Abstract: An electrolytic cell is divided into two compartments by an electrolyte separator. Each compartment contains an electrode which has a surface adjacent the separator. These surfaces each comprise at least one ridge and at least one groove. A ridge of one electrode is opposite a groove of the other electrode and extends at least partially within the groove, thereby retaining the electrolyte separator partially within the groove. Each ridge has a crown portion which is positioned nearest the separator. The crown portions may be tapered and may comprise a nonconductive insulating material.