Constructing Highly Li⁺ Conductive Electrode Electrolyte Interphases for 4.6 V Li||LiCoO₂ Batteries via Electrolyte Additive Engineering

Abstract

To improve voltage is considered to effectively address the energy-density question of Li||LiCoO₂ batteries. However, it is restricted by the instability of electrode electrolyte interphases in carbonate electrolytes, which mainly originates from Li dendrite growth and structural instability of LiCoO₂ at high voltage. Herein, an electrolyte additive strategy is proposed for constructing efficient LiN_x O_y -contained cathode electrolyte interphase for 4.6 V LiCoO₂ and LiF-rich solid electrolyte interphase for Li anode to enhance the stability of Li||LiCoO₂ battery using 4-nitrophthalic anhydride as the additive. As expected, the Li||LiCoO₂ battery can stably operate up to 4.6 V, with a high specific capacity of 216.9 mAh g^-1 during the 1st cycle and a capacity retention of 167.1 mAh g^-1 after 200 cycles at 0.3 C. This work provides an available strategy to realize the application of high-voltage Li||LiCoO₂ battery.