κ‐carrageenan/polyvinyl alcohol‐graphene oxide biopolymer composite membrane for application of air‐breathing passive direct ethanol fuel cells

Abstract

AbstractIn this article, new biopolymer composite membranes based on κ‐carrageenan, polyvinyl alcohol and graphene oxide (designated as κ‐car/PVA‐GO) were synthesized by casting method for the application of passive direct ethanol fuel cell (DEFCs). FTIR, XRD, and FESEM analysis proved that the κ‐car/PVA‐GO biopolymer composite membrane has been successfully fabricated. The fabrication of the κ‐car/PVA‐GO biopolymer composite membrane effectively increases the proton conductivity and ethanol barrier. The high proton conductivity is achieved 2.67 × 10−3 S/cm and the reduced permeability of ethanol 1.95 × 10−7 cm2/s at 30°C. Besides, PVA blend modification and the introduction of GO improve the mechanical properties of the κ‐car biopolymer. The maximum power density of the passive DEFCs is 3.84 mW/cm2 using the κ‐car/PVA‐GO biopolymer composite membrane, which is higher than the Nafion membrane, which achieved only 2.02 mW/cm2 in a similar operating condition of passive DEFCs at 30°C. Furthermore, the κ‐car/PVA‐GO biopolymer composite membrane could be maintained in a fuel cell atmosphere for 1000 h. According to our review of the literature, there are no studies have used the carrageenan‐based membrane in the application of passive DEFCs. This is a promising biopolymer electrolyte membrane for use in passive DEFCs.