Liquid metal cathode electrochemical cell and cathode frame

A horizontal electrolytic cell having a liquid metal cathode in a catholyte compartment, an anode, a separator, a catholyte inlet and catholyte outlet for the flow of catholyte into and out of the catholyte compartment in the cell comprising:

• at least two electrode frame each having a pair of opposing ends having a first generally uniform height and a pair of opposing sides meeting the opposing ends at a plurality of corners, each opposing side having an obliquely angled portion extending from each corner at the first generally uniform height slopingly to an extended portion at a different lower level, each frame having a continuous interior intermediate surface against which lies the membrane such that each interior intermediate surface is substantially coplanar with the membrane and the extended portion lies substantially coplanar with the major portion of the separator positioned in the extended plane, the obliquely and slopingly angled portion supporting the membrane in an obliquely angled relationship adjacent a gap between the anode and the cathode and being positioned only immediately adjacent each of the plurality of corners formed by the pair of opposing ends and pair of opposing sides.