Battery arrangement and method for cooling a battery arrangement

Abstract

Battery arrangement (1) with at least two battery cells (11) which are electrically connected to each other, in particular in parallel, via their poles by means of at least one cell connector (20) of the battery arrangement (1) to form a cell pack (10), wherein, for cooling the battery arrangement (1), the cell connector (20) can be brought into thermal contact with a cooling device, via which the heat generated in the battery arrangement (1) can be thermally dissipated, and wherein the cell connector (20) has at least one cavity (23) for conveying coolant with at least two connections (24, 25) for integration into a coolant circuit of the cooling device, characterized by that at least one cell connector (20) is designed as an evaporator plate which extends over a plane, wherein refrigerant can be used as a coolant and wherein the evaporator plate is manufactured using a roll bonding process, that in the at least one cell connector (20) at least one contact area (26) is present, within which at least one of the battery cells (11) is in electrically conductive contact with the cell connector (20), wherein no cavity (23) is formed in the contact area (26) in the cell connector (20) and that the cell connector (20) has joining areas (27) in the contact area(s) (26) in which the battery cells (11) are each attached to the cell connector (20).

Description

[0001] The invention relates to a battery arrangement with at least two battery cells which are electrically connected to each other, in particular in parallel, via their poles by means of at least one cell connector of the battery arrangement to form a cell pack, wherein, for cooling the battery arrangement, the cell connector can be brought into thermal contact with a cooling device through which the heat generated in the battery arrangement can be thermally dissipated. The invention further relates to a method for cooling a battery arrangement.

[0002] Modern battery systems, such as those used in the automotive sector, consist of electrically connected individual battery cells. The required battery capacity is achieved through parallel connection, and the required battery voltage through series connection. Typically, several battery cells are connected in parallel to form a cell pack using, for example, flat cell connectors, and several cell packs are then connected in series to create a battery assembly. For parallel connection, two cell connectors, positioned on opposite terminals, are advantageously used, and these are electrically connected to each other via the battery cells.

[0003] During operation, and especially during fast charging, significant waste heat is generated in the battery cells, which must be dissipated from the battery system. Battery systems can be temperature-controlled in various ways, using different cooling media such as air, water, or special coolants. The thermal interface with the battery housing is also relevant. In so-called surge arrester cooling, a particularly efficient method, cooling is achieved, for example, via a cooling device that is in thermal contact with at least one terminal of the battery cells. In this way, the interior of the battery cells is cooled directly via the surge arresters and electrodes, thus utilizing the direct electrically conductive path, which also possesses good thermal conductivity, into the individual battery cells.This cooling concept often incorporates the cell connector, from which heat is dissipated via a coolant such as air, water, or a water-glycol mixture, and cooling elements. It is important to ensure that the thermal conductivity path is decoupled from the electrical conductivity path at a suitable point by electrical insulation, thus preventing unwanted electrical current flows that could, for example, lead to a short circuit.

[0004] Such a cooling concept, which, as mentioned above, is also the basis of the present invention, with a battery arrangement and a corresponding method, are disclosed in DE 10 2013 015 422 A1. In this concept, a cooling medium is directed towards the battery cells and cell connectors via a cooling medium supply device, the cooling medium supply device being arranged at a certain distance from the cell connectors without contact. The cooling medium is directed perpendicularly onto the cell connectors via discharge devices, flows over them, thereby cooling the cell connectors, and then flows laterally and downwards. The cell connector can be provided with surface-enhancing elements such as ribs or fins. However, the perpendicularly offset arrangement of the cooling medium supply device and the discharge of the cooling medium require a certain amount of installation space, which reduces the possible packing density of the battery arrangement.

[0005] Other battery arrangements with different cooling concepts are known, for example, from US 2008 / 0248379 A1, WO 2010 / 012343 A1, DE 102013018395 A1, and US 5424143 A. A heat sink for a high-voltage battery is described in DE 102013021670 A1.

[0006] German patent DE 10 2011 118 686 A1 discloses a battery with a plurality of battery cells whose poles are electrically connected to each other by means of a busbar. The busbar is permeable to a coolant, which may be evaporable.

[0007] DE 10 2014 001 975 A1 discloses a battery for a motor vehicle, wherein several battery cells are electrically connected to one another via a busbar. A temperature control element is attached to the busbar, defining a cavity for guiding a temperature control fluid. The cavity extends along the busbar. The temperature control element is made of an electrically insulating material.

