O₂ (NCM85E) cathode for electrochemical evaluation. The results show that with the addition of LFO, the initial discharge capacity of SiC950/NCM85E full cells can increase from 151.0 mA h g⁻¹ to 193.4 mA h g⁻¹ by 28.1% with a high cathode loading up to about 20 mg cm⁻². After 200 cycles, the specific capacity also increased by 25.1%.