Battery cell

Abstract

Battery cell (1) with: a cell casing (3), and a cell terminal, preferably an external contact element (11), characterized by that at least one thermal conductor is arranged between the cell terminal, preferably the outer contact element (11), and the cell housing (3), and that preferably the outer contact element (11) is connected to the cell housing (3) via the thermal conductor in a thermally conductive and preferably electrically insulating manner.

Description

[0001] The invention relates to a battery cell according to the preamble of claim 1.

[0002] A typical battery cell heats up during charging and discharging, primarily in the area of ​​the cell core. However, particularly under higher current loads and due to ohmic losses in the cell terminal, the cell terminal can also heat up significantly, in some cases even more than the core. Since the cell terminal is thermally connected to the core, heat can be transferred from the terminal to the core. This causes the area near the core—as well as the cell terminal—to heat up considerably, creating a so-called hot spot. This hot spot increases the charging time required to fully charge the battery cell. The disadvantage of this hot spot is that it reduces the battery cell's charging performance.

[0003] A cell module is known from DE 10 2016 223 063 A1. DE 10 2023 123 073 A1 discloses a cylindrical cell and a module of cylindrical cells. WO 2023 / 209 247 A2 discloses an energy storage cell and a manufacturing process. DE 10 2021 126 133 A1 discloses a motor vehicle and a battery with a cooling element. An electrical storage device and an electrical storage unit are known from DE 20 2012 013 288 U1. DE 10 2015 217 790 B4 discloses an arrangement for cooling battery cells of a drive energy storage system of a motor vehicle. A termination structure of an electric battery is known from DE 10 2017 116 891 A1. WO 2024 / 046 982 A1 discloses an energy storage cell and a method for manufacturing such an energy storage cell.

[0004] One object of the invention is to provide a battery cell that has a higher charging performance compared to a known battery cell.

[0005] This problem is solved by the features of the independent claim. Preferred embodiments of the invention are disclosed in the dependent claims.

[0006] The invention proposes a battery cell comprising a cell housing and a cell terminal, preferably an external contact element. According to the invention, at least one thermal conductor is arranged between the cell terminal, preferably the external contact element, and the cell housing. Preferably, the external contact element is connected to the cell housing via the thermal conductor in a thermally conductive and, more preferably, electrically insulating manner. This has the advantage that heat is transferred from the cell terminal, preferably the external contact element, to the cell housing via the thermal conductor. This prevents the formation of a hot spot in the terminal-adjacent region of the battery cell's core. Consequently, the charging performance of the battery cell is increased in a structurally simple manner.The heat is then transferred from the cell casing to cooling plates of a cooling system for the battery cell, with the cooling plates being in thermally conductive contact with the cell casing.

[0007] To obtain a battery cell that is easy to manufacture, it can be provided, for example, that the external contact element and / or an insulating element of the battery cell is part and / or parts of a cell terminal of the battery cell, and / or that the external contact element is connected to the cell core of the battery cell, preferably an electrode of the battery cell, preferably the cell core, via a connecting element, preferably a connecting bolt, preferably electrically.

[0008] To reliably protect a cell core of the battery cell, preferably electrodes of the cell core, from mechanical influences, it can preferably be provided that the cell housing defines an interior space to the outside, wherein it is preferably provided that the cell core, preferably one or more electrodes of the battery cell, is arranged in the interior space.

[0009] To ensure reliable electrical insulation, simplified assembly of the battery cell, and to prevent electric current from flowing between the cell housing and the insulating element, an exemplary embodiment may provide that the battery cell has an insulating element, and that the insulating element, preferably for insulation against electric current flow, is arranged between the cell housing and the outer contact element, and that the insulating element is assigned a first penetration and / or a second penetration.

[0010] To improve the mechanical stability of the insulating element, it is preferable that the first opening and / or the second opening is / are each bounded externally by the insulating element. By way of example, it is possible that the first opening and / or the second opening each have the geometry of a circular cylinder or a cuboid.

