Connection assembly of a battery cell, and battery cell

Abstract

A connection assembly (3) of a battery cell (1) for electrically connecting the battery cell (1) to a circuit comprises a contacting region (11), which is intended for electrically connecting a current collector (7) of the battery cell (1) to the connection assembly (3), and an absorption element (10), which is intended for absorbing a load acting on an electrode stack (6) via the connection assembly (3), the absorption element (10) being designed to distribute the load over the surface of the absorption element (10) and / or deform in order to absorb mechanical energy.

Description

[0001] Description

[0002] Connection arrangement of a battery cell and battery cell

[0003] The present invention relates to a connection arrangement of a battery cell and to a battery cell with a connection arrangement.

[0004] Battery cells, especially lithium-ion battery cells, are increasingly used in various applications such as electric vehicles, portable electronic devices, and stationary energy storage systems. A key challenge in battery cell design is ensuring a reliable and efficient electrical connection between the battery cell and the circuit, for example, via the battery cell terminals, as well as guaranteeing reliable mechanical stability of the battery cell and its individual components.

[0005] From DE 102021 122 009 A1, a battery cell comprising a housing with a first terminal and a second terminal, and an electrode stack arranged in the housing consisting of stacked anodes, cathodes, and separators arranged alternately, is known. Each anode is electrically connected to the first terminal via first terminals, and each cathode is electrically connected to the second terminal via second terminals. The electrodes, i.e., the anodes and cathodes, can be connected to a circuit located outside the housing via the terminals.

[0006] US Patent 5,773,164 A discloses a U-shaped connection arrangement to which drain tabs can be contacted.

[0007] The object of the present invention is to provide an improved connection arrangement of a battery cell and an improved battery cell.

[0008] This problem is solved by the connection arrangement according to claim 1 and the battery cell according to claim 11.

[0009] Further advantageous embodiments of the invention will become apparent from the dependent claims and the following description of preferred embodiments of the present invention. It has been recognized that a battery cell can be subjected to external stresses, for example, impacts. Furthermore, it has been recognized that a connection arrangement with a contact area can be advantageous for the electrical connection of the conductor tabs to the terminal (connection arrangement).

[0010] An inventive connection arrangement of a battery cell for electrically connecting the battery cell to a circuit therefore comprises a contact area for electrically connecting a current collector of the battery cell to the connection arrangement, and an absorption element for receiving a load acting on an electrode stack via the connection arrangement, wherein the absorption element is designed in such a way that it distributes the load over the entire surface of the absorption element and thus contributes to avoiding local loads on the electrode stack and / or deforms in order to absorb mechanical energy, for example impact energy.

[0011] Thus, the connection arrangement can be electrically connected to the active material of the battery cell via the contact area, and at the same time, the connection arrangement can withstand external stresses via the absorption element without penetrating the electrode stack of the battery cell, thereby preventing damage to the electrode stack.

[0012] Accordingly, the connection arrangement according to the invention is both mechanically robust and contact-optimized, and therefore electrically efficient. Due to the contact optimization described above, the proportion of non-active material, such as the contact tabs that electrically connect the electrodes and terminals, can be reduced, since the contact tabs can be shorter. This maximizes the space available for active material and allows for a higher energy density. Consequently, the performance and storage capacity of the battery cell are improved while simultaneously ensuring mechanical stability. This is also relevant, for example, in the case of a double stack, since, despite the larger size of the battery cell, short contact tabs can be attached to the contact area without the need for additional, costly, or complex extensions.

[0013] A battery cell, for example a lithium-ion battery cell, can be a prismatic battery cell. A prismatic battery cell comprises a rigid casing in which a stack of electrodes is arranged. Alternatively, the battery cell can also be designed as a pouch cell with a flexible casing or as a cylindrical cell, also called a round cell.

[0014] A battery cell comprises electrodes made of active material, at least an anode and a cathode, and a separator may be positioned between the electrodes. The separator prevents direct contact between the electrodes while simultaneously allowing ion flow within the cell.

[0015] The electrodes can be configured as an electrode stack, with stacked anodes, cathodes, and separators arranged alternately. The electrode stack can be configured as a jelly roll or a jelly stack. The electrode stack can then be sealed in a casing, such as a housing, which protects the battery cell from external influences and ensures its structural integrity.

[0016] The battery cell can comprise one (single stack) or several, for example two (double stack), electrode stacks.

