Battery cell connector for connecting battery cells in series

Abstract

The invention relates to a battery cell connector (2) for connecting battery cells (4) in series, comprising a first connecting element (2a) for establishing a connection to a first battery pole (6a) of a first battery cell (4a), and a second connecting element (2b) for establishing a connection to a second battery pole (6b) of a second battery cell (4b), wherein the connecting elements (2a, 2b) are configured to correspond in shape with respect to one another and can be connected to one another in series in such a way that a contact surface (8) surrounding the battery cells (4) can be maximized in order to ensure effective cooling of the battery cells (4).

Description

Technical Field

[0001] The invention relates to an apparatus of the type according to the independent apparatus claim, a system of the type according to the independent system claim, and a method of the type according to the independent method claim. Background Art

[0002] Today's electric and hybrid vehicles operate with high-energy or high-power batteries. To achieve satisfactory power delivery and service life, the batteries must operate within a narrow temperature range. To achieve this, the battery system must be cooled accordingly using an effective cooling system. Liquid cooling solutions have proven particularly suitable in situations with high power requirements and / or high ambient temperatures. However, even such cooling systems have limitations under high loads and restrict the power capabilities of the battery system, as the system must be regularly throttled to prevent overheating. Summary of the Invention

[0003] According to a first aspect, the subject matter of the present invention is an apparatus having the features of the independent apparatus claim, a system having the features of the independent system claim, and a method having the features of the independent method claim. Further features and details of the invention are derived from the corresponding dependent claims, the description, and the drawings. Features and details described in conjunction with the apparatus according to the invention naturally also apply in conjunction with the system according to the invention and the method according to the invention, and vice versa, such that the disclosure of the various inventive aspects always refers to or can refer to one another.

[0004] The battery cell connector according to the invention, as claimed in the independent claim, is particularly useful for connecting battery cells in series. The advantage of the battery cell connector lies in its particularly effective cooling of the battery cells due to its design according to the invention, thereby enabling a high power capacity of the battery system while ensuring a long service life. Furthermore, the optimized cooling also achieves a high thermal reliability with very small temperature differences within the battery system. Furthermore, the design according to the invention allows for a particularly compact battery system design with reduced transition resistances.

[0005] The battery cell connector according to the invention can preferably be used in motor vehicles, in particular electric or hybrid vehicles. It is also conceivable to use it in trucks, cranes, forklifts, ships, aircraft or stationary systems.

[0006] The battery cell connector according to the invention for connecting battery cells in series comprises a first connecting element for establishing a connection to a first cell pole of a first battery cell and a second connecting element for establishing a connection to a second cell pole of a second battery cell. The connecting elements are designed according to the invention to correspond in shape with one another and can be connected in series in such a way that the contact surface surrounding the battery cells is maximized in order to ensure effective cooling of the battery cells.

[0007] The battery cell connector according to the present invention is preferably constructed in two parts and consists of a first and a second connecting element. The battery cell connector is advantageously designed for electrically connecting round cells and, in particular, can connect two cells arranged one above the other in series. To ensure a stable arrangement, the present battery cell connector is at least partially formed from a metallic material. To ensure the lowest possible loss in the electrical connection, the battery cell connector is preferably made at least partially from copper, at least partially from aluminum, or at least partially from iron. The first pole of the battery cell can preferably be the positive pole of the associated battery cell, while the second pole of the battery cell is correspondingly configured as the negative pole. At least the first and second poles are polarized differently, so that one of the two poles forms the positive pole and the other forms the negative pole. Within the scope of the present invention, a configuration corresponding in shape to one another is understood to mean that the shape of the first connecting element is at least partially complementary to that of the second connecting element, so that, for example, the shape of the first connecting element can be at least partially precisely adapted to fit within the shape of the second connecting element, or vice versa. The present connecting elements preferably have an at least partially cylindrical, conical, cuboid, spherical, or pyramidal shape and advantageously have a connecting region for connecting the connecting elements to one another and a fastening region for fastening the connecting elements to the poles of the battery cells. For easier connection of the connecting elements, the connecting regions of the connecting elements, in particular the connecting regions of the relevant connecting elements, can also, for example, be at least partially funnel-shaped and have an insertion bevel for easier insertion of a second connecting element of corresponding shape. Conversely, the fastening regions of the present connecting elements are preferably at least partially flattened or plate-shaped to ensure easier fastening of the connecting elements to the poles of the battery cells.

