Thermal Behavior of Lithiated Graphite with Electrolyte in Lithium-Ion Batteries

A C80 calorimeter was used to study the thermal behaviors of and in electrolyte. C80 results show that alone shows one exothermic peak, which is attributed to the solid electrolyte interphase (SEI) decomposition. Four exothermic peaks were detected in electrolyte samples. These four peaks are attributed to SEI decomposition, Li-electrolyte reaction as well as new SEI film formation, new SEI film decomposition, and Li with PVDF/other products reactions. The apparent activation energy of and -electrolyte at different states of charge was calculated, and it was found that with intercalated lithium increasing, the activation energy shows a decreasing trend.