Varta Batterie Aktiengesellschaft

Dietrich Sprengel

Rudolf Tepel

Eberhard Niggemann

Wolfgang Knabenbauer

Uwe Kohler

Halbig, Helmut

Karl Glotzel

Jurgen Heydecke

Karl Glotzl

A prismatic electrochemical cell includes electrode plate blocks in which the stacked positive and negative electrode plates are separated by separators and are connected by current conductors to the corresponding terminal posts by crimping current conductors in the form of wires to collar-shaped portions of the terminal posts.

Electrochemical cell

A multicell storage battery, especially of the nickel/hydride type, is provided with pressure safeties for protection against high internal pressures. The pressure safeties respond at a preassigned critical pressure, causing mechanical changes in shape or through destruction which can be optically or electrically monitored. For example, a hinged lid is caused to swing up responsive to a rupture disk, interrupting a light beam. Alternatively, a rupture disk is coated with a conducting enamel and is connected by lead wires to form an electrical circuit which is interrupted responsive to damage of the enamel layer (e.g., responsive to bursting of the membrane).

Multicell storage battery

The cell of a gas-tight alkaline battery is balanced by subdividing the negative excess capacity into the necessary charge and discharge reserves by individually treating the two electrode polarities prior to their assembly, while avoiding open cell forming. When combining a charged, dried, positive sintered electrode which is suitable for storage with a negative electro-deposited electrode, the latter inherently receives a charge reserve due to partial chemical oxidation with H.sub.2 O.sub.2 l or K.sub.2 S.sub.2 O.sub.8. When a discharged, but preformed positive sintered electrode is combined with a negative sintered electrode, the latter is electrochemically partially charged to the extent necessary to achieve the desired discharge reserve, and thereafter preserved by immersion in a solution containing sulfuric acid, and possibly CdSO.sub.4.

Process for producing a gas-tight, sealed alkaline battery

The cell of a gas-tight alkaline battery is balanced by subdividing the negative excess capacity into the necessary charge and discharge reserves by individually treating the two electrode polarities prior to their assembly, while avoiding open cell forming. When combining a charged, dried, positive sintered electrode which is suitable for storage with a negative electro-deposited electrode, the latter inherently receives a charge reserve due to partial chemical oxidation with H.sub.2 O.sub.2 or K.sub.2 S.sub.2 O.sub.8. When a discharged, but preformed positive sintered electrode is combined with a negative sintered electrode, the latter is electrochemically partially charged to the extent necessary to achieve the desired discharge reserve, and thereafter preserved by immersion in a solution containing sulfuric acid, and possibly CdSO.sub.4.

For oxygen reduction in a battery an auxiliary electrode is provided having two layers, one with hydrophilic characteristics, the other hydrophobic. The hydrophilic layer is preferably of activated carbon bound in plastic and the hydrophobic layer of porous polytetrafluorethylene. Electrical contact is established between a conductor on the outside of the activated carbon layer and the negative main electrode. Preferably the exposed surface of the auxiliary electrode is provided with a metal ion barrier. Also preferably at least two such auxiliary electrodes are provided to make the battery orientation insensitive.

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Halver, Germany

Dietrich Sprengel