Germanium nanowires-based carbon composite as anodes for lithium-ion batteries

Lithium-ion batteries have been actively researched in recent years due to it being one of the most promising energy storage systems. Herein, we report a novel approach where germanium nanowires (Ge NW) are grown in gold-seeded porous carbon via the solution-liquid-solid mechanism, and the corresponding improvement observed in terms of the specific capacity of this porous carbon-germanium nanowires (PC-Ge NW) composite anode. At a current density of 160 mAg(-1) and voltage window of 0.001-1.5 V. a specific capacity of 789 mAhg(-1) during the 50th cycle for PC-Ge NW is achieved as compared to 624 mAhg(-1) during the 50th cycle for pure Ge NW. Even though the content of the Ge is only 53.5 weight percent in the PC-Ge NW composite, it yields a better stability and higher specific capacity, indicating a synergistic effect between porous carbon and Ge nanowires. There is also potential cost savings since the use of a lower amount of Ge can bring about good cycling properties. (C) 2012 Elsevier B.V. All rights reserved.