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

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.