ELECTROCHEMICAL CELL USING A DITHIONITE COMPOUND OF AN ALKALINE METAL AS THE CHARGE TRANSFER AGENT

An ambient temperature electric cell of primary and secondary nature, characterized by the use of a dithionite radical of an alkaline metal as the charge transfer agent, and including processes for manufacturing and for operating the same. The dithionite is dissolved in an anhydrous electrolyte comprised of a suitable solvent, which may also contain a salt of the same alkaline metal and be saturated with sulfur dioxide. A sealed and evacuated cell (negative electrode, inert highly porous space, and positive current gathering electrode) is filled with the electrolyte and subjected to a charging current sufficient to plate the alkaline metal onto the negative electrode while further saturating the electrolyte with sulfur dioxide. In the case of a secondary cell, the electrolyte is capable of redissolving the dithionite produced upon discharge, such procedure being enhanced by a system for forced circulation of the electrolyte. In the case of a primary cell, redissolution is not necessary and the final cell potential and discharge characteristics can be enhanced by replacing the dithionite electrolyte with other anhydrous electrolyte solutions (e.g., sulfuryl chloride or thionyl chloride). The cell is characterized by extremely low internal resistance, long shelf life, excellent performance over a wide temperature range, and negligible depletion of the active dithionite charge transfer agent. In a particular high energy battery system, an electrolyte containing dissolved dithionite is circulated between a battery chamber and an auxiliary chamber containing solid dithionite salt (e.g., lithium dithionite). The electrolyte circulates from the auxiliary chamber through a solids separating means (centrifugal separator) to the battery chamber, where the electrolyte containing freshly dissolved dithionite is passed through a highly porous intermediate passage between an elongate active anode (e.g., copper) and an adjacent elongate current gathering cathode (e.g., finely divided carbon), in such fashion as to minimize internal resistance to current flow while substantially increasing the energy storage capacity of the battery cell.