Traction battery for vehicle

Abstract

The invention relates to a traction battery for a vehicle, the traction battery comprising a plurality of battery cells (104) and a cooling unit comprising a fluid coolant and a cooling channel (100; the invention relates to a cooling system (100, 102) for a battery cell (104), in which the coolant is disposed in the cooling channel and configured to flow in the cooling channel around the battery cell (104) and to absorb heat, characterized in that the coolant is configured to be at least partially converted into a fire extinguishing foam by a trigger event.

Description

Technical Field

[0001] The invention relates to a traction battery for a vehicle. Background Art

[0002] From CN 206 535026U a battery cooling circuit is known which is connected to a container with an aerosol fire extinguishing agent which, if necessary, flows around the battery cells. Summary of the invention

[0003] In contrast, the basic object of the present invention is to provide a traction battery by which, in the event of a fire, the spread of the fire can be particularly effectively slowed down or prevented. In addition, a motor vehicle having such a traction battery is provided.

[0004] This object is achieved by a traction battery and a motor vehicle having the features described below. In the following, embodiments of the invention are described in detail.

[0005] The traction battery includes a plurality of battery cells and a cooling unit. The cooling unit includes a fluid coolant and a cooling channel. In the context of this specification, the fluid coolant is understood to specifically refer to a liquid. The coolant is disposed in the cooling channel and is configured to flow around the battery cells in the cooling channel and absorb heat. Preferably, the coolant may be configured to flow through the entire cooling channel.

[0006] The coolant is also configured to be at least partially converted into a fire-extinguishing foam by a triggering event. For example, the coolant can be a mixture of multiple components. It can include, for example, a cooling liquid with a particularly high specific heat capacity, in particular greater than 2 kJ / (kg*K), preferably greater than 3 kJ / (kg*K), and a foam generating device, which is configured to convert the coolant at least partially into a fire-extinguishing foam by a triggering event. In particular, the fire-extinguishing foam can contain air. Therein, if, for example, the cooling channel has been damaged by fire, air can be incorporated into the fire-extinguishing foam from the surroundings of the cooling channel. For example, for the foam generating device, substances used in the prior art for immersion cooling are suitable. This can be a dielectric liquid in particular.

[0007] Such a traction battery is advantageous in that the coolant is particularly suitable for removing heat generated by the battery cells during operation and, in the event of a fire, automatically and effectively suppresses or prevents the spread of the fire.

[0008] The traction battery is configured for use in a vehicle. This can be, for example, a motor vehicle, or also a rail vehicle, such as an ICE.

[0009] The coolants mentioned in this specification may also be used in combination with lithium-ion batteries to slow or prevent the spread of fire.

[0010] According to one embodiment of the invention, the triggering event may be exceeding a threshold temperature of the coolant, applying a voltage to the coolant, contact of the coolant with oxygen, and / or applying a mechanical force to the coolant. For example, if the threshold temperature is exceeded, a chemical reaction may be triggered which at least partially converts the coolant into a fire extinguishing foam. Contact of the coolant with oxygen may occur, for example, if damage occurs to the housing of the traction battery.

[0011] According to one embodiment of the present invention, the coolant may include a cooling liquid and a foam generating device. The foam generating device may be configured to trigger the coolant to at least partially transform into a fire extinguishing foam. For example, a separated hydrofluoroether C may be used. 4 F 9 OC 2 H 5 Or methoxy nonafluorobutane C 4 F 9 OCH 3 As a foam generating device.

[0012] According to one embodiment of the invention, the cooling unit can include a valve which is configured to allow the escape of fire-extinguishing foam from the cooling channel by at least partially converting the coolant into fire-extinguishing foam if a pressure threshold in the cooling channel is exceeded. In this way, the spread of fire can be particularly effectively impeded or even prevented.

[0013] According to one embodiment of the invention, the battery cells may be arranged in a plurality of groups. The battery cells of each group may each be arranged around the center of the respective group. The cooling channel may have a plurality of protrusions, each protruding into the center. For example, each group may have exactly one single center, around which the battery cells of the group are arranged. In particular, the battery cells may be held in this arrangement by a holding device. In particular, the coolant may also flow through the protrusions.

[0014] In this embodiment, the heat generated by the battery cells during operation is dissipated particularly effectively.

[0015] According to one embodiment of the present invention, the protrusion may abut the battery cell.

