Traction batteries for motor vehicles

Abstract

A traction battery for a motor vehicle, the traction battery having a plurality of battery modules (11), wherein the battery modules (11) of the traction battery (10) are electrically coupled via an electrical busbar (15), wherein each battery module (11) has a module housing (12) and a battery cell (13) accommodated in the respective module housing (12), wherein the battery cells (13) of each battery module (11) are electrically coupled. At least one heat conductor (25, 26) is arranged between the electrical busbar (15) for electrically coupling the battery modules (11) and an adjacent housing of the traction battery, or an adjacent structural component of a body of the motor vehicle, or an adjacent module housing (12) of the battery module (11).

Description

Technical Field

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

[0002] Traction batteries of motor vehicles designed as electric vehicles or hybrid vehicles serve to store electrical drive energy for the motor vehicle. Such traction batteries have a plurality of battery modules, each of which has a module housing and battery cells accommodated by the module housing. The traction battery can have a battery housing that accommodates the battery modules and seals them from the surroundings. If there are no separate battery housings, the module housings of the battery modules seal the battery cells of each battery module individually from the surroundings, wherein structural components of the body of the motor vehicle thus assume the function of structural reinforcement of the battery housing.

[0003] The individual cells of each battery module of the traction battery are coupled one above the other via current conductors known as busbars. These current conductors, known as busbars, for electrically coupling the individual cells of the respective battery modules extend within the module housing of the respective battery module.

[0004] The battery modules of the traction battery are electrically coupled via electrical busbars, which extend outside the module housings of the battery modules to be coupled.

[0005] The electrical busbars for electrically coupling the battery modules of a traction battery carry relatively high currents. As a result, these electrical busbars are also subject to relatively high temperature increases. To date, it has been difficult to effectively dissipate the heat in the electrical busbars for electrically coupling the battery modules of a traction battery.

[0006] A battery module for a traction battery of a motor vehicle is known from DE 10 2019 122 754 A1. The battery module has a plurality of battery cells which are electrically coupled via a busbar. The busbar is made of copper and is connected to a cooling body in a heat-conducting manner. Thus, heat can be conducted away from the corresponding busbar.

[0007] US2020 / 0136326 A1 discloses an electrical unit having an electrical contact and a busbar connected to the electrical contact. The busbar connected to the electrical contact is connected to a cooling body. Here, the cooling body is positioned between the busbar and the electrical contact.

[0008] Although embodiments for cooling busbars for electrically coupling battery cells of a battery module of a traction battery are known from the prior art, embodiments for effectively protecting busbars for electrically coupling battery modules of a traction battery of a motor vehicle from thermal overload are not disclosed from the prior art. Summary of the invention

[0009] The object of the present invention is to provide a novel traction battery for a motor vehicle in which electrical busbars for electrically coupling battery modules of the traction battery are effectively protected from thermal overload.

[0010] This object is achieved by a traction battery according to the following description.

[0011] According to the invention, at least one heat conductor is arranged between an electrical busbar for electrically coupling the battery module and an adjoining housing of the traction battery or an adjoining structural component of the body of the motor vehicle or an adjoining module housing of the battery module.

[0012] The invention here proposes for the first time that at least one heat conductor is arranged between electrical busbars for electrically coupling battery modules of a traction battery and adjacent components in order to dissipate heat from the respective electrical busbar to the respective adjacent component via the heat conductor and thus protect the electrical busbar from excessive thermal stress.

[0013] The adjacent housing of the traction battery or adjacent structural components of the body of the motor vehicle or adjacent module housings of the battery modules are preferably actively cooled, in particular fluid cooled, and / or are connected to actively cooled, in particular fluid cooled components. Heat can thereby be dissipated particularly advantageously.

[0014] According to an advantageous first development, at least one of the electrical busbars for electrically coupling the battery modules of the traction battery has a busbar core made of an electrically conductive material and a busbar housing made of an electrically non-conductive material which surrounds the busbar core at a distance from the outside. A first heat conductor is arranged between the busbar core and the busbar housing of the respective electrical busbar. A second heat conductor is arranged between the busbar housing of the respective electrical busbar and an adjacent housing of the traction battery, or an adjacent structural component of the body of the motor vehicle, or an adjacent module housing of the respective battery module. The electrical busbars according to the advantageous first development are in particular such busbars of the traction battery which are relatively short and are used for the electrical coupling of in particular directly adjacent battery modules of the traction battery.

