WO2012110168A1

WO2012110168A1 - Battery cell

Info

Publication number: WO2012110168A1
Application number: PCT/EP2011/074265
Authority: WO
Inventors: Stefan Pfeiffer; Kai Kuhlmann; Thomas Kretschmar
Original assignee: Robert Bosch Gmbh
Priority date: 2011-02-14
Filing date: 2011-12-29
Publication date: 2012-08-23
Also published as: DE102011004033A1

Abstract

The invention relates to a battery cell, in particular to a lithium ion battery cell, which comprises a housing, wherein the housing contains a spring element which applies an outwardly directed force to at least one first section of the housing.

Description

Description title

battery cell

State of the art

The invention relates to a battery cell according to the preamble of the independent claim.

Various types of batteries are known in the art. Such a battery is shown for example in DE 10 2007 063 190 A1. A battery (or a battery system), such as in hybrid or

Electric vehicles usually consists of several battery modules, which in turn are composed of individual battery cells (for example, lithium-ion battery cells). A single battery cell has a housing and electrical storage elements (also referred to as galvanic cells or simply cells) arranged in the housing. The heat generated during the charging and discharging of the battery cell by current flow loss must be dissipated by cooling. Due to the sometimes high power density high demands are placed on the cooling. There are a number of proposals for efficient cooling of

Battery cells known, but often too expensive, too expensive to manufacture or limited in terms of their performance.

For example, a battery is known from DE 10 2007 063 190 A1, in which the heat dissipation from the battery is ensured by a temperature control unit designed as a cooling plate. This cooling plate contains recesses comparable to a cooling fin, wherein the battery cells are receivable in the recesses. Between a battery cell and the recess of the cooling plate is a good thermal conductivity potting compound, the Heat transfer between battery cell and cooling plate ensures and ensures the fixation of the battery cell within the recess of the heat sink.

Furthermore, the battery cell can be fixed in the recess with the aid of a U-shaped insert, which in addition has good thermal conductivity in order to produce good heat transfer between the battery cell and the heat sink. A disadvantage of this device is that the battery cell is not in direct contact with the cooling plate and requires heat transfer as well as fixation of the battery cell within the recess of the heat sink of an auxiliary device in the form of a potting compound located outside the housing or an insert located outside the housing. Missing the thermally conductive potting compound or the thermally conductive insert, there is neither a good heat transfer from the battery cell to the cooling plate still sufficient fixation of the battery cell in the recess of the cooling plate instead.

It is the object of the invention to provide a battery cell which can be effectively cooled and easily connected to a heat sink.

Advantages of the invention

The battery cell according to the invention with the characterizing part of claim 1 has the advantage that it can be easily connected to a heat sink and is in direct contact with it, whereby the heat can be removed highly efficiently from the battery.

For this purpose, the invention provides that the housing includes a spring element which exerts an outwardly directed force on at least a first portion of the housing. Advantageously, an outward bulge of the housing of the battery cell is effected by the outwardly directed force of the spring element. For cooling the battery cell, for example, a heat sink is used which has recesses. In these recesses is the

Battery cell plugged. Due to the bulge of the housing in the region of the spring element is advantageously a clamping action between the battery cell and Produced heat sink, whereby on the one hand the housing wall of the battery cell is pressed by the outwardly directed force to the heat sink and thus has a good heat transfer result and on the other hand, a frictional

Connection between battery cell and heat sink is achieved. Furthermore, it is advantageous that the spring element is arranged within the housing and does not protrude from this. This eliminates the need to lavishly seal the battery cell at the point of passage of the spring element or the

Spring element outside the housing to connect to the battery cell.

Same advantages result according to the invention according to claim 11 for the claimed battery system.

The measures mentioned in the dependent claims advantageous developments of the device specified in the independent claim are possible.

Advantageously, the first portion, on which the spring element exerts an outward force, a first end portion of the housing. The battery cell is advantageously inserted with the first end portion in recesses of a heat sink.

