Battery module for a vehicle and vehicle

Abstract

Battery module (1) for a vehicle (10), wherein the battery module (1) comprises a plurality of cylindrical battery cells (2) and a cooling arrangement (5), wherein the cooling arrangement (5) has a plurality of cooling elements (4) and is connected to the battery cells (2) for cooling, where, the cooling arrangement (5) is arranged such that a contact surface at which a respective one of the battery cells (2) contacts at least one of the cooling elements (4) is the same size for all battery cells (2), wherein the battery module (1) comprises exactly six battery cells (2a-f) each of the same dimension and three cooling elements (4) each of the same dimension, that the battery cells (2) have the same cylinder center axis direction, wherein the battery cells (2a-f) are arranged such that in a cross-section of the battery module (1) perpendicular to the cylinder center axis direction, three battery cells (2a, 2b, 2c; 2c, 2e, 2f; 2f, 2d, 2a) each form one side of an equilateral triangle (8) such that each of the three sides of the triangle (8) is formed by a line segment which connects the cylinder center axes (17) of the battery cells (2) belonging to the respective side, wherein each of the three cooling elements (4) contacts a battery cell (2a; 2c; 2f) arranged in the cross-section at a corner of the triangle (8) and the two battery cells (2b, 2d; 2b, 2e; 2d, 2e) in immediate proximity thereto for cooling purposes, wherein a first contact surface which each of the cooling elements (4) has with the respective battery cell (2a; 2c; 2f) arranged in the cross-section at a corner of the triangle (8) is twice as large as a second contact surface which the respective cooling element (4) has with the two other battery cells (2b, 2d; 2b, 2e; 2d, 2e) contacted by the respective cooling element (4).

Description

[0001] The present invention relates to a battery module for a vehicle and a vehicle.

[0002] WO 2008 / 142 223 A1 relates to an electric battery comprising several elements that generate electrical energy and a system for mechanically and thermally assembling the elements.

[0003] EP 0 599 137 B1 describes an accumulator system which has at least one battery module, each battery module comprising a plurality of batteries.

[0004] US 4 853 100 A relates to electrochemical energy converters and improved processes for electrochemical energy conversion.

[0005] WO 2008 / 147 598 A2 describes batteries with improved cooling systems and methods for cooling batteries.

[0006] FR 2 915 320 A1 discloses an electric battery comprising a plurality of battery cells and a system for mechanically and thermally conditioning these battery cells. The system comprises a bed on which the cells are arranged such that a lateral space remains between adjacent cells. The system further comprises a plurality of thermal conditioning modules, each provided with a fluid flow path between an upstream port and a downstream port.

[0007] US 2006 / 0 078 789 A1 discloses a battery with an electrochemical storage cell and a cooling device. The at least one electrochemical storage cell is arranged between parts of the cooling device. A liquid cooling medium flows through the cooling device. Each electrochemical storage cell is accommodated within an opening of the cooling device and is at least partially in frictional contact with the cooling device via at least one outer surface that is curved in a direction perpendicular to a longitudinal axis of the electrochemical storage cell.

[0008] DE 199 04 524 A1 discloses a battery cell sleeve assembly comprising a continuous thermal sleeve. This sleeve extends between near and far ends and has a longitudinal axis with a plurality of elongated thermally conductive fibers extending approximately longitudinally in one direction. The thermally conductive fibers are embedded in a base material, with the thermal sleeve abutting the outer peripheral surface of a battery cell.

[0009] Modern batteries, which are used to power a vehicle, for example, require cooling. According to the state of the art, a coolant is introduced from one side of a battery module and discharged on the opposite side of the battery module. If the coolant is guided axially (along the axis of a cylindrical battery module), a coolant connection is therefore on the same side as the battery's electrical connections, which can lead to problems if the coolant leaks out. In addition, the state of the art entails problems with so-called hot spots, i.e. areas on the battery module that are warmer than others.

[0010] Therefore, the object of the present invention is to avoid these problems according to the prior art.

[0011] According to the invention, this object is achieved by a battery module for a vehicle according to claim 1 and a vehicle according to claim 7. The dependent claims define preferred and advantageous embodiments of the present invention.

