Template-free synthesized Ni nanofoams as nanostructured current collectors for high-performance electrodes in lithium ion batteries

3D interconnected network Ni nanofoams with large surface area were fabricated by a template-free approach. Their pore size and skeleton diameter are 150-350 nm and 200-300 nm, respectively. The homogeneous foaming structure and the metallic ductility of the Ni nanofoams make them suitable to be used as nanostructured current collectors. The Ni/NiO nanostructures were prepared by in situ thermal oxidation of the obtained Ni nanofoams. As anodes of lithium ion batteries, the Ni/NiO nanofoam electrodes deliver excellent cycling stability, superior rate capability, and high areal capacity. A high reversible capacity of 835 mA h g(-1), which corresponds to an areal capacity of 2.1 mA h cm(-2), was obtained after 200 cycles at a current rate of 0.5 C (1 C = 718 mA g(-1)). The Ni nanofoams exhibit an excellent electrochemical stability in electrolytes and are compatible with various electrochemically active materials as potential nanostructured current collectors for high-performance energy storage devices. Moreover, the preparation approach of the Ni nanofoams is facile, cost-effective, and can be used for large-scale production.