Nanoporous CuO/Cu composite materials with a bicontinuous structure are prepared by corroding a Cu–Al alloy. The obtained nanoporous CuO/Cu composites exhibit excellent performance as anodes for lithium ion batteries, which show a capacity of 600 mA h g⁻¹ at a current density of 500 mA g⁻¹ and maintain the capacity for 200 cycles and 445 mA h g⁻¹ at 1000 mA g⁻¹. The excellent electrochemical performance is attributed to the nanoporous and Cu-doped structure.