DE102014013576A1 - Electrochemical cell with a cell housing and battery system with corresponding electrochemical cells - Google Patents

Abstract

An electrochemical cell (100) for constructing an electrochemical energy store, in particular an energy store designed for use in a motor vehicle, has an active area with an enclosure (1) having at least one sealed seam and a cell housing (21, 22). At least one first region (4) is attached to the sealed seam of the envelope (1), the first region (4) being configured to open at a predetermined internal pressure in the active region, and wherein in the cell case (21, 22) is a security component (10) is arranged with at least one second region (12) such that the second region (12) of the security component (10) is designed and arranged for fluid communication with the first region (4) at the sealing seam of the envelope (1). The second region (12) is configured to pass fluids at a predetermined pressure or above a predetermined pressure.

Description

The present invention relates to an electrochemical cell having a cell housing for constructing an electrochemical energy store, in particular an energy store designed for use in a motor vehicle, and a battery system having a number of corresponding electrochemical cells.

As electrochemical energy storage batteries (primary storage) and accumulators (secondary storage) are known, which are composed of one or more memory cells in which upon application of a charging current, electrical energy in an electrochemical charging reaction between a cathode and an anode in or between an electrolyte in chemical Energy is converted and stored and in which when connecting an electrical load chemical energy is converted into electrical energy in an electrochemical discharge reaction. In this context, it should be noted that, especially in the automotive sector, rechargeable batteries are also referred to as batteries.

The present invention will be described in the context of lithium ion battery for electric powered vehicles. It should be noted that the invention can be used independently of the chemical composition of the electrochemical cell or independently of its use.

The WO 2011/051386 A1 concerns a battery cell arrangement with a battery cell designed as a foil cell, in which on a side facing away from the end faces of the cell body of the frame assembly, a vent opening is provided to allow the escape of gases from the battery cell assembly in case of damage.

It is an object of the present invention to provide an improved electrochemical cell having a cell housing and an improved battery system with corresponding electrochemical cells.

This object is achieved by an electrochemical cell according to claim 1 and by a battery system according to claim 14. Advantageous embodiments and further developments are the subject of the dependent claims.

A first aspect of the present invention relates to an electrochemical cell for constructing an electrochemical energy store, in particular an energy store designed for use in a motor vehicle. In this case, the electrochemical cell has an active region with an enclosure having at least one sealed seam and a cell housing. At least one first region is arranged at the sealing seam of the envelope and configured such that the first region opens at a predetermined internal pressure in the active region. A safety component with at least one second region is arranged in the cell housing such that the second region lies opposite the first region, wherein the second region is configured in such a way that the second region transmits fluids at a predetermined pressure or above a predetermined pressure. An advantage of this embodiment may be that, in the case of an increased internal pressure, the fluids which are formed in the active region, in particular the reaction gases, can be directed out of the electrochemical cell in a targeted manner. Another advantage of this embodiment may be that a mechanical destruction can be avoided by an overpressure. Another advantage of this embodiment may be that damage to neighboring cells can be avoided.

An "electrochemical energy store" in the sense of the invention means any type of energy store to which electrical energy can be taken, wherein an electrochemical reaction takes place in the interior of the energy store. The term includes energy storage of all kinds, in particular primary batteries and secondary batteries. In particular, an electrochemical energy store can have at least one electrochemical cell with an active region, or a plurality of electrochemical cells with corresponding active regions. The plurality of electrochemical cells may be connected in parallel to store a larger amount of charge, or may be connected in series to provide a desired operating voltage, or may be a combination of parallel and series connection.

An "electrochemical cell" in the sense of the invention means a device which serves to deliver electrical energy, the energy being stored in chemical form. In the case of rechargeable secondary batteries, the cell is also designed to receive electrical energy, convert it to chemical energy, and store it.

Such an electrochemical cell usually has an electrode arrangement in an active region, which is at least partially enclosed by an envelope. In this context, an "electrode arrangement" in the sense of the invention is understood to mean an arrangement of at least two electrodes and an electrolyte arranged therebetween. The electrolyte may be partially received by a separator, the separator then separating the electrodes. Preferably, the electrode arrangement has a plurality of layers of electrodes and separators, wherein the electrodes of the same polarity are in each case preferably electrically connected to one another, in particular connected in parallel. The electrodes are for example plate-shaped or foil-like and are preferably arranged substantially parallel to one another (prismatic energy storage cells). The electrode arrangement may also comprise lithium or another alkali metal in ionic form.