[0017] The anodes and cathodes in the electrode stack can be connected to the terminal assembly via one or more current collectors. For example, a current collector can be configured as a series of terminals. A single current collector can also group several terminals together. Each anode and each cathode can be connected to the terminal assembly via terminals. Furthermore, each anode can be electrically connected to a first terminal via a series of terminals, and each cathode can be electrically connected to a second terminal via a series of terminals.

[0018] The connection arrangement can therefore include the first and / or second connection. Alternatively, each connection can be designed as a separate connection arrangement.

[0019] The current collector or the current-discharge tabs can be connected to the terminal assembly at the contact area. The terminal assembly can comprise multiple contact areas, for example, two contact areas. Multiple contact areas can include one contact area for the current collector or current-discharge tabs of the anode(s) and one contact area for the current collector or current-discharge tabs of the cathode(s). Alternatively, multiple contact areas can be provided for the current collectors or current-discharge tabs of the anode(s) or cathode(s) of one or more electrode stacks, with, for example, the current collector or all current-discharge tabs of one electrode type (anode or cathode) of an electrode stack contacting at the same contact area.

[0020] For example, in the case of a double stack, two contact areas are provided, and all the anode tabs of the first electrode stack contact the first contact area, and all the anode tabs of the second electrode stack contact the second contact area. A corresponding arrangement can also be provided for the cathode.

[0021] The current collector can be welded to the contact area, e.g., by ultrasonic welding, laser beam welding, cold welding, or resistance welding, or it can be electrically attached by crimping, gluing, soldering, etc. For example, the contact area can be designed as a single weld point or a weld area with multiple weld points.

[0022] The contact area can include metal, such as copper or aluminum, to ensure electrical conductivity.

[0023] The connection assembly is electrically connected to the current collector and can also electrically connect the battery cell to a circuit. The absorption element can absorb a load acting on the electrode stack via the connection assembly.

[0024] A load can be an external force, such as an impact load or a pressure load, which can lead to intrusion into the battery cell and / or deformation of the battery cell.

[0025] However, the absorption element is designed in such a way that it distributes the load over the entire surface of the absorption element and / or deforms in order to absorb mechanical energy, for example impact energy.

[0026] Even though the connection assembly is positioned between the load and the electrode stack, the acting load is absorbed or evenly distributed by the absorption element, for example by distributing the load over a surface area and / or deforming before it is transferred to the electrode stack. This prevents the connection assembly or parts of it from shifting towards the electrode stack and thus preventing damage to the electrode stack.

[0027] The load transfer between the connection arrangement and the electrode stack can therefore be influenced in such a way as to avoid point stresses or local overloads on the electrode stack, for example by having a flat surface on the absorption element so that the load is transferred evenly to the electrode stack over a flat area.

[0028] The absorption element can therefore be formed as a flat surface on a side facing the electrode stack.

[0029] Alternatively or additionally, the load transfer can also be influenced by a deformation property of the absorption element. For example, the absorption element can be designed to deform under a pressure load or an impact load, thereby absorbing the energy emanating from the load, such as impact energy, before it is transferred to the electrode stack.

[0030] Consequently, energy emanating from the external load and transferred to the connection arrangement can be absorbed, at least partially, by the absorption element, whereby the energy emanating from the load can, for example, be transferred into deformation energy of the absorption element, and / or be distributed over a surface.

[0031] The connection arrangement according to the invention offers several advantages. The even distribution of the load across the absorption element ensures a uniform load on the electrode stack, which increases mechanical stability. Furthermore, the absorption element's ability to deform and absorb mechanical energy, such as impact energy, provides improved protection for the battery cell against mechanical shocks and vibrations. This contributes to extending the battery cell's service life and increasing operational reliability.

[0032] The absorption element can comprise a hollow profile with an open (e.g., C-profile or U-profile, etc.) or closed cross-section (e.g., a tube, such as a square tube, rectangular tube, round tube, oval tube, etc.). The hollow profile can be designed as a hollow body with at least one closed end. The absorption element can also comprise multiple hollow profiles.

[0033] The hollow profile can contain webs, creating multiple cavities. This hollow profile can also serve as a gas channel for venting gas within the battery cell. Gas can accumulate inside the battery cell due to overcharging, thermal runaway, mechanical damage to the separator (leading to a short circuit), or aging. Typically, the battery cell incorporates a pressure relief valve as a safety mechanism, allowing gas to escape in a controlled manner and preventing the cell from bursting or exploding.

