Abstract: Zinc-bromine battery with recirculating electrolyte and multi-cell array, with predominant concentration of the bromine in the array at all stages of battery cycling; an array of bipolar electrode assemblies (16) with anode (26A) and cathode (26C) faces, including in each such assembly a chamber of unbound--but well contacted (electrically)--charcoal (C) stored at the cathode face and means for controlling zinc plating and deplating at the anode face; and with provision of surface area enhancement at the anode and cathode faces; electrolyte flow, pH and recirculation controls inherent in the construction, all comprising an anti-degradation combination generally.

Abstract: Fuel cell liquid-liquid system comprising aqueous anolyte solution containing sulfite or bisulfite ion in high concentration recirculating through the anolyte compartment of a two electrolyte fuel cell. After converting its chemical energy to electrical energy in the cell, the spent anolyte is readily reactable to useful new products or reconstituted to fresh anolyte for re-use in the fuel cell. A class of distinctly advantageous embodiments within the general scope of the invention produces a re-usable effluent mixture of spent anolyte and catholyte to avoid the cost of handling the two effluent liquids separately, while gaining the economic advantage of maximum utilization of both fluids. The same combinable effluent characteristic makes the system tolerant to molecular diffusion or other leakage across anolyte/catholyte separating barriers.

Abstract: Fuel cell comprising anolyte and catholyte compartments separated by a diffusion barrier and using sodium sulfide aqueous solution as anolyte and an aqueous catholyte solution. The apparatus is controlled to maintain a positive pressure differential across the anolyte/catholyte interface in the barrier towards the anolyte side to attenuate sulfide ion migration to the catholyte and reduce solid sulfur precipitation in the catholyte and thereby attenuate consequent cathode passivation or other forms of catholyte compartment poisoning.