Accelerating Li+/Li redox through the regulation of the electric double layer for efficient lithium metal anodes

Abstract

High performance lithium metal anode is of great importance to achieve batteries with high energy density. Due to the intrinsic high reactivity of Li metal anode and the insufficient understanding of lithium redox at the Li/electrolyte interface, the fast and dendrite-free Li metal deposition still remains a grand challenge. In this work, we accelerate Li+/Li redox through the regulation of the electric double layer (EDL), in which 2-Mercaptopyridine (2-MP), a conjugated weak-base molecule with stable electrochemical properties, can be specifically adsorbed on Li metal surface and promote charge transfer. It fundamentally avoided the formation of Li metal dendrites and enabled fast Li plating/stripping process, leading to uniform Li deposition as well as superior cycling performances of batteries. This work provides a significant contribution to the understanding of battery chemistry at the electrode/electrolyte interface.