Constructing Highly Li + Conductive Electrode Electrolyte Interphases for 4.6 V Li||LiCoO 2 Batteries via Electrolyte Additive Engineering.

To improve voltage is considered to effectively address the energy-density question of Li||LiCoO 2 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 LiCoO 2 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 LiCoO 2 and LiF-rich solid electrolyte interphase for Li anode to enhance the stability of Li||LiCoO 2 battery using 4-nitrophthalic anhydride as the additive. As expected, the Li||LiCoO 2 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||LiCoO 2 battery.