Mesoporous polyaniline/TiO2 microspheres with core-shell structure as anode materials for lithium ion battery

Mesoporous polyaniline/anatase TiO2 composite microspheres with the core-shell structure for lithium-ion battery applications are prepared via a facile hydrothermal route. The structure of as-prepared sample is characterized by electron microscopy (TEM), and scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) surface area. It is suggested that the formation of the core-shell structure can be designated as a two-step assembly process induced by the polymerization of the aniline. The electrochemical tests demonstrate that the discharge capacity of the as-prepared polyaniline/anatase TiO2 microspheres can be stably retained at 157.1 mAh g(-1) after 50th cycle at the high current density of 1500 mA g(-1). The high rate performance of the as-prepared sample at various current densities from 200 to 2000 mA g(-1) is also investigated. The discharge capacity of 123.9 mAh g(-1) can be obtained at the high current density of 2000 mA g(-1), which is about 73.4% of that at the low current density of 200 mA g(-1) upon cycling, indicating that the as-prepared sample can endure great changes of various current densities to retain a good stability due to the core shell mesoporous structure. (C) 2011 Elsevier B.V. All rights reserved.