Entangled germanium nanowires and graphite nanofibers for the anode of lithium-ion batteries

High performance negative electrode materials for lithium-ion batteries were fabricated using germanium nanowire (GeNW) and graphite nanofiber (GNF) composites prepared by a low-pressure chemical vapor deposition (CVD) method. The promising high power rate anode material GeNWs were grown on the surface of a GNF bundle to mutually form the entangled structure. The high contact area between the GeNWs and GNFs enabled electrons to be efficiently transported and the GeNWs entwined with GNFs minimized the degradation of the electrochemical characteristics. These composite materials for the anode of lithium-ion batteries showed a very constant high specific capacity of ∼1,200 mAh g ^-1 with little decline of the cycling performance while the rate capability was significantly improved.