Single-Crystalline LiMn2O4 Nanotubes Synthesized Via Template-Engaged Reaction as Cathodes for High-Power Lithium Ion Batteries

Single‐crystalline nanotubes of spinel LiMn2O4 with a diameter of about 600 nm, a wall thickness of about 200 nm and a length of 1–4 μm have been synthesized via a template‐engaged reaction using β‐MnO2 nanotubes as a self‐sacrifice template. In this fabrication, a minimal structural reorganization can be responsible for the chemical transformation from [001]‐oriented β‐MnO2 template to [110]‐oriented LiMn2O4. Galvanostatic charge/discharge measurements indicate that the nanotubes exhibit superior high‐rate capabilities and good cycling stability. About 70% of its initial capacity can be retained after 1500 cycles at 5 C rate. Importantly, the tubular nanostructures and the single‐crystalline nature of the most LiMn2O4 nanotubes are also well preserved after prolonged charge/discharge cycling at a relatively high current density, indicating good structural stability of the single‐crystalline nanotubes during lithium intercalation/deintercalation process. As is confirmed from Raman spectra analyses, no evident microstructural changes occur upon long‐term cycling. These results reveal that single‐crystalline nanotubes of LiMn2O4 will be one of the most promising cathode materials for high‐power lithium ion batteries. 1D single‐crystalline nanotubes of spinel LiMn2O4 targeted for high‐power lithium ion batteries are fabricated based on a template‐engaged reaction. This product delivers superior high‐rate capabilities and good cycling stability. Even after prolonged cycling at high‐current densities, the tubular morphology and high‐crystallinity characteristics of LiMn2O4 can be retained, indicating their potential application in high‐power lithium ion batteries, especially for electric vehicles.