Designing three-dimensional lithiophilic dual-skeletons-supported lithium metal anodes for long-life lithium metal batteries

Lithium metal is one of the most promising anode materials for use in the next generation of high-energy lithium batteries. However, uneven Li deposition and large volume changes severely restrict the practical use of lithium metal anodes. Here, a dendrite-free three-dimensional (3D) composite Li anode (Li-B-Sn) with dual-skeletons was produced by a simple melting method. The unique dual-skeleton structure was composed of LiB fiber phase and Li 22 Sn 5 phase, which enabled even Li stripping and plating processes and reduced the volume variations to improve the performance of the Li-B-Sn anode. The Li-B-Sn anode exhibited a long lifespan of 1100 h during cycling operating under a large areal capacity of 10 mA h cm −2 in a symmetrical cell. In addition, full batteries assembled with the high mass loading LiFePO 4 cathode (∼11 mg cm −2 ) and the Li-B-Sn composite anode showed superior electrochemical performance, with a high capacity retention of 92.5% at 2 C after 430 cycles. Li-S pouch cells based on the Li-B-Sn composite anode survived over 30 cycles, which constituted better cycling stability than that of the Li-B anode. This work describes new 3D skeletons for practical use in lithium metal batteries.