[0016] According to one embodiment of the present invention, the cooling unit may include a first element and a second element. The first element and the second element may each include a region of a cooling channel. For example, the two elements may be composed of an elastomer, a thermoplastic, or an elastic polymer. The first element may be adjacent to the first side of the battery cell with a first adjacent surface, and include a first coolant inlet and a first coolant outlet. In the context of this specification, the coolant inlet is understood to mean an area through which the coolant flows into the corresponding component during operation. In the context of this specification, the coolant outlet is understood to mean an area through which the coolant flows out of the corresponding component during operation. The coolant flowing through the coolant outlet has a higher temperature than the coolant flowing through the coolant inlet.

[0017] The second element may abut the second side of the battery cell with a second abutting surface. The second side may be arranged opposite to the first side. The second side may include a second coolant inlet and a second coolant outlet. The first element may include a plurality of first protrusions. The second element may include a plurality of second protrusions. A plurality of first protrusions extend from the first abutting surface into the center. A plurality of second protrusions extend from the second abutting surface into the center. In particular, the coolant may also be configured to flow through the protrusions.

[0018] For example, a plurality of first protrusions and a plurality of second protrusions may protrude into each center, respectively.

[0019] The plurality of first protrusions and the plurality of second protrusions may also each extend together over more than three quarters of the distance between the first side and the second side of the battery cell.

[0020] The plurality of first protrusions and the plurality of second protrusions may also contact each other in the center. The protrusions may each have the same length, wherein the protrusions extend with their length into the center.

[0021] Preferably, the first plurality of protrusions and the second plurality of protrusions are fluidly separated. This may particularly mean that coolant cannot flow directly from one of the first plurality of protrusions into one of the second plurality of protrusions.

[0022] By means of this embodiment, a particularly good removal of the heat generated by the battery cells during operation can be achieved. Furthermore, the traction battery can be produced particularly easily. It is also possible to adapt the traction battery to requirements, since individual battery cell groups can be added or removed. Only the first element and the second element then need to be adapted.

[0023] According to one embodiment of the present invention, the protrusion may have a cylindrical shape.

[0024] According to an embodiment of the present invention, the battery cell may have a cylindrical shape. In particular, the height of the cylinder may correspond in particular to the distance between the first side and the second side of the battery cell.

[0025] The cooling channel can also flow around the battery only on one side. For example, the cooling channel can be arranged above or below a battery module with multiple battery cells. In addition, multiple cooling channels can be provided, for example, one cooling channel is arranged above a single battery module with multiple battery cells and one cooling channel is arranged below a single battery module with multiple battery cells. The cooling channel can also be arranged between two battery modules.

[0026] For example, the cooling channel can be part of a cooling element, in particular if it is arranged only above or below a battery module or between two battery modules, which has an elastic modulus of less than 5 GPa at 20° C., preferably less than 2 GPa at 20° C.

[0027] The motor vehicle of the invention comprises an electric drive system and a traction battery according to one embodiment of the invention. The traction battery is configured to supply electrical energy to the electric drive system. In particular, the electric drive system is understood herein to mean a motor configured to move the entire motor vehicle.

[0028] In general, the present invention discloses the following technical solutions 1 and 10, and the following 2-9 are preferred technical solutions:

[0029] 1. A traction battery for a vehicle, the traction battery comprising a plurality of battery cells (104) and a cooling unit, the cooling unit comprising a fluid coolant and a cooling channel (100; 102), wherein the coolant is disposed in the cooling channel and is configured to flow around the battery cells (104) in the cooling channel and absorb heat, wherein the coolant is configured to be at least partially converted into fire extinguishing foam by a triggering event.

[0030] 2. The traction battery according to claim 1, wherein the triggering event is exceeding a threshold temperature of the coolant, applying a voltage to the coolant, contacting the coolant with oxygen, and / or applying a mechanical force to the coolant.

[0031] 3. The traction battery according to any one of the above schemes 1-2, characterized in that the coolant includes a cooling liquid and a foam generating device, and the foam generating device is configured to trigger the coolant to be at least partially converted into fire extinguishing foam.

[0032] 4. A traction battery according to any one of the preceding solutions 1 to 3, characterized in that the cooling unit comprises a valve, which is configured to enable fire extinguishing foam to be discharged from the cooling channel (100; 102) by at least partially converting the coolant into fire extinguishing foam if a pressure threshold in the cooling channel is exceeded.

[0033] 5. A traction battery according to any one of the preceding solutions 1 to 4, characterized in that the battery cells (104) are arranged in a plurality of groups, wherein the battery cells (104) of each of the groups are arranged around a center of the corresponding group, and wherein the cooling channel (100; 102) comprises a plurality of protrusions (101; 103), each protruding into the center.

