Microfluidic Redox Batteries

I have been active in this field since 2005, when I joined the University of Victoria as a Ph.D. student, inspired by the notion of a low-cost fuel cell without manbrane or catalyst. My initial research endeavors culminated in a Ph.D. dissertation entitled Microfluidic fuel cells [1], which was subsequently awarded with the Governor General s Gold Medal and launched my career as a researcher and scholar. Since 2009, I have continued my research on microfluidic fuel cells as a faculty member at Simon Fraser University (SFU), where I established the SFU Fuel Cell Research Laboratory (FCReL) and expanded the scope of this research to include microfluidic redox flow batteries. 

Fig. 4.8 Symmetric and monolithic microfluidic redox battery architecture with flow-through porous electrodes and full recirculation and regeneration capabilities [73]...

The co-laminar flow principles of microfluidic electrochemical cells enable mixed media operation, in contrast to traditional types of fuel cells aud redox flow batteries operating under all-acidic or all-alkaline conditions imposed by the membranes. The unique mixed media capability allows independent tuning of half-cell conditions for optimization of reaction kinetics and cell potential. In nuxed media conditions, the open-circuit cell voltage can be increased by shifting the reversible... 

Liquid phase reactant chemistries originally developed for redox flow batteries can be exploited to great effect in microfluidic electrochemical cells. Most commonly, vanadium redox flow battery technology utilizes soluble vanadium redox couples in both half-cells for regenerative electrochemical energy storage units [53]. The combination of aqueous redox pairs in vanadium redox cells, and VO V... 

Fundamentally, both MEA-based and membraneless cells require two electrodes with an ionically conductive electrolyte between them. It is therefore proposed that a volumetric power density normalized by the essential volume of the electrochani-cal chamber, including both electrodes and the separating electrolyte, would be the most universally applicable metric for these devices. This metric captures any variations in electrolyte channel separation and electrode thickness with the only assumption being that the inlet/outlet flow field manifolds and other structural support elements are comparable between cells. With this new convention, the key microfluidic electrochemical cell technologies with the highest power densities reported to date were converted where possible and presented in Table 6.1. For comparative purposes, estimates for a typical MEA-based vanadium redox battery (VRB) [17, 18] and a DMFC [19] are also included. 

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