[0008] JP 2011-029 103 A describes a battery cooling system. The electrical terminals of the batteries are connected by connecting conductors. Coolant lines are integrated within these block-shaped conductors.

[0009] The invention is based on the objective of providing a battery arrangement with efficient cooling that allows a high packing density of battery cells, as well as a corresponding method for cooling the battery arrangement.

[0010] The problem is solved for the battery arrangement with the features of claim 1 and for the method with the features of claim 10. In the battery arrangement, the cell connector is provided to have at least one cavity for conveying coolant with at least two connections for integration into a coolant circuit of the cooling device.

[0011] The method provides that, for cooling the cell connector, coolant from the cooling device is passed through at least one cavity of the cell connector.

[0012] In a parallel connection, at least two cell connectors, arranged on opposite pole sides, are advantageously provided. The inventive design with the cavity relates to at least one of the cell connectors. The at least one cavity can, for example, be flat or channel-like, and several flat and / or channel-like cavities may also be present. Coolant flowing through the cell connector is carried in the coolant circuit via the at least two connections, one of which serves as the supply line and the other as the outlet for coolant. The cell connector is flat, extending in particular along a plane. The at least one cavity is preferably arranged between two walls of the cell connector, which, for example, rise symmetrically in both vertical directions relative to the plane along which the cell connector extends.Alternatively, only one of the walls can rise vertically relative to the other to form the cavity. Depending on factors such as the installation situation, one variant or the other may be advantageous.

[0013] The inventive design of the battery assembly allows the cell connector to additionally function as a cooling element and a conductor section. This eliminates the need for an additional cooling element and conductor arrangement in the area of ​​the cell connector. Consequently, both the number of components and the space required for the cooled battery assembly are reduced. The packing density can thus be increased while simultaneously ensuring efficient cooling.

[0014] In an advantageous embodiment of the battery arrangement, a non-conductive fluid is used as the coolant. This prevents unwanted electrical conduction processes via the fluid, which can, for example, cause short circuits. This allows for greater flexibility in the interconnection of, for example, multiple cell connectors with different electrical potentials. The battery arrangement can thus be designed much more flexibly, which is advantageous for adapting it to different applications.

[0015] In the embodiment according to the invention, at least one cell connector is designed as an evaporator plate, with refrigerant being used as the coolant. When designed as an evaporator plate, the cell connector must meet certain stability requirements, in particular exhibiting a certain pressure resistance. This requires, for example, a suitable material (e.g., aluminum) and / or a sufficient minimum wall thickness (e.g., 0.4 mm per wall). Such an evaporator plate is advantageously manufactured using a roll bonding process, which enables precise formation of the evaporator plate in an efficient manufacturing process. The refrigerant referred to here is a special coolant that at least partially evaporates in the cell connector designed as an evaporator plate. Preferably, an expansion valve is arranged in the coolant circuit, which is connected upstream of the cell connector(s). According to the invention, evaporation is controlled, for example, by...The system is controlled by a downstream pressure and temperature sensor in such a way that the refrigerant behind the most upstream cell connector (in the case of multiple cell connectors connected in series) has not yet completely or just barely evaporated (i.e., no temperature increase has yet occurred in the refrigerant). This cooling design offers the advantage that the temperature of the refrigerant across the cell connectors remains constant, since the introduced heat energy is absorbed as enthalpy of vaporization and does not result in a temperature increase. In this way, efficient and uniform cooling can be achieved.

[0016] For efficient manufacturing and high reliability of the battery assembly, the invention provides that at least one cell connector has at least one contact area within which at least one of the battery cells is in electrically conductive contact with the cell connector, wherein (by definition) no cavity is formed in the cell connector within the contact area. Because there is no cavity in the contact area, it is suitable for mounting battery cells, minimizing or eliminating the risk of leakage due to damage to the cavity. To generate sufficient cooling in the contact area, it is preferably at least partially enclosed by the cavity area, e.g., on at least two sides. The design of the contact area, e.g., with regard to its surface shape, can vary.If a single contact area is present, it is preferably configured such that several battery cells are in contact with the cell connector within the contact area. In another embodiment, several contact areas are provided for contacting one or more battery cells. A preferred variant is such that each contact area is in contact with a battery cell, the contact area being surrounded by the cavity. If several battery cells are accommodated in one contact area, an elongated, e.g., channel-like, cavity for cooling can be provided on both sides of the contact area, which may be elongated.

