An ultra-stable and enhanced reversibility lithium metal anode with a sufficient O2 design for Li-O2 battery

Li metal is used as anode for Li-O2 batteries because of its high specific capacity and low negative electrochemical potential. However, Li metal exhibits low Coulombic efficiency and limited cycle life, which hinder its practical use. In this study, we demonstrate that the performance of the Li metal anode was significantly improved by cycling in O2-rich electrolyte. In the presence of sufficient O2, the growth of Li dendrites was suppressed by the formation of flexible and mechanical strong solid electrolyte interphase layers. Consequently, Li metal anode remained stable over 800 cycles with 98.7% Coulombic efficiency. The origination of the superior performance was further analyzed through ion etching-assisted XPS and in situ electrochemical Raman spectroscopy. Our research provides a distinct and effective approach used to improve the stability and reversibility of Li metal anodes and reveal the superiority of Li metal systems in the presence of sufficient O2 for Li-O2 battery.