[0015] According to an advantageous second development, at least one of the electrical busbars for electrically coupling the battery modules of the traction battery has a busbar core made of an electrically conductive material and a busbar cover made of an electrically non-conductive material surrounding the busbar core on the outside, the busbar cover being directly in contact with the busbar core of the respective electrical busbar. A heat conductor is arranged between the busbar cover of the respective electrical busbar and an adjacent housing of the traction battery or an adjacent structural component of the body of the motor vehicle or an adjacent module housing of the respective battery module. The electrical busbar according to the advantageous second development of the invention is in particular designed to be relatively long and in particular electrically couples the battery modules of the traction battery that are spaced further apart from one another.

[0016] Preferably, in a second advantageous development, the respective heat conductor connects the respective busbar directly to the cover component or the bottom component and additionally indirectly via the EMC carrier to a frame component which forms a side wall of the housing of the traction battery or an adjacent structural component of the vehicle body. Heat can thus be dissipated from the respective busbar via two paths.

[0017] In general, the present invention discloses the following technical solution 1, and the following 2-10 are preferred technical solutions:

[0018] 1. A traction battery (10) for a motor vehicle,

[0019] A plurality of battery modules (11) are provided.

[0020] The battery modules (11) of the traction battery (10) are electrically coupled via electrical busbars (14, 15, 32, 33),

[0021] Each battery module (11) has a module housing (12) and a battery cell (13) accommodated in the corresponding module housing (12).

[0022] The battery cells (13) of each battery module (11) are electrically coupled,

[0023] It is characterized in that

[0024] At least one heat conductor (18, 19, 25, 26, 36) is arranged between the electrical busbar (14, 15, 32, 33) for electrically coupling the battery module (11) and an adjacent housing of the traction battery or an adjacent structural component of the body of the motor vehicle or an adjacent module housing (12) of the battery module (11).

[0025] 2. The traction battery according to item 1 above, characterized in that:

[0026] At least one of the electrical busbars (14, 15) for electrically coupling the battery modules (11) comprises a busbar core (16, 23) made of an electrically conductive material and a busbar housing (17, 24) made of an electrically non-conductive material and surrounding the busbar core (16, 23) externally,

[0027] A first heat conductor (18, 25) is arranged between a busbar core (16, 23) and a busbar housing (17, 24) of a corresponding electrical busbar (14, 15).

[0028] A second heat conductor (19, 26) is arranged between a busbar housing (17, 24) of a respective electrical busbar (14, 15) and an adjacent housing of the traction battery or an adjacent structural component of the body of the motor vehicle or an adjacent module housing (12) of a respective battery module (11).

[0029] 3. The traction battery according to item 2 above, characterized in that the respective first heat-conducting body (18, 25) is a casting material body.

[0030] 4. The traction battery according to item 2 or 3 above, characterized in that the corresponding second heat conductor (19, 26) is a heat conductive pad.

[0031] 5. A traction battery according to any one of 1 to 4 above, characterized in that:

[0032] At least one of the electrical busbars (32, 33) for electrically coupling the battery modules (11) comprises a busbar core (34) made of a conductive material and a busbar cover (35) made of a non-conductive material and surrounding the busbar core (34) on the outside, the busbar cover being directly in contact with the busbar core (34) of the corresponding electrical busbar (32, 33).

[0033] A heat conductor (36) is arranged between a busbar housing (34) of a respective electrical busbar (32, 33) and an adjacent housing of the traction battery or an adjacent structural component of the body of the motor vehicle or an adjacent module housing (12) of a respective battery module (11).

[0034] 6. The traction battery according to 5 above, characterized in that the respective heat conducting body (36) is a casting material body.

[0035] 7. The traction battery according to item 5 or 6 above, characterized in that the corresponding heat conductor (36) directly connects the corresponding busbar (32, 33) to the cover member (37) or the bottom member.

[0036] 8. A traction battery according to any one of the preceding 5 to 7, characterized in that the respective heat conductor (36) indirectly connects the respective busbar (32, 33) via an EMC carrier (38) to a frame component (31), which forms a side wall of the housing of the traction battery or an adjacent structural component of the vehicle body.

[0037] 9. A traction battery according to any one of 1 to 8 above, characterized in that an adjacent housing of the traction battery or an adjacent structural component of the body of the motor vehicle or an adjacent module housing (12) of the battery module (11) is actively cooled and / or is connected to an actively cooled component.

