Stable Lithium Metal Anode Enabled by 3D Soft Host

Lithium (Li) metal is among the most promising anode materials for next-generation rechargeable batteries. However, inevitable Li dendrite growth and huge volume expansion severely restrict its practical application. Here, we propose a melamine sponge@silver nanowires (MS@AgNWs) current collector to achieve highly reversible Li storage. By combining the strength advantages of lithophilic nanoseeds, 3D current rectification structure and stress-releasing soft substrate, the MS@AgNWs host can successfully release the compress stress generated during the Li-plating process and hence give rise to uniform Li deposition. In particular, the MS@AgNWs-Li composite anode shows high Coulomb efficiency of 99.1% over 300 cycles and ultralow overpotentials of 10 mV at 1 mA cm–2 and 19 mV at 2 mA h cm–2. Superior long-term cycle stability over 1000 h is attained in symmetric cell under various densities. The assembled full cells with LiFePO4 cathode deliver excellent cycle performance with capacity retention of 138.2 mAh g–1 at 1C after 400 cycles and outstanding rate performance (discharge capacity of 119 mAh g–1 at 10 C). Scalable fabrication of 3D MS@AgNWs flexible host can be easily realized, which is potential for developing practical flexible Li metal based batteries.