For the purposes of the present invention, an "envelope" is to be understood as an apparatus which is suitable for preventing the exchange of chemicals and / or gases from the electrode arrangement and the surroundings and for protecting the components of the electrode arrangement from damaging external influences. The envelope is preferably formed of a sealable material and may be formed in one or more layers.

A "cell housing" in the context of the present invention is understood to mean any device which is suitable for shielding the active region of an electrochemical cell against undesirable or interfering influences from the outside and / or the environment of the active region of the electrochemical cell against undesired influences protect that may result from the operation of such electrochemical cells. Such a cell housing preferably prevents or impedes unwanted mass transport or mass transfer or energy exchange between the interior of the cell housing and the environment.

Hereinafter, variants and preferred embodiments and further developments of the electrochemical cell according to the first aspect of the invention will be described, each of which, unless this is expressly excluded, can also be combined with one another as desired.

In the case of the electrochemical cell, the second region of the safety component is preferably arranged opposite the first region on the sealing seam of the sheath. An advantage of this embodiment may be that the fluid communication can be carried out particularly safely and easily.

In the case of the electrochemical cell, the safety component is preferably designed as an insert part with at least one connection contour, wherein the connection contour is designed for connection to the sealed seam. An advantage of this embodiment may be that the assembly of the electrochemical cells is simplified because z. B. the manufacture of the insert can be done outside of a drying room. Preferably, the insert is formed of a material which is resistant to the electrolyte used and electrically insulating.

In the case of the electrochemical cell, the connection contour of the safety component is preferably designed to be sealed with the enclosure of the active region. Furthermore, the material of the safety component is preferably designed sealable. An advantage of this embodiment may be that the stability of the connection of the safety component to the enclosure can be improved.

In the case of the electrochemical cell, the safety component preferably has a number of recesses, preferably two recesses, which are designed and arranged to center the safety component. An advantage of this embodiment may be that the assembly of the electrochemical cells can be improved by a simpler and more accurate alignment of the security component.

In the case of the electrochemical cell, the cell housing preferably has at least one outlet region, which in the assembled state is arranged opposite the second region. An advantage of this embodiment may be that the reaction gases can be removed more easily, without causing additional adverse effects on the electrochemical cell.

In the case of the electrochemical cell, the cell housing preferably has an upper housing part and a lower housing part, and the outlet area is configured as a housing upper part recess and / or as a lower housing recess. An advantage of this embodiment may be that the assembly of the electrochemical cells can be simplified.

The electrochemical cell is preferably designed as a flat cell having two end faces and two longitudinal sides, and arresters are arranged on one of the two end faces and the safety component is arranged on the other of the two end faces. An advantage of this embodiment may lie in the fact that the safety can be increased by the heat flow or the flow of current from a possible flow of the reaction gases are spatially separated as far as possible.

In the case of the electrochemical cell, a gas guide channel is preferably arranged in the cell housing, which is designed to guide fluids from the second region of the safety component to the outlet region of the cell housing. An advantage of this embodiment may be that the fluids formed in the active region, in particular, the reaction gases can be conducted better from the electrochemical cell.

In the case of the electrochemical cell, a membrane is preferably arranged in the second region of the safety component, which membrane is designed to form an opening during a pressure increase. An advantage of this embodiment may be that the pressure at which the reaction gases are discharged can be adjusted. This is preferably designed as a valve. An advantage of this embodiment may lie in the fact that the active area can be better protected against external influences.

In the case of the electrochemical cell, two (or more) diaphragms are preferably arranged in the second region of the safety component, which pressure elevations are configured to form successive openings An advantage of this design with a plurality of diaphragms may lie in causing a multi-stage opening.

In the case of the electrochemical cell, a pressure sensor is preferably arranged on the second region or in the second region. An advantage of this embodiment is that the functionality of the corresponding electrochemical cells can be detected.

Preferably, in the case of the electrochemical cell, the pressure sensor is connected wirelessly or by wire to a controller and / or a display device. An advantage of this embodiment is that z. B. upon detection of a malfunction of an electrochemical cell, a Schonbetrieb can be performed, which prevents further damage to the electrochemical cell, but still allows a certain power output. This is especially true in connection with a safety component, which has a valve or in which a plurality of membranes are arranged for a multi-stage opening, so that z. B. at an opening after the first stage still a gentle operation of the electrochemical cell can be driven, while at an opening after a second stage, the relevant electrochemical cell is disconnected or switched off.