Advantageously, the spring element is supported on opposite housing walls. By supporting a uniform pressure on the

generated opposite housing walls, which leads to a uniform bulging of the housing walls. This ensures good positioning of the battery cell in recesses of a heat sink.

Advantageously, the opposite housing walls on inwardly located holding elements over which the spring element is supported. By the holder of the spring element ensures that this is not spatially

can move and the outward force is always exerted on the same point of the housing. Advantageously, a cooling baffle is arranged between at least two storage elements, wherein the spring element is part of the Kühlleitblechs. About the

Cooling baffle can be dissipated excess heat that arises during charging and discharging of the battery. The heat is transferred from the Kühlleitblech to the spring element. From this, the heat is transferred to the housing and finally delivered to the heat sink, whereby an efficient cooling effect is ensured.

Advantageously, the spring element is within the first end portion of the

Housing bent circular or circular segment. The circular or circular-segment-shaped shape of the spring element is particularly easy to produce by the corresponding bending of the Kühlleitblechs. In addition, a uniformly distributed, outwardly directed force is caused on the first portion of the housing due to the circular or circular segment-shaped design of the spring element.

Advantageously, the cooling baffle has several, the spring element forming

Kühlleitblechabschnitte, wherein the Kühlleitblechabschnitte are bent in alternating order in the opposite direction. The

Subdivision of the Kühlleitblechs in individual Kühlleitblechabschnitte is effected by simply slit-shaped cutting of the Kühlleitblechs. If the individual Kühlleitblechabschnitte bent in alternating order in the opposite direction, the spring element is formed. This type of direct production of the spring element from the cooling baffle is easy to do without much material and also cost.

Advantageously, the Kühlleitblechabschnitte are bent so that they rest tangentially on the housing. Due to the tangential abutment of the Kühlleitblechabschnitte a good heat transfer from the spring element to the housing and finally ensured by the housing on the heat sink. Furthermore, a selective power transmission from the spring element to the housing wall, whereby the latter could be damaged, avoided. Advantageously, a second end portion facing the first end portion, wherein the cooling baffle is in contact with the second end portion of the housing. As a result, a force with which the second end section is acted upon is transmitted directly to the spring element. If the battery cell is inserted into the recess of a heat sink, a force is exerted on the housing of the battery cell during insertion in order to place it on the one hand in the

To press recess and on the other hand there on the spring action of the

Clamp the spring element. However, if the housing wall of the battery cell is made very thin, it may be undesirable in the plugging process

Housing deformation come. By the contact of the Kühlleitblechs with the second end portion of the housing, the force with which the housing is pressed into the recess of a heat sink, advantageously directly to the

Transfer cooling plate and thus transferred to the spring element. Thereby, a force on the second end portion is advantageously forwarded via the Kühlleitblech on the spring element and finally the first end portion of the battery cell housing, without it can lead to an undesirable housing deformation. In addition, the force leads to a widening of the spring element and thus an increased outward force of the spring element. Accordingly causes a permanent force on the second end portion of a reinforced clamping action and thus an improved frictional connection between the battery cell and heat sink.

Advantageously, the housing has a smaller width in the first end section than in the second end section. This taper within the first end portion of the battery allows a plurality of battery cells can be tightly fitted next to each other in designated recesses of a heat sink and clamped there. It is thus an advantageous use of space within a battery module possible. drawing

The invention will be explained in more detail in several embodiments with reference to the accompanying drawings.

FIG. 1 shows a sectional view of a battery cell.

Figure 2 shows a perspective view of a Kühlleitblechs.

FIG. 3 shows a plan view of a slotted cooling guide plate.

Figure 4 shows a perspective view of a Kühlleitblechs with

bent Kühlleitblechabschnitten.

FIG. 5 shows a further schematic illustration of a battery cell and a heat sink.

FIG. 6 shows a further schematic representation of two battery cells and heat sinks arranged next to one another.

