Growth and lithium storage properties of vertically aligned carbon nanotubes

High-purity vertically aligned carbon nanotubes (CNTs) were prepared on a quartz substrate by thermal chemical vapour deposition (CVD). The as-prepared carbon nanotubes have an outer diameter of 40-60 nm and a length of 70-80 μm. HRTEM observation revealed that there were compartment structures in the carbon nanotubes. The vertically aligned CNTs exhibit a high reversible lithium storage capacity of 950 xAh/g in lithium-ion cells