Varta Batterie Aktiengesellschaft

Wolfgang Kappus

Waldemar Borger

Rudolf Eckardt

Karl-Friedrich Gutlich

Herbert Zweigardt

In an electric storage battery having plate electrodes, the capacity and useful life is improved through uniform distribution of concentration and temperature of the electrolyte by means of electrolyte circulation. A synthetic plastic plate positioned between the plate electrodes and the housing wall of the storage battery contains a plurality of vertically extending transport tubes which are open at their upper and lower ends. The bottom portions of the transport tubes, which are immersed in the electrolyte, are connected to compressed air ducts. The compressed air is mixed with the electrolyte present in the transport tube in such a manner that the electrolyte-air mixture present therein is lifted, due to its lower specific gravity, by the electrolyte which surrounds the transport tube. The electrolyte leaving the transport tube produces continuous circulation within the storage battery, and this ensures permanent exchange of the electrolyte present between the plate electrodes.

Electric storage battery with gas driven electrolyte movement

In a high-temperature cell using, for example, the system Li(Al)/LiCl, KCl/MeS (wherein Me is a heavy metal) the operating temperatures and the composition of the molten electrolyte are so selected that a solid phase is created through partial precipitation of at least one of the components of the salt mixture, which provides the separator function between the electrode plates. For example, a non-eutectically composed molten electrolyte of 80% by volume LiCl and 20% by volume KCl, at a given temperature corresponding to the operating point in the phase diagram, contains a solid LiCl frame whose pore volume of about 50% is filled with ion-conducting residual molten LiCl and KCl. Through combination with non-electron conducting inert material in grid or powder form, the permeability of the precipitated solid separator can be further controlled.

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Viernheim, Germany

Wolfgang Kappus