[0038] 10. A traction battery according to any one of 1 to 9 above, characterized in that an adjacent housing of the traction battery or an adjacent structural component of the body of the motor vehicle or an adjacent module housing (12) of the battery module (11) is fluid-cooled and / or connected to a fluid-cooled component. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Preferred improvements of the present invention are obtained from the following description. Embodiments of the present invention will be described in detail with the aid of the accompanying drawings, but are not limited thereto. In the accompanying drawings:

[0040] Figure 1 shows a detail of a traction battery in the area of ​​four battery modules arranged next to each other and one above the other,

[0041] Figure 2 Show Figure 1 a first detail II in the region of a battery module and a busbar for coupling the battery module to another battery module,

[0042] Figure 3 Show Figure 1 a second detail III in the area of ​​a battery module and a busbar for coupling the battery module to another battery module,

[0043] Figure 4 Show Figure 3 A variation of the details III,

[0044] Figure 5 A further detail of the traction battery is shown in the region of a battery module and in the region of a busbar which serves to couple the battery module to another battery module. DETAILED DESCRIPTION

[0045] The invention relates to a traction battery for a motor vehicle. Such a traction battery for a motor vehicle is used to store electric drive energy for the motor vehicle. The traction battery has a plurality of battery modules, wherein each battery module has a plurality of battery cells.

[0046] Figure 1 A detail of a traction battery 10 of a motor vehicle is shown in the region of four battery modules 11, wherein Figure 1 The battery modules 11 shown in the figure are arranged side by side on the one hand and on top of each other on the other hand. Each battery module 11 has a module housing 12 and a battery cell 13 arranged in the module housing 12. The battery cells 13 of each battery module 11 are electrically coupled via current conductors. The current conductors for electrically coupling the battery cells 13 of the respective battery modules 11 are also referred to as busbars.

[0047] In the traction battery 10 , the battery modules 11 are also electrically coupled, more precisely via busbars, wherein Figure 1 The busbars 14 and 15 shown in FIG. Figure 2 or Figure 3 Shown in greater detail.

[0048] The present invention relates to effectively dissipating heat from electrical busbars for electrically coupling battery modules 11 in order to protect the electrical busbars from thermal overload.

[0049] According to the invention, at least one heat conductor is arranged between a respective electrical busbar for electrically coupling a battery module 11 of a traction battery 10 and an adjacent housing of the traction battery 10 or an adjacent structural component of a body of a motor vehicle or an adjacent module housing 12 of an adjacent battery module 11, wherein heat can be dissipated from the respective busbar in the direction of the respective adjacent component via the heat conductor.

[0050] In this case, the respective adjacent components, ie the adjacent housing of traction battery 10 or the adjacent structural components of the body of the motor vehicle or the adjacent module housing 12 are preferably actively cooled and / or are coupled to actively cooled components, wherein in this case the heat can then be dissipated particularly effectively.

[0051] Actively cooled components are, in particular, liquid-cooled components, such as water-cooled components.

[0052] exist Figure 2 Shown in Figure 1 Detail II in the area of ​​the first electrical busbar 14, which is used to connect Figure 2 The battery module 11 shown in FIG. 1 is in electrical contact with another battery module 11 , wherein the two battery modules 11 to be electrically coupled via the first electrical busbar 14 are arranged directly next to each other. Figure 1 in the upper plane.

[0053] exist Figure 2 The electrical busbar 14 shown in FIG. 1 for electrically coupling two battery modules 11 has a busbar core 16 made of an electrically conductive material (eg copper) and a busbar housing 17 made of an electrically non-conductive material (eg plastic) which surrounds the busbar core 16 at a distance from the outside.

[0054] exist Figure 2 A first heat conductor 18 is arranged between the busbar core 16 of the busbar 14 shown in the figure and the busbar housing 17, wherein the heat conductor 18 thermally couples the busbar core 16 to the busbar housing 17. In addition, a second heat conductor 19 is arranged between the busbar housing 17 and the adjacent module housing 12 of the battery module 11, and the second heat conductor thermally couples the busbar 14 to the battery module housing 12 of the battery module 11.

