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.

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► Coaxial MnO/C nanotube 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 has been prepared based on an in-situ reduction route in acetylene using β-MnO2 nanotubes as self-templates.
► The product exhibits higher rate capability and cycling performance than bare MnO nanotubes and nanoparticles.
► The coaxial carbon layer and one-dimensional structures for MnO/C nanotubes are responsible for the improved rate capabilities and cycling performance.
► The coaxial carbon layer of MnO/C nanotubes is beneficial to improving the electric conductivity and protecting MnO from electrolyte etching.