Effect of Different Surface States of Electrolytic Copper Foils on the Performance of Lithium-Ion Batteries

Abstract

Currently, the field of lithium-ion batteries faces an urgent challenge, which is how to effectively inhibit the growth of dendrites, thereby improving the coulombic efficiency of plated/stripped lithium on copper foils and enhancing the cycling stability of the batteries. In this paper, the surface of copper foil is roughened by annealing post-treatment, which in turn improves the interfacial adhesion between the copper foil and the active material. This treatment helps the anode current collector to form a flat graphite electrode sheet and a uniform solid electrolyte interphase film, reducing the growth of lithium dendrites as well as extending the cycle life of the batteries. Among them, the annealed electrode exhibits extremely high roughness (0.533 μm) and elongation (9.91%), with the initial discharge capacity of the prepared lithium battery reaching as high as 384.22 mAh/g. It also maintains good cycling performance at different rates, which confirms the gain effect of surface roughening on battery capacity.