[0017] Because, according to the invention, the cell connector has joining areas in the contact area(s) where the battery cells are attached to the cell connector, these areas can be advantageously designed for optimized attachment. In extreme cases, the joining areas can correspond in area to the contact areas or be smaller.

[0018] For example, it is advantageous if the wall thickness of the cell connector is less than the wall thickness in the cavity area, at least in the joining areas. The thickness can be less than the sum of the two cavity walls, preferably less than the thickness of one of the walls. It can be, for example, 0.1 to 0.3 mm, preferably 0.2 mm. This allows for the advantageous use of efficient fastening methods for the battery cells to the cell connector during assembly, such as resistance welding, pulse welding, arc welding, laser welding, or ultrasonic welding.

[0019] In a further advantageous embodiment, the contact area, at least in the joining areas, is shaped in such a way that it essentially positively engages a pole region of a battery cell. The pole region of a battery cell comprises at least one pole and, optionally, a portion of the battery wall around the pole, e.g., up to the outer diameter of the battery cell or even a portion of a cylindrical circumferential wall. In this embodiment, for example, the joining area and / or a portion of the contact area encompassing the joining area has a relief that is essentially complementary to the pole region. The transition to the cavity can also be included in the relief or form the relief itself. The relief can, for example, include a recess for receiving the pole.This simplifies assembly, as the battery cells can be easily pre-positioned opposite the cell connector before the joining process.

[0020] A particularly high packing density can be achieved when the battery cells are cylindrical. For cylindrical battery cells, the heat sink cooling method is very efficient because heat conduction along the electrical path is significantly higher than in the radial direction of a battery cell.

[0021] A high cooling effect combined with a defined electrical connection can be achieved by having at least two cell connectors on the cell pack, each with at least one cavity. These connectors are positioned at opposite poles of the battery cells and are thus electrically connected via the battery cells. The cavities are electrically insulated from each other via a first transition, particularly through a (at least partially electrically insulated) coolant line. A voltage drop occurs across the different poles of the battery cells, resulting in the cell connectors being at different potential levels.The electrically insulating fluid-mechanical connection allows this potential difference to be maintained in a defined manner, since the electrically insulating fluid connection interrupts the electrical connection between the cell connectors, except for the battery cells themselves. The connection can be designed, for example, by a coolant line that is at least partially insulated (e.g., a pipe). The arrangement of the cell connectors relative to each other depends on the arrangement of the terminals. If, for example, the terminals are located on opposite end faces (top and bottom), the cell connectors will also be positioned opposite each other on these end faces.

[0022] A sufficiently high battery voltage can be achieved by having at least two cell packs connected in series and several cell connectors, each with at least one cavity. For the transfer of coolant, a second terminal of one cell connector is in flow connection with a first terminal of the other cell connector. The second terminal serves to drain the coolant from one cell connector, and the first terminal serves to supply the coolant to the other cell connector.

[0023] Preferably, two cell packs are electrically connected in series, such that, according to a first embodiment, a cell connector on one pole of one cell pack is electrically connected to another cell connector on the other pole of the other cell pack. The cell connectors are in flow connection via a second transition, in particular via a coolant line. This results in essentially the same electrical potential at both cell connectors. Therefore, in this embodiment, no electrical insulation is required for the existing second transition, which establishes the flow connection, preferably via the first and second connections, e.g., via an intermediate line section. In this embodiment, each cell pack is assigned two separate cell connectors.If n cell packets are connected in series, the total number of cell connectors in the arrangement is therefore preferably 2*n.

[0024] In another preferred embodiment, two cell packs are electrically connected in series by arranging them with opposite pole faces on a common cell connector and connecting them electrically via this connector. The common cell connector is designed to be connected to two cell packs, i.e., it has a corresponding area and number of contact or joining areas. The cavity(ies) of the cell connector are preferably continuous, so that, from a fluid dynamics perspective, a separate second transition between the two cell packs is unnecessary or can be integrated into the cell connector. The first and last cell connectors of the series connection are preferably each assigned to only one cell pack and, for example, to corresponding electrical connections of a peripheral device. If n cell packs are connected in series, this results, for example, in...A total number of cell connectors, taking into account the connectors located at the ends (i.e., the first and last), of n+1. This allows for the advantageous use of fewer cell connectors than in the first variant, resulting in a beneficial reduction in the number of parts. Furthermore, by eliminating the second connections, the pressure drop of the coolant in the coolant circuit can be reduced, thereby increasing the efficiency of the cooling system in which the battery assembly is integrated during operation.