[0055] Here, in Figure 2 The busbar 14 shown in FIG. 1 is thermally coupled to a cover 12 a of a module housing 12 of a battery module 11, wherein the cover 12 a is thermally coupled to a bottom wall 12 c of the module housing 12 via a side wall 12 b of the module housing 12, and the bottom wall is thermally coupled to an actively cooled component 20. The actively cooled component 20 is Figure 1 , Figure 2 The following components are arranged in Figure 2 , and is arranged above the battery module 11 arranged below the battery module 11 (see Figure 1 ). The assembly 20 is an assembly of a battery housing or a structural member of a vehicle body.

[0056] The respective first heat-conducting body 18 arranged between the respective busbar core 16 and the respective busbar housing 17 of the electrical busbar 14 is a potting compound body made of a heat-conducting material which is arranged in a liquid state in a cavity between the busbar core 16 and the busbar housing 17 and hardens there.

[0057] Arranged between the corresponding busbar housing 17 and the adjacent components, Figure 2 The respective second heat-conducting body 19 arranged between the busbar housing 17 and the cover 12 a of the module housing 12 is preferably a heat-conducting mat.

[0058] Figure 1 and Figure 2 A frame component 21 is shown between the battery modules 11 shown here, wherein the frame component 21 can be a side wall of a housing of a traction battery or a structural component of a body of a motor vehicle.

[0059] Figure 1Also shown are frame components 22 located between the battery modules 11 of the lower layer of battery modules 11 , which frame components are side walls of the housing of the traction battery or adjoining structural components of the body of the motor vehicle.

[0060] Figure 3 Shown in Figure 1 In the region of the lower battery module 11 of the battery module 11 shown in FIG. 1 , more precisely in the region for Figure 3 The battery module 11 shown in FIG. 1 is electrically coupled to the busbar 15 in the region of FIG. Figure 1 Details of the traction battery 10 III.

[0061] The busbar 15 also has a busbar core 23 made of an electrically conductive material (for example copper) and a busbar housing 24 made of an electrically non-conductive material (for example plastic) which surrounds the busbar core 23 on the outside at a distance.

[0062] The busbar housing 24 surrounds the busbar core 23 on the outside, wherein Figure 3 and Figure 2 The same thing is that a first heat conductor 25 is arranged between the busbar core 23 and the busbar housing 24 on the one hand, and a second heat conductor 26 is arranged between the busbar housing 24 and the adjacent frame component 22 on the other hand.

[0063] The first heat-conducting body 25 is preferably again a potting material body, and the second heat-conducting body 26 is preferably again a heat-conducting mat.

[0064] In this way, in Figure 3 The busbar core 23 of the busbar 15 shown in FIG. 1 is thermally coupled to a frame component 22 via a busbar housing 24 , wherein the frame component 22 is thermally coupled to an actively cooled component 27 extending below the frame component 22 and below the battery module 11 .

[0065] The actively cooled component 27 is a floor component of the housing of the traction battery or a floor component of the body of the motor vehicle.

[0066] Figure 4 Show Figure 3 A variant of detail III in the area of ​​busbar 15, in which Figure 4 The middle busbar 15 is not thermally coupled to the frame member 22 but is thermally coupled to the cover member 28. Figure 4 The first heat conductor 25 is again arranged between the busbar core 23 and the busbar housing 24 , and the second heat conductor 26 is arranged between the busbar housing 24 and the cover member 28 .

[0067] exist Figure 3 and Figure 4 The contact between the busbar core 23 and the electrical connector 29 of the battery module 11 can be clearly seen in FIG. Figure 3 and Figure 4 The busbar 15 shown in FIG. 1 is therefore used for Figure 3 and Figure 4 Electrical contacting of the two battery modules 11 shown in FIG. 1 and positioned next to each other.

[0068] Figure 5 A further detail of the traction battery 10 according to the invention is shown in the region of the battery module 11, wherein the battery module 11 is arranged between two frame elements 30, 31. The frame elements 30, 31 can in turn be side walls of a battery housing of the traction battery or structural elements of the body of the motor vehicle. Two busbars 32, 33 extend above the battery module 11, wherein each of these busbars 32, 33 serves for electrical contacting of a battery module 11 of the traction battery 10.

[0069] Each of these busbars 32, 33 has a busbar core 34 made of an electrically conductive material (for example, copper) and a busbar jacket 35 made of an electrically non-conductive material (for example, plastic or rubber) surrounding the respective busbar core 34 on the outside. Figure 5 In the electrical busbars 32, 33, the corresponding busbar cover 35 is directly or indirectly attached to the corresponding busbar core 34 without forming a cavity therebetween. A heat conductor 36 is arranged between the busbar cover 35 of the corresponding busbar 32, 33 and the adjacent component. The heat conductor 36 is preferably a casting material body.

