Fabrication of Bilayer High-Strength Nanoporous Copper Current Collector via Electrodeposition-Dealloying

Abstract

High-performance lithium-metal batteries are prone to lithium dendrite growth and volume expansion in commercial applications, leading to a significant decrease in the cycling stability of the battery system and safety hazards. The construction of a three-dimensional porous current collector can effectively suppress lithium dendrite growth and improve the electrochemical performance of batteries. Therefore, in this study, we designed a simple and efficient electrodeposition-chemical dealloying process. Initially, a highly dense and uniform copper-zinc alloy coating was successfully prepared on the substrate copper foil through a two-step electrodeposition process. The effects of the substrate copper foil condition and electrodeposition parameters on the microstructure and properties of the alloy coating were systematically investigated. Subsequently, the copper-zinc alloy foil was subjected to chemical dealloying treatment, resulting in a high-porosity, high-performance porous copper current collector with a thickness of 12 µm, a porosity of 36.9% and a mechanical strength of 362 MPa. Electrochemical tests on the prepared porous copper current collector showed that the Coulombic efficiency of the half-cell remained 98.05% after 240 cycles; the capacity of Li@3DCu@5 min//LFP reached 124 mAh·g^-1 after 300 cycles, with a capacity retention rate of 84.9%, and the de-alloyed porous copper current collector demonstrated more excellent Coulombic efficiency and cycle stability.