Multi-cell storage battery

• US 6,146,783 A
• Filed: 05/21/1998
• Issued: 11/14/2000
• Est. Priority Date: 05/22/1997
• Status: Expired due to Term

• Current Assignee: Varta Automotive Systems GmbH
• Original Assignee: Varta Batterie AG (Michael Tojner, PhD, LLD)
• Inventors: Brohm, Thomas, Bottcher, Friedhelm
• Primary Examiner(s): Nuzzolillo, Maria
• Assistant Examiner(s): Martin, Angela J.
• Application Number:
  US09/082,653
• Time in Patent Office: 908 Days
• Field of Search: 429/61, 429/62, 429/120, 429/129, 429/231.95
• US Class Current: 429/62
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 50/24 adapted for protecting batteries from their environment, e.g. from corrosion thermal insulation H01M10/658
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A multi-cell storage battery, in particular to a lithium storage battery, which contains a temperature control device and in which groups of one or more individual cells arranged alongside one another are separated from one another by a thermally insulating solid layer whose coefficient of thermal conductivity lies between 0.01 and 0.2 W/(m*K), the thermal resistance of the solid layer being greater by at least a factor λ than the thermal resistance of the individual cell. The individual cell is connected, at least in a region free of insulating material, to a heat exchanger, the thermal resistance of the heat exchanger in the direction toward the neighboring cell being selected to be greater by at least a factor λ than the thermal resistance of the individual cell and, in addition, the thermal resistance of the heat exchanger toward the temperature control medium being selected to be smaller by at least a factor of about 10 than the thermal resistance of the individual cell, and λ being the ratio of the energy content of the individual cell to the amount of energy that is needed to trigger a thermally induced cell failure at a defined upper operating temperature limit.

Claims

1. A battery having a plurality of individual storage cells and a temperature control device, wherein:

the individual cells are arranged into two or more groups of cells, each group having one or more individual cells arranged alongside one another and separated from one another by a cell space filled with a thermally insulating solid material;

the groups of one or more cells are separated from one another by a space, said space being filled with a thermally insulating solid material, the thermal resistance of the solid material being greater by at least a first factor than the thermal resistance of each cell; and

each group of one or more cells is thermally connected to a heat exchanger having a temperature control medium, wherein;

the thermal resistance of the heat exchanger in a direction toward a neighboring group of one or more cells is selected to be greater by at least the first factor than the thermal resistance of each cell; and

the thermal resistance of the heat exchanger in a direction toward the temperature control medium is selected to be smaller by at least a second factor then the thermal resistance of each cell.

2. The battery of claim 1, wherein:

the coefficient of thermal conductivity of the thermally insulating solid material lies between about 0.01 and about 0.2 W/(m*K);

the first factor is approximately equal to the ratio of the energy content of a group of cells to the amount of energy which is needed to trigger a thermally induced cell failure at a defined upper operating temperature limit; and

the second factor is the ratio of the thermal resistance of each cell to the thermal resistance of the heat exchanger in a direction toward the temperature control medium.

3. The battery of claim 1, wherein an insulating material of a microporous mineral fiber layer is arranged between each neighboring group of one or more cells.

4. The battery of claim 1, wherein the defined upper operating temperature limit is between about 50°

C. and about 70°

C.

5. The battery of claim 4, wherein the defined upper operating temperature limit is about 60°

C.

6. The battery of claim 4, wherein the battery is a lithium storage battery with a liquid electrolyte.

7. The battery of claim 1, wherein the maximum energy content of each group of one or more cells is less than about 1 kWh.

8. The battery of claim 1, wherein the heat exchanger comprises a metal plate adjacent to one end of each group of one or more cells.

9. The battery of claim 1, wherein the heat exchanger comprises a hollow metal body through which cooling liquid flows.

10. The battery of claim 1, further comprising an outer thermally insulated solid material between the outer wall of the battery and an adjacent group of one or more cells, wherein the thermal resistance of the outer thermally insulating solid material is about half of the thermal resistance of the thermally insulated solid material between adjacent groups of one or more cells, such that, when two or more batteries are placed side by side, the thermal resistance between two groups of one or more cells from different batteries is approximately equal to the thermal resistance between two groups of one or more cells from a single battery.

