Lithiophilic Cu₃Sn Modified Cu Foil as Current Collector for Stable Lithium Metal Anodes

The development of lithium metal battery is severely restricted by its uncontrolled dendrite growth and volume change. In this work, we designed a controllable lithiophilic Cu3Sn modified commercial Cu foil as current collector via simple industrial electroplating and heat treatment. As a Li-reservoir substrate for efficient deposition/stripping of Li metal, the introduction of Cu3Sn not only increases multiple active sites for the deposition of Li, but also provides more transfer paths for lithium ions. The Li metal anodes prepared by molten Li on the Cu current collector with dispersed Cu3Sn active sites provide a uniform lithiophilic surface, which could effectively promote a uniform Li deposition/stripping and suppress the formation of lithium dendrites. As a result, the assembled symmetric battery is stable at a low over-point position for 1600 h without short circuit at 1 mA cm(-2) with 1 mAh cm(-2), the full battery paired with LiFePO4 still maintains a high-capacity retention rate of 97.1 % and a coulombic efficiency (CE) of 99.5 % after 400 cycles at a current density of 2 C. This work provides a facile and controllable strategy for the design of current collectors with high lithium affinity for stable lithium metal anode applications.