Abstract
Germanium nanowires and copper nanowires were combined to manufacture germanium/copper nanowire fabrics with a layered inorganic nanowires structure. The fabrics are flexible and resilient. The lithium ion half cells made of the germanium/copper nanowire fabric with an electrolyte composed of FEC/DEC have excellent cycle performance and stability. After 500 cycles at a rate of 1C, the cell exhibited a reversible capacity of 830 mAh/g. The germanium/copper nanowire fabrics also exhibited high rate capacity, having a reversible capacity of 350 mAh/g at a rate of 20 C. In addition, it can allow ultrafast discharge at 50 C when charged at 1C. By calculating the total weight of the electrodes (active materials + conductive agents + binder + current collector) and comparing with the relevant literature, we found that the weight capacities of germanium/copper nanowire fabric electrode were 2~7 times higher than other types of germanium or silicon electrode. The germanium/copper nanowire fabric electrodes have potential for some applications which require rapid cycling rates and can significantly reduce battery weight. Furthermore, We prepared a large area Ge/Cu nanowire fabric anode (5 cm *8 cm) to assemble full cells with commercial Li(NiCoMn)O2 cathode. The full cells were able to power a lot of LEDs. This work demonstrated that our development of layered inorganic nanowires structure make progress toward practical Li-ion battery applications.