[0025] In both variants, the output potential of one cell pack serves as the input potential of the cell pack connected downstream, in accordance with a series connection. Depending on requirements, e.g., spatial constraints, both variants can be combined, for example, by connecting a certain number of cell packs via common connectors linking two cell packs each, and other cell packs via separate cell connectors.

[0026] Preferably, the cell connectors are arranged on opposite end faces of the cell packs, corresponding to the opposing pole sides. In a preferred embodiment, identical cell connectors are used, at least within a single wiring configuration (via common or separate cell connectors). Cell connectors with separate functions or positions within the series connection, e.g., those that terminate the connection (at the beginning and end of the series connection) or form a transition to another wiring configuration, can be designed differently. Using identical cell connectors for their intended purpose advantageously reduces the number of parts and can thus simplify manufacturing. However, if expedient, e.g., for spatial arrangement, different cell connectors can also be used, e.g., identical ones on opposite end faces.

[0027] A particularly advantageous flow pattern results when the two terminals of the respective cell connectors are arranged on opposite sides of the connector. In a preferred embodiment, the terminals are located, for example, on the respective longitudinal sides of the cell connector and are laterally offset from a central axis, e.g., centered on the halves located on either side of the central axis. When coolant flows through, an S-shaped flow pattern develops from the first to the second terminal, resulting in a largely uniform flow through the cavity around the contact areas. This ensures well-distributed cooling of all battery cells in the cell pack.

[0028] In another embodiment, the terminals of a cell connector can be arranged on opposite, particularly short, sides of the cell connector on one end face of the battery assembly, while the terminals of the cell connector on the other end face of the battery assembly are arranged on the same longitudinal side of the cell connector. This allows for a different spatial arrangement of the transitions or the cell packs relative to each other, which may also be advantageous depending on the installation situation.

[0029] If an electrically non-conductive fluid is used as a coolant in the cooling process, especially when connecting several cell connectors, this reduces the risk of short circuits and allows a defined current flow via the designated electrical conductor paths.

[0030] An efficient cooling method with a substantially constant coolant temperature level can be achieved according to the invention by using a refrigerant as the coolant, which at least partially evaporates in the at least one cell connector and is circulated in a refrigerant circuit designed as a refrigeration circuit of the cooling device, in which the at least one cell connector acts as an evaporator and in which the refrigerant is further circulated through a compressor, a condenser, and an expansion valve. The cooling device with the corresponding refrigeration circuit components (compressor, condenser, and expansion valve) can be at least partially integrated into or formed by a cooling device already present in the overall system (e.g., a motor vehicle), such as an air conditioning system. Alternatively, a separate cooling device can be provided for cooling the battery assembly.

[0031] The invention will now be explained in more detail using exemplary embodiments and with reference to the drawings. The drawings show: Fig. 1 a cell pack of a battery arrangement according to the invention in perspective view on a cell connector, Fig. 2A-C each show a part of a cell connector with a battery cell attached to it in different variants in side view, Fig. 3 schematically a connection of several cell packs to form a battery arrangement according to the invention, which is cooled via the method according to the invention, Fig. 4A, B a variant of several interconnected cell packages with a cell connector extending over two cell packages in perspective view from below (4A) and above (4B) and Fig. 5A, B another variant of several interconnected cell packages with a cell connector extending over two cell packages in perspective view from below (5A) and above (5B).

[0032] Fig. Figure 1 shows a battery arrangement 1 in which several individual battery cells 11, here cylindrically designed, are electrically connected in parallel to form a cell pack 10 by means of a cell connector 20. A second cell connector, which is usually present on the opposite pole side of the battery cells 11, is not shown. The cell connector 20 has a cavity 23 that rises vertically relative to a flat base plate 28 of the cell connector 20 lying in a plane. The cavity 23 is bounded by an upper wall 22 facing away from the battery cells 11 and a lower wall 21 opposite it. Alternatively, several separate flat and / or channel-like cavities 23 could also be present. During operation, the cavity 23 serves to conduct coolant, thereby cooling the battery arrangement 1. The cell connector 20 is designed as an evaporator plate, i.e.,It meets the corresponding requirements for stability, in particular compressive strength. For example, the walls 21, 22 bounding the cavity 23 have a certain minimum thickness, e.g. 0.3 to 0.8 mm, preferably 0.4 mm. A refrigerant is used as the coolant, which at least partially evaporates in the cell connector 20.

