Dual-Anion-Modulated Solvation and Flame Retardant Additive Enable Efficient High-Voltage Lithium-Ion Batteries Based on Ni-Rich Cathodes

The poor flame retardancy and limited electrochemical window of conventional electrolytes severely undermine the electrochemical performance of lithium-ion batteries, thus hindering their practical industrial applications. To address this, a rationally designed dual-anion, medium-concentration flame retardant electrolyte is developed in our work. By modulation of the solvation structure of the electrolyte, this innovation enhances the cycle stability of lithium-ion batteries under high-voltage conditions and improves the safety performance of the batteries. The assembled Li||NMC811 battery, operating at a high cutoff voltage of 4.6 V, delivers a discharge specific capacity of 145.1 mAh/g after 500 cycles at 1 C. This work offers a perspective for the study of high-voltage flame retardant safety electrolytes.