Li–B–Cu Anodes with a Stable Three-Dimensional Composite Skeleton for Lithium Metal Batteries

Abstract

Lithium metal is considered one of the most ideal anode materials as a result of its extremely high theoretical capacity and energy density. However, the problems of dendrite growth and volume change of lithium metal anodes are prone to cause safety hazards, which seriously restrict the development of their commercial applications. In this paper, Li–B–Cu composite anodes with a three-dimensional skeleton structure were prepared in situ via the vacuum melting method. The lithiophilic LiB fibers can effectively reduce the local current density based on which the addition of Cu further strengthens the structural stability of the electrode material and optimized interfacial electric field distribution, inhibiting the growth of lithium dendrites and the volume change of the anode. The electrode material achieves a long cycle (1700 h and 1 mAh cm–2) in symmetric cells and shows ultrastable performance in high-capacity cycling tests. Moreover, the Li–B–Cu composite anode exhibits better electrochemical performance when assembling full cells with S and highly loaded LiFePO4 as the cathode. This work verifies that alloying can achieve stable and reliable lithium metal anodes and provides ideas for the practical application of lithium metal batteries.