Varta Batterie Aktiengesellschaft

Varta Batterie Aktiengesellshaft

Jurgen Vollbert

Dieter Bechtold

Dietrich Bartke

Peter Kramer

Frank Mengel

Jorg Kumpers

Klaus Brandt

Reiner Kretzschmar

The invention relates to a rechargeable lithium-ion cell, a method for its manufacture, and its application. The cell is distinguished by the fact that it has a metallic housing (21) which is electrically insulated internally by two half shells (15), which cover electrode plates (8) and main output tabs (7) and are composed of a non-conductive material, where the metallic housing is electrically insulated externally by means of an insulation coating. The cell also has a bursting membrane (4) which, in its normal position, is located above the electrolyte level of the cell (1). In addition, the cell has a twisting protection (6) which extends over the entire surface of the cover (2) and provides centering and assembly functions for the electrode package, which comprises the electrode plates (8).

Rechargeable lithium-ion cell

A prismatic galvanic cell having a large number of electrode pairs separated by separators is provided with electrode plates having current tapping lugs which extend from upper or lateral edges of the plates, and which include flexible tongues extending along and parallel to the plate edges. The flexible tongues of grouped electrode plates of the same polarity are connected to the terminal posts of the cell in a manner which precludes short circuiting and which accommodates the increased bending stresses typical of such cells.

Prismatic galvanic cell having a current topping lug

A lead storage battery is filled with electrolyte in two steps. In a first step, the filling electrolyte is a sulfuric acid which does not contain a gelling agent, and the amount of electrolyte introduced into the battery casing is selected so that the electrolyte fills only the pores in the active compound of the electrodes and the pores of the separators (to the extent that they are capable of retaining the absorbed liquid by capillary action). In a second step, the filling electrolyte is a thixotropic mixture of sulfuric acid and silicic acid, which fills the remaining electrolyte space. The state of the electrode plates that are used (i.e., formed or unformed) determines the density of the sulfuric acid used in both portions of the filling process. In the case of formed plates, the density conforms to the normal final acid density for a charged storage battery. In the case of unformed plates, the acid is diluted so that the density reaches the normal final acid density during subsequent formation of the storage battery, which can be performed as a monobloc formation.

Process for producing a lead storage battery with a thixotropic gel

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Hattersheim, Germany

Jurgen Vollbert