Tough lithium-rich organic film via molecular layer deposition for highly stable lithium metal anode

Abstract

Lithium (Li) dendrite growth is a major challenge for lithium metal anode. The construction of artificial ultrathin solid electrolyte interphase (SEI) is one of the most effective strategies for the suppression of Li dendrite and improvement of electrochemical performance. However, it is difficult to fabricate artificial SEI with precisely controllable thickness, superior mechanical properties and high ionic conductivity. Herein, a tough lithium-rich organic film (TLOF) is proposed as surface protection layer of Li metal via molecular layer deposition technique for high-performance Li metal batteries. This artificial SEI significantly enhances electrochemical performance and suppresses dendritic growth in both ester electrolyte and ether electrolyte due to its excellent toughness and relatively high ion conductivity. Furthermore, the Li–O2 battery with Li@TLOF anode shows outstanding cycle stability for over 500 h. It is believed that the TLOF protected Li metal anode opens up new opportunities for the realization of next-generation high energy density Li metal batteries.