[0034] The hollow profile as a gas channel enables a more efficient flow of gas inside the battery cell to the pressure relief valve, thereby ensuring safe pressure relief, whereby in the case of multiple cavities, multiple gas channels can also be formed.

[0035] The absorption element can comprise a U-shaped component. For example, it can comprise two U-shaped components. The two U-shaped components can be arranged so that their open sides face each other and the legs touch or rest against each other, for example, nested so that the arms of the U-profiles interlock. This creates a solid connection that increases the stability of the overall structure and enables even load distribution. This configuration is particularly useful for preventing displacement of the absorption element and mechanically stabilizing the connection.

[0036] The absorption element can be made from an extruded or pressed profile.

[0037] The contact area can be arranged on the absorption element. For example, several contact areas, such as two contact areas, can be arranged on the absorption element. These contact areas can be configured as described above.

[0038] The absorption element can be electrically conductive, for example, if the contact area is located on the absorption element. Thus, the absorption element can comprise metal, such as copper or aluminum.

[0039] The absorption element can be made entirely of metal and / or it can incorporate engineering plastics, e.g., PP, PPA, PPS, or PA. For example, the interior of the absorption element can be made of plastic, such as the struts, while the exterior, e.g., the contact area, can be made of metal (metal-plastic composite or hybrid component). Similarly, only one or more surfaces on the outside of the absorption element can be made of metal.

[0040] The absorption element can be designed as a plastic insert. For example, the absorption element can be made entirely of plastic. The plastic insert can, for instance, be placed in a U-shaped element that has contact areas on its arms.

[0041] The terminal assembly can be arranged on a lid to close the battery cell housing, and the contact area and absorption element can be located on the inside of the lid. The lid can thus enclose the contact area and absorption element of the terminal assembly within the battery cell housing. The terminal assembly can also be designed as a feed-through terminal, passing through the lid. In this case, the contact area and absorption element of the terminal assembly can be located inside the housing and be inaccessible, while the outer part of the terminal assembly is easily accessible for integrating the battery cell into the circuit.

[0042] The battery cell can comprise two terminal assemblies at opposite ends, for example, an anode terminal assembly at one end and a cathode terminal assembly at the other. In this case, the terminal assemblies can each be located on a lid of the battery cell, which can thus have two lids. Alternatively, the terminal assembly with one anode terminal and one cathode terminal can be located on one side of the housing, for example, the lid. Thus, a battery cell with only one lid is possible. Multiple terminal assemblies can also be located on one side of the housing, for example, the lid, such as an anode terminal assembly and a cathode terminal assembly, which can, for example, have separate absorption elements.

[0043] The absorption element, for example the hollow profile, can be made of thin-walled metal that is suitable to deform under a load, for example an impact, in order to absorb energy and protect the electrode stack of the battery cell.

[0044] Some embodiments relate to a battery cell comprising an electrode stack, a housing in which the electrode stack is arranged, a lid for closing the housing, the terminal arrangement as described above, and a current collector for electrically connecting the electrode stack to the terminal arrangement. The terminal arrangement of the battery cell may include any feature as described above or below.

[0045] Exemplary embodiments of the invention are now described by way of example and with reference to the accompanying drawing, in which:

[0046] Fig. 1 schematically shows a side view of a battery cell with connection arrangement without absorption element in the case of crushing / crash;

[0047] Fig. 2a schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0048] Fig. 2b schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0049] Fig. 2c schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0050] Fig. 2d schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0051] Fig. 2e schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0052] Fig. 2f schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0053] Fig. 2g schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0054] Fig. 2h schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0055] Fig. 2i schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0056] Fig. 2j schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0057] Fig. 2k schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0058] Fig. 2I schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0059] Fig. 2m schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment; Fig. 2n schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0060] Fig. 2o schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0061] Fig. 2p schematically shows a side view of a connection arrangement with contact area and absorption element according to one embodiment;

[0062] Fig. 3a schematically shows a semi-transparent perspective view of an absorption element with gas channels according to one embodiment;

[0063] Fig. 3b schematically shows a perspective view of a connection arrangement with contact area and absorption element with gas channels according to one embodiment;

[0064] Fig. 4a schematically shows a side view of a battery cell according to one embodiment; and

[0065] Fig. 4b schematically shows a perspective view of a battery cell according to one embodiment.

[0066] Fig. 1 shows a side view of a battery cell with connection arrangement without absorption element in a crush / crash case (the battery cell housing is not shown for clarity).

