Electrolytic cell

The invention provides an electrolytic cell which comprises an electrolytic cell body which is rectangular overall and a corner heat insulation device coating the outer side of the corner of the electrolytic cell body. The corner heat insulation device comprises a metal plate coating the outer side of the corner of the electrolytic cell body and multiple horizontal rib plates protruding out of the electrolytic cell body perpendicularly from the metal plate. The horizontal rib plates are parallel to the horizontal plane. Multiple horizontal insulation windows are defined by the horizontal rib plates and the metal plate jointly and filled with a heat insulation material. Compared with the prior art, the electrolytic cell has the beneficial effects that through the additional arrangement of the corner heat insulation device and reasonable control over the thicknesses of the heat insulation material in different positions of an anode, corner heat dissipation is reduced, the corner current intensity is increased, a primary crystal temperature isotherm of an electrolytic cell corner electrolyte is moved outwards, corner stretches are prevented and eliminated, a hearth is sorted, and the purposes of safety, stability, high efficiency and low consumption of the electrolytic cell are achieved.