Enthalpy measurement of lithium meta-titanate by drop calorimetry and its derived heat capacity

Enthalpy of Li2TiO3, which was synthesized by a neutralizing method and its Li/Ti ratio was determined to be Li/Ti ratio (mol/mol) = 1.97, was measured by a drop calorimeter, and its heat capacity was derived as a function of temperature. XRD (X-ray diffraction) analysis of the sample before and after the enthalpy measurement indicated no phase change during the measurement and a single phase of Li2TiO3 was observed. The enthalpy data were expressed as H(T) − H(323.17) (J/g) = 2.2 × 10−5·T2 + 1.4·T + 2.7 × 104/T − 5.6 × 102 (373–1273 K), where T is temperature in K. The heat capacity was calculated as Cp (J/g K) = 2.2 × 2 × 10−5·T + 1.4–2.7 × 104/T2 by differentiating the equation by temperature. These equations have accuracy of 3%.