The shape (i.e., in particular the size and the geometry) of an electrochemical cell is arbitrary and can in particular be chosen depending on the available installation space. In particular, the electrochemical cell may be substantially prismatic.

A second aspect of the present invention relates to a battery system having one or more of the electrochemical cells described above.

In this case, at least one discharge at the second regions of the individual electrochemical cells for discharging the gases emerging from the first regions of the casing is arranged and configured. An advantage of such a battery system according to the invention can be that the reaction gases occurring in the active regions of the electrochemical cells can be conducted more reliably out of the battery system. Another advantage of this battery system can be that any damage to the electrochemical cells by reaction gases and / or by mechanical loads can be reduced or avoided.

Hereinafter, variants and preferred embodiments and further developments of the battery system according to the second aspect of the invention will be described, each of which, unless this is expressly excluded, can also be combined with one another as desired. In the case of the battery system, the pressure sensors associated with the electrochemical cells are preferably connected to a battery controller wirelessly or by wire. An advantage of this embodiment of the battery system may be that a gentle operation of endangered electrochemical cells can be performed better depending on their load. An advantage of this embodiment may be that z. B. the driver of an electrically powered vehicle are displayed that a maintenance of the batteries is required.

Preferably, the battery system is configured for use in an electrically powered motor vehicle.

According to a preferred embodiment, a total of at least one discharge in the battery system is arranged. According to another preferred embodiment, in each case at least one discharge for the electrochemical cells is arranged in the battery system.

Further advantages, features and applications of the present invention will become apparent from the following description taken in conjunction with the drawings. It shows:

1 a perspective schematic representation of an insert with a first region for an electrochemical cell according to an embodiment of the present invention;

2 a further perspective schematic representation of the insert with the second region;

3 an enlarged schematic representation of the second portion of the insert;

4 a perspective schematic representation of the enclosure with a first region;

5 a side view of an exploded view of the electrochemical cell according to the invention; and

6 a perspective view of an exploded view of the electrochemical cell according to the invention.

The 1 and 2 show perspective schematic representations of an insert 10 with a second area 12 in a cell housing for an electrochemical cell according to an embodiment of the present invention. After the embodiment shown in these figures, the insert 10 connecting contours 11 to join with a serving 1 of the active region of the electrochemical cell. Furthermore, in this embodiment, the insert part 10 four recesses 15 on, which in the assembly z. B. to align the insert 10 can be used, with the number of recesses 15 is not limited to four. Furthermore, in the embodiment shown in these figures, a single second area 12 arranged in the middle. However, it is possible on the insert 10 Provide several second areas and / or not to arrange the second area in the middle.

The 3 shows an enlarged view of the second area 12 on the insert 10 , From this figure it can be seen that on the outwardly facing side of the second area 12 a membrane 14 can be appropriate. It is also possible to provide several membranes. According to another embodiment, a valve arrangement may preferably also be provided. Furthermore, the second area 12 z. B. semi-tubular guides 16 which, for the derivation of reaction gases and / or for connection to a first region shown in the following figure 4 are formed and arranged.

The 4 shows a perspective schematic representation of an enclosure 1 of the active area with a first area 4 , which at a sealing seam of the enclosure 1 the active region of the electrochemical cell is arranged. The first area 4 may preferably be formed as a predetermined weakening of the sealing seam such that at a predetermined internal pressure targeted escape of gases on this weakening of the sealing area is made possible.

The 5 and 6 show a side view and a perspective view of an exploded view of the electrochemical cell 100 according to an embodiment of the present invention. In the present embodiment, the electrochemical cell 100 designed as a two end faces and two longitudinal sides having flat cell, wherein the cell housing of the electrochemical cell 100 an upper housing part 21 and a housing lower part 22 having. Preference is given to an arrester 2 first polarity and an arrester 3 second polarity disposed on one of the two end faces, while the safety component 10 at the other end of the envelope 1 is appropriate. The upper housing part 21 and the lower housing part 22 can have a housing top recess 23 or a housing lower part recess 24 which are configured and arranged such that over the second region 12 of the safety component 10 escaping gases from the electrochemical cell 100 can be directed.

