Boosting the proton conductivity, chemical stability, and fuel cell performance of nafion membrane at high operating temperatures and low humidity levels by incorporating phytic acid

Abstract

Nafion as a conducting polymer faces conduction challenges at high operating temperatures and low humidity levels, leading to an undesired fuel cell performance. Here, we offer a step forward towards the use of Nafion as a high-temperature/low-humidity membrane in fuel cells through the incorporation of phytic acid (IP6) by a doping process. The synergetic effect of IP6 on the physicochemical properties, mechanical characteristics, oxidative durability, proton conductivity, and fuel cell performance of Nafion membrane is studied. Compared to the pristine Nafion, the Nafion-IP6 membrane has shown a 3-fold increase in Young's modulus, a 83%-increase in water uptake, and around 6-fold increase in proton conductivity at 100 °C under 25% RH. The Ea has reached 8.3 kJ/mol, indicating a vehicular/Grotthuss proton conduction mechanism. The Nafion-IP6 based MEA has shown a 71%-increase in the output power density and a 54%-increase in the limiting current density compared to the pristine Nafion-based MEA.