Proton selective ionic graphene-based membrane for high concentration direct methanol fuel cells

• Published in: Journal of membrane science 2014-10, Vol.467, p.217-225
• Main Authors: Paneri, Abhilash, Heo, Yunseon, Ehlert, Gregory, Cottrill, Anton, Sodano, Henry, Pintauro, Peter, Moghaddam, Saeed
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemistry; Colloidal state and disperse state; Density; Direct energy conversion and energy accumulation; Direct methanol fuel cell (DMFC); Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exchange; Fuel cells; General and physical chemistry; Graphene oxide (GO) membrane; High methanol concentration; Impact tests; Membranes; Methanol crossover; Methyl alcohol; Nanostructure; Proton selectivity; Transport
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2014.05.002

Development of a proton exchange membrane (PEM) with insignificant methanol permeability at highly concentrated methanol supply is considered a major advancement in the direct methanol fuel cell (DMFC) technology. Here, we investigate the potential of graphene-based membranes for achieving this objective. A membrane is prepared through the lamination of graphene-oxide (GO) nanoplatelets and its transport characteristics are studied. The studies suggest that the membrane methanol permeation rate decreases linearly as the nanoplatelets size is increased, while proton conductivity changes rather insignificantly. The observed transport characteristics are attributed to either different adopted conduction pathways or surface mobility of protons and methanol molecules. The findings imply that the GO nanoplatelets contain atomic formations that are more selective to protons than to methanol molecules. Direct methanol fuel cell measurements of the membrane at high fuel concentrations showed almost no drop in the open circuit potential (OCP) and significant improvements in power density compared to that of a Nafion membrane. •Transport characteristics of a graphene oxide (GO) PEM is studied.•Methanol permeability was found to be a function of the GO nanoplatelet size.•Proton conductivity was found to be independent of the GO nanoplatelet size.•GO exhibited 3 orders of magnitude lower methanol permeability that Nafion.•Tests at 10M methanol solution showed almost no drop in open circuit potential.