Enhanced Elevated-Temperature Performance of Al-Doped Single-Crystalline LiMn₂O₄ Nanotubes as Cathodes for Lithium Ion Batteries

Abstract

Al-doped LiMn2O4 nanotubes have been synthesized using β-MnO2 nanotubes as self-templates. Singe-crystalline structure of the Al-doped spinel was verified by high-resolution transmission electron microscopy and selected area electron diffraction techniques. Galvanostatic charge/discharge tests indicate that the Al-doped single-crystalline spinel nanotube delivers a discharge capacity of 110 mAh g–1 at 0.1C rate and retains about 80% of its initial capacity after 200 cycles at 5C rate at 55 °C, indicating superior elevated-temperature cycling performance at a high current rate. Furthermore, high crystallinity, single-crystalline nature, and tubular morphology can be well preserved after aging tests for 30 days at 55 °C, revealing their good structural stability.