Facile synthesis of hollow carbonized polyaniline spheres to encapsulate selenium for advanced rechargeable lithium-selenium batteries

A hollow carbonized polyaniline spheres/selenium (HCPS/Se) composite was prepared by a simple combination method of a self-assembly method, pyrolysis and vapor phase infusion process as a cathode material for Li-Se rechargeable batteries. The composites were characterized and examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, the X-ray photoelectron spectroscopy and electrochemical methods, such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. The HCPS/Se composite cathode can deliver relative high capacity, high Coulombic efficiency and good cycling performance. The electrochemical results show that the HCPS/Se composite cathode exhibits an initial discharge specific capacity of 571.5 mA h g(-1) and retains 298.7 mA h g(-1) with high Coulombic efficiency after 100 cycles at a high rate of 0.5 C (337.5 mA h g(-1)), which are higher than that of the pristine selenium cathode. The excellent electrochemical properties benefit from the high conductivity and the hollow structures of the carbonized polyaniline spheres. (C) 2014 Elsevier B.V. All rights reserved.