Fabricating lithiophilic Sn nanolayer via vacuum evaporation coating for anode-free lithium metal battery

Abstract

Lithium metal batteries (LMBs) have great advantages such like high energy density and capacity and low cost, which are widely studied by many researchers. As a type of LMBs, anode-free LMBs have zero Li excess, i.e., the entire Li is stripped from the cathode or current collector, obviously reducing the waste of excessive Li metal and improving the energy density of battery. However, the uneven deposition of Li will lead to the growth of Li dendrites, which reduces the columbic efficiency and cycling life of anode-free LMBs. In this work, the vacuum evaporation coating is used to synthesize a lithiophilic Sn nanolayer on Cu substrate, providing uniform deposition sites for Li. The polarization of Li deposition is reduced and the cyclability of anode-free LMBs is improved. As a result, a stable cycling performance for over 200 h at 3 mA cm−2 under 1 mAh cm−2 is achieved, demonstrating the superior Li-deposition regulation effect of Sn nanolayer.