[0070] exist Figure 5 In the embodiment of the present invention, the casting material body 36 thermally couples the respective busbars 32, 33 directly to the cover component 37 on the one hand and, on the other hand, in particular indirectly via the EMC carrier 38, to the frame component 31, which is a side wall of the housing of the traction battery or an adjacent structural component of the body of the motor vehicle. The cover component 37 and / or the frame component 31 are thermally coupled to actively cooled components, in particular to fluid-cooled components, as already described in connection with the invention. Figure 2 , Figure 3 and Figure 4 The details are as described.

[0071] The invention makes it possible to effectively remove heat from the busbars 14, 15, 32, 33 of the traction battery 10 of a motor vehicle, in order to avoid an inadmissibly high thermal load on the busbars 14, 15, 32, 33. Higher currents can flow through the busbars 14, 15, 32, 33 without the risk of thermal overload. As a result, an electric vehicle or hybrid vehicle can be operated more efficiently, in particular when charging the traction battery. During charging, it is possible to operate at a higher charging power for a longer period of time. This can of course also be done during discharge.

Claims

1. A traction battery (10) for a motor vehicle, A plurality of battery modules (11) are provided. The battery modules (11) of the traction battery (10) are electrically coupled via a first electrical busbar (14, 15) and a second electrical busbar (32, 33), Each battery module (11) has a module housing (12) and a battery cell (13) accommodated in the corresponding module housing (12). The battery cells (13) of each battery module (11) are electrically coupled, It is characterized in that at least one heat conductor is arranged between the first electrical busbar (14, 15) for electrically coupling the battery module (11) and an adjacent housing of the traction battery, or an adjacent structural component of the body of the motor vehicle, or an adjacent module housing (12) of the battery module (11); At least one of the first electrical busbars (14, 15) for electrically coupling the battery modules (11) comprises a first busbar core (16, 23) made of an electrically conductive material and a busbar housing (17, 24) made of an electrically non-conductive material and surrounding the first busbar core (16, 23) externally, A first heat conductor (18, 25) is arranged between a first busbar core (16, 23) and a busbar housing (17, 24) of a corresponding first electrical busbar (14, 15), and A second heat conductor (19, 26) is arranged between a busbar housing (17, 24) of a respective first electrical busbar (14, 15) and an adjacent housing of the traction battery or an adjacent structural component of a body of the motor vehicle or an adjacent module housing (12) of a respective battery module (11); as well as At least one of the second electrical busbars (32, 33) for electrically coupling the battery module (11) has a second busbar core (34) made of a conductive material and a busbar cover (35) made of a non-conductive material and surrounding the second busbar core (34) on the outside, the busbar cover being directly attached to the second busbar core (34) of the corresponding second electrical busbar (32, 33), and A third heat conductor (36) is arranged between a busbar housing (35) of a respective second electrical busbar (32, 33) and an adjacent housing of the traction battery or an adjacent structural component of the body of the motor vehicle or an adjacent module housing (12) of a respective battery module (11).

2. The traction battery according to claim 1, characterized in that The respective first heat-conducting body (18, 25) is a potting material body.

3. The traction battery according to claim 1 or 2, characterized in that The corresponding second heat conductor (19, 26) is a heat conductive pad.

4. The traction battery according to claim 1 or 2, characterized in that: An adjoining housing of the traction battery or an adjoining structural component of the body of the motor vehicle or an adjoining module housing (12) of the battery module (11) is actively cooled and / or is coupled to an actively cooled component.

5. The traction battery according to claim 1 or 2, characterized in that: The adjacent housing of the traction battery or the adjacent structural component of the body of the motor vehicle or the adjacent module housing (12) of the battery module (11) is fluid-cooled and / or is coupled to a fluid-cooled component.

6. The traction battery according to claim 1, characterized in that The corresponding third heat-conducting body (36) is a potting material body.

7. The traction battery according to claim 1, characterized in that The corresponding third heat conductor (36) directly connects the corresponding second electrical busbar (32, 33) to the cover member (37) or the bottom member.

8. The traction battery according to claim 1, characterized in that The respective third heat conductor (36) indirectly couples the respective second electrical busbar (32, 33) via an EMC carrier (38) to a frame component (31) which forms a side wall of the housing of the traction battery or an adjacent structural component of the vehicle body.

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