Fabricating Dendrite-Free Porous Hosts of Li for Li-Metal Batteries via Electrodeposition.

Li metal anode is the ultimate choice for Li-chemistry-based batteries owing to its highest theoretical capacity (3860 mAh/g). Yet, the safety problems and low Coulombic efficiency resulting from Li dendrites are the remaining challenges for commercial applications.<br/><br/>Previously, we reported a 3D porous Cu current collector fabricated via a facile one-step electrodeposition method directly on commercial Cu foils. [1] This 3D porous Cu current collector showed stable long-term cycling with a high areal capacity up to 6 mAh/cm² without Li dendrites formation. However, for this one-step electrodeposition method, the thickness of the porous Cu layer is limited. Recently, we developed a new two-step electrochemical process to fabricate thick and porous Cu layers [2]. A thick Cu-Zn alloy was first electrodeposited on commercial Cu foil, and Zn was then removed electrochemically, leaving a thick and highly porous 3D Cu layer. Compared to our previous method, this 3D Cu layer has a high thickness of ~14 um and porosity of ~72%. This new 3D Cu current collector can achieve stable Li cycling up to 230 h at a high areal capacity of 10 mAh/cm² at a current density as high as 10 mAh/cm², demonstrating its high commercial application potential in Li-metal batteries. In situ XRD method was used to reveal the deposition of CuZn alloy and the electrochemical dissolution of Zn.<br/><br/>1. Ma, X., Z. Liu, and H. Chen, <i>Facile and scalable electrodeposition of copper current collectors for high-performance Li-metal batteries.</i> Nano Energy, 2019. <b>59</b>: p. 500-507.<br/>2. Ma, Y.F., et al., <i>Electrochemically Dealloyed 3D Porous Copper Nanostructure as Anode Current Collector of Li-Metal Batteries.</i> Small, 2023.