Flow-through porous electrode

Marrocino, J. M., Coeuret, F. and Langglois, S. (1987) A first investigation of flow-through porous electrodes made of metallic felts or foams. Electrochim. Acta 32,1303-1309. 

When the electrode is completely immersed in the electrolyte solution, only a two-phase interface (i.e., liquid-solid) is present in the electrode structure. In form it may be either a consolidated powdered active carbon or a confined but unconsolidated bed of carbon particles. These are u.sed for flow-through porous electrodes in many electrochemical systems. The other mode of operation is the gas-diffusion electrode, in which the electrode pores contain both the electrolyte solution and a gaseous phase. Numerous publications [29-31] have reported on a theoretical analysis of flow-through porous electrodes and gas-diffusion electrodes, which takes into account the physicochemical characteristics of carbon electrode materials. There does not seem to be a uniform explanation for the effects of structural and chemical heterogeneity in carbons. 

Consider a flow-through porous electrode of length L (cm) and cross-sectional area A (cm ) immersed in a stream of volumetric flow rate v (cm /s) (Figure 11.6.2). The linear flow velocity of the stream, U (cm/s), is given by... 

For very low concentrations (of the order of 1 mg/1 and lower), electrolysers have been designed with a large-surface area cathode, which is, in substance, a flow-through porous electrode. This is realized in various ways, e.g. by a graphite felt... 

Microfluidic Fuel Cells, Fig. 4 Schematic of a microfluidic fuel cell with flow-through porous electrodes, using aqueous fuel (V ) and oxidant (VO2 ) (Reproduced with permission from Kjeang et al. [6]. Copyright American Chemical Society (2008))... 

Another important breakthrough in this field was realized by a flow-through porous electrode architecture with vanadium redox electrolytes [6]. As shown in Fig. 4, the fuel and oxidant were supplied into the inlet ports and guided to flow through the porous carbon electrodes in the... 

An Impedance Study of Flow-Through Porous Electrodes, Ph.D. Thesis, the University, Southampton, England. 

Olive H, Lacoste G (1980) Application of volumetric electrodes to the recuperation of metals in industrial effluents - 11. Design of an axial field flow through porous electrodes. Electrochim Acta 25 1303-1308. doi 10.1016/0013-4686(80)87138-6... 

Doherty T, Sunderland JG, Roberts EPL, Pickett DJ (1996) An improved model of potential and current distribution within a flow-through porous electrode. Electrochim Acta 41 519-526. doi 10.1016/0013-4686(96)81774-9... 

Fig. 4.4 (a) Schematic and (b-d) annotated images of a microfluidic fuel cell with flow-through porous electrodes. The images show regular fuel cell operation at (b) open-circuit and... 

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

Despite the variability in conditions, several useful trends can be extracted from the performance data in Table 6.1. For the cells with flow-through porous electrodes, the performance of the original cell by Kjeang et al. appears to surpass the modified cell by Lee et al. when normalized by projected electrode area. 

Kjeang, E., Michel, R., Harrington, D.A., Djilali, N., and Sinton, D. (2008) A microfluidic fuel cell with flow-through porous electrodes. Journal of the American Chemical Society, 130 (12), 4000-4006. 

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