3D Porous Cu Current Collector/Li-Metal Composite Anode for Stable Lithium-Metal Batteries

Lithium-metal batteries are of particular interest for next-generation electrical energy storage because of their high energy density on both volumetric and gravimetric bases. Effective strategies to stabilize the Li-metal anode are the prerequisite for the progress of these exceptional storage technologies, such as Li-S and Li-O-2 batteries. Various challenges, such as uneven Li electro-deposition, anode volume expansion, and dendrite-induced short-circuit have hindered the practical application of rechargeable Li-metal batteries. Herein, a one-step facile and cost-effective strategy for stabilizing lithium-metal batteries via 3D porous Cu current collector/Li-metal composite anode is reported. The porous structure of the composite electrode provides a "cage" for the redeposition of "hostless" lithium and accommodates the anode volume expansion during cycling. Compared with planar Cu foil, its high specific surface area favors the electrochemical reaction kinetics and lowers the local current density along the anode. It leads to low interfacial resistance and stabilizes the Li electrodeposition. On this basis, galvanostatic measurements are performed on both symmetric cells and Li/Li4Ti5O12 cells and it is found that the electrodes exhibit exceptional abilities of promoting cell lifetime and stabilizing the cycling behavior. Although this work focuses on lithium metal, this novel tactic is easy to generalize to other metal electrodes.