[0067] Battery cell 1a comprises two electrode stacks 6 (double stacks) with anodes, cathodes, and separators stacked alternately on top of each other. The anodes and cathodes are electrically connected to the terminal arrangement 3a via current collectors 7. The electrode stacks 6 are configured as a jelly stack.

[0068] Fig. 1 shows only a section of the left side of battery cell 1a, showing only current collectors 7 for one electrode type (anode or cathode) per electrode stack 6. On the opposite, right side of battery cell 1a, a further connection arrangement for connecting additional current collectors, for example of the other electrode type (anode or cathode), can be arranged.

[0069] Connection arrangement 3a is arranged as a feed-through connection on the cover 4 of the housing (not visible) of the battery cell 1a. Elements of connection arrangement 3a are arranged on the inside of the cover 4, facing the electrode stacks 6, and elements of connection arrangement 3a that serve to electrically connect the battery cell 1a to a circuit are arranged on the outside of the cover 4. Connection arrangement 3a comprises a U-shaped element with two arms 8, which is arranged on the inside of the cover 4. Current collectors 7 are welded to the arms 8 to establish an electrical connection with the electrode stacks 6 or with the active material (anode or cathode) of the electrode stacks 6.

[0070] The arms 8 of the U-shaped element are arranged towards the electrode stacks 6, such that the angular ends of the arms 8 point towards the electrode stacks 6. In the event of a crush / crash, for example, if an external impact acts on the battery cell 1a, the ends of the arms 8 shift towards the electrode stacks 6, penetrating them and causing localized stresses / deformations of the jelly stack, thus damaging the electrode stacks 6. The direction of movement of the arms 8 is indicated by the two arrows in Fig. 1. Furthermore, the effect of the crush / crash is indicated by the two intrusion zones 9. Within these two intrusion zones 9, the electrodes of the electrode stack 6 are damaged (e.g., crushed, bent, sheared, etc.).folded over), which occurs after the arms 8 have moved towards the electrode stacks 6, as indicated by the two movement arrows.

[0071] Damage to battery cell 1a in the event of a crush / crash can be reduced, for example, if the sharp edges of the arms 8 are rounded. However, the damage can be prevented by the embodiments shown below.

[0072] Figs. 2a - 2p show schematic side views of connection arrangements with contact area 11 and absorption element 10 according to various embodiments, wherein the connection arrangements 3 are shown arranged on a battery cell (only partially shown).

[0073] Furthermore, Figures 2a-2p each show a schematic section of the left side of battery cell 1, where only one current collector 7 per electrode stack 6 is shown in the left section. On the opposite, right side of the respective battery cells 1 (not visible, see e.g., Figure 1, Figures 4a and 4b), a further connection arrangement for connecting additional current collectors of the electrode stacks 6, for example, current collectors of a different electrode type (anode or cathode), can be arranged. Furthermore, another cover for closing the housing can be arranged on the opposite side. Electrode stacks 6 are designed as a jelly stack (see Figure 6, Figure 1). The jelly stack is designed as a double stack, consisting of two individual stacks (electrode stacks 6).

[0074] Current collector 7 and electrode stack 6 of Figures 2a-2p and 3b are schematically represented as a block, with current collector 7 being configured as several conductor tabs and each of the two electrode stacks 6 comprising several alternating layers of anodes, cathodes, and separators (see Figure 6, Figure 1). The housing (e.g., 2, Figures 4a and 4b), in which the battery cell 1 is arranged and which is closed by cover 4, is not visible in Figures 2a-2p and 3b to illustrate the other components.

[0075] For the sake of clarity, the parts of battery cell 1 that are present in several figures 2a - 2p, such as battery cell 1, electrode stack 6, current collector 7, cover 4, are not marked separately with reference symbols in each figure.

[0076] In Figs. 2a-2e and 2g-2p, connection arrangements 3 are designed such that the two ends of the electrically conductive absorption element 10 opposite each other in the y-direction comprise the contact areas 11. The two electrode stacks 6 of the battery cell 1 are electrically connected to the absorption element 10 and thus to the connection arrangement 3 via current collectors 7 at the contact areas 11.

[0077] In Figures 2a to 2c, absorption element 10 is designed as a rectangular hollow profile (two short and two long sides) with a closed cross-section and several webs 12 arranged inside the hollow profile. Absorption element 10 is arranged on the inside of the cover 4.