[0008] In order to ensure a stable, reliable, and long-lasting connection of the battery cells, the present invention can advantageously provide for recesses for the removal of gas. The recesses for the removal of gas can preferably be provided in the second connecting element and are preferably designed as holes or the like introduced laterally into the connecting element. Instead of laterally introduced holes, the connecting element can also have tab-like recesses of varying sizes, which are preferably regularly distributed along the connecting element. As an alternative to or in addition to the recesses arranged in the first connecting element, recesses can also be provided in the second connecting element.

[0009] With regard to a simple and stable connection of the battery cells, the invention can also provide that the connecting elements can be connected to one another in a force-locking manner, preferably with threads being provided for the force-locking connection. Within the scope of the force-locking connection between the connecting elements, a threaded connection can in particular be provided, wherein the second connecting element is preferably an internal thread and the first connecting element includes an at least partially corresponding external thread, and the connecting elements can thus be connected to one another in a simple manner in a force-locking manner via the threaded connection. It will be appreciated that it is also possible to provide an internal thread on the second connecting element and an external thread on the first connecting element.

[0010] Furthermore, for a simple and stable connection of the battery cells, it is also conceivable that the connecting elements can be connected to one another in a form-fitting manner, wherein preferably a plug connection for the form-fitting connection is provided. The plug connection can preferably be designed as a clamping connection, wherein in particular the second connecting element has a preferably centrally arranged recess for inserting the first connecting element, which can then be reversibly clamped within the second connecting element by means of a force acting in the connection direction. To apply the clamping force, the first and / or second connecting element can in particular be designed to be spring-elastic. Alternatively or additionally, small, protruding clamping elements, such as barbs or the like, can optionally be provided to hold the battery cells in a clamped manner. Furthermore, it goes without saying that as an alternative, the first connecting element can also have a recess for inserting the second connecting element, so that the second connecting element can then be reversibly clamped within the first connecting element.

[0011] Furthermore, within the scope of a secure and stable connection, provision can be made for the connecting element to be cohesively connected to the battery cell, wherein the connecting element can preferably be welded. The connecting element preferably has a fastening region, which is provided as a potential connection point for a cohesive connection to a battery cell pole. The fastening region is preferably designed to be easily accessible, in particular at least partially adapted to the shape of the battery pole, so that, for example, a cohesive connection can be easily established between the connecting element and the relevant battery pole. As an alternative to a welded cohesive connection, a cohesive connection by adhesive bonding or soldering is also conceivable.

[0012] Furthermore, the subject matter of the present invention is a battery system. The battery system comprises a plurality of battery cells, a plurality of the aforementioned battery cell connectors, and a cell holder for accommodating the battery cells. The present battery system is characterized in that the battery cells are arranged in the cell holder and connected to one another in series via the battery cell connectors in such a way that the contact surface surrounding the battery cells can be maximized in order to ensure effective cooling of the battery cells. As a result, the system has the same advantages as those already described in detail with respect to the battery cell connector according to the present invention. The cell holder provided in the present invention is preferably at least partially composed of a non-conductive material having a strength of at least less than 10 -5 S / cm, and in particular, is at least partially made of plastic. The cell holder can optionally also be made of a metallic material and provided with a corresponding plastic coating for insulation. In addition to the multiple battery cell connectors described above for connecting battery cells in series, a parallel connection can also be provided with additional connecting elements for connecting battery cells in parallel to increase the charging capacity of the battery system. The additional connecting elements can be in the form of tab-shaped connecting means or, in simple cases, cables. These additional connecting elements are preferably made at least partially of a metallic material, in particular, at least partially of copper, aluminum, or iron.

[0013] In order to make the battery system as efficient as possible, it can be advantageously provided that a cooling channel for cooling the battery cells is integrated into the current battery system, wherein the cooling channel is preferably arranged between the battery cell and the cell holder, and wherein the battery cell is arranged in particular inside the cell holder in such a way that the surface of the cooling channel can be maximized. The maximization of the contact surface surrounding the battery cell or the maximization of the surface of the cooling channel is based in particular on the special design and arrangement of the battery cell connector according to the invention, in such a way that, despite the stable fixing of the battery cell, only the smallest area of ​​the external contact surface of the battery cell is used as a connection surface. In this case, the maximum surface means the maximum surface for heat dissipation. For heat dissipation or as a heat transfer medium, in particular a heat transfer medium having a heat transfer capacity of less than 10 % under standard conditions is provided. -5 A liquid, advantageously non-conductive coolant with a specific conductivity of 1000 S / cm, such as, for example, distilled water, hydrofluoroether or a dielectric liquid.