[0011] To ensure that the cell terminal takes up as little installation space as possible, it can be provided, for example, that the insulating element is essentially U-shaped in cross-section, and / or that the insulating element is essentially trough-shaped.

[0012] In order to enable a defined heat transfer between the outer contact element and the cell housing in a structurally simple manner, a specific embodiment may provide that the thermal conductivity is formed at least partially by a first breakthrough thermal conductivity material and / or by a second breakthrough thermal conductivity material, wherein the first breakthrough thermal conductivity material is arranged in the first breakthrough, and / or wherein the second breakthrough thermal conductivity material is arranged in the second breakthrough.

[0013] For the most effective and efficient heat transfer possible, in an exemplary embodiment it can be provided that the outer contact element is preferably directly in contact with and / or, preferably directly, thermally conductive and / or, preferably directly, electrically insulating with the first breakthrough heat conductor and / or the second breakthrough heat conductor, and / or that the cell housing, preferably a cover of the cell housing, is preferably directly in contact with and / or, preferably directly, thermally conductive and / or, preferably directly, electrically insulating with the first breakthrough heat conductor and / or the second breakthrough heat conductor.

[0014] In order to make it easy to integrate the battery cell into a cell stack or into a group of battery cells, an exemplary embodiment may provide that the battery cell has a cell connector, wherein the cell connector is preferably directly electrically connected to the cell terminal, preferably the external contact element, and / or wherein the cell connector is preferably directly electrically connected to a connecting element of the battery cell.

[0015] In order to enable not only heat transfer between the cell terminal and the cell housing, but also, in a structurally simple manner, additional or alternative heat transfer from the cell connector to the cell housing, a specific embodiment may provide that the thermal conductivity is formed at least partially by a first connector thermal conductivity and / or by a second connector thermal conductivity, wherein the first connector thermal conductivity and / or the second connector thermal conductivity is arranged between the cell connector and the cell housing, preferably a cover of the cell housing, and wherein it is preferably provided that the cell connector is connected to the cell housing, preferably a cover of the cell housing, via the first connector thermal conductivity and / or the second connector thermal conductivity in a heat-transferring and preferably electrically insulating manner.

[0016] To make the cell connector particularly easy to manufacture, a preferred embodiment may provide that the cell connector has a base section as well as a first leg and / or a second leg, wherein it is preferably provided that the base section lies flat against the outer contact element, and / or wherein it is preferably provided that the first leg and / or the second leg projects from the base section, preferably at right angles to a longitudinal axis of the connecting element of the battery cell, in the direction of the cell housing, preferably a cover of the cell housing.

[0017] In order to achieve a particularly simple method of heat transfer from the cell connector to the cell housing, an exemplary embodiment may provide that the first leg has a front surface facing the cell housing, preferably a lid of the cell housing, and that the first connector heat conductor is arranged between the front surface of the first leg and the cell housing, preferably a lid of the cell housing, and / or that the second leg has a front surface facing the cell housing, preferably a lid of the cell housing, and that the second connector heat conductor is arranged between the front surface of the second leg and the cell housing, preferably a lid of the cell housing.

[0018] To reliably prevent the connector heat conductors from slipping relative to the cell connector, an exemplary embodiment may provide that a first collar of the first leg adjoins the front surface of the first leg in the direction of the cell housing, preferably a lid of the cell housing, wherein an inner surface of the first collar of the first leg, together with the front surface of the first leg, defines a first receiving pocket to the outside in which the first connector heat conductor is at least partially arranged, and / or that a second collar of the second leg adjoins the front surface of the second leg in the direction of the cell housing, preferably a lid of the cell housing, wherein an inner surface of the second collar of the second leg, together with the front surface of the second leg, defines a second receiving pocket to the outside.in which the second connector thermal conductor is at least partially arranged.

