Differential scanning calorimetry study of the reactivity of carbon anodes in plastic Li-ion batteries

Chemical reactions taking place at elevated temperatures in a polymer-bonded lithiated carbon anode were studied by differential scanning calorimetry. The influences of parameters such as degree of intercalation, number of cycles, specific surface area, and chemical nature of the binder were elucidated. It was clearly established that the first reaction taking place at ca. 120-140°C was the transformation of the passivation layer products into lithium carbonate, and that lithiated carbon reacted with the molten binder via dehydrofluorination only at T > 300°C. Both reactions strongly depend on the specific surface area of the electrodes and the degree of lithiation.