LIST OF REFERENCE NUMBERS

1

Serving the active area

2

Arrester of the first polarity

3

Arrester of second polarity

4

first area

10

safety component

11

connecting contour

12

second area

14

membrane

15

recess

21

Housing top

22

Housing bottom

23

Housing top notch

24

Housing base recess

100

electrochemical cell

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2011/051386 A1 [0004]

Claims (16)

Electrochemical cell ( 100 ) for constructing an electrochemical energy store, in particular an energy store designed for use in a motor vehicle, the electrochemical cell ( 100 ) an active area with an at least one seal having envelope ( 1 ) and a cell housing ( 21 . 22 ), characterized in that at the sealing seam of the envelope at least a first area ( 4 ) is arranged and configured so that at a predetermined internal pressure in the active region of the first region ( 4 ), wherein in the cell housing ( 21 . 22 ) a safety component ( 10 ) with at least one second area ( 12 ) is arranged such that the second area ( 12 ) of the safety component ( 10 ) for fluid communication with the first area ( 4 ) at the sealing seam of the envelope ( 1 ) is arranged and arranged, and wherein the second area ( 12 ) is configured such that at a predetermined pressure and / or above a predetermined pressure of the second region ( 12 ) Passes fluids. Electrochemical cell ( 100 ) according to claim 1, characterized in that the second region ( 12 ) of the safety component ( 10 ) the first area ( 4 ) at the sealing seam of the envelope ( 1 ) is arranged opposite one another. Electrochemical cell ( 100 ) according to claim 1 or 2, characterized in that the safety component ( 10 ) as an insert with at least one connection contour ( 11 ) is configured, wherein the connection contour ( 11 ) is configured to connect to the sealing seam. Electrochemical cell ( 100 ) according to claim 3, characterized in that the connection contour ( 11 ) of the safety component ( 10 ), with the enclosure of the active area ( 1 ) to be sealed. Electrochemical cell ( 100 ) according to claim 3 or 4, characterized in that the safety component ( 10 ) a number of recesses ( 15 ), preferably two recesses ( 15 ), which leads to a centering of the safety component ( 10 ) are configured and arranged. Electrochemical cell ( 100 ) according to one of claims 1 to 5, characterized in that the cell housing ( 21 . 22 ) at least one outlet area ( 23 . 24 ), which in the assembled state, the second area ( 12 ) is arranged opposite one another. Electrochemical cell ( 100 ) according to claim 6, characterized in that the cell housing an upper housing part ( 21 ) and a housing lower part ( 22 ) and that the outlet area as an upper housing recess ( 23 ) and / or as a housing base recess ( 24 ) is configured. Electrochemical cell ( 100 ) according to one of claims 1 to 7, characterized in that the electrochemical cell ( 100 ) is formed as a flat two end faces and two longitudinal sides having cell and that at one of the two end sides arrester ( 2 . 3 ) are arranged, while at the other of the two end faces the safety component ( 10 ) is arranged. Electrochemical cell ( 100 ) according to one of claims 1 to 8, characterized in that in the cell housing ( 21 . 22 ) a gas guide channel is arranged, which is for guiding gases from the second region ( 12 ) of the safety component ( 10 ) to the outlet area ( 23 . 24 ) of the cell housing ( 21 . 22 ) is configured. Electrochemical cell ( 100 ) according to one of claims 1 to 9, characterized in that in the second area ( 12 ) of the safety component ( 10 ) a membrane ( 14 ) arranged to an opening at a predetermined pressure. Electrochemical cell ( 100 ) according to one of claims 1 to 9, characterized in that in the second area ( 12 ) of the safety component ( 10 ) two or more membranes ( 14 ) are arranged, which are configured to successive openings at predetermined pressures. Electrochemical cell ( 100 ) according to one of claims 1 to 11, characterized in that at the second area ( 12 ) or in the second area ( 12 ) A pressure sensor is arranged. Electrochemical cell ( 100 ) according to claim 12, characterized in that the pressure sensor is wirelessly or wired connected to a controller and / or with a display device. Battery system with one or more electrochemical cells ( 100 ) according to one of claims 1 to 13, characterized in that at least one discharge at the second regions ( 12 ) of the individual electrochemical cells ( 100 ) for the derivation of the first areas ( 4 ) leaving fluids is arranged and configured. Battery system according to claim 14 when dependent on claim 12 or 13, characterized in that the pressure sensors in the and / or at the second regions ( 12 ) of the safety components ( 10 ) in the cell housings ( 21 . 22 ) of the electrochemical cells ( 100 ) are connected to a battery controller wireless or wired. Battery system according to claim 14 or 15, characterized in that it is designed for use in an electrically operated motor vehicle.

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