| Li-ion battery is expected to support the effective utility of electric energy in coming soft energy pass society. However degradation of the battery may lead to self ignition. To avoid such risks, understanding of degradation mechanism is of large importace. In this study, degradation behaviour of Li-ion battery was measured by V-C characteristics for different voltage scan ranges. With investigation of chemical composition and X ray diffraction analysis, degradation is associated with production of diethylfluorophosphate in electrolyte and lattice constant increase of LiCoO2 electrode. |