Germanium Nanotubes Prepared by Using the Kirkendall Effect as Anodes for High‐Rate Lithium Batteries

Ultralong germanium nanotubes (Ge NTs; see picture) are synthesized in high yield from core–shell Ge–Sb nanowires by utilizing the Kirkendall effect at 700 °C. The Ge NTs have an exceptionally high rate capability (40 Ag−1) while maintaining a reversible capacity of more than 1000 mAhg−1 over 400 cycles, with minimal capacity fading when paired with a LiCoO2 cathode in a lithium-ion cell.