Sodium sulphur accumulator with solid electrolyte partition - has capillary layer in sodium chamber to keep level constant

摘要

An electrochemical storage cell comprises anode and cathode chambers sepd. by a solid electrolyte partition; at least one of reactants in the chambers is liq. and, during discharging of the cell, permeates through the solid electrolyte partition as ions into the other chamber, to undergo chemical combination with the other reactant. In one of the chambers there is a capillary layer fitted close to the electrolyte partition, so that as the level of liq. in this chamber falls, it is nevertheless maintained by the capillary action in the layer so that almost the entire area of the partition is utilised. Pref. the reactant which produces cations to permeate through the solid electrolyte partition is an alkali(ne earth) metal, or mixture or alloy of such, which is liq. during operation, esp. because it is heated while the other reactant contains S, esp. in the form of polysulphides. Used esp. for Na-S accumulators for vehicle propulsion. By maintaing the sodium level constant in the anode chamber, the internal resistance of the cell is also kept constant.