High-performance CuO/Cu composite current collectors with array-pattern porous structures for lithium-ion batteries

The surface structure and material composition of current collectors significantly affect the electrochemical performances of lithium-ion batteries. This study forms array-pattern blind holes and creates a layer of copper oxide (CuO) on the surface of thin copper plates using the chemical etching method. This copper plate is made into a CuO/Cu composite current collector with array-pattern porous structures for lithium-ion batteries. Using mesocarbon microbead graphite powders as the anode material, this new composite current collector is assembled into CR2032 coin half-cells for electrochemical tests. Batteries with this porous current collector exhibit high reversible discharge capacities of 383.9 mAh g−1 at 0.5 mA and 374 mAh g−1 even after 0.2C and 0.5C rate cycles, whereas batteries with a complanate current collector deliver only 309.6 mAh g−1 and 296.7 mAh g−1. It is believed that the array-pattern blind holes coupled with the morphological effects of the oatmeal-like CuO significantly enhance the electrochemical performances of batteries in terms of reversible capacity, cycling stability, electrical conductivity and coulombic efficiency.