The intercalation reactions in Li/TiO₂ batteries have been investigated. X-ray diffraction measurements showed that the reaction is not a simple intercalation reaction, but involved the conversion of TiO₂ to a structurally different phase:Li- TiO₂. The concentration(x) of Li intercalated in TiO₂ were measured through the use of conlometric titration, Thermodynamic properties were determined from intermittent equilibrium measurements giving e. m. f., lithium chemical potential in TiO₂, as a function of x.Furthermore,the free energy, entropy and enthalpy of intercalation as well as the free energy, entropy and enthalpy of formation of Lix-TiO₂ were reported.