[0019] In order to achieve a particularly effective and efficient heat transfer at low cost, a specific embodiment may provide that the thermal conductivity is formed by a thermally conductive mat and / or by a thermally conductive paste, preferably curable and / or cured, and / or that the first breakthrough thermal conductivity and / or the second breakthrough thermal conductivity and / or the first connector thermal conductivity and / or the second connector thermal conductivity, preferably each, is formed by a thermally conductive mat and / or by a thermally conductive paste, preferably curable and / or cured.

[0020] The following are descriptions of embodiments of the invention with reference to the accompanying figures.

[0021] They show: Fig. 1 in a side section view a section of a battery cell, wherein an outer contact element of the battery cell is thermally connected to a cell housing of the battery cell via breakdown thermal conductors; Fig. 2 in a side section view according to the Fig. 1 the battery cell, wherein a cell connector of the battery cell is additionally connected to a cell housing of the battery cell via a thermally conductive connector thermal conductor; Fig. 3. In a perspective view, the battery cell according to the Fig. 2, and Fig. 4 in a perspective view one half of the cell connector.

[0022] In the Fig. Figure 1 shows a battery cell 1 for a traction battery of a battery-electric vehicle (not shown). The battery cell 1 has a cell housing 3 with a cover 5 that rests against the housing walls of the cell housing 3. The cell housing 3 defines an interior space. Additionally, the battery cell 1 has a cell core 7, which is at least partially formed by electrodes (not shown) of the battery cell 1. The cell core 7 is located within the interior space of the housing.

[0023] Furthermore, battery cell 1 has a cell terminal. The cell terminal has an external contact element 11, which, for illustrative purposes only, has a plate-shaped geometry. The external contact element 11 is electrically, mechanically, and thermally connected to the cell core 7 via a connecting element 13. The connecting element 13 is, for illustrative purposes only, formed by a connecting bolt.

[0024] Between the outer contact element 11 and the cover 5, a trough-shaped insulating element 15 is arranged (here shown only as an example). The insulating element 15 is designed and / or suitable to prevent any electric current from flowing between the outer contact element 11 and the cover 5. The insulating element 15 has a first opening 21 and a second opening 23, each of which is completely enclosed by the insulating element 15.

[0025] In general, a thermal conductor is arranged between the cell terminal, specifically the outer contact element 11, and the cell housing 3, specifically the cover 5, whereby the outer contact element 11 is thermally conductive and electrically insulatingly connected to the cover 5 via the thermal conductor. Heat is thus transferred directly from the outer contact element 11 to the cover 5 via the thermal conductor.

[0026] During the Fig. 1 and Fig. In the embodiment of battery cell 1 shown in Figure 2, the thermal conductor is formed partly by a first through-hole thermal conductor 31 and partly by a second through-hole thermal conductor 33. The first through-hole thermal conductor 31 is arranged in the first through-hole 21 and has direct contact with both the outer contact element 11 and the cover 5. The second through-hole thermal conductor 33 is arranged in the second through-hole 23 and has direct contact with both the outer contact element 11 and the cover 5.

[0027] As this is shown in the Fig. As shown in Figure 2, the battery cell 1 additionally has a cell connector 41, which is essentially C-shaped. The cell connector 41 has a base section 42, a first leg 43, and a second leg 45. The first leg 43 and the second leg 45 each project at right angles from the base section 42 towards the cover 5. The cell connector 41 rests with its base section 42 flat against the outer contact element 11 and is, here only by way of example, directly electrically connected to the cell terminal, specifically the outer contact element 11. Furthermore, the cell connector 41 is, here only by way of example, directly electrically connected to the connecting element 13.

