Parametric Study of Zinc Deposition on Porous Carbon in a Flowing Electrolyte Cell

X‐ray radiography coupled with high resolution optical densitometry, as well as optical and scanning electron microscopy, was employed to study the effect of pivotal zinc deposition parameters on the zinc morphology within a porous C foam electrode. Deposition was carried out in zinc‐bromine and zinc‐zinc cells with circulating electrolyte. Results on the effects of flow rate, substrate thickness, current density, and electrolyte composition on zinc distribution in the substrate and on its surface are described. This study has shown that in the absence of organic inhibitors, very nonuniform zinc deposition occurs within the porous electrode. This zinc deposition corresponds to the nonuniform primary current distribution dominated by ohmic resistance. This study has led to the conclusions that high electrolyte flow rates, moderate current densities, and thick foams all aid in producing increasingly uniform zinc deposits. The most beneficial effects on the zinc morphology, however, were obtained by adding to the electrolyte a dendrite inhibitor‐solubilizer combination consisting of certain fluorosurfactants and butyrolactone.