[0034] 6. The traction battery according to the preceding solution 5, characterized in that the protrusion (101; 103) abuts against the battery cell (104).

[0035] 7. A traction battery according to one of the two preceding aspects 6-7, characterized in that the cooling unit comprises a first element (100) and a second element (102), wherein the first element (100) and the second element (102) each comprise a region of the cooling channel, wherein the first element (100) abuts a first side of the battery cell (104) with a first abutment surface and comprises a first coolant inlet (106) and a first coolant outlet (107), wherein the second element (102) abuts a second side of the battery cell (104) with a second abutment surface and comprises a second coolant inlet (108) and a second coolant outlet (109), wherein the first element (100) comprises a first plurality of first protrusions (101), wherein the second element (102) comprises a second plurality of second protrusions (103), wherein the first plurality of first protrusions (101) extend from the first abutment surface into the center, and wherein the second plurality of second protrusions (103) extend from the second abutment surface into the center.

[0036] 8. The traction battery according to claim 7, characterized in that the protrusion (101; 103) has a cylindrical shape.

[0037] 9. The traction battery according to any one of the preceding solutions 1 to 8, characterized in that the battery cell (104) has a cylindrical shape.

[0038] 10. A motor vehicle comprising an electric drive system and a traction battery according to one of the preceding claims 1 to 9, wherein the traction battery is designed to supply electrical energy to the electric drive system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Other features and advantages of the present invention are disclosed in the following description of preferred exemplary embodiments with reference to the accompanying drawings. The same reference numerals are used for the same or similar components and components having the same or similar functions. In the drawings:

[0040] Figure 1 shows a schematic exploded view of a traction battery according to one embodiment of the invention;

[0041] Figure 2 shows a schematic perspective view of a holding device according to one embodiment of the present invention;

[0042] Figure 3 Shown by Figure 1 A schematic cross-sectional view of a traction battery;

[0043] Figure 4 Shows Figure 1 A schematic perspective view of a traction battery;

[0044] Figure 5 Shows Figure 4 A schematic cross-sectional view of a traction battery along the cross-sectional line AA;

[0045] Figure 6 shows a schematic cross-sectional view of a traction battery according to an embodiment of the invention, wherein a cooling element is arranged above the battery module;

[0046] Figure 7 shows a schematic cross-sectional view of a traction battery according to an embodiment of the invention, wherein a cooling element is arranged below the battery module; and

[0047] Figure 8 A schematic cross-sectional view of a traction battery according to an exemplary embodiment of the invention is shown, wherein a cooling element is arranged between two battery modules. DETAILED DESCRIPTION

[0048] The traction battery comprises a first element 100 having a plurality of first projections 101, not all of which are provided with reference numerals for the sake of clarity. The first element 100 comprises a region of cooling channels. The cooling channels also extend into the projections 101. For this purpose, during operation, a coolant flows into the first element 100 through a coolant inlet 106 of the first element 100, flows through the element comprising the projections 101 and again flows out of the first element 100 through a coolant outlet 107 of the first element 100.

[0049] The traction battery further comprises a second element 102 having a plurality of second projections 103, not all of which are provided with reference numerals for the sake of clarity. The second element 102 comprises a region of cooling channels. The cooling channels also extend into the projections 103. For this purpose, during operation, a coolant flows into the second element 102 through a coolant inlet 108 of the second element 102, flows through the element comprising the projections 103 and again flows out of the second element 102 through a coolant outlet 109 of the second element 102.

[0050] Both the protrusion 101 and the protrusion 103 have a cylindrical shape.

[0051] Between the first element 100 and the second element 102, a battery cell 104 is arranged in a holder 105. For the sake of clarity, the battery cell 104 and the holder 105 are also not all provided with reference numerals. The battery cell 104 has a cylindrical shape and is in contact with the first element 100 and the second element 102 with its end surfaces.

[0052] The battery cells 104 are arranged in groups, with six battery cells 104 forming each group. Each group is arranged on a circular line around the center, with mutually adjacent battery cells 104 of the group in contact with each other.

[0053] The protrusion 101 of the first element 100 protrudes from the first end surface of the battery cell 104 into the corresponding center. The protrusion 103 of the second element 102 protrudes from the second end surface of the battery cell 104 into the corresponding center. In the middle between the two end surfaces, the protrusions 101 and 103 contact each other. This applies to all groups of battery cells 104 and the corresponding centers.