[0033] The cavity 23 of the cell connector 20 has two connections, a first connection 24 for the coolant supply and a second connection 25 for the coolant discharge. More than two connections would also be possible. The cell connector 20 can be integrated into a coolant circuit of a cooling system, which is present in a complete system (for example, a motor vehicle), via connections 24 and 25. The cooling system may already be at least partially integrated into the complete system and may also operate other components, such as an air conditioning system, or it may be provided separately for battery cooling.

[0034] Within the area where the cavity 23 is formed on the base plate 28, i.e., surrounded by the cavity 23, contact areas 26 are arranged. No cavity 23 is formed within the contact areas 26. Within the contact areas 26, the battery cells 11 are in electrically conductive contact with the cell connector 20. In this case, the number of contact areas 26 corresponds to the number of battery cells 11, i.e., each contact area 26 is assigned one battery cell 11. Each contact area 26 also has a joining area 27, which is circular in this case and has a smaller area than the contact area 26. The identical terminal faces of the battery cells 11 are attached to this joining area.

[0035] The joining area 27 preferably has a smaller wall thickness than the upper wall 21 and the lower wall 22 that define the cavity 23, for example 0.1 to 0.3 mm, preferably 0.2 mm. This allows the battery cells 11 to be attached to the cell connector 20 using efficient joining methods, such as laser or ultrasonic welding. Because no cavity 23 for coolant conduction is formed in the contact area 26 with the joining area 27, the risk of leakage in the cell connector 20 is minimized when the battery cells 11 are attached. Furthermore, as described above, the wall thickness can be correspondingly smaller than in the cavity 23 area, since the stability requirements are not as high as in the cavity 23 area.

[0036] The contact areas 26 have a circular circumference and are each completely enclosed by the cavity 23. This allows for a high cooling effect on the individual battery cells 11. Instead of a planar cavity 23, this could also be channel-like, i.e., with a significantly greater length than the flow cross-section, possibly also with several branches. This could result in a smaller volume, thus advantageously requiring a smaller amount of coolant.

[0037] As the Fig. As shown in Figures 2A and C, the lower side of the cell connector 20, which points towards the battery cells 11, can be configured within the contact areas 26 such that it essentially engages the battery cells 11 with their pole areas 12 (i.e., the pole-encompassing areas) in a form-fitting manner. Fig. In the embodiments shown in Figures 2A and C, a relief of a recess is formed in the contact areas 26, which essentially corresponds to the shape of the pole area 12 of a battery cell 11. The relief results in each case from the transition to the cavity 23. Fig. 2A, the lower wall 21 of the cell connector is convex, pointing towards battery cell 10, i.e., by definition downwards, while the upper wall 22 is flat. Thus, the cavity 23 extends from a plane with a level N, on which the base plate 28 also lies, only in one vertical direction, namely towards the battery cells 11. Fig. In 2C, however, both walls 21, 22 are bulged outwards relative to the base plate 28, so that the cavity 23 extends in both vertical directions from the base plate 28. Fig. Figure 2B shows a variant without relief, in which the lower wall 21 is flat and the upper wall 22 is convex. In another variant, not shown here, with a pole area 12 that is smaller than the contact area, it would also be possible for the relief to be formed only in a smaller area of ​​the contact area 26, encompassing the joining area 27, for example, by embossing. The relief allows the battery cells 11 to be precisely pre-positioned relative to the cell connector 20 during manufacturing, before they are attached, thus simplifying production.

[0038] In cooling mode, where the cell connector 20 is connected to the coolant circuit of the cooling device via connections 24 and 25, the coolant flows from connection 24 into the cavity 23. There, the coolant flows around the contact areas 26 and absorbs heat energy generated in the battery cells 11, which is conducted into the cell connector 20 via the joining areas 27 and contact areas 26. When a refrigerant is used as the coolant, the refrigerant evaporates at least partially as it flows through the cell connector 20, which is designed as an evaporator plate, since the absorbed heat energy acts as the enthalpy of vaporization. The temperature in the refrigerant thus remains essentially constant.