[0012] Within the scope of the present invention, a battery module for a vehicle is provided, wherein the battery module comprises a plurality of battery cells and a cooling arrangement. The cooling arrangement has a plurality of cooling elements and is connected to the battery cells for cooling the battery module. The cooling arrangement is arranged such that a contact surface at which one of the battery cells contacts one or more of the cooling elements is the same size for all battery cells, i.e., the respective contact surface has the same area for all battery cells.

[0013] The battery cells of the battery module are advantageously cylindrical and arranged parallel to one another in the battery module.

[0014] In particular, each cooling element is in contact with one or more of the battery cells over the same length along the cylinder axis of the battery cell(s) connected to it. The wrap angle (or the sum of wrap angles) over which the respective battery cell is in contact with one or more of the cooling elements is the same for each battery cell. The wrap angle is measured relative to the circular area of ​​the cylinder body of the respective battery cell.

[0015] Since the wrap angle is the same for each battery cell and each cooling element has the same length, the requirement is met that the contact area over which the respective battery cell is cooled by one or more cooling elements is the same size for all battery cells.

[0016] The battery module comprises exactly six battery cells, each with the same first dimension, and three cooling elements, each with the same second dimension. The cylindrical battery cells, arranged parallel to one another, have the same cylinder axis direction. The battery cells are arranged such that, with respect to a cross-section of the battery module perpendicular to the cylinder axis direction, three battery cells each form one side of an equilateral triangle. Each of the three sides of the triangle is formed by a line segment that connects the intersection points of the cylinder center axes of the battery cells belonging to the respective side with the respective cross-sectional plane (the drawing plane in which the cross-section is located). In other words, each side of the equilateral triangle is formed by three battery cells lying on a straight line.One side of the equilateral triangle is defined by points of intersection which form the respective cylinder center axis of the corresponding battery cell with the cross-sectional plane. More precisely, one side of the triangle is formed by connecting the two points of intersection of the two battery cells located at the outer edge of the respective side, whereby the point of intersection of the battery cell located in the middle of the side also lies on the line defining the side. Since the three battery cells located at the three corners of the equilateral triangle each belong to two sides of the equilateral triangle, the battery module is formed by six battery cells. Each of the three cooling elements contacts one of the three battery cells arranged at a corner of the equilateral triangle and also the two battery cells which are directly adjacent to the respective corner battery cell.

[0017] A first contact surface of each cooling element, which the corresponding cooling element has with the respective corner battery cell, has an area just as large as the combined area of ​​two second contact surfaces of the corresponding cooling element, which the corresponding cooling element has with the two other battery cells contacted by the corresponding cooling element. In other words, each cooling element has three contact surfaces with three battery cells. A first contact surface contacts the corner battery cell, and one of two second contact surfaces contacts one of the two battery cells that are directly connected to the corresponding corner battery cell. The area of ​​the first contact surface is just as large as the sum of the areas of the two second contact surfaces.

[0018] Since the three corner battery cells are each connected to only one cooling element (with one unit area) and the three battery cells located in the middle of each side of the equilateral triangle are each contacted by two cooling elements (each with half a unit area), the total contact area and thus the total cooling capacity is the same for each battery cell.

[0019] Advantageously, the cooling elements are connected to one another in series in such a way that the cooling fluid flows through all the cooling elements one after the other.

[0020] In particular, a cross-section of a flow channel in which the cooling fluid flows through the cooling arrangement is of the same size at all points, ie in each cooling element and also at the connecting elements between the cooling elements.

[0021] Because the cross-section of the flow channel is the same size everywhere, there is a uniform flow velocity in the flow channel, which also leads to a uniform cooling performance for the battery cells and thus avoids hot spots.

[0022] Preferably, the battery cells are arranged such that an electrical connection of each battery cell is located on the same side of the battery module, referred to as the first side. The cooling arrangement is connected to the battery cells for cooling the battery module, wherein the cooling arrangement has an inlet and an outlet for a cooling fluid. The inlet and the outlet are arranged on the same side of the battery module, referred to as the second side. The first side is opposite the second side.

