In Situ Formed LiZn Alloy Skeleton for Stable Lithium Anodes

Lithium metal is the most promising anode for developing high-energy density rechargeable batteries because of its ultrahigh theoretical capacity and extremely low reduction potential. However, the formation of dendritic lithium and the huge volume change of the anode during the charge/discharge process severely hinder the practical application of the lithium anode. Obtaining high-performance, simple methods that can simultaneously modify the interface and restrict the volume change of the Li anode are highly required. Herein, the lithiophilic Zn nanoparticles are introduced into molten lithium directly to obtain a composite anode filled with in situ formed LiZn alloy rods. These micrometer-sized alloy rods can serve as a skeleton to provide a large number of lithium deposition sites as well as volume suppression for lithium deposition. Benefiting from these two aspects, the composite anode exhibits superior electrochemical performance by means of lowering the overpotential and prolonging the cycle life of symmetrical cells. Furthermore, the full cell paired with this composite anode and LiFePO₄ cathode also demonstrates a better capacity retention than its counterpart with raw Li anode.