Brown, Boveri & Cie Ag

Bbc Brown Boveri Ag

Henner Meinhold

Wilfried Fischer

Wilhelm Haar

Dieter Hasenauer

Franz-Josef Rohr

Botho Ziegenbein

Bernd Hartmann

Gunther Petri

The bypass element is connected in parallel with a single battery cell or a group of battery cells of a high-temperature storage battery including a plurality of series-connected electrochemical battery cells and is used both for balancing the charging state of undamaged battery cells and for the irreversible bypassing of destroyed cells which have failed with high impedance. The bypass element includes two series-connected semiconductor components, in particular semiconductor diodes, varistors or NTC resistances in each case having a different current/voltage characteristic or curve. In the event of potentiostatic overcharging of a battery cell, the first semiconductor component goes to low impedance so that the current flow necessary for charging further battery cells is determined only by the leakage current of the second semiconductor component. If a destroyed battery cell fails with high impedance, both semiconductor components break down and irreversibly short-circuit the cell with a low impedance.

Bypass element for safeguarding battery cells

Method for measuring the free oxygen concentration in gas mixtures, especially combustion gases, with an electrochemical measuring device which comprises an oxygen ion-conducting solid electrolyte and two electrodes to which the supply voltage U.sub.s is fed. The supply voltage U.sub.s is formed from the sum of at least two voltage components U.sub.a and U.sub.v. The first voltage component U.sub.a is kept at a constant predeterminable value which is required for ionizing the free oxygen. The second voltage component U.sub.v is kept variable and its respective value is determined as a function of the magnitude of the probe current I.sub.s flowing between the electrodes.

Method for measuring the oxygen concentration in gas mixtures

High-temperature battery with at least one electrochemical storage cell which is surrounded by thermal insulation as well as by feed and discharge lines for the cooling air. At least one module which can be inserted into the high-temperature battery, contains the storage cells. The module has a feedline for cooling air and a discharge for the cooling air which are arranged so that the cooling air can be introduced into the module against the force of gravity and discharged from the module with the force of gravity.

High-temperature battery

Circuit for the uniform charging and discharging of electrochemical storage cells of the alkali metal and chalcogen type having a protective element in the circuit. The protective element is a container filled with a chemical compound which easily dissociates and easily recombines. The outer surface of the container forms an anode. An electrically conducting rod which forms a cathode extends into and also out of the container, and is electrically insulated in its mounting.

Circuit for protecting storage cells

Battery formed of electrochemical storage cells of the alkali metal and chalcogen type in series or groups of several parallel-connected storage cells connected in series. To assure uniform charging and discharging of the storage cells, each series-connected cell or each group of parallel-connected cells, has parallel-connected to the cell or group of cells, a protective circuit. Upon reaching a given maximum charge or discharge, a cell or group of cells, the circuit acts to bridge i.e. short the cell or group of cells which has reached a maximum charge or discharge, and prevent further charge or discharge of such cell or group of cells. The circuit is functionally connected to a switch which is conductively connectible directly to the negative and positive electrodes of the cells and to the electric terminals. The protective circuit is directly connected to both terminals and the storage cell to at least one of the two terminals via the switch.

Electrochemical storage cell of the alkali metal and chalcogen type with an anode and a cathode chamber separated by a solid electrolyte wall and confined by a metal wall. A first current collector has an outer sub-part which extends outside the reactant chamber enclosed by the solid electrolyte, and an inner sub-part which extends into the interior of this reactant chamber. The outer sub-part and the inner sub-part are connected to an electrically conducting contact element which melts at a predetermined temperature exceeding the operating temperature of the cell. A second current collector is formed by part of the metal wall which confines the other reactant chamber.

Electrochemical storage cell

Electrochemical storage cell with an anode chamber and a cathode chamber separated by a solid electrolyte. At least one of the chamber adjacent to the solid electrolyte and a supply chamber shield from both the solid electrolyte and the reaction chamber. At least one connected between the reaction chamber and the supply chamber for flow of reactants, and temperature controlled shut-off means for closing off the connection when a predetermined temperature above the operating temperature of the cell is reached.

Growing community of inventors

Sandhausen, Germany

Henner Meinhold