11. The battery of claim 1, wherein:

the battery is a lithium storage battery with a liquid electrolyte;

the coefficient of thermal conductivity of the thermally insulating solid material lies between about 0.01 and about 0.2 W/(m*K);

the first factor is approximately equal to the ratio of the energy content of a group of one or more cells to the amount of energy which is needed to trigger a thermally induced cell failure at a defined upper operating temperature limit;

the second factor is the ratio of the thermal resistance of each cell to the thermal resistance of the heat exchanger in a direction toward the temperature control medium;

an insulating material of a microporous mineral fiber layer is arranged between each neighboring group of one or more cells;

the defined upper operating temperature limit is between about 50°

C. and about 70°

C.;

the maximum energy content of each group of one or more cells is less than about 1 kWh;

the heat exchanger comprises a metal plate adjacent to one end of each group of one or more cells and a hollow metal body through which cooling liquid flows; and

further comprising an outer thermally insulated solid material between the outer wall of the battery and an adjacent group of one or more cells, wherein the thermal resistance of the outer thermally insulating solid material is about half of the thermal resistance of the thermally insulated solid material between adjacent groups of one or more cells, such that, when two or more batteries are placed side by side, the thermal resistance between two groups of one or more cells from different batteries is approximately equal to the thermal resistance between two groups of one or more cells from a single battery.

12. The battery of claim 11, wherein the defined upper operating temperature limit is about 60°

C.

13. The battery of claim 1, wherein the second factor is about 10.

14. The battery of claim 11, wherein the second factor is about 10.

15. A battery having a plurality of individual storage cells and a temperature control device, wherein:

the individual cells are arranged into two or more groups of cells, each group having one or more individual cells arranged alongside one another and separated from one another by a cell space filled with a thermally insulating solid material;

the groups of one or more cells are separated from one another by a space, said space containing a thermally insulating solid material, the thermal resistance of the solid material being greater by at least a first factor than the thermal resistance of each cell, any space remaining between groups of cells being filled with a solid carrier material; and

each group of one or more cells is thermally connected to a heat exchanger having a temperature control medium, wherein;

the thermal resistance of the heat exchanger in a direction toward a neighboring group of one or more cells is selected to be greater by at least a first factor than the thermal resistance of each cell; and

the thermal resistance of the heat exchanger in a direction toward the temperature control medium is selected to be smaller by at least a second factor than the thermal resistance of each cell.

16. The battery of claim 15, wherein:

the coefficient of thermal conductivity of the thermally insulating solid material lies between about 0.01 and about 0.2 W/(m*K);

the first factor is approximately equal to the ratio of the energy content of a group of cells to the amount of energy which is needed to trigger a thermally induced cell failure at a defined upper operating temperature limit; and

the second factor is the ratio of the thermal resistance of each cell to the thermal resistance of the heat exchanger in a direction toward the temperature control medium.

17. The battery of claim 15, wherein an insulating material of a microporous mineral fiber layer is arranged between each neighboring group of one or more cells.

18. The battery of claim 15, wherein the defined upper operating temperature limit is between about 50°

C. and about 70°

C.

19. The battery of claim 18, wherein the defined upper operating temperature limit is about 60°

C.

20. The battery of claim 18, wherein the battery is a lithium storage battery with a liquid electrolyte.

21. The battery of claim 15, wherein the maximum energy content of each group of one or more cells is less than about 1 kWh.

22. The battery of claim 15, wherein the heat exchanger comprises a metal plate adjacent to one end of each group of one or more cells.

23. The battery of claim 15, wherein the heat exchanger comprises a hollow metal body through which cooling liquid flows.

24. The battery of claim 15, wherein the second factor is about 10.