Synthesis of alloy-type materials (X) is one of the most effective approaches to limit lithium dendrites in Li metal anode (LMA) because of their satisfactory lithiophilicity and easy electrochemical reaction with lithium. However, current investigations have only focused on the influence of the resulting alloyed products (LiX) on the properties of LMA, but the alloying reaction process between Li+ and X has been mostly ignored. Herein, by masterly taking advantage of the alloying reaction process, a novel approach is developed to more effectively inhibit lithium dendrites than the conventional strategy that just considers the utilization of alloyed products LiX. A three-dimensional substrate material loaded with metallic Zn on the surface of Cu foam is synthesized by a simple electrodeposition process. During Li plating/stripping, both alloy reaction processes between Li+ and Zn and LiZn product are involved, which makes the disordered Li+ flux near the substrate first react with Zn metal and then results in an even Li+ concentration for more uniform Li nucleation and growth. The full cell (Li-Cu@Zn-15//LFP) exhibits the reversible capacity of 122.5 mAh g-1, and a high capacity retention of 95% is achieved after 180 cycles. This work proposes a valuable concept for the development of alloy-type materials in energy storage devices.
Keywords: Cu foam; LiZn alloy; alloy reaction; lithiophilicity; lithium metal anode.