Ultrathin alumina-coated carbon nanotubes as an anode for high capacity Li-ion batteries

Alumina-coated carbon nanotubes (CNTs) were synthesized on a copper substrate and have been used as an anode in Li-ion batteries. CNTs were grown directly on the copper current collector by chemical vapor deposition and an ultrathin layer of alumina was deposited on the CNTs by atomic layer deposition, thus forming the binder-free electrode for the Li-ion battery. While CNTs, which form the core of the structure, provide excellent conductivity, structural integrity and Li-ion intercalation ability, the aluminium oxide coating provides additional stability to the electrode, with further enhancement of capacity. The anode showed very high specific capacity, good capacity retention ability and excellent rate capability. This novel anode may be considered as an advanced anode for future Li-ion batteries.