Rolled electrodeposited copper foil with modified surface morphology as anode current collector for high corrosion resistance in lithium-ion battery electrolyte

Abstract

A novel preparation method has been proposed that using electrodeposited copper foil as raw material and then performing asymmetrical rolling and surface morphology modification to improve the corrosion resistance of the copper foil current collector in lithium-ion battery electrolyte for long-term storage. The results of electrochemical experiments show that the corrosion current density of rolled electrodeposited (RE) copper foil is only 10% of that of electrodeposited (ED) copper foil. After RE copper foil is stored in the electrolyte for 100 days, its capacity retention rate is ~91.2%, which is much higher than 75.6% of ED copper foil and 80.8% of rolled copper foil. The fraction of low-Σ CSL boundaries of RE copper foil is 33.6%, which is much higher than 2.2% for rolled copper foil and 8.7% for ED copper foil. The large fraction of low-Σ CSL boundaries and disrupted RHABN in RE copper foil is an effective structure to inhibit corrosion; Asymmetrical rolling and surface morphology modification significantly increase the compressive residual stress and surface roughness of RE copper foil, which can effectively improve the corrosion performance of copper foil. The RE copper foil with modified surface morphology provides a new idea for the next generation of high-performance lithium-ion battery current collector materials.