Heat capacity of ethylene carbonate and ethyl methyl carbonate for the liquid phase at elevated temperatures

Abstract

The heat capacities of liquid ethylene carbonate (EC) and ethyl methyl carbonate (EMC), two important electrolyte components for capacitors and Lithium-ion-batteries, were measured using differential scanning calorimetry in the temperature range from 263 to 500 K in heating mode and from 493 to 273 K in cooling mode for EC. The effect of the supercooled liquid of EC on the heat capacity is discussed. The heat capacity of EMC was determined from 211 to 360 K in heating mode. Based on the obtained heat capacities and the literature data, a simplified Maier–Kelley-fit for the heat capacities is provided. The temperature range of the experimentally determined heat capacity of the liquid state was extended to higher temperatures than previously reported in literature.