[0023] The battery module according to the invention advantageously has a small installation space requirement and enables a targeted, forced flow of the cooling fluid through the cooling arrangement.

[0024] In one embodiment of the battery module according to the invention, the cooling arrangement comprises a heat sink, via which the cooling elements are cooled. In particular, no cooling fluid flows through the cooling elements, so that the risk of a cooling fluid coming into contact with the electrical connections of the battery cells is even lower in this embodiment than in the previously outlined embodiments. The cooling elements are advantageously made of a highly thermally conductive material (e.g., copper) in order to transport the heat away from the battery cells via the heat sink. The heat sink itself can have a cooling fluid flowing through it for cooling purposes.

[0025] Finally, within the scope of the present invention, a vehicle is also provided which comprises a battery module according to the invention as described above.

[0026] The present invention is particularly suitable for motor vehicles that are at least temporarily additionally powered by electrical energy. Of course, the present invention is not limited to this preferred field of application, as the present invention could also be used generally outside and independently of vehicles, for example, as a battery module for supplying energy to a house. Furthermore, the present invention could be used in ships, aircraft, and rail-bound vehicles.

[0027] In the following, the present invention is explained in detail using preferred embodiments of the invention with reference to the figures. Fig. 1 shows a perspective view of a battery module according to the invention in the direction of the electrical connections of the battery cells. Fig. 2 represents in perspective the Fig. 1, viewed from the side of the battery module opposite the electrical connections. In Fig. 3 is the battery module according to the invention of the Fig. 1 and Fig. 2 shown without module housing. Fig. 4 shows in perspective the cooling arrangement of the Fig. 1 to 3. In Fig. 5 is the cooling arrangement of the Fig. 4 shown enlarged. In Fig. 6 shows the battery module according to the invention in a cross-section perpendicular to the cylinder axes of the battery cells. Fig. 7 schematically shows a cooling arrangement according to the invention with a heat sink for cooling the cooling elements. Fig. 8 schematically shows a vehicle according to the invention with several arrangements of battery modules according to the invention.

[0028] In Fig. 1 shows a perspective view of a battery module 1 according to the invention, wherein the viewing direction of an observer falls on the electrical connection side 11 of the battery module 1, on which the cylindrical battery cells 2 of the battery module 1 have their electrical connections 16.

[0029] In Fig. 2 is the Fig. 1 is shown in perspective such that the viewer's line of sight falls on the battery module side 15 opposite the electrical connection side 11 and which is referred to as the bottom side 15 of the battery module. On this bottom side 15 there are both a cooling fluid inlet 12 and a cooling fluid outlet 13 of a cooling arrangement 5 for cooling the battery module 1, so that the cooling fluid supply (i.e., transport to and from the battery module) occurs exclusively from the bottom side 15. The battery module 1 is surrounded by a module housing 3.

[0030] In Fig. 3 is the battery module of the Fig. 1 and Fig. 2 without module housing 3. The cylindrical shape of the battery cells 2 can be seen, and it can be seen that the battery cells 2 are arranged parallel to one another, so that the cylinder center axes 17 of all six battery cells 2 are parallel to one another.

[0031] In Fig. 4, the cooling arrangement 5 is shown alone without the battery cells 2. The cooling arrangement 5 comprises three cooling elements 4, with two of these cooling elements 4 being connected by one of two cooling connecting elements 6.

[0032] In Fig. 5 is the cooling arrangement 5 of the Fig. 4 is shown enlarged. The cooling arrangement 5 has the cooling fluid inlet 12 on a first cooling element 4 and the cooling fluid outlet 13 on a third cooling element 4. In Fig. 5 also shows the flow direction 14 of the cooling fluid flowing through the three cooling elements 4 and the two cooling connecting elements 6. The cooling fluid enters the cooling arrangement 5 at the cooling fluid inlet 12 and flows upwards in the first cooling element 4 in the longitudinal direction of this cooling element 4 and along a deflection body or deflection plate 7 within the cooling element 4 in a first flow channel of this cooling element 4. From above, the cooling fluid flows in the reverse flow direction 14, again along the deflection body 7 along a second flow channel of this cooling element 4 downwards into a first cooling connecting element 6, which connects the first cooling element 4 to a second cooling element 4.In the second cooling element 4, the cooling fluid again flows upwards along the deflecting body 7 of this cooling element 4 in a first flow channel of this cooling element 4 and then downwards along the deflecting body 7 in a second flow channel of this cooling element 4 into a second cooling connection element 6, which connects the second cooling element 4 to the third cooling element 4. In this third cooling element 4, too, the cooling fluid flows upwards along the deflecting body 7 in a first flow channel of this cooling element 4 and, on the other side of the deflecting body 7, downwards in a second flow channel of this cooling element 4 to the cooling fluid outlet 13, at which the cooling fluid leaves the cooling arrangement 5.

