Systems and methods of protecting electrolysis cell sidewalls

An electrolysis cell comprising:

• a cell body having a bottom and at least one sidewall, wherein the cell body is configured to retain a molten electrolyte bath, wherein the sidewall comprises:
• a first sidewall portion, configured to fit onto a thermal insulation package of the sidewall and retain the electrolyte, the first sidewall portion comprising an anodically polarized sidewall portion, wherein the anodically polarized sidewall is positioned above the bottom of the cell body and adjacent to the bath-vapor interface, such that the anodically polarized sidewall is in communication with the bath-vapor interface;
• a second sidewall portion configured to extend up from the bottom of the cell body, wherein the second sidewall portion overlapping a first sidewall portion and wherein the overlap is from 0% to not greater than 90% of a total height of the cell sidewall,
• wherein the second sidewall portion is longitudinally spaced from the first sidewall portion, such that the first sidewall portion, the second sidewall portion, and a base between the first portion and the second sidewall portion define a trough the trough having a width of 10 mm to not greater than 500 mm;
• wherein the trough is configured to receive a protecting deposit and retain the protecting deposit separate from the cell bottom.

A method, comprising:

• passing current from an anode through a molten electrolyte bath to a cathode in an electrolysis cell;
• concomitant to the first step, maintaining the bath at a temperature not exceeding 980° C.;
• feeding a feed material into the electrolysis cell at a location adjacent to a cell wall, such that the feed material is retained in a trough defined adjacent to sidewall, wherein the sidewall comprises a second sidewall portion overlapping a first sidewall portion and wherein the overlap is from 0% to not greater than 90% of a total height of the cell sidewall, and wherein the sidewall comprise an anodically polarized sidewall positioned above the bottom of the cell body and adjacent to the bath-vapor interface, such that the anodically polarized sidewall is in communication with the bath-vapor interface;
• and
• via the feeding step, maintaining the sidewall in the molten electrolyte during cell operation, wherein the sidewall is constructed of at least one component which is within about 95% of saturation in the molten electrolyte bath, wherein sidewalls of the cells are substantially free of a frozen ledge.