Embodiments of the invention

Figure 1 shows a first embodiment of the invention, a battery cell 11 in a sectional view. The battery cell 11 is substantially rectangular and flat and has a small thickness. There are two electrical storage elements 24, 25 in the housing 12 of the battery cell 11, which are designed in particular as lithium-ion memory cells in a flat design without inherently rigid shell ("Jelly Rolls" or "Coffee Bag"). Furthermore, located within the housing 12, a spring element 16. The spring element 16 is as

arcuate bent sheet metal, which bears tangentially on the inside of the housing 12 and an outwardly directed force on a first portion 15 which at an end portion 29 of the housing 12 of the

Battery cell 11 is arranged exercises. To avoid that Spring element 16 moves spatially due to the spring force, the opposite housing walls 17, 18 have inner holding elements 19, 20, which are embodied for example in the form of bulges, on which the spring element 16 is spatially fixed or supported. The battery cell 11 is inserted with the end portion 29 in a heat sink 13, which has one or more receptacles 14, for example in the form of a cooling fin. Due to the spring force of the spring element 16, the housing 12 of the battery cell 11 bulges in the

End portion 29 to the outside and thus generates in the inserted state in the receptacle 14 of the heat sink 13 between the battery cell 11 and heat sink 13, a clamping action, which ensures the frictional connection of battery cell 11 and heat sink 13. Due to the frictional connection of battery cell 11 and heat sink 13, the housing walls 17, 18 pressed against the heat sink, whereby a good heat transfer is possible.

FIG. 2 shows, as a further exemplary embodiment of the invention, a cooling guide plate 21, the spring element 16 being part of the cooling guide plate 21. The Kühlleitblech 21 is bent on one side circular or circular segment. Of the

The cooling guide plate 21 is located with the flat portion 33 of Figure 2 between two or more memory elements 24, 25 (not shown here), whereas the spring element 16 on the inside of the Housing 12 tangentially to the housing wall 17, 18 is applied. In this case, the spring element with the circular or circular segment-shaped spring element 16 exerts an outwardly directed force on an end portion 29 of the housing 12 of the battery cell 11.

FIG. 3 shows, as a further exemplary embodiment of the invention, a cooling guide plate 21 which has a plurality of cooling guide plate sections 27 forming the spring element 16. The Kühlleitblechabschnitt 27 are prepared by cutting the Kühlleitblechs 21 by slotted incisions 26 are made in the cooling baffle 21. Figure 4 shows a further embodiment of the invention, the Kühlleitblech 21 of Figure 4, wherein the Kühlleitblechabschnitte 27 are bent in alternating order in the opposite direction. By bending the Kühlleitblechabschnitte 27, the spring element 16, which is part of the

Kühlleitblechs 21 is. The bent Kühlleitblechabschnitte 27 are tangential on the inside of the housing on the opposite

Housing walls 17, 18 and exert an outward force on this.

Figure 5 shows a further embodiment of the invention, a battery cell 11 in a lateral view. The battery cell 11 is substantially rectangular and flat and has a small thickness. There are two electrical storage elements 24, 25 in the housing 12 of the battery cell 11, which are designed in particular as lithium-ion memory cells in a flat design without inherently rigid shell ("Jelly Rolls" or "Coffee Bag"). Furthermore, a cooling guide plate 21, which is arranged between the storage elements 24, 25, is located within the housing 12. A spring element 16 is part of the Kühlleitblechs 21, wherein the spring element comparable to Figure 4 Kühlleitblechabschnitte 27 which are bent in alternating order in each opposite direction or designed as a circular segment curved sheet (not here

shown). The spring element 16 touches the housing 12 tangentially on the inside of the housing 12 and exerts an outwardly directed force on it in a first section 15, which represents a first end section 29 of the housing 12 of the battery cell 11. Will the battery cell 11 with the first

End portion 29 inserted into a heat sink 13 having receptacles 14 similar to a cooling fin, so the first end portion 29 corresponds to the housing bottom 22. The first end portion 29 is opposite to a second end portion 30 which corresponds to the housing cover 23. The second end portion 30 and the