[0033] The three cooling elements 4 are essentially structurally identical. Each cooling element 4 is divided into two equal parts by its deflecting body 7, so that the cooling fluid can flow out on one side (through the first flow channel) and back on the other side (through the second flow channel). The two flow channels of the three cooling elements 4 have the same flow cross-section and are designed such that, with the exception of the deflecting body 7, the outer walls of the two flow channels correspond to the outer walls of the respective cooling element 4. In other words, the outer walls of each cooling element 4 are cooled by the cooling fluid.

[0034] In Fig. Figure 6 shows a battery module 1 without a module housing 3 in cross-section perpendicular to the cylinder center axes 17 of the cylindrical battery cells 2. It can be seen that the six battery cells 2a - 2f form an equilateral triangle. The three battery cells 2a, 2c, 2f are located at the corners of the equilateral triangle. The remaining three battery cells 2b, 2d, 2e are each located in the middle of one of the three sides of the equilateral triangle. Fig. 6 shows the center points 18 for each circular area of ​​each battery cell. These center points 18 correspond to the respective intersection point of the cylinder center axis 17 of each battery cell 2 with the representation plane. Connecting two of these center points 18 of two battery cells 2 located at the corners of the equilateral triangle results in the equilateral triangle.

[0035] In addition, Fig. 6 shows the three cooling elements 4 together with the cooling fluid inlet 12 and the cooling fluid outlet 13. Each of the three cooling elements 4 contacts a battery cell 2a, 2c, 2f arranged at the corner of the equilateral triangle and additionally the two battery cells 2 adjacent to this cooling element 4 arranged at the corner. Each cooling element 4 is constructed and arranged such that a contact surface between the cooling element 4 and the battery cell 2 arranged at the corner of the equilateral triangle is twice as large as a cooling surface or contact surface between this cooling element 4 and one of the two other battery cells 2 connected to this cooling element.Since this structure of the cooling arrangement 5 or the structure of the three cooling elements 4 means that the three battery cells 2a, 2c, 2f arranged at the corners of the equilateral triangle are connected to only one cooling element 4 and the three other battery cells 2b, 2d, 2e are each connected to two cooling elements 4, the sum of the cooling surfaces for each of the six battery cells 2 is the same size, so that each of the six battery cells 2 is cooled to the same extent.

[0036] Since the battery cells 2 are cylindrical, the cooling elements 4 have outer surfaces which are circular in cross-section. Thus, each cooling element 4 partially surrounds three battery cells 2 and forms a Fig. 6, each of these three battery cells 2 forms a type of wrap angle, which defines the size of a circular arc over which the corresponding cooling element 4 and the corresponding battery cell touch each other in cross-section. The wrap angle over which a cooling element 4 touches a corner battery cell 2a, 2c, 2f is twice as large as the wrap angle over which a cooling element 4 touches a battery cell 2b, 2d, 2e located in the middle of one side of the equilateral triangle, which in Fig. 6 is indicated by “1” and “1 / 2”.

[0037] In Fig. Figure 7 schematically shows a cooling arrangement according to the invention, which comprises a heat sink 19. The heat sink 19 cools the three cooling elements 4, which in turn cool the battery cells 2. The special feature of this embodiment is that the cooling elements 4 themselves are not subjected to any cooling fluid, but are instead made of a material that conducts heat very well, thus dissipating the heat from the battery cells 2 to the heat sink 19.