[0014] Within the scope of effective cooling of the present battery system, it can also advantageously be provided that a sealing device is provided for sealing the cooling channel to the outside, wherein the sealing device is preferably arranged at least partially between the cell holder wall and the poles of the battery cell. The present sealing device can preferably be made of plastic, in particular rubber. In this case, the sealing device can be designed and pressed into the cell holder wall in such a way that the seal remains sealed under all operating conditions throughout the entire service life. In particular, additional fixing elements such as screws, rivets, or the like can be provided to press the seal against the cell holder wall.

[0015] With regard to the rapid retrofitting of current battery systems, in particular with regard to rapid filling and emptying, it can be advantageously provided according to the invention that the cell holder has an inlet and an outlet for introducing and removing the coolant. The inlet and outlet can preferably be designed in the form of holes and, in particular, be arranged between two battery cells and / or battery cell connectors arranged side by side.

[0016] Within the scope of a long-life, reliable, and scalable battery system, it is also conceivable to provide channels for gas discharge and electrical connection. The channel for gas discharge preferably extends at least partially through a recess advantageously provided within the connecting element and is arranged within the cell holder, so that additional connecting elements for connecting battery cells in parallel can also extend through the channel. In addition to the simple and flexibly accessible voltage tapping of the current battery system, taps for voltage tapping can also be provided, which are preferably integrally connected to the connecting element and, in particular, are arranged on the outside of the cell holder.

[0017] The present invention also relates to a method for producing a battery system. The method comprises the steps of establishing a first integrally bonded connection between a first connecting element and a first pole of a first battery cell, establishing a second integrally bonded connection between a second connecting element and a second pole of a second battery cell, and establishing a force-locking or form-locking connection between the first and second connecting elements for connecting the first and second battery cells in series. This method thus offers the same advantages as those already described in detail with respect to the battery cell connector and the system according to the invention. Of course, the individual steps of the method according to the invention can also be performed in a different order. In addition to the steps described, the method according to the invention can also include the step of inserting a battery cell connected to the existing battery cell connector in a force-locking or form-locking manner into a cell holder.

[0018] Furthermore, the present invention also relates to a motor vehicle comprising the aforementioned battery cell connector, in particular comprising the aforementioned battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further advantages, features and details of the present invention are apparent from the following description, in which exemplary embodiments of the present invention are described in detail with reference to the accompanying drawings. The features mentioned in the claims and the description may be essential to the invention individually or in any combination.

[0020] It shows:

[0021] Figure 1 A schematic diagram of a battery cell connector according to the invention for connecting battery cells in series is shown in cross-section according to a first embodiment.

[0022] Figure 2 A schematic diagram showing a battery cell connector according to the invention for connecting battery cells in series according to a second embodiment is shown in a sectional view,

[0023] Figure 3 A schematic diagram of a battery system according to the present invention is shown in a top view, which includes a plurality of battery cells, a plurality of battery cell connectors and a cell holder for accommodating the battery cells.

[0024] Figure 4 The cross-sectional view along the section line II shows Figure 3 A schematic diagram of a battery system according to the present invention is shown in FIG.

[0025] Figure 5 Show Figure 4 Another schematic diagram of a battery system according to the invention in FIG. 1 with a diagram of the gas distribution.

[0026] In the drawings, the same reference numerals are used for the same technical features. DETAILED DESCRIPTION

[0027] Figure 1 A schematic cross-sectional view shows a battery cell connector 2 according to the present invention for connecting battery cells 4 in series, according to a first embodiment. The battery cell connector 2 comprises a first connecting element 2a for establishing a connection to a first battery pole 6a of a first battery cell 4a and a second connecting element 2b for establishing a connection to a second battery pole 6b of a second battery cell 4b. The connecting elements 2a, 2b are configured to correspond in shape with one another and are connected in series to maximize the contact surface 8 surrounding the battery cells 4, thereby ensuring effective cooling of the battery cells 4. The connecting elements 2a and 2b of the two-part battery cell connector 2 are connected to one another in a force-locking manner. For this purpose, an external thread 12a is provided on the first connecting element 2a, and a corresponding internal thread 12b is provided on the second connecting element 2b. This allows for a simple and stable connection of the battery cells 4a and 4b via a simple screw connection.

