Abstract
The thermal decomposition of LiMn2O4LiMn2O4 charged to 4.2 V was studied using a combination of accelerating rate calorimetry and X-ray diffraction. The electrolyte and solvent were removed from the surface of the electrode using a rinsing procedure. Then electrode samples were either heated dry with solvent added or with electrolyte added. The dry electrode was determined to convert from the λ­MnO2λ­MnO2 structure to the β­MnO2β­MnO2 structure upon exposure to elevated temperatures (below 300°C). In the presence of solvent, there is solvent oxidation and reduction to MnO. The reaction of LixMn2O4LixMn2O4 with xMxM LiPF6/EC:DECLiPF6/EC:DEC (0<x<1.5)(0LiMn2O4,LiMn2O4, since electrodes in electrolytes with lower concentrations of LiPF6LiPF6 than, for example, 1 M, demonstrate improved thermal behavior. © 2001 The Electrochemical Society. All rights reserved.