title: A microfluidic fuel cell with flow-through porous electrodes.
abstract: A microfluidic fuel cell architecture incorporating flow-through porous electrodes is demonstrated. The design is based on cross-flow of aqueous vanadium redox species through the electrodes into an orthogonally arranged co-laminar exit channel, where the waste solutions provide ionic charge transfer in a membraneless configuration. This flow-through architecture enables improved utilization of the three-dimensional active area inside the porous electrodes and provides enhanced rates of convective/diffusive transport without increasing the parasitic loss required to drive the flow. Prototype fuel cells are fabricated by rapid prototyping with total material cost estimated at 2 USD/unit. Improved performance as compared to previous microfluidic fuel cells is demonstrated, including power densities at room temperature up to 131 mW cm-2. In addition, high overall energy conversion efficiency is obtained through a combination of relatively high levels of fuel utilization and cell voltage. When operated at 1 microL min-1 flow rate, the fuel cell produced 20 mW cm-2 at 0.8 V combined with an active fuel utilization of 94%. Finally, we demonstrate in situ fuel and oxidant regeneration by running the flow-through architecture fuel cell in reverse.
authors.affiliation: Department of Mechanical Engineering, Institute for Integrated Energy Systems (IESVic), University of Victoria, 3800 Finnerty Road, Victoria, BC, V8W2Y2, Canada.
authors.forename: Erik
authors.initials: E
authors.lastname: Kjeang
authors.forename: Raphaelle
authors.initials: R
authors.lastname: Michel
authors.forename: David A
authors.initials: DA
authors.lastname: Harrington
authors.forename: Ned
authors.initials: N
authors.lastname: Djilali
authors.forename: David
authors.initials: D
authors.lastname: Sinton
mesh_terms: D011211:Electric Power Supplies; D004566:Electrodes; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D010084:Oxidation-Reduction; D016062:Porosity; D012680:Sensitivity and Specificity; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D014639:Vanadium / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014639:Vanadium; D014867:Water