[0028] A recess 10 for gas drainage is also provided in the second connecting element 2b. The recess 10 serves, in particular, to drain battery gases generated during operation of the battery system 1 and to ensure a stable and reliable, particularly long-lasting, connection of the battery cells 4. The recess 10 for degassing can preferably be formed in the form of a hole introduced laterally into the connecting element 2b. Instead of a laterally introduced hole, the connecting element 2b can also have web-shaped recesses of varying sizes, which are preferably regularly distributed along the connecting element 2b. As an alternative to or in addition to the recess 10 arranged in the second connecting element 2b, a recess can also be arranged in the first connecting element 2a. The connecting elements 2a, 2b are currently connected to the battery cells 4 in a material-locked manner at the fixing region 3. Within the scope of the material-locked connection, the connecting elements 2a, 2b can, in particular, be welded to the battery cells 4. The fixing region 3 is preferably designed to be easily accessible and, in particular, at least partially adapted to the shape of the battery poles 6a, 6b, so that a material-locking connection can be easily established between the connecting elements 2a, 2b and the associated battery poles 6a, 6b. As an alternative to a welded material-locking connection, an adhesive or soldered material-locking connection is also conceivable.

[0029] Figure 2A schematic cross-sectional view shows a battery cell connector 2 according to the invention for connecting battery cells 4 in series according to a second embodiment. According to this second embodiment, the connecting elements 2a, 2b are connected to each other not in a force-locking but in a form-locking manner via a plug-in connection 14. The plug-in connection 14 is designed in the present case as a clamping connection, wherein the second connecting element 2b has a centrally arranged recess for inserting the first connecting element 2a. The first connecting element 2a is then reversibly clamped within the second connecting element 2b by means of a force acting in the connection direction. Optionally, small protruding clamping elements (not shown here) such as barbs or the like can also be provided to hold the battery cells 4 in the clamped position. It goes without saying that, as an alternative, the first connecting element 2a can also have a recess for inserting the second connecting element 2b, so that the second connecting element 2b can then be reversibly clamped within the first connecting element 2a.

[0030] Figure 3 A schematic diagram of a battery system 1 according to the invention is shown in a top view, comprising a plurality of battery cells 4, a plurality of battery cell connectors 2, and a cell holder 16 for accommodating the battery cells 4. In the top view shown here, only the fixing elements 32 arranged above the battery cells 4 on the top side of the present cell holder 16 can be seen, which are directly attached to the battery cell connectors 2 according to the invention. Furthermore, the inlet 24a for introducing a coolant can be seen here.

[0031] Figure 4 The cross-sectional view along the section line II shows Figure 3Schematic diagram of the battery system 1 according to the present invention in FIG. According to the cross-sectional view shown, two first and second battery cells 4a, 4b, connected in series, are arranged within a cell holder 16. The series connection of the battery cells 4 is achieved via the cell connector 2 according to the present invention. The battery cells 4 are connected in series with the aid of the cell connector 2 in such a way that the contact surface 8 surrounding the battery cells 4 is maximized to ensure effective cooling of the battery cells 4. The cell holder 16 for accommodating the battery cells 4 is preferably made of plastic and has cooling channels 18 for cooling the battery cells 4. The cooling channels 18 are preferably arranged between the battery cells 4 and the cell holder wall 20. For heat dissipation or as a heat transfer medium, a liquid, advantageously non-conductive coolant such as distilled water, hydrofluoroether, or a dielectric liquid can be introduced into the channels 18. To seal the channels 18 from the outside, a sealing means 22 is provided, which is at least partially arranged between the cell holder 16 and the poles 6a, 6b of the battery cells 4. The sealing element 22 can preferably be formed from plastic, in particular rubber or the like. The sealing element 22 can be designed and adapted to the cell holder so that the seal 22 remains sealed under all operating conditions, preferably throughout the entire service life of the battery system 1. In the present case, a fixing element 30 in the form of a screw is provided to adapt the sealing element 22. In addition to a plurality of battery cell connectors 2 according to the present invention for connecting battery cells 4 in series, a parallel connection using additional connecting elements 28 is also provided to increase the charging capacity of the battery system 1. In addition to the connections designed in the present case in the form of tabs, such connections can also be designed in the form of cables or the like in the simplest case. For the introduction and removal of coolant, the cell holder 16 further comprises inlet and outlet openings 24a, 24b, through which the corresponding coolant can be introduced into and removed from the cell holder. The inlet and outlet openings 24a, 24b can preferably be designed in the form of holes or the like and, in particular, each be arranged between two battery cells 4 and / or battery cell connectors 2 arranged side by side.