[0054] During operation, the battery cells 104 generate heat. The coolant flows into the first element 100 and into the second element 102 through the coolant inlets 106 and 108. The coolant also passes through the protrusions 101 and 103. Therefore, the battery cells 104 are surrounded by the coolant flow at their end surfaces and also in the middle of the center around which they are arranged. Through the coolant outlets 107 and 109, the coolant flows back out from the first element 100 and the second element 102. Therefore, the heat absorbed from the battery cells is dissipated from the first element 100 and the second element 102.

[0055] The coolant comprises a cooling liquid and a foam generating device. The foam generating device is configured to convert the coolant at least partially into a fire extinguishing foam. The conversion may be triggered by a triggering event. For example, the triggering event may be heating above a threshold temperature. Preferably, the threshold temperature is selected to be exceeded only in the event of a fire in one of the battery cells. In this case, the converted coolant inhibits or prevents the spread of the fire.

[0056] Figure 6 The traction battery 600 shown in FIG. 6 comprises a battery module 601 having a plurality of battery cells. A cooling element 602 having cooling channels is arranged only above the battery module 601 .

[0057] Figure 7 The traction battery 600 shown in FIG. 6 comprises a battery module 601 having a plurality of battery cells. A cooling element 602 having cooling channels is arranged only below the battery module 601 .

[0058] Figure 8 The traction battery 600 shown in FIG. 6 comprises two battery modules 601 , each of which has a plurality of battery cells. A cooling element 602 is arranged only between the battery modules 601 .

[0059] The coolant may flow in each cooling channel of the cooling element 602 .

[0060] Figures 6 to 8 The arrangement of the cooling element 602 shown in the figure can also be combined. For example, the cooling element 602 can be arranged above the battery module, and the cooling element 602 can be arranged below the battery module. It is also possible to arrange the cooling element 602 below the lower battery module 601, to arrange the cooling element 602 between two battery modules 601, and to arrange the cooling element 602 above the battery module 601.

Claims

1. A traction battery for a vehicle, the traction battery comprising a plurality of battery cells (104) and a cooling unit, the cooling unit comprising a fluid coolant and a cooling channel (100; 102), wherein the coolant is disposed in the cooling channel and configured to flow around the battery cells (104) in the cooling channel and absorb heat, characterized in that: The coolant is configured to be at least partially converted into fire extinguishing foam upon a triggering event.

2. The traction battery according to claim 1, characterized in that The triggering event is exceeding a threshold temperature of the coolant, applying a voltage to the coolant, contacting the coolant with oxygen, and / or applying a mechanical force to the coolant.

3. The traction battery according to claim 1 or 2, characterized in that The coolant includes a cooling liquid and a foam generating device configured to trigger at least partial conversion of the coolant into a fire extinguishing foam.

4. The traction battery according to claim 1 or 2, characterized in that: The cooling unit comprises a valve configured to enable fire extinguishing foam to be discharged from the cooling channel (100; 102) by at least partially converting the coolant into fire extinguishing foam if a pressure threshold in the cooling channel is exceeded.

5. The traction battery according to claim 1 or 2, characterized in that: The battery cells (104) are arranged in a plurality of groups, wherein the battery cells (104) of each of the groups are arranged around a center of the corresponding group, and wherein the cooling channel (100; 102) comprises a plurality of protrusions (101; 103), each protruding into the center.

6. The traction battery according to claim 5, characterized in that The protrusion (101; 103) abuts the battery cell (104).

7. The traction battery according to claim 5, characterized in that The cooling unit comprises a first element (100) and a second element (102), wherein the first element (100) and the second element (102) each comprise an area of ​​the cooling channel, wherein the first element (100) abuts a first side of the battery cell (104) with a first abutting surface and comprises a first coolant inlet (106) and a first coolant outlet (107), wherein the second element (102) abuts a second side of the battery cell (104) with a second abutting surface and comprises a second coolant inlet (108) and a second coolant outlet (109), wherein the first element (100) comprises a plurality of first protrusions (101), wherein the second element (102) comprises a plurality of second protrusions (103), wherein the plurality of first protrusions (101) extend from the first abutting surface into the center, and wherein the plurality of second protrusions (103) extend from the second abutting surface into the center.

8. The traction battery according to claim 7, characterized in that The protrusion (101; 103) has a cylindrical shape.

9. The traction battery according to claim 1 or 2, characterized in that: The battery cell (104) has a cylindrical shape. 10 . A motor vehicle comprising an electric drive system and a traction battery according to one of the preceding claims, wherein the traction battery is designed to supply electrical energy to the electric drive system.

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