Traction battery for a motor vehicle, motor vehicle

Abstract

A traction battery (1) for a motor vehicle (100) is proposed, comprising a plurality of battery cells (2) and a plurality of cooling surfaces (3) arranged between the battery cells (2). The cooling surfaces (3) are fluidically connected to a coolant channel (4) for the flow of a coolant through them. The coolant channel (4) has plug-in elements (5), each associated with a cooling surface (3) and plugged together at plug-in areas (6) for fluidic connection. A leakage line (7) is provided for collecting and removing coolant escaping from the coolant channel (4) and / or from the cooling surfaces (3). A motor vehicle (100) is also proposed.

Description

[0001] The present invention relates to a traction battery for a motor vehicle, comprising a plurality of battery cells and a plurality of cooling surfaces arranged between the battery cells, wherein the cooling surfaces are fluidly connected to a coolant channel for flow through the cooling surfaces. Furthermore, the invention relates to a motor vehicle with a traction battery.

[0002] High-performance motor vehicles with electric drive units are typically limited in performance by thermal constraints. Therefore, considerable effort is put into keeping the heat-sensitive parts of the drivetrain, such as the windings of the electric motor, the power electronics, and the traction battery, at an optimal temperature level. Liquid cooling has been shown to be highly effective in dissipating waste heat.

[0003] There are different approaches to cooling the traction battery. One approach involves flushing the battery cells with a liquid coolant and applying it directly. Another approach involves arranging cooling surfaces between the battery cells. The cooling surfaces have cooling chambers inside, through which the coolant flows. To produce a traction battery, battery cells and cooling surfaces can be arranged alternately in the battery housing, so that a cooling surface is always located between the battery cells. The cooling surfaces are arranged directly or indirectly, for example, via a thermal paste or the like, adjacent to the battery cells.

[0004] The cooling surfaces are connected to a coolant channel through which the coolant is introduced into the cooling surfaces. With a high number of battery cells and a correspondingly high number of cooling surfaces, there are also numerous connection points and branches of the coolant channel, which represent potential leaks and increase the likelihood of coolant leakage within the traction battery.

[0005] It is therefore an object of the present invention to provide a traction battery and a motor vehicle with a traction battery in which the risk of an unwanted coolant leakage within the traction battery is significantly reduced.

[0006] This object is achieved by a traction battery according to claim 1 and by a motor vehicle according to claim 10.

[0007] The traction battery according to the invention for a motor vehicle has a plurality of battery cells and a plurality of cooling surfaces arranged between the battery cells. The cooling surfaces are fluidly connected to a coolant through a coolant channel for flowing through the cooling surfaces. According to the invention, the coolant channel has plug-in elements, each of which is assigned to a cooling surface and is plugged together at plug-in areas for fluidic connection. This significantly simplifies the assembly of the traction battery, since only cooling surfaces with the plug-in elements and battery cells need to be arranged alternately in a battery housing. The traction battery according to the invention further has a leakage line for receiving and discharging coolant escaping from the coolant channel and / or the cooling surfaces.This advantageously ensures that any leaking coolant is safely removed from the critical area within the traction battery. It is conceivable that the coolant from the leak line could be fed into a cooling circuit.

[0008] Preferably, the cooling surfaces are made of a metal, for example, aluminum. This significantly increases cooling efficiency. It is also conceivable for the plug-in elements and / or the leakage line to be made of a plastic, for example, injection-molded.

[0009] Advantageous embodiments and further developments of the invention can be found in the dependent claims and the description with reference to the drawings.

[0010] According to a preferred embodiment of the present invention, the coolant channel and the cooling surfaces are designed for the coolant to flow through under high pressure. High pressure, within the meaning of the present invention, is a pressure of more than 1 bar, in particular between 2 and 3.5 bar. In other words, the coolant channel and the cooling surfaces are mechanically designed to permanently withstand high coolant pressures. The leakage line is preferably not designed for the coolant to flow through it under high pressure. This allows material to be saved and the leakage line to be kept structurally simple.

[0011] In particular, it is provided that the coolant channel in the plug-in area is sealed with a high-pressure seal toward the leak line, with the leak line preferably being sealed to the outside with an additional seal. The high-pressure seal and the additional seal can be, for example, O-rings made of a rubber material. However, other seals are also conceivable, such as hollow chamber seals, P- or V-shaped seals, or seals with sealing lips. Seals made of soft metals are also conceivable.

[0012] According to a further preferred embodiment of the present invention, it is provided that the coolant channel is arranged at least partially and preferably completely within the leakage line. In other words, the coolant channel is partially surrounded by the leakage line. This advantageously ensures that even in the event of leaks in the coolant channel itself, for example due to material fatigue or manufacturing errors, coolant escaping is collected and safely led out of the battery housing. It is particularly conceivable for the leakage line to be continuous below the coolant channel and for the cooling surface, in particular with a cooling chamber, to be arranged directly adjacent to the coolant channel in the region of the cooling surface above and preferably to the side of the coolant channel.