[0032] Figure 5 Show Figure 4 , with an illustration of a gas distribution path 34. The battery gases formed during operation of the present battery system 1 can be discharged to the outside via the channels 26, which are arranged in the cell holder 16, for gas discharge and electrical connection. This ensures a stable, reliable, and long-lasting connection of the battery cells 4. The channels 26 for gas discharge preferably extend at least partially through the recesses 10 provided within the connecting element 2. The arrangement of the channels 26 also makes it possible to connect the battery cells 4 in parallel by introducing connecting means 28.

[0033] The battery cell connector 2 according to the invention, the battery system 1 according to the invention, and the method according to the invention for producing the present battery system 1 make it possible, in particular, to operate the liquid cooling device particularly efficiently, thereby enabling a high performance capacity of the correspondingly cooled battery system while ensuring a long service life. Furthermore, the optimized cooling also achieves a high thermal reliability with very small temperature differences within the battery system. Furthermore, the structure according to the invention allows for a particularly compact battery system design with reduced transition resistances.

Claims

1. A battery system (1), comprising: - a plurality of battery cells (4), - a plurality of battery cell connectors (2), - a cell support (16) for accommodating the battery cell (4), It is characterized by: The battery cells (4) are arranged within the cell holder (16) and connected in series with one another via the cell connectors (2) in such a way that the contact surface (8) surrounding the battery cells (4) can be maximized in order to ensure effective cooling of the battery cells (4). A cooling channel (18) is provided for cooling the battery cell (4), wherein the cooling channel (18) is arranged between the battery cell (4) and a cell holder wall (20), and wherein the battery cell (4) is arranged in the cell holder (16) in such a way that the surface of the cooling channel (18) can be maximized. The battery cell connector (2) for connecting battery cells (4) in series comprises: a first connecting element for establishing a connection to a first battery pole of a first battery cell (4a), a second connecting element for establishing a connection to a second battery pole of a second battery cell (4b), in, The first and second connecting elements are designed to correspond in shape with respect to one another and can be connected in series in such a way that the contact surface (8) surrounding the battery cell (4) can be maximized in order to ensure effective cooling of the battery cell (4). A recess (10) for gas discharge is provided, which is in the form of a hole opened laterally into the first connecting element and / or the second connecting element.

2. The battery system (1) according to claim 1, It is characterized by: The first and second connecting elements can be connected to each other in a non-positive manner, wherein a thread (12) is provided for the non-positive connection.

3. The battery system (1) according to claim 1, It is characterized by: The first and second connecting elements can be connected to one another in a form-fitting manner, wherein a plug connection (14) is provided for the form-fitting connection.

4. The battery system (1) according to claim 1, It is characterized by: The first and second connecting elements can be connected to the battery cell (4) in a material-locking manner, wherein the first and second connecting elements can be welded.

5. The battery system (1) according to claim 1, It is characterized by: Sealing means (22) are provided for sealing the cooling channel (18) toward the outside, wherein the sealing means (22) are at least partially arranged between the cell holder wall (20) and the poles of the battery cell (4).

6. The battery system (1) according to claim 1, It is characterized by: The cell support (16) has an inlet and an outlet (24a, 24b) for introducing and leading out a coolant.

7. The battery system (1) according to any one of claims 1 to 6, It is characterized by: A channel (26) is provided for gas extraction and electrical connection.

8. A method for producing a battery system (1) according to any one of claims 1 to 7, comprising the following steps: - establishing a first integrally bonded connection between the first connecting element and the first pole of the first battery cell (4a), - establishing a second integrally bonded connection between the second connecting element and the second pole of the second battery cell (4b), - a force-locking or form-locking connection is produced between the first connecting element and the second connecting element in order to connect the first battery cell (4a) and the second battery cell (4b) in series.

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