Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Battery Technology, Liaocheng University, Liaocheng, 252000, China.
Institute of Materials and Technology, Dalian Maritime University, Dalian, 116026, China.
Dalton Trans. 2023 May 22;52(20):6876-6881. doi: 10.1039/d3dt00260h.
Despite the fact that lithium metal batteries (LMBs) have the advantage of higher energy density than traditional lithium-ion batteries (LIBs), the development of Li anodes is hindered by the issues of dendritic Li growth and parasitic reactions during cycling, which can cause a coulombic efficiency decrease and capacity decay. Herein, a Li-Sn composite anode is developed by a facile rolling method. The generated LiSn nanoparticles are uniformly distributed in the Li-Sn anode after the rolling process. The LiSn nanoparticles on the surface of the electrode exhibit excellent lithiophilicity, reducing the Li nucleation barrier. Multiphysics phase simulation discloses the distribution of local current density around the holes, guiding Li preferentially to deposit back onto the sites of previous Li stripping, and then realizing a controllable plating/stripping behavior of Li on the Li-Sn composite anode. Consequently, the symmetrical cell of Li-Sn||Li-Sn achieves a stable cycling lifetime of more than 1200 h at a current density of 1 mA cm with a fixed capacity of 1 mA h cm. Besides, the full cell pairing with the LiFePO cathode delivers excellent rate performance and capacity retention after long cycles. This work provides new insight to modify the Li metal for preparing dendrite-free anodes.
尽管锂金属电池（LMBs）比传统的锂离子电池（LIBs）具有更高的能量密度优势，但由于枝晶锂生长和循环过程中的寄生反应等问题，Li 阳极的发展受到了阻碍，这会导致库仑效率降低和容量衰减。在此，通过简便的轧制方法开发了一种 Li-Sn 复合阳极。轧制过程后，生成的 LiSn 纳米颗粒均匀分布在 Li-Sn 阳极中。电极表面的 LiSn 纳米颗粒表现出优异的亲锂性，降低了 Li 成核势垒。多物理相模拟揭示了孔周围局部电流密度的分布，引导 Li 优先沉积回先前 Li 剥离的位置，从而实现 Li 在 Li-Sn 复合阳极上的可控电镀/剥离行为。因此，Li-Sn||Li-Sn 的对称电池在 1 mA cm 的电流密度下以 1 mA h cm 的固定容量稳定循环 1200 h 以上。此外，与 LiFePO4 正极配对的全电池在长循环后表现出优异的倍率性能和容量保持率。这项工作为修饰 Li 金属以制备无枝晶阳极提供了新的见解。
