Hollow hematite nanosphere/carbon nanotube composite: mass production and its high-rate lithium storage properties

Spray pyrolysis was used to produce hollow hematite (alpha-Fe2O3) nanosphere (HHNS)/carbon nanotube (CNT) composite on a large scale. The method offers simplicity, high productivity, versatility, low cost, and suitability for industry. The structure is composed of hollow nanospheres in a network of CNTs. The possible formation mechanism of hollow alpha-Fe2O3 nanospheres is due to the rapid evaporation of water and the super-hydrophobicity of the CNT surface. The electrochemical tests show that the HHNS/CNT composite is a promising lithium storage material in terms of high capacity (similar to 700 mAh g(-1)), good high-rate capability, and good cycle life (up to 150 cycles). The materials improve both lithium ion and electron transport, which are limiting factors on the high-rate capability of lithium-ion batteries. The production method can be easily adapted to produce a wide range of hollow metal oxide nanosphere/CNT composites.