Dual Additives to Stabilize the Electrode–Electrolyte Interface of Lithium-Rich Layered Cathodes for High-Energy Batteries

Lithium-rich manganese-based oxides (LMOs) are regarded as promising cathodes for next-generation high-energy Li-ion batteries due to their ultrahigh discharge capacity (>250 mAh/g) and low cost. However, their practical application is significantly hindered by issues such as transition metal dissolution and structural evolution under high working voltage. In this study, a stable SEI protective film based on carbon phosphorus is successfully constructed by introducing two solid–liquid interface-stabilizing additives, ethylene carbonate (VC) and tri(pentafluorophenyl)borane (TPFPB), into the base electrolyte. This significantly enhances the interface stability between the lithium-rich manganese-based cathode material and the electrolyte, suppresses the generation of harmful HF and the dissolution of transition metals, thereby improving the overall stability of the electrode–electrolyte system. Experimental results indicate that after 200 cycles, the capacity retention of the LMO cathode is increased by 21% due to the significant suppression of nanopore formation and phase transitions. This additive optimization strategy provides promising technical guidance for the application of lithium-rich manganese-based oxide cathode materials in next-generation high-energy-density rechargeable batteries.