[0028] The thermal interface material is formed partly by a first connector thermal interface material 47 and partly by a second connector thermal interface material 49. The first connector thermal interface material 47 is arranged between the cell connector 41, specifically the first leg 43, or more specifically, a front surface of the first leg 43, and the cover 5. The first leg 43, specifically the front surface of the first leg 43, is directly thermally and electrically insulated from the first connector thermal interface material 47, and the first connector thermal interface material 47 is directly thermally and electrically insulated from the cover 5. The second connector thermal interface material 49 is arranged between the cell connector 41, specifically the second leg 45, or more specifically, a front surface of the second leg 45, and the cover 5.The second leg 45, specifically the front surface of the second leg 45, is directly thermally conductive and electrically insulating connected to the second connector thermal conductor 49, and the second connector thermal conductor 49 is directly thermally conductive and electrically insulating connected to the cover 5.

[0029] As is particularly evident in the Fig. 2, is attached to the front surface of the first leg 43 in the direction of the cover 5, a - especially in the Fig. 4. The first collar 51 of the first leg 43 is visible. An inner surface of the first collar 51 of the first leg 43, together with the front surface of the first leg 43, defines a first receiving pocket on the outside, in which the first connector heat conductor 47 is at least partially arranged. A second collar 53 of the second leg 45 adjoins the front surface of the second leg 45 in the direction of the cover 5. An inner surface of the second collar 53 of the second leg 45, together with the front surface of the second leg 45, defines a second receiving pocket on the outside, in which the second connector heat conductor 49 is at least partially arranged.

[0030] In the Fig. Figure 3 also shows a section of battery cell 1, specifically in a perspective view. Visible in the Fig.4 among others the cell connector 41, the insulating element 15, the lid 5 as well as the first connector thermal conductor 47 and the second connector thermal conductor 49.

[0031] It is hereby expressly pointed out that in this or another embodiment of the battery cell 1, the outer contact element 11 is thermally connected to the cover 5, for example, only via one or both of the penetration heat conductors 31 and 33, or, preferably with the cell connector 41 interposed, only via one or both of the connector heat conductors 47 and 49. Furthermore, it is also conceivable that in this or another embodiment of the battery cell 1, the outer contact element 11 is thermally connected to the cover 5, for example, only via one of the penetration heat conductors 31 or 33 and only via one of the connector heat conductors 47 or 49.

[0032] In battery cell 1, the first breakthrough thermal conductor 31 and the second breakthrough thermal conductor 33, as well as the first connector thermal conductor 47 and the second connector thermal conductor 49, are each formed by a thermally conductive mat. However, in this or another embodiment of battery cell 1, the first breakthrough thermal conductor 31 and / or the second breakthrough thermal conductor 33 and / or the first connector thermal conductor 47 and / or the second connector thermal conductor 49, preferably each, can be formed by a thermally conductive mat and / or by a thermally conductive paste, preferably curable and / or cured, and / or by a thermally conductive adhesive, preferably curable and / or cured. Reference symbol list 1 battery cell 3 cell casings 5 lids 7 Cell nucleus 11 External contact element 13 Connecting element 15 insulating element 21 first breakthrough 23 second breakthrough 31 first breakthrough thermal conductor 33 second breakthrough thermal conductor 41 cell connectors 42 Basic section 43 first thigh 45 second thigh 47 first connector thermal conductor 49 second connector thermal conductor 51 first collar 53 second collar

