Mechano-thermally Activated Solid-State Synthesis of Li4Ti5O12 Spinel from Li2CO3-TiO2 Mixtures

Simultaneous TG/DSC measurements performed on mixtures 2Li2CO3-5TiO2 (anatase) subjected to high-energy milling showed that both the temperature and the enthalpy of Li2CO3 decomposition are much lower than in the case of TG/DSC runs performed on a sample of a physical mixture. On the basis of the thermoanalytical evidence a solid state synthesis of the spinel compound Li4Ti5O12 has been proposed that combines mechanical (by high energy milling) and thermal activation (8 h annealing at 973 K): the obtained compound shows a lattice constant in very good agreement with that expected for the pure phase Li1+xTi2-xO4 (x = 0.333). The molar heat capacity of Li4Ti5O12 has been determined in the temperature range 323-633 K by quasi-isothermal Modulated Differential Scanning Calorimetry (MDSC). The specific surface area of Li4Ti5O12 has been determined by gas adsorption.