Redox flow battery composite electrode

Most commonly, the battery will be configured with a stack of bipolar cells (10 -100 cells per stack) to give a useful output voltage and with parallel flows for the electrolytes to each of the cells in the stack. Hence, the electrodes will be bipolar with a solid core from carbon, graphite, or a carbon/polymer composite and the three-dimensional elements bonded or pressed onto either side of the solid core. The composites are a blend of a chemically stable polymer and a micron-scaled carbon powder, most commonly an activated carbon Radford et al. [127] have considered the influence of the source of the carbon and the chemical and thermal treatments on the properties of such activated carbons, especially the pore size and distribution [126]. Even though reticulated vitreous carbon has been used for the three-dimensional elements [117], the predominant materials are graphite cloths or felts with a thickness of up to 5 mm, and it is clear that such layers are essential to scale the current density and thereby achieve an acceptable power density. Details of electrode performance in the more developed flow batteries are not available but, for example, Skyllas-Kazacos et al. [124] have tabulated an overview of the development of the all vanadium redox flow battery that includes the electrode materials and the chemical and thermal treatments used to enhance activity and stability. 

Leung PK, Ponce-de-Leon C, Low CTJ, Walsh FC (2011) Zinc deposition and dissolution in methanesulfonic acid onto a carbon composite electrode as the negative electrode reactions in a hybrid redox flow battery. Electrochim Acta 56 6536-6546. doi 10.1016/j.electacta.2011.04. Ill... 

Zhua HQ, Zhang YM, Yuea L, Li WS, Li GL, Shu D, et al. Graphite-carbon nanotube composite electrodes for aU vanadium redox flow batteries. J Power Sources 2008 184 637-40. 

W.Y. Li, J.G. Liu and C.W. Yan, Graphite-graphite oxide composite electrode for vanadium redox flow battery, Electrochim. Acta 56,2011,5290-5294. 

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