The Effect of Multiple Current Collectors on the Performance of Flow-Through Porous Electrodes

A one-dimensional model for flow-through porous electrodes is used to predict the variation in electric driving force within the porous electrode and the effluent concentration for current collectors placed at the front and the back of the electrode. Results are obtained for upstream and downstream placement of the counterelectrode relative to the fluid inlet. Analytical expressions have been developed for an electrode operating under limiting current conditions. A computer model is used to predict electrode behavior above and below the limiting current of a metal deposition reaction. Results show that the variation in electric driving force within the electrode and the effluent reactant concentration can be minimized for any set value of the solution to matrix conductivity ratio (k/o) by varying the current passed at each current collector. For the limiting current case, conditions for the minimum electric driving force variation can be predicted analytically. For the above and below limiting current case, conditions for the minimum electric driving force variation and the effluent concentration have also been obtained.