PDF(Pubmed)
Abstract：
Porous copper (Cu) current collectors show promise in stabilizing Li metal anodes (LMAs). However, insufficient lithiophilicity of pure Cu and limited porosity in three-dimensional (3D) porous Cu structures led to an inefficient Li-Cu composite preparation and poor electrochemical performance of Li-Cu composite anodes. Herein, we propose a porous Cu-CuZn (DG-CCZ) host for Li composite anodes to tackle these issues. This architecture features a pore size distribution and lithiophilic-lithiophobic characteristics designed in a gradient distribution from the inside to the outside of the anode structure. This dual-gradient porous Cu-CuZn exhibits exceptional capillary wettability to molten Li and provides a high porosity of up to 66.05%. This design promotes preferential Li deposition in the interior of the porous structure during battery operation, effectively inhibiting Li dendrite formation. Consequently, all cell systems achieve significantly improved cycling stability, including Li half-cells, Li-Li symmetric cells, and Li-LFP full cells. When paired synergistically with the double-coated LiFePO4 cathode, the pouch cell configured with multiple electrodes demonstrates an impressive discharge capacity of 159.3 mAh g-1 at 1C. We believe this study can inspire the design of future 3D Li anodes with enhanced Li utilization efficiency and facilitate the development of future high-energy Li metal batteries.
摘要：
多孔铜(Cu)集流体在稳定Li金属阳极(LMA)方面显示出希望。然而,纯Cu的亲锂性不足和三维（3D）多孔Cu结构中有限的孔隙率导致Li-Cu复合阳极的制备效率低下和电化学性能差。在这里，我们提出了一种用于Li复合阳极的多孔Cu-CuZn（DG-CCZ）主体来解决这些问题。这种结构的特征是孔径分布和亲石-疏石特性，从阳极结构的内部到外部呈梯度分布。这种双梯度多孔Cu-CuZn对熔融Li表现出优异的毛细管润湿性,并提供高达66.05%的高孔隙率。这种设计促进了在电池运行期间在多孔结构内部的Li优先沉积。有效抑制Li枝晶的形成。因此,所有电池系统均实现了显着改善的循环稳定性，包括Li半细胞，Li-Li对称电池，和Li-LFP全电池。当与双涂层LiFePO4阴极协同配对时，配置有多个电极的软包电池在1C时表现出159.3mAhg-1的令人印象深刻的放电容量。我们相信这项研究可以激发未来3DLi阳极的设计，提高Li的利用效率，并促进未来高能Li金属电池的发展。
