Preparation of Ge nanotube arrays from an ionic liquid for lithium ion battery anodes with improved cycling stability.

Ge nanotube array anodes are prepared by template-assisted electrodeposition from an ionic liquid to obtain superior cycling performance. They show remarkable cycling ability at 0.2 C, with a very high initial discharge capacity of 1641 mA h g(-1) and a charge capacity of 1260 mA h g(-1). After 250 cycles the capacity retention is 98% relative to that at the 50th cycle.