Coaxial MnO/C nanotubes as anodes for lithium-ion batteries

Coaxial MnO/C nanotubes with an average diameter of about 450 nm, a wall thickness of about 150 nm, a length of 1–5 μm and a 10 nm thick carbon layer have been prepared using β-MnO₂ nanotubes as self-templates in acetylene at 600 °C. The microstructure of the product has been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and Raman spectroscopy. The electrochemical performance of the product has been evaluated by galvanostatic charge/discharge cycling. It is found that the product exhibits a reversible capacity of nearly 500 mAh g⁻¹ at a current density of 188.9 mA g⁻¹, and 83.9% of capacity retention, higher than bare MnO nanotubes (58.2%) and MnO nanoparticles (25.8%). The results reveal that coaxial MnO/C nanotubes would be a promising anode material for next-generation lithium-ion batteries.