Thermal stability and lifetime of [AMIM]Cl-PFSA composite membranes

Abstract

1-Allyl-3-methylimidazolium chloride [AMIM]Cl hybrid perfluorosulfonic acid (PFSA) composite electrolyte membrane was prepared and characterized by TG and FTIR technique. The conductivity was measured using AC impedance method. The results showed that when raised from 20 to 90 °C, the conductivity of composite membrane was increased from 4.50 × 10−6 to 1.34 × 10−5 S cm−1, before and after the modification of triethylamine, the thermal stability of composite membrane was not changed, but the TEA-PFSA with [AMIM]Cl reactivity was a little difference. However, the heat resistance of composite membrane was significantly enhanced compared with that of PFSA membrane, the peak temperature of composite membrane almost disappeared in first stage, and offset to the high-temperature zone. When heated at 350 °C, the decomposition rate of PFSA, 10%[AMIM]Cl-PFSA and 10%[AMIM]Cl-TEA-PFSA membrane was 13.71, 3.67 and 1.26%, respectively. If the decomposition process follows isothermal first-order reaction and the conversion rate α is 10%, the activation energy Eα of the composite membrane is 97.4 kJ mol−1. Besides, the isothermal lifetime of composite membrane was also measured.