In-situ vertical growth of integrated CuO@Cu electrode for enhanced Li-ion storage kinetics

The CuO anode prepared by the traditional slurry coating method still suffers from limited lithium-ion transport kinetics due to the long diffusion lengths and tortuous transport paths resulting from the addition of conductive agents and binders. In this study, we have prepared the integrated CuO@Cu electrode with the porous CuO nanosheets in situ vertically grown on Cu current collector using a chemical etching method. The integrated electrode design improves the electrical conductivity of the electrode, and the porous nanosheets increase the contact area of the electrolyte and buffer the volume variation of CuO during cycling. Moreover, the vertically grown CuO nanosheets can shorten the lithium ion diffusion path and reduce the tortuosity of lithium ion transport pathways, thus realizing fast lithium ion storage kinetics. While the slurry coating CuO powder electrode shows a capacity of 13.3 mAh g −1 at 20 A g −1 , our integrated CuO@Cu electrode still delivers a capacity of 181.6 mAh g −1 at 20 A g −1 . This study demonstrates that rational structural design can significantly improve Li-ion storage kinetics.