Lightweight and Flexible 3D ERGO@Cu/PA Mesh Current Collector of Li Metal Battery for Dendrite Suppression

Abstract

The utilization of 3D Cu current collectors has been approved to be an efficient design to suppress the uncontrolled dendrite growth of Li metal anodes. However, the widely used 3D metallic Cu often has high self-weight and impaired mechanical properties and cannot meet the requirements of high energy density and industrial production. Here, we developed a lightweight, malleable, lithiophilic, and reticular composite Cu-based current collector using a nylon (PA) framework as the 3D substrate, by a synergized approach of combining the conductive Cu/PA with lithiophilic reducing graphene oxide (ERGO) coating. The 3D grid arrangement lowered the regional current density, and the lithiophilic ERGO layer induced Li nucleation, all of which endowed the ERGO@Cu/PA mesh as an anode current collector with attractive performance. The ERGO@Cu/PA composite was applied to display the necessary dendrite-free Li deposition behavior. It delivered an impressive Li plating/stripping behavior and electrochemical performance in half cells and Li/Li symmetric battery tests. The full cell using the ERGO@Cu/PA composite with predeposited Li as the anode and LiFePO4 as the cathode achieved stable cycling and excellent rate performance. Notably, the synergistic combination of light and flexible 3D Cu/PA mesh with lithiophilic ERGO coating proved a valid path to adjust Li anodes in the fields such as flexible wearable devices.