Incorporation of ultralow manganese dioxide for improving the durability of sulfonated poly (ether ether ketone) membranes in passive direct methanol fuel cell

Abstract

In this study, a novel composite membrane is prepared by incorporating the manganese dioxide (MnO2) nanorod into sulfonated poly (ether ether ketone) (SPEEK) matrix to wrestle with the limitation of poor durability on the development of SPEEK membranes. In Fenton's solution, the start broken-up time of the composite membrane with only 2.5% MnO2 loading, prepared by the solution-casting method, is about 4 times that of pure SPEEK membrane. This suggests that the MnO2 addition effectively improves the durability of SPEEK membranes. In the passive direct methanol fuel cell (DMFC) test, SPEEK-2.5% MnO2 membrane exhibits the max power density of 24 mW cm−2 (at 8 M methanol and 25 °C) and better durability than pure SPEEK membrane, as well as the possibility of SPEEK-MnO2 composite membrane for the fuel cell application. The addition of low-cost MnO2 improved the stability of the SPEEK membrane, contributing to the promotion of its commercialization process.