Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential. However, undesirable parasitic reactions, poor cycling stability and safety concerns could be caused by uncontrolled dendrite and high reactivity of Li metal, which hinder the practical application of Li-metal anode in high-energy rechargeable Li metal batteries (LMBs). Here, a facile way is reported to stabilize Li metal anode by building high lithiophilic Mg-Li-Cu alloy. Due to the delocalization of electrons on the deposited lithium enhanced by Cu self-diffusion into Mg-Li alloy, the growth of lithium dendrites could be inhibited by Mg-Li-Cu alloy. Moreover, the parasitic reactions with electrolyte could be avoided by the Mg-Li-Cu alloy anode. It is noteworthy that the symmetric battery life of Mg-Li-Cu alloy electrodes exceeds 9000 h at 1 mA cm−2 and 1 mAh cm−2. The full cell (LiFePO4 || Mg-Li-Cu) exhibits a specific capacity of 148.2 mAh g−1, with a capacity retention of 96.4%, at 1 C after 500 cycles. This work not only pave the way for application of flexible alloy anode in highly stable LMBs, but also provides novel strategies for preparation and optimization of Mg alloy.

中文翻译：

---

用于高度可逆锂金属电池的 Mg-Li-Cu 合金负极

金属锂因其理论比容量高、电位低，被认为是下一代二次电池最有前途的负极材料。然而，不受控制的枝晶和锂金属的高反应性可能会导致不良的寄生反应、不良的循环稳定性和安全问题，这阻碍了锂金属负极在高能可充电锂金属电池 （LMB） 中的实际应用。在这里，报道了一种通过构建高亲石性 Mg-Li-Cu 合金来稳定锂金属负极的简单方法。由于 Cu 自扩散到 Mg-Li 合金中增强了沉积锂上的电子离域，因此 Mg-Li-Cu 合金可以抑制锂枝晶的生长。此外，Mg-Li-Cu 合金负极可以避免与电解质的寄生反应。值得注意的是，Mg-Li-Cu 合金电极在 1 mA cm-2 和 1 mAh cm-2 时的对称电池寿命超过 9000 小时。全电池 （LiFePO4 ||Mg-Li-Cu）在 1 C 下循环 500 次后表现出 148.2 mAh g-1 的比容量，容量保持率为 96.4%。这项工作不仅为柔性合金负极在高稳定性 LMB 中的应用铺平了道路，而且为 Mg 合金的制备和优化提供了新的策略。