[0078] A long side 10b of the hollow profile with rounded corners faces the electrode stacks 6. The short sides of the hollow profile, on which the contact areas 11 are arranged, correspond approximately to the height of the electrode stacks 6 in the z-direction (see 10, Figs. 3a and 3b). The side 10b of the absorption element 10 facing the electrode stacks 6 corresponds approximately to the dimensions of the stack height and width (z-direction, y-direction) of the double stack (see 10b, Figs. 3a and 3b), which helps to homogenize the mechanical load acting on the current collectors 7 and the jelly stack.

[0079] In the event of a crush / crash, the mechanical energy is therefore distributed over the entire surface of the absorption element 10, thus preventing point penetration of the connection arrangement 3 into the electrode stacks 6. The hollow structure of the absorption element 10 can deform in a crush / crash scenario and thus contribute to energy absorption.

[0080] The hollow structure can also create gas pathways, which is described in more detail with regard to Figures 3a and 3b.

[0081] The width of the short side of the absorption element 10 also facilitates the attachment (e.g. welding) of the current collectors 7 to the contact areas 11, since the contact area 11 is easily accessible, e.g. for a laser beam.

[0082] In Fig. 2a, absorption element 10 is electrically connected to lid 4 via an intermediate element 10a.

[0083] In Figs. 2b and 2c, absorption element 10 is designed without intermediate element 10a and is thus a slimmer embodiment of the connection arrangement 3, wherein in Fig. 2c the absorption element 10 rests directly against the inside of the lid 4.

[0084] The distance 20 between cover 4 and electrode stack 6 is therefore larger in the embodiment of Fig. 2a than in the embodiments of Figs. 2b and 2c, and the distance 20 is smaller in the embodiment of Fig. 2c than in the embodiment of Fig. 2b. The smaller the distance 20, the greater the volumetric energy density (VED) that is possible.

[0085] In Fig. 2d and 2e, absorption element 10 is also designed as a hollow profile, but without webs (see 12, Fig. 2a-c), with two short sides each, which are designed as contacting areas 11 and two long sides.

[0086] One flat side of the hollow profile faces the electrode stacks 6. The dimensions of the flat side correspond approximately to the dimensions of the stack height and width (z-direction, y-direction) of the double stack, which helps to homogenize the mechanical load acting on the current collectors 7 and the electrode stacks 6.

[0087] In Fig. 2e, the flat side of the hollow profile facing the electrode stacks 6 is straight, while in Fig. 2d it is corrugated. Thus, Fig. 2e corresponds to the hollow profile from Fig. 2a without webs. The aforementioned advantages of the flat distribution and deformation of the hollow structure, gas channel formation, and easier attachment of the current collector to the wide contact area 11 also exist in the embodiments of Figs. 2d and 2e, with embodiments 2a to 2c being optimized with regard to these advantages, for example, in a crush / crash scenario.

[0088] Fig. 2f shows an embodiment of a connection arrangement 3, in which the connection arrangement 3 comprises a U-shaped element with two contact areas 11 and the absorption element 10 of the connection arrangement 3 is designed as a plastic insert. The plastic insert is arranged between the arms of the U-shaped element. The plastic insert ensures that load peaks are avoided, so that the ends of the U-shaped element do not penetrate the jelly stack with sharp edges in a crush / crash scenario.

[0089] The advantages of the flat distribution and deformation, as well as easier attachment of the current collector to the wide contact area 11, also exist in the embodiment shown in Fig. 2f.

[0090] Fig. 2g - 2m show a connection arrangement 3 in which the absorption element 10 comprises a rectangular hollow profile with two lateral contact areas 11.

[0091] In Fig. 2g, absorption element 10 is designed as a rectangular profile without webs, and in Fig. 2h, absorption element 10 is designed as a rectangular profile with webs 12 inside. The two short sides of the rectangular profile each serve as contact areas 11.

[0092] In Figs. 2g-2j, a flat side of the hollow profile faces the electrode stacks 6. In contrast to the rectangular profile of Figs. 2a-2c, the respective rectangular profiles of Figs. 2g-2j have pointed corners.

[0093] In Fig. 2g and Fig. 2h, the dimensions of the flat side opposite the electrode stacks 6 correspond approximately to the dimensions of the stack height and width (z-direction, y-direction) of the double stack, which helps to homogenize a mechanical load acting on the current collectors 7 and the electrode stacks 6. In Fig. 2i, the absorption element 10 is designed as a double rectangular profile, which is also suitable for distributing an external load over the two flat sides 10b facing the electrode stacks, which extend in the z-direction following the electrode stacks 6.