[0039] In one embodiment, two cell connectors 20 can advantageously be arranged on the cell pack 10, each on opposite pole sides 12.1, 12.2 of the batteries. Preferably, both cell connectors 20 have a cavity 23 and are filled with coolant during operation. This allows for a particularly high cooling effect. The cell connectors 20 are fluidically connected in series, with the cavities 23 of the cell connectors 20 being electrically insulated from one another, for example, via a coolant line that is at least partially electrically insulated. The electrical connection of the cell connectors 20 is defined via the battery cells 11. Particularly when several cell connectors 20 are connected, an electrically non-conductive fluid is preferably used as the coolant to prevent undesired electrical conduction via the coolant, especially short circuits.

[0040] How Fig. As shown schematically in Figure 3, several cell packs 10 can be connected in series to form a battery arrangement 1. This shows Fig. Figure 3 shows four cell packs 10 connected in series. Each cell pack 10 has two cell connectors 20, each in electrical and thermal contact with the opposite terminals 12.1, 12.2 of the battery cells 11. Coolant flows through the cell connectors 20 via the cavities 23. For this purpose, they are integrated into a pipe arrangement 30 of a cooling device (not shown in detail here). The current flow in the battery arrangement 1 is represented by unfilled arrows, and the coolant flow by filled arrows.

[0041] The electric current flows into the first cell connector 20, which is located on terminal 12.1 and connects the battery cells 11 of the first cell pack 10 in parallel. A voltage difference is created across the battery cells 11. On the opposite terminal 12.2 of the battery cells 11, the current continues in the second cell connector 20. The second cell connector 20 on terminal 12.2 of the first cell pack 10 is electrically connected to a third cell connector 20, located on terminal 12.1 of a second cell pack 10, in order to connect the first and second cell packs 10 in series. Alternatively, instead of the separate second and third cell connectors 20, a common cell connector 20 can be used, to which the terminals 12.2 of one cell pack 10 (here, the first) and the other terminals 12.1 are connected.1 of the other, here second cell pack 10 are arranged and are in electrically conductive and thermal connection (see e.g. . Fig. 4, Fig. 5) The current flow continues in the same manner.

[0042] From a fluid mechanics perspective, all cell connectors 20 of the cell packs 10 are connected in series. The refrigerant flows through the pipe arrangement 30, first via an inlet 31 into the first cell connector 20, where it partially evaporates. The refrigerant then flows through a first transition 32, which is electrically insulated, for example, by means of a partially insulated pipe. In this way, the two cell connectors 20 of the first cell pack 10 are electrically decoupled from each other, or rather, are only electrically connected via the battery cells 11. The refrigerant then flows through the second cell connector 20, where it continues to evaporate, and subsequently through a second transition 33 into the third cell connector, which is assigned to the second cell pack 10. Due to the existing electrical connection of the second and third cell connectors 20, electrical insulation of the second transition 33 is not required.In the variant where a common cell connector 20 is used instead of the second and third cell connectors 20, preferably no separate second transition 33 is present, or it is integrated into the cell connector 20. The refrigerant flows through the remaining cell connectors 20 in the same way, evaporating more and more. Downstream of the last cell connector 20, the refrigerant is directed via a drain 34 into a subsequent section of the cooling device. Preferably, the cooling device is controlled such that the refrigerant has just completely evaporated downstream of the last cell connector 20 connected in series. In this way, the refrigerant does not yet reach the superheating range, in which the temperature rises.This keeps the temperature in the refrigerant circuit between the individual cell connectors 20 essentially constant, contributing to uniform, controllable cooling of the individual battery cells 11.

[0043] In the Fig. 4A and Fig. 4B and the Fig. 5A and Fig. 5B are variants of a battery arrangement 1 with several cell packs 10, 10' connected in series in a perspective view from one side ( Fig. 4A or Fig. 5A) and the opposite side ( Fig. 4B or Fig. Figure 5B) illustrates this. Only two cell packs 10, 10' of the series connection are shown as examples. In the exemplary embodiments, nine battery cells 11 are connected together to form a cell pack 10, although the number can, of course, vary. The two cell packs 10, 10' are electrically connected in series, with the different pole faces 12.1, 12.2 of the two cell packs 10, 10' facing the two opposite end faces of the cell packs 10, 10' or of the battery arrangement 1.

