Abstract
In the high performance Li-ion battery anode material, silicon, germanium and tin have high capacities due to their ability to react with abundant of Li-ion, compared with graphite that used in the market today. Germanium has been widely studied not only because it has high theoretical capacity (1384mAh/g), but also it has the room-temperature diffusion rate two order higher than that of silicon. However, the cost of producing germanium material is really high and cannot be continuously produced. In this study, we propose a novel and environmental-friendly method, which is carried out in a reverse micelle system, for the synthesis of germanium oxide nanoparticles. High yield (almost 100%) and good crystallinity germanium oxide nanoparticles were synthesized. The electrochemical performance of germanium oxide nanoparticles in Li-ion battery is obviously promising, in comparison to amorphous germanium oxide thin film. These anodes which are made of germanium oxide have a reversible capacity approximately 1050mAh/g at a rate of 0.1C. The anode reversible capacity is about 250mAh/g when cycled at 8C. Finally, we attempt to develop a continuous scale-up procedure in producing germanium oxide nanoparticles, and we successfully manufacture high capacity pouch type cell for a variety of electronic devices.