Three-dimensional nanocable arrays with a copper core and cupric oxide shell for high power lithium ion batteries

CuO is an attractive anode material for Li-ion batteries because of its high specific capacity. However, conventional CuO powders suffer from a large volume expansion during the Li insertion–extraction process, resulting in contact loss between the active material and the current collector. In this work, a nano-architecture made of metallic Cu core–CuO shell nanocable arrays is fabricated directly on a metallic collector by partial oxidation of three-dimensional Cu nanowire arrays. This type of binder/additive free electrode achieves a high specific capacity (840 mA h g at 0.1 C) and excellent capacity retention ability (y600 mA h g after 200 cycles at 0.5 C). The improved cyclic stability is attributed to its excellent adhesion of the active material on the current collector and short ionic/electronic transport pathways during cycling.