Preparation and characterization of spinel Li4Ti5O12 anode material from industrial titanyl sulfate solution

Spinel Li4Ti5O12 anode material is successfully synthesized by a solid-state method using lithium carbonate and titanium precursors which are prepared by the low cost industrial titanyl sulfate solution. The characters of H2TiO3 and TiO2 precursors are determined by TG/DTA and SEM methods. TG-DAT and EDS methods show that H2TiO3 can absorb sulphate ions which can be present as impurities. XRD method shows that the impure phases of Li2SO4 and rutile TiO2 appear in Li4Ti5O12 synthesized by H2TiO3. The formation of Li2SO4 is identified in thermodynamics during the process of calcination. Owing to the formation of Li2SO4 impurity, the capacity of the Li4Ti5O12 synthesized by H2TiO3 is low. One effective way that can tackle this problem is to remove the sulphur by calcining H2TiO3, after calcinations, the production will have a thermal treatment with Li2CO3. The obtained Li4Ti5O12 shows better electrochemical performance. The specific capacities can be increased by 20 mAhg(-1) at 0.1, 0.5 and 1C rates. (C) 2010 Elsevier B.V. All rights reserved.