High Rate and Low-Temperature Stable Lithium Metal Batteries Enabled by Lithiophilic 3D Cu-CuSn Porous Framework

Lithium (Li) metal is regarded as the "Holy Grail" of anodes for high-energy rechargeable lithium batteries by virtue of its ultrahigh theoretical specific capacity and the lowest redox potential. However, the Li dendrite impedes the practical application of Li metal anodes. Herein, lithiophilic three-dimensional Cu-CuSn porous framework (3D Cu-CuSn) was fabricated by a vapor phase dealloying strategy via the difference in saturated vapor pressure between different metals and the Kirkendall effect. CuSn alloy sites were converted into LiSn alloy sites through the molten Li infusion method, and composite Li metal anodes (3D Cu-LiSn-Li) are achieved. Alloyed tin, as the bridge between the porous copper substrate and metallic Li, plays a critical role in optimizing Li nucleation and enhancing the fast lithium migration kinetics. This work demonstrates that lithiophilic binary copper alloys are an effective way to achieve room-temperature high rate performance and satisfied low-temperature cycling stability for Li metal batteries.