Enhancement on the Quaternized sodium alginate/polyvinyl alcohol membrane performance in the application of passive DEFCs

Abstract There are two significant characterizations of anion exchange membrane (AEM membrane) that affect the performance of passive direct ethanol fuel cells (DEFCs), namely ionic conductivity and ethanol permeability. Reducing the AEM membrane thickness leads to an increase in ionic conductivity by decreasing ion diffusion distance. Unfortunately, decreasing the AEM membrane thickness causes high ethanol permeability occurred, which deteriorates the performance of passive DEFCs. Therefore, it is necessary to balance two significant characterizations and obtain the optimal AEM membrane thickness to achieve high membrane selectivity and enhanced the performance of passive DEFCs. In this study, the effect of membrane thickness of Quaternized sodium alginate/polyvinyl alcohol (QSA/PVA) membrane was investigated to enhance the performance of passive DEFCs. The various membrane thicknesses from 12 μm to 24 μm were investigated. Based on our previous research, QSA/PVA membrane demonstrated dense morphology and virtuous characterization for AEM membrane, which is potentially for use in passive DEFCs. The 20 μm thickness membrane of the QSA/PVA membrane obtained the highest membrane selectivity (i.e., 13.57 × 104 S s cm-3), and the maximum power density of passive DEFCs reached 11.2 mW cm-2. Finally, the QSA/PVA membrane has successfully maintained the operating condition without cell degradation for 1000 hours.