Core/shell (Cu/Cu₂O) nanotubes as high performance anode materials for Li-ion rechargeable batteries

A direct electrodeposition technique for very high quality Cu nanotube arrays and subsequent conversion of the deposited Cu into Cu₂O has been developed. The Cu₂O nanotube arrays have high capacity, high cyclability and high rate capability. The cycling performance of Cu₂O nanotubes show a high level of structural integrity with capacity retention even after 94 cycles when cycled at 1.67 mA/cm². The outstanding electrochemical performance of the Cu₂O nanotubes comes from high surface area, easy infiltration of electrolytes, high electrical conductivity of Cu core support and structural integrity of the oxide shell active material. The Cu₂O nanotubes also eliminate the requirement of ancillary materials currently used in Li-ion batteries, such as carbon particles to increase conductivity. The easy fabrication and performance of Cu₂O nanotube arrays may make them suitable for next generation Li-ion batteries.