Abstract
We investigated the relation between the thermodynamic stability and cathode performance of lithium manganese spinels as cathode active materials for the lithium secondary batteries. The heat of dissolution of these samples was measured by the solution calorimetry method. The standard enthalpy of formation, ΔfH0, the enthalpy change of reaction, ΔH, and the enthalpy change per mole of atoms for the formation reaction, ΔHR, were calculated from the heat of dissolution. The larger |ΔH| or |ΔHR| means a thermodynamically more stable sample. A more thermodynamically stable sample makes a stable crystal structure and leads to a good cycle performance.