[0038] In Fig. 8 shows a vehicle 10 according to the invention, which comprises a plurality of arrangements 9, each comprising a plurality of battery modules 1 according to the invention. One module arrangement 9 is arranged in the area of ​​the tunnel of the vehicle 10, one module arrangement 9 is arranged under the rear seat of the vehicle 10, and one module arrangement 9 is arranged in the trunk of the vehicle 10. LIST OF REFERENCE SYMBOLS 1 battery module 2 battery cells 2a-f battery cell 3 module housings 4 Cooling element 5 Cooling arrangement 6 Cooling connection element 7 Deflection body, deflection plate 8 equilateral triangle 9 Module arrangement 10 vehicles 11 electrical connection side, first side 12 Cooling fluid inlet 13 Cooling fluid outlet 14 Flow direction 15 Battery module side or bottom side, second side 16 electrical connections 17 Cylinder center axis 18 Circle center 19 heat sinks

Claims

[1] Battery module (1) for a vehicle (10), wherein the battery module (1) comprises a plurality of cylindrical battery cells (2) and a cooling arrangement (5), wherein the cooling arrangement (5) has a plurality of cooling elements (4) and is connected to the battery cells (2) for cooling, where, the cooling arrangement (5) is arranged such that a contact surface at which a respective one of the battery cells (2) contacts at least one of the cooling elements (4) is the same size for all battery cells (2), wherein the battery module (1) comprises exactly six battery cells (2a-f) each of the same dimension and three cooling elements (4) each of the same dimension, that the battery cells (2) have the same cylinder center axis direction, wherein the battery cells (2a-f) are arranged such that in a cross-section of the battery module (1) perpendicular to the cylinder center axis direction, three battery cells (2a, 2b, 2c; 2c, 2e, 2f; 2f, 2d, 2a) each form one side of an equilateral triangle (8) such that each of the three sides of the triangle (8) is formed by a line segment which connects the cylinder center axes (17) of the battery cells (2) belonging to the respective side, wherein each of the three cooling elements (4) contacts a battery cell (2a; 2c; 2f) arranged in the cross-section at a corner of the triangle (8) and the two battery cells (2b, 2d; 2b, 2e; 2d, 2e) in immediate proximity thereto for cooling purposes, wherein a first contact surface which each of the cooling elements (4) has with the respective battery cell (2a; 2c; 2f) arranged in the cross-section at a corner of the triangle (8) is twice as large as a second contact surface which the respective cooling element (4) has with the two other battery cells (2b, 2d; 2b, 2e; 2d, 2e) contacted by the respective cooling element (4). [2] Battery module (1) according to claim 1, characterized by , that each of the cooling elements (4) has the same length, over which the respective cooling element (4) is in contact with at least one of the battery cells (2), that a wrap angle over which one of the battery cells (2) is in contact with at least one of the cooling elements (4) and which is measured with respect to the circular area of ​​the respective cylindrical battery cell (2) is the same for each battery cell (2). [3] Battery module (1) according to one of claims 1 or 2, characterized by that the cooling arrangement (5) comprises a heat sink (19) via which the cooling elements (4) can be cooled. [4] Battery module (1) according to one of claims 1-3, characterized by that the cooling elements (4) are connected to one another in the form of a series circuit in such a way that a cooling fluid flows through all the cooling elements (4) one after the other. [5] Battery module (1) according to claim 4, characterized by that a cross-section of a flow channel in which the cooling fluid flows through the cooling arrangement (5) is the same size everywhere. [6] Battery module (1) according to one of claims 1-5, characterized bythat the battery cells (2) are arranged such that an electrical connection (16) of each battery cell (2) is located on a same first side (11) of the battery module (1), wherein the cooling arrangement (5) is connected to the battery cells (2) for cooling, and wherein the cooling arrangement (5) has an inlet (12) and an outlet (13) for a cooling fluid, and that the cooling arrangement (5) is arranged such that the inlet (12) and the outlet (13) are arranged on a same second side (15) of the battery module (1), and that the first side (11) is opposite the second side (15). [7] Vehicle (10) with at least one battery module (1) according to one of claims 1-6.

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