Housing cover 23 is in contact with the cooling guide plate 21, so that a force with which the second end portion 30 is acted upon, directly to the

Spring element 16 is transmitted. The force occurs, for example, when the battery cell 11 is inserted into a receptacle 14 of a heat sink 13. When inserting the battery cell 12, the force is transmitted from the second end portion 30 and the housing cover 23 via the Kühlleitblech 21 on the Spring element 26 and finally to the first end portion 29 of the battery cell. About the Kühlleitbleich 21 thus the press-in force is introduced, with which the battery cell 11 is inserted into the receptacle 14 of the heat sink. Due to the spring force of the spring element 16, the housing 12 of the battery cell 11 bulges in the end portion 29 to the outside and thus generates in the inserted state in the receptacle 14 of the heat sink 13 between the battery cell 11 and heat sink 13, a clamping action for the non-positive connection of battery cell 11 and Heatsink 13 provides.

FIG. 6 shows, as a further exemplary embodiment of the invention, a battery cell 11 according to FIG. 5 in a lateral plan view, which is arranged next to a further battery cell 11_2. Both battery cells 11 and 11_2, in contrast to the embodiment in Figure 5 in the first end portion 29 has a smaller width than in the opposite second end portion 30. Thus, the respective housing 12 is designed as a two-stage drawn metal housing. By this type of tapering of the housing in the first end portion 29, the arrangement of several such battery cells 11, 11_2 close together possible. The heat sinks 13, 13_1, in which the battery cell 11, 11_2 are inserted, may each be present separately or connected to one another or be formed as a single heat sink 13.

Claims

claims

1. battery cell (11), in particular lithium-ion battery cell, comprising a housing (12),

dad u rch ge ken nzeich n et that

the housing (12) includes a spring member (16) which exerts an outward force on at least a first portion (15) of the housing (12).

2. Battery cell (11) according to claim 1,

dad u rch e n t sign, d ass

the first portion (15) is disposed at the first end portion (29) of the housing.

3. Battery cell (11) according to one of the preceding claims,

dad u rch e n t sign, d ass

the spring element (16) on opposite housing walls (17, 18) is supported.

4. Battery cell (11) according to one of the preceding claims,

dad u rch e n t sign, d ass

the opposite housing walls (17, 18) inside

Holding elements (19, 20) over which the spring element (16) is supported.

5. battery cell (11) according to claim 1,

dad u rch e n t sign, d ass

a Kühlleitblech between at least two electrical storage elements

(24, 25) is arranged and that

the spring element (16) is part of the Kühlleitblechs (21).

6. Battery cell (11) according to one of the preceding claims,

dad u rch e n t sign, d ass

the spring element (16) within the first end portion (29) of the

Housing (12) is bent circular or circular segment.

7. Battery cell (11) according to one of the preceding claims,

dad u rch e n t sign, d ass

the Kühlleitblech (21) in the first end portion (29) a plurality, the

Has spring element (16) forming Kühlleitblechabschnitte (27), wherein the Kühlleitblechabschnitte (27) are bent in alternating order in the opposite direction.

8. battery cell (11) according to claim 7,

dad u rch e n t sign, d ass

the Kühlleitblechabschnitte (27) are bent so that they rest tangentially on the housing (12).

9. battery cell (11) according to one of the preceding claims,

dad u rch e n t sign, d ass

the first end portion (29) of the housing faces a second end portion (30) and the cooling baffle (21) is in contact with the second end portion (30) of the housing (12) so that a force is applied to the second end portion (30); 30) is applied to the spring element (16) is transmitted.

10. battery cell (11) according to any one of claims 1 or 2,

dad u rch e n t sign, d ass

the housing (12) has a smaller width in the first end section (29) than in the second end section (30). A battery system (31) comprising a battery cell (11) according to

Claims 1 to 10 and a heat sink (13),

dad u rch e n t sign, d ass

the battery cell (11) with its first end portion (29) in a receptacle

(14) of the heat sink (13) is arranged.