Ultrasonic-assisted enhancement of lithium-oxygen battery

Lithium-oxygen batteries have attracted much attention due to their high theoretical specific capacity, but their high overpotential and poor cyclic stability limit further development. These are usually closely related to the reversible reactions of the formation and decomposition of the discharge product Li2O2. This study presents the feasibility of ultrasonic-assisted enhancement of lithium-oxygen battery performance. Under the application of ultrasonic charging with 5:5 duty cycle and 675 W power, the rapid upward trend of charging voltage can be effectively suppressed, and the original overpotential of the lithium-oxygen battery can be reduced by 25.9%. In addition, at a limited specific capacity of 400 mAh g−1and a current density of 800 mA g−1, when applying ultrasonic charging process with above ultrasonic condition every 20 cycles, the cycle life of lithium-oxygen battery with Co3O4as the positive electrode can reach 321 cycles. Ultrasonic charging has positive effects on suppressing concentration polarization, enhancing mass transfer, and improving oxygen evolution reaction kinetics. It can effectively promote the rapid decomposition of the discharge product Li2O2, reduce the overpotential, and improve the battery cycle performance and stability.