Claims

[1] Battery cell (1) with: a cell casing (3), and a cell terminal, preferably an external contact element (11), characterized by , that at least one thermal conductor is arranged between the cell terminal, preferably the outer contact element (11), and the cell housing (3), and that preferably the outer contact element (11) is connected to the cell housing (3) via the thermal conductor in a thermally conductive and preferably electrically insulating manner. [2] Battery cell (1) according to claim 1, characterized by , that the battery cell (1) has an insulating element (15), and that the insulating element (15), preferably for insulation against electric current flow, is arranged between the cell housing (3) and the outer contact element (11), and that the insulating element (15) is associated with a first opening (21) and / or a second opening (23). [3] Battery cell (1) according to claim 2, characterized by, that the thermal conductor is formed at least partially by a first penetration thermal conductor (31) and / or by a second penetration thermal conductor (33), wherein the first penetration thermal conductor (31) is arranged in the first penetration (21), and / or wherein the second penetration thermal conductor (33) is arranged in the second breakthrough (23) is arranged. [4] Battery cell (1) according to claim 3, characterized by, that the outer contact element (11) is preferably directly in contact with and / or, preferably directly, thermally conductive and / or, preferably directly, electrically insulating with the first breakthrough thermal conductor (31) and / or the second breakthrough thermal conductor (33), and / or that the cell housing (3), preferably a cover (5) of the cell housing (3), is preferably directly in contact with and / or, preferably directly, thermally conductive and / or, preferably directly, electrically insulating with the first breakthrough thermal conductor (31) and / or the second breakthrough thermal conductor (33). [5] Battery cell (1) according to any one of the preceding claims, characterized by, that the battery cell (1) has a cell connector (41), wherein the cell connector (41) is preferably directly, electrically connected to the cell terminal, preferably to the outer contact element (11), and / or wherein the cell connector (41) is preferably directly, electrically connected to a connecting element (13) of the battery cell (1). [6] Battery cell (1) according to claim 5, characterized by, that the thermal conductivity is formed at least partially by a first connector thermal conductivity (47) and / or by a second connector thermal conductivity (49), wherein it is provided that the first connector thermal conductivity (47) and / or the second connector thermal conductivity (49) is arranged between the cell connector (41) and the cell housing (3), preferably a cover (5) of the cell housing (3), wherein it is preferably provided that the cell connector (41) is connected to the cell housing (3), preferably a cover (5) of the cell housing (3), via the first connector thermal conductivity (47) and / or via the second connector thermal conductivity (49) in a heat-transferring and preferably electrically insulating manner. [7] Battery cell (1) according to claim 5 or 6, characterized by, that the cell connector (41) has a base section (42) as well as a first leg (43) and / or a second leg (45), wherein it is preferably provided that the base section (42) lies flat against the outer contact element (11), and / or wherein it is preferably provided that the first leg (43) and / or the second leg (45) extends and / or projects from the base section (42), preferably perpendicular to a longitudinal axis of the connecting element (13) of the battery cell (1), in the direction of the cell housing (3), preferably a cover (5) of the cell housing (3). [8] Battery cell (1) according to claim 7, characterized by, that the first leg (43) has a front surface facing the cell housing (3), preferably a lid (5) of the cell housing (3), and that the first connector heat conductor (47) is arranged between the front surface of the first leg (43) and the cell housing (3), preferably a lid (5) of the cell housing (3), and / or that the second leg (45) has a front surface facing the cell housing (3), preferably a lid (5) of the cell housing (3), and that the second connector heat conductor (49) is arranged between the front surface of the second leg (45) and the cell housing (3), preferably a lid (5) of the cell housing (3). [9] Battery cell (1) according to claim 8, characterized by, that a first collar (51) of the first leg (43) adjoins the front surface of the first leg (43) in the direction of the cell housing (3), preferably a lid (5) of the cell housing (3), wherein it is provided that an inner surface of the first collar (51) of the first leg (43), together with the front surface of the first leg (43), defines a first receiving pocket to the outside in which the first connector thermal conductor (47) is at least partially arranged, and / or that a second collar (53) of the second leg (45) adjoins the front surface of the second leg (45) in the direction of the cell housing (3), preferably a lid (5) of the cell housing (3), wherein it is provided that an inner surface of the second collar (53) of the second leg (45), together with the front surface of the second leg (45), defines a second receiving pocket to the outside in which the second Connector thermal conductor (49) is at least partially arranged. [10] Battery cell (1) according to any of the preceding claims, characterized by , that the thermal conductor is formed by a thermal conducting mat and / or by a thermally conductive paste, preferably curable and / or cured, and / or the first breakthrough thermal conductor (31) and / or the second breakthrough thermal conductor (33) and / or the first connector thermal conductor (47) and / or the second connector thermal conductor (49), preferably each, is formed by a thermally conductive mat and / or by a thermally conductive paste, preferably curable and / or cured.

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