[0013] Preferably, the coolant channel of the plug-in element and the leakage line of the plug-in element encompass the coolant channel of another plug-in element and the leakage line of another plug-in element in the plug-in area. This ensures a secure, continuous connection between the coolant channel and the leakage line.

[0014] In particular, it is provided that the coolant channel has openings arranged on its circumference for introducing the coolant into the cooling surface, in particular into the cooling space of the cooling surface, so that the coolant can advantageously enter the cooling surface from the coolant channel for cooling without detours and thus without any significant pressure loss.

[0015] According to a further preferred embodiment of the present invention, it is provided that the leakage line is fluidically connected to the plug-in areas by means of leakage collection spaces, wherein the leakage collection spaces preferably enclose the plug-in areas. The coolant can advantageously be guided through the leakage collection spaces from the plug-in areas away from the battery cells towards the leakage line. A particular advantage of this is that the leakage line can be arranged further away from the cooling channel, the cooling surfaces and the battery cells in a space-saving manner, so that more installation space is available there. In particular, it is provided for this purpose that the coolant channel is arranged outside the leakage line, wherein the coolant channel and the leakage line are arranged parallel to one another.

[0016] Preferably, it is further provided that an inlet chamber of the cooling surface is arranged between an upstream first side and a downstream second side of the plug-in element associated with the cooling surface. The plug-in elements are thus not inserted into the cooling surfaces, but rather encompass the cooling surfaces in the region of the inlet chamber.

[0017] In particular, it is conceivable that the coolant channel is a coolant supply line. It is conceivable for the cooling surfaces of the traction battery to be fluidly connected to another coolant channel, which is a coolant return line. It is conceivable for the traction battery to have another leakage line for receiving and discharging coolant emerging from the other coolant channel and / or the cooling surfaces. Preferably, all features, details, and advantages disclosed for the coolant channel and the leakage line also relate to the other coolant channel and the other leakage line.

[0018] A further object of the present invention to solve the problem formulated at the outset is a motor vehicle having a traction battery according to the invention.

[0019] All details, features and advantages previously disclosed in connection with the traction battery according to the invention also relate to the motor vehicle according to the invention.

[0020] Further details, features, and advantages of the invention will become apparent from the drawings and the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the scope of the invention. Fig. 1 a) and Fig. 1 b) schematically illustrate a detail of a traction battery according to an exemplary embodiment of the present invention. Fig. 2 a) and Fig. 2 b) schematically illustrate a detail of a traction battery according to an exemplary embodiment of the present invention. Fig. 3 a) and Fig. 3 b) schematically illustrate a detail of a traction battery according to an exemplary embodiment of the present invention. Fig. 4 a) and Fig. 4 b) schematically illustrate a detail of a traction battery according to an exemplary embodiment of the present invention. Fig. 5 schematically illustrates a detail of a traction battery according to an exemplary embodiment of the present invention. Fig. 6 schematically illustrates a motor vehicle according to an exemplary embodiment of the present invention with a traction battery according to an exemplary embodiment of the present invention.

[0021] In the Fig. 1 to 5 schematically show details of a traction battery 1 according to different embodiments of the present invention. The traction battery 1 is intended for use in a motor vehicle 100 (see Fig. 6) and supplies the power electronics and the electrical machines (both not shown) of the motor vehicle 100 with electrical energy.

[0022] Such traction batteries 1 must be cooled during operation, i.e., during the release and absorption of electrical energy. Effective cooling of the traction battery 1 is essential for the functioning of a motor vehicle 100, particularly a high-performance motor vehicle 100. Due to its high efficiency, cooling with a liquid coolant has become established. The coolant is pumped under high pressure through a coolant channel 4, which fluidically connects several cooling surfaces 3 to one another. The cooling surfaces 3 are arranged between battery cells 2 of the traction battery 1 and contact them directly or indirectly, so that waste heat from the battery cells 2 can be transferred to the cooling surfaces 3.The coolant flows from the coolant channel 4, which can be designed, for example, as a coolant supply line, into the cooling surfaces 3, cools the cooling surfaces 3 and thereby absorbs the waste heat from the battery cells 2 and dissipates it, for example, in a coolant return line (not shown).

[0023] To simplify the manufacture of the traction battery 1, the cooling surfaces 3 and the battery cells 2 are arranged alternately within a battery housing 12 of the traction battery 1. To create a continuous coolant channel 4, each cooling surface 3 is assigned a plug-in element 5. When arranging the cooling surfaces 3 and the battery cells 2, the plug-in elements 5 are inserted into one another at plug-in areas 6. The totality of all plug-in elements 5 arranged and inserted into one another in the battery housing 12 forms the coolant channel 4.

