WO2009085315A2

WO2009085315A2 - Battery cell switch

Info

Publication number: WO2009085315A2
Application number: PCT/US2008/014119
Authority: WO
Inventors: Wilhelm Kullberg
Original assignee: Electrolysis Technologies Company
Priority date: 2007-12-29
Filing date: 2008-12-29
Publication date: 2009-07-09
Also published as: WO2009085315A8; WO2009085315A3

Abstract

A switch-system comprising multiple switch armatures, primarily for serial arranged battery cells is disclosed. The battery switch-system has application in automotive power systems and resolves safety & reliability concerns for high-rate Lithium-Ion batteries.

Description

BATTERY CELL SWITCH

BACKGROUND OF THE INVENTION

The present invention is a switch mechanism for connecting & disconnecting cells in; a serial, parallel or serial/parallel battery arrangernent. The state of the art switch mechanisms do not include a centralized switch-system for switching groups of cells in and out of a serial battery arrangement.

Serial arranged high-rate Lithium-Ion battery cells, need for reliability & safety reasons from time to time being disconnected. Using one switch for each cell, the wire arrangement will be heavy, too comprehensive and very expensive. It might not even be feasible. A serial battery cell arrangement for powering an automobile with up to 80 single cells might be needed.

It is well known among electrochemists that Lithium-Ion cells arranged in series has the unique potential of powering an electrical motor in a modern mid-size automobile. Thermal runaway causing a harmful chemical reaction is a very serious problem which has not been resolved for the state of the art serial arranged high-rate Lithium-Ion battery. Lithium-Ion cells comprising other materials, faces thermal runaway problems at different temperature levels. Any state of the art Lithium-Ion battery following problems; i) heat develops between the many different anode and cathode layers, and it might be an impossible chemical engineering task, reducing the thermal development; ii) Lithium has a low melting point (180⁰C MP) which most likely will result in that Lithium melts and comes in contact with the anode, causing a harmful chemical reaction; iii) each Lithium-Ion (Li-ion) cell need to be recharged separately and disconnected close before fully recharged, because the manufacturing process does not give the option of producing two cells with same charge value. A very low number of cells will overheat and need to be switched out of the serial arrangement. Drop in voltage is another method of determine if a cell needs to be switched out of the serial arrangement. Determine which cells needs to be switched out of the serial arrangement, and the time for it, is impossible without a battery cell management controller. At the time point of occurrence, the cell has to be

i switched out of the serial arrangement before remaining serial arranged cells can continue to operate reliably. Disconnecting any single cell option of the 80 serial connected Lithium-Ion (Li-ion) cells, involves at least 3 electromagnetic relays per cell, a large relay box with about 275 separate electromagnetic relays, connected by a network of heavy wires. Alternatively, some of the 275 electromagnetic relays could be eliminated if the cell is rewired every time one cell breaks down, which is not very practical. Such a power unit will be too spacious, too heavy and it will be a too complex engineering task, which might not be feasible.

DESCRIPTION OF THE PREFFERED EMBODIMENT

According to figure 1, the switch-system comprises 4 independently operated switch armatures; 1, 2, 3 and 4, all armatures turn/operate independently on same axis. Each armature switching 2 cells in the serial battery cell arrangement; armature #1 connecting cell 5 and 6 in serial arrangement, armature #2 disconnecting cell 7 and 8 from the serial arrangement, armature #3 connecting cell 9 and 10 in the serial arrangement, armature #4 connecting cell 11 and 12 in the serial arrangement. All armatures operating independently upon a control signal from the automobiles control unit. Lever 17 connected to shaft 18/14, oriented through hollow passage of shaft 13, operating armature 2. Lever 19 connected to hollow shaft 13, operating armature 1. Lever 22 connected to hollow shaft 16, operate armature 4. Lever 20 connected to shaft 15/21, oriented through hollow passage of shaft 16, operating armature 3. A first side combined switch, operate levers 17 and 19 switching respective armature 1 and 2 independently after receiving control signals. A second side combined switch, operate levers 20 and 22, switching respective armature 3 and 4 independently after receiving control signals from the battery management controller. A cell group may consist of from 2 to 30 serial arranged cells. BRIEF DESCRIPTION OF THE DRAWING

According to figure 1, four separate switch armatures sections arranged in line with all switch armatures turning independently on same axis, connecting 8 battery cells in a serial battery arrangement, wherein each armature switching 2 serial battery cells. Switch armature #2, according to the drawing has been disengaged for one or another reason.

Claims

Claims:

1. A battery switch, wherein a central switch mechanism connect at lest one cell group in a serial battery arrangement.

2. A battery switch, wherein a central switch mechanism disconnect at least one cell group in a serial battery arrangement.

3. A battery switch, according to claims 1 & 2, wherein each armature operate different cell groups, said each armature can be operated independently.

4. A battery switch, according to claims 1 - 3, wherein generally all armatures turn/operate on same axis.

5. A battery switch, according to claims 1 - A, wherein at least one armature for a cell group has a hollow shaft passage with an armature shaft from a second armature group passing through & turn independently in said hollow shaft passage, switching said second armature.

6. A switch mechanism, according to claims 1 - 5, wherein one switch on each shaft ends operate at least two armatures independently, one armature at a time for each side.

7. A battery switch, according to claims 1 - 6, wherein at least one lever move in an operating relationship with at least one cam, releasing at least one spring, turning the armature for fast circuit switching.

8. A battery switch, according to claims 1 - 7, wherein the switch mechanism is operated by at least one; ferromagnetic plunger pulled by an electromagnetic coil, servo/gear motor, pneumatic or -hydraulic cylinder, or any automatic or manual switch.

9. A battery switch, according to claims 1 - 8, wherein the switch contacts have a plane contact design or a matching fork configuration.

10. A battery switch, according to claims 1 - 9, wherein the switch may control a serial/parallel arranged battery.

11. A battery switch, according to claims 1 - 10, wherein the switch is controlled by a computer.