[0044] On one end face, the different pole faces 12.1, 12.2 of the two cell packages 10, 10' connected in series are connected by a common cell connector 20. On the opposite end face, the two cell packages 10, 10' are each assigned to other cell connectors 20, each of which is designed to be connected to another cell package 10 connected before or after the respective cell package 10 or 10'.

[0045] In the common cell connectors 20, the second transitions 33 between the cell packages 10 and 10' are omitted or integrated into the cell connectors 20. As a result, the cell connector 20 transitions unchanged from the area connected to one cell package 10 to the area connected to the other cell package 10'.

[0046] The two cell connectors 20, each of which is arranged on a cell pack 10,10' on its different pole sides 12.1, 12.2, are fluidically connected to each other via the first transition 32, i.e. electrically insulating, here formed as a conductor section t, with their cavities 23.

[0047] In the Fig. 4A and Fig. In the variant shown in 4B, the cell connectors 20 arranged on the opposite end faces are each configured differently. In the Fig. 4A On the upward-pointing cell connectors 20, the two terminals 24, 25 are located opposite each other on the short sides of the cell connector 20. On the opposite end face (see Fig. In contrast, in the cell connectors 20 arranged as shown in 4B), the two terminals 24, 25 are arranged on one longitudinal side of each cell connector 20. The cell connectors 20 arranged on the opposite end faces are rotated 90° relative to each other in their longitudinal orientation. This design and arrangement of the cell connectors 20 is advantageous when blocks of two consecutive cell packages 10, 10' are arranged side by side. In each case, a first terminal 24 is arranged opposite a second terminal 25, thus advantageously achieving a short path for the first transition 32.

[0048] In the Fig. 5A and Fig. In the variant shown in Figure 5B, identical cell connectors 20 are used on the opposing end faces. This reduces the number of parts and thus the manufacturing effort. The longitudinal orientations of the cell connectors 20 on the two end faces are identical. In series connection, each cell pack 10, 10' is arranged in a single row next to the other. The two terminals 24, 25 are located on the opposite longitudinal sides of the cell connectors 20. They are offset from each other and positioned approximately in the middle of the respective halves of the longitudinal sides.In this way, an advantageous flow pattern is achieved, in which the refrigerant flows in an S-shaped pattern from the first connection 24 transversely to the longitudinal orientation of the cell connector into the cavity 23, aligns itself in the direction of the longitudinal orientation, and finally flows out of the cavity 23 transversely to the longitudinal axis through the second connection 25. In this way, the contact areas 26 are cooled and surrounded by a largely uniform flow.

[0049] Both in the version variant Fig. 4A and B as well as the one in the Fig. In sections 5A and B, the lower wall 21, which faces the respective battery cells 11, is flat. This allows battery cells 11 with differently shaped pole areas 12, in particular with different pole faces 12.1, 12.2, to be securely attached to the cell connector 20. This reduces manufacturing effort, as different reliefs do not need to be formed on a single cell connector 20.

[0050] Through the in the Fig. In the variants shown in Figures 4A, B and 5A, B, where several, especially two, cell packs 10, 10' are connected by a common cell connector 20, the number of cell connectors is significantly reduced and the manufacturing effort is lowered. At the same time, a high packing density can be achieved with efficient cooling. In addition, the total pressure loss in the pipe arrangement 30 is reduced, since the second transitions 33 can be omitted, which benefits the overall efficiency of the cooling system.

[0051] The battery arrangement 1 according to the invention, which is cooled using the method according to the invention, allows for a high packing density of the battery arrangement 1, while simultaneously ensuring efficient cooling. Reference symbol list 1 Battery arrangement 10-cell pack 11 battery cell 12 pole range 12.1 first pole 12.2 second pole side 20 cell connectors 21 lower wall 22 upper wall 23 Cavity 24 first connection 25 second connection 26 Contact area 27 Joining area 28 Base plate 30 Line arrangement 31 Inflow 32 first transition 33 second transition 34 Procedure