[0024] The use of a high-pressure liquid as a coolant within the traction battery 1 is critical. To protect the traction battery 1, leaks must be avoided at all costs. The risk of leaks is particularly high in the plug-in areas 6 and at the connection areas where the coolant flows from the coolant channel 4 into the cooling surfaces 3. A leakage line 7 is arranged parallel to the coolant channel 4, which collects and returns any escaping coolant. The flow of coolant through the coolant channel 4 is Fig. 3 b) and Fig. 5 are each represented by a large arrow. A possible leak and the resulting coolant escaping are indicated by small arrows in these figures.

[0025] In the Fig. 1 to 3, the coolant channel 4 is arranged within the leakage line 7. After plugging together the plug elements 5 of the preferred embodiment shown here, the coolant channel 4 of one plug element 5 (here the right plug element 5) encompasses the coolant channel 4 of another plug element 5 (here the left plug element 5). This is particularly clear in the Fig. 3 b). Furthermore, the leakage line 7 of one plug-in element 5 (here also the right-hand plug-in element 5) encompasses the leakage line 7 of another plug-in element 5 (here also the left-hand plug-in element 5). This arrangement of the cooling channel 4 and the leakage line 7 ensures particularly high security against coolant leakage. Openings 13 arranged on the circumference of the coolant channel 4 can be seen to allow the coolant to enter the cooling surfaces 3 from the coolant channel 4. To seal the coolant channel 4 of the plug-in elements 5 which are plugged into one another, these each have a high-pressure seal 9, for example an O-ring. The leakage line 7, which is not under high pressure, is sealed to the outside with a further seal 10.

[0026] In the Fig. 4 to 5 each show a detail of a traction battery 1 according to a further particularly preferred embodiment of the present invention. In contrast to the Fig. 1 to 3, the leakage line 7 does not enclose the coolant channel 4, but is arranged parallel to it and in particular at a distance from the cooling surfaces 3. The plug-in elements 5 shown here are also plugged into one another at plug-in areas 6 and sealed with high-pressure seals 9. Leakage collection spaces 8 are also arranged at these plug-in areas 6, which serve to collect coolant that has passed through the high-pressure seal 9 and to guide it into the leakage line 7. This is shown in the Fig.5 is represented by the small arrows. The leakage collection chambers 8 enclose the plug-in areas 6. In the embodiment shown here, the plug-in elements 5 are arranged on both sides, i.e., upstream and downstream, of an inlet chamber 11 of the cooling surfaces 3. From the coolant channel 4, the coolant flows through the inlet chambers 11 into the cooling surfaces 3. List of reference symbols 1 traction battery 2 battery cells 3 Cooling surface 4 coolant channel 5 plug-in element 6 Plug-in area 7 Leakage line 8 Leakage collection chamber 9 High-pressure seal 10 more seals 11 Inlet chamber 12 Battery housing 13 openings 100 motor vehicles

Claims

[1] Traction battery (1) for a motor vehicle (100), comprising a plurality of battery cells (2) and a plurality of cooling surfaces (3) arranged between the battery cells (2), wherein the cooling surfaces (3) are fluidly connected to a coolant through a coolant channel (4) for flow through the cooling surfaces (3), characterized by that the coolant channel (4) has plug-in elements (5) which are each assigned to a cooling surface (3) and are plugged together at plug-in areas (6) for fluidic connection, and that a leakage line (7) is provided for receiving and discharging coolant emerging from the coolant channel (4) and / or from the cooling surfaces (3). [2] Traction battery (1) according to claim 1, characterized by that the coolant channel (4) and the cooling surfaces (3) are provided for the coolant to flow through under high pressure. [3] Traction battery (1) according to one of the preceding claims, characterized bythat the coolant channel (4) in the plug-in area (6) is sealed with a high-pressure seal (9) towards the leakage line (7), wherein the leakage line (7) is preferably sealed to the outside with a further seal (10). [4] Traction battery (1) according to one of the preceding claims, characterized by that the coolant channel (4) is arranged at least partially and preferably completely within the leakage line (7). [5] Traction battery (1) according to claim 4, characterized by that in the plug-in area (6) the coolant channel (4) of the plug-in element (5) and the leakage line (7) of the plug-in element (5) encompass the coolant channel (4) of a further plug-in element (5) and the leakage line (7) of a further plug-in element (5). [6] Traction battery (1) according to one of claims 4 to 5, characterized bythat the coolant channel (4) has openings (13) arranged on its circumference for introducing the coolant into the cooling surface (3). [7] Traction battery (1) according to one of claims 1 to 3, characterized by that the leakage line (7) is fluidically connected to the plug-in areas (6) by leakage collection spaces (8), wherein the leakage collection spaces (8) preferably enclose the plug-in areas (6). [8] Traction battery (1) according to claim 6, characterized by that the coolant channel (4) is arranged outside the leakage line (7), wherein the coolant channel (4) and the leakage line (7) are arranged parallel to one another. [9] Traction battery (1) according to one of claims 6 to 7, characterized by that an inlet chamber (11) of the cooling surface (3) is arranged between an upstream first side and a downstream second side of the plug-in element (5) assigned to the cooling surface (3). [10] Motor vehicle (100) comprising a traction battery (1) according to one of the preceding claims.

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