Electrochemically Dealloyed 3D Porous Copper Nanostructure as Anode Current Collector of Li‐Metal Batteries

Abstract The commercialization of high‐energy Li‐metal batteries is impeded by Li dendrites formed during electrochemical cycling and the safety hazards it causes. Here, a novel porous copper current collector that can effectively mitigate the dendritic growth of Li is reported. This porous Cu foil is fabricated via a simple two‐step electrochemical process, where Cu‐Zn alloy is electrodeposited on commercial copper foil and then Zn is electrochemically dissolved to form a 3D porous structure of Cu. The 3D porous Cu layers on average have a thickness of ≈14 um and porosity of ≈72%. This current collector can effectively suppress Li dendrites in cells cycled with a high areal capacity of 10 mAh cm −2 and under a high current density of 10 mA cm −2 . This electrochemical fabrication method is facile and scalable for mass production. Results of advanced in situ synchrotron X‐ray diffraction reveal the phase evolution of the electrochemical deposition and dealloying processes.