Pulse current charging strategy towards high performance of lithium-oxygen batteries

Large overpotential and poor cyclability are the main constraints for lithium-oxygen batteries (LOBs), which are usually related to the slow decomposition of the discharge product during oxygen evolution reaction (OER) of charging process. In this paper, a novel method of pulse current charging is developed for solving these problems. The results show, compared with the normal constant current samples, when duty cycle is 50% and frequency is 1 Hz and, the overpotential decreases up to 25% and the cycle life improves more than 4 times. During charging process, pulse current can reduce the concentration polarization and promote the decomposition of Li2O2, and increase the reaction kinetics of OER process, leading to the reduction of overpotential and improvement of electrochemical performance.