Claims

[1] Battery arrangement (1) with at least two battery cells (11) which are electrically connected to each other, in particular in parallel, via their poles by means of at least one cell connector (20) of the battery arrangement (1) to form a cell pack (10), wherein, for cooling the battery arrangement (1), the cell connector (20) can be brought into thermal contact with a cooling device, via which the heat generated in the battery arrangement (1) can be thermally dissipated, and wherein the cell connector (20) has at least one cavity (23) for conveying coolant with at least two connections (24, 25) for integration into a coolant circuit of the cooling device, characterized by , that at least one cell connector (20) is designed as an evaporator plate which extends over a plane, wherein refrigerant can be used as a coolant and wherein the evaporator plate is manufactured using a roll bonding process, that in the at least one cell connector (20) at least one contact area (26) is present, within which at least one of the battery cells (11) is in electrically conductive contact with the cell connector (20), wherein no cavity (23) is formed in the contact area (26) in the cell connector (20) and that the cell connector (20) has joining areas (27) in the contact area(s) (26) in which the battery cells (11) are each attached to the cell connector (20). [2] Battery arrangement (1) according to claim 1, characterized by that an electrically non-conductive fluid can be used as a coolant. [3] Battery arrangement (1) according to claim 1 or 2, characterized by , that the wall thickness of the cell connector (20) is less than the wall thickness in the cavity area (23), at least in the joining areas (27). [4] Battery arrangement (1) according to any one of the preceding claims, characterized by, that the contact area (26) is shaped in such a way, at least in the joining areas (27), that it receives a pole area (12) of a battery cell (11) in a substantially form-fitting manner. [5] Battery arrangement (1) according to any one of the preceding claims, characterized by , that the battery cells (11) are cylindrical in shape. [6] Battery arrangement (1) according to any one of the preceding claims, characterized by , that at least two cell connectors (20), each having at least one cavity (23), are present on the cell pack (10), which are arranged on different pole sides (12.1, 12.2) of the battery cells (11) and are thus electrically connected via the battery cells (11), wherein the cavities (23), in particular via a coolant line, are electrically insulated from each other via a first transition (32). [7] Battery arrangement (1) according to any one of the preceding claims, characterized by , that at least two cell packages (10, 10') connected in series and several cell connectors (20), each having at least one cavity (23), are present, wherein for the transfer of coolant a second connection (25) of one of the cell connectors (20) is in flow connection with a first connection (24) of another cell connector (20) connected in series behind it. [8] Battery arrangement (1) according to claim 7, characterized by , that each pair of cell packets (10, 10') are electrically connected in series, by - a cell connector (20) on one pole side (12.1, 12.2) of one cell pack (10, 10') is electrically connected to another cell connector (20) on the other pole side (12.1, 12.2) of the other cell pack (10, 10'), wherein the cell connectors (20) are in flow connection via a second transition (33), in particular via a coolant line, or - the two cell packages (10, 10') with different pole sides (12.1, 12.2) are arranged on a common cell connector (20) and are electrically connected to each other via this connector. [9] Battery arrangement (1) according to one of claims 7 or 8, characterized by , that the cell connectors (20) are arranged on opposite end faces of the cell packages (10, 10'), preferably using cell connectors (20) of the same design, the terminals (24, 25) of which are preferably arranged on opposite sides of the respective cell connector (20). [10] A method for cooling a battery arrangement (1), in particular according to one of the preceding claims, in which at least one cell connector (20) of the battery arrangement (1), which electrically connects at least two battery cells (11) of the battery arrangement (1) to form a cell pack (10) via their poles in a cell-conducting manner, in particular in parallel, is cooled by a cooling device and heat generated in the battery arrangement (1) is thermally dissipated in this way, wherein, for cooling the cell connector (20), coolant of the cooling device is passed through at least one cavity (23) of the cell connector (20) and wherein a refrigerant is used as the coolant, which at least partially evaporates in the at least one cell connector (20) and which is carried in a coolant circuit designed as a refrigeration circuit of the cooling device, in which the at least one cell connector (20) acts as an evaporator and in which the refrigerant is further compressed by a compressor,a condenser and an expansion valve are routed, , characterized by , that the evaporation is regulated via a downstream pressure and temperature sensor in such a way that the refrigerant behind the cell connector (20) located furthest upstream has not yet completely or just evaporated. [11] Method according to claim 10, characterized by that an electrically non-conductive fluid is used as a coolant.

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