A New Membrane-Less Porous Electrode Cell Design for Zinc-Iodide Redox Flow Battery

Tuesday, 30 May 2017: 16:20
Grand Salon B - Section 12 (Hilton New Orleans Riverside)
F. Shakeri Hosseinabad, D. Fofana, J. Li, and E. P. L. Roberts (University of Calgary)
A new flow field using a flow through porous electrode for membrane-less flow battery has been evaluated using the zinc-iodide redox system. The flow through the porous electrode enables good mass transport at the zinc electrode, and thus good performance was obtained. The flow through arrangement also allowed separation of the charged species without the use of a membrane. An electrolyte system of zinc-iodide, iodine, and zinc chloride was used. A 5cm2 carbon paper (39AA SIGRACET) was used as the electrode. Cyclic voltammetry studies were carried out for the electrolyte system using a glassy carbon working electrode in the range of -2 to 2V (versus Ag/AgCl) , and the effect of zinc-iodide concentration and different range of scan rate was investigated. Mass transfer modeling of the zinc iodine system during the discharge process was carried out and the concentration profile was obtained. The variation of zinc-iodide concentration along the length of the cathode, resulted in spatial variation in mass flux and current density. The 2-D model is reduced to an equivalent 1-D model for the concentration profile by using realistic boundary conditions at the electrode along with using similarity technique. The effect of Péclet number, zinc-iodide concentration and flow rate on columbic and energy efficiency of the new cell will be presented.