[0094] In Figs. 2j-2I, the absorption element 10 is designed as a hollow profile with an open cross-section (C-profile), which is more material-efficient than the closed hollow profile, with the hollow profile in Figs. 2k and 2I being smaller and wider than in Fig. 2j. Furthermore, the hollow profile 10 of Fig. 2I has rounded corners 16 on the side 10b facing the electrode stacks 6, which improves the force distribution.

[0095] In Fig. 2m the absorption element 10 is smaller than in Fig. 2k and 2I, but is designed as a closed hollow profile, as a D-profile, with a side curved relative to the electrode stacking 6.

[0096] The advantages of the planar distribution and deformation of the hollow structure, gas channel formation, and easier attachment of the current collector 7 to the wide contact area 11 also exist in the embodiments of Figs. 2g to 2m.

[0097] For example, in the case of a crush / crash, the arms of the open hollow profile of the absorption element 10 of Fig. 2j to 2I can deform in such a way that they bend inwards and form two closed chambers which can serve as gas chambers.

[0098] The D-profile of Fig. 2m is advantageous in that it is narrower than the absorption elements 10 of Fig. 2k and 2I, so that the distance 20 between cover 4 and electrode stack 6 is shorter, thereby enabling an increased volumetric energy density.

[0099] In Figs. 2n-2p, the absorption element 10 is designed as a hollow profile with an open cross-section (U-shaped), with one open side abutting the cover 4 and the closed side 10b facing the electrode stacks 6. Consequently, the arms, or rather the ends of the arms, of the U-shaped element are directed towards the cover 4 and not towards the electrode stacks 6.

[0100] Furthermore, the side 10b of the absorption element 10 opposite the electrode stacks 6 is straight in Fig. 2n, with an inward curvature directed away from the electrode stacks 6 in Fig. 2p and with two rectangular protrusions directed towards the electrode stacks 6 in Fig. 2o.

[0101] The advantages of the planar distribution and deformation of the hollow structure, gas channel formation, and easier attachment of the current collector 7 to the wide contact area 11 also exist in the embodiments of Figs. 2n to 2p.

[0102] The embodiment of Fig. 2n is advantageous in that it is narrower than the absorption elements 10 of the other embodiments, so that the distance 20 between cover 4 and electrode stack 6 is shorter, thereby enabling an increased volumetric energy density.

[0103] Fig. 3a shows a schematic semi-transparent perspective view of an absorption element of a connection arrangement with gas channels according to one embodiment.

[0104] Absorption element 1 has the rectangular hollow profile shape with internal webs 12 and rounded corners on one side, as shown in absorption element 10 of Figs. 2a-2c. The dimensions of absorption element 10 also correspond to those of absorption element 10 of Figs. 2a-2c.

[0105] Absorption element 10 has two opposite short sides which are electrically conductive as contact areas 11, and two opposite long sides, the long side 10b having rounded corners for better force distribution towards the electrode stack (see Fig. 3b).

[0106] The advantages of the planar distribution and deformation of the hollow structure, gas channel formation and easier attachment to the wide contact area 11 therefore also apply with regard to the absorption element 10 of Fig. 3a.

[0107] The webs 12 can be made of plastic or electrically conductive material, such as aluminum, while the outer surfaces of the absorption element 10, for example contact areas 11, are made of electrically conductive material, such as aluminum. Webs 12 inside the absorption element 11 form hollow chambers, which are designed as gas chambers, as explained in more detail in Fig. 3b (arrows indicate the flow direction 15 of the gases and particles).

[0108] Fig. 3b shows a schematic perspective view of a connection arrangement with absorption element 10 from Fig. 3a, which is arranged on a battery cell.

[0109] The connection arrangement 3 from Fig. 3b comprises the absorption element 10 from Fig. 3a, as well as a connecting rivet 14. Other parts of the connection arrangement 10, as well as the cover and housing of the battery cell 1, are not visible.

[0110] Battery cell 1 comprises connection arrangement 3, electrode stack 6 (shown as a block) and current collector 7. The active material of the electrode stack 6 is electrically conductively welded to contact areas 11 via the current collector 7, as already explained above with reference to Fig. 2a to Fig. 2p.

[0111] If gas formation occurs within the battery cell, i.e., within the housing (e.g., 2, Fig. 4a, 4b) of battery cell 1, the gas can be directed through the gas channels 13 of the absorption element 10 through the battery cell 1 to the pressure relief valve (e.g., 5, Fig. 4b), which is located, for example, in the