A 3D Porous Inverse Opal Ni Structure on a Cu Current Collector for Stable Lithium‐Metal Batteries

Abstract Lithium (Li) metal is considered the best anode material for next‐generation high‐energy density Li‐metal batteries. However, Li dendrite formation and growth hinder the practical applications of Li metal anodes. Herein, we report a three‐dimensional (3D) porous inverse opal nickel structure on a copper foil current collector (Ni IO@Cu) that has a controllable pore size and thickness and is fabricated via colloidal self‐assembly and electrodeposition. The uniform interconnected pores with a large surface area of the Ni IO@Cu structure can effectively dissipate high areal current densities, resulting in the stable formation of a solid electrolyte interface and dense, dendrite‐free, flat lithium deposits. In comparison to the use of bare Cu, the use of the Ni IO@Cu current collector resulted in greatly improved stability and lowered the voltage hysteresis in various Li plating/stripping tests. Moreover, Li‐ion battery and Li‐sulfur battery full cells prepared using the Ni IO@Cu also displayed excellent cycling performance. This work further demonstrates the significance of the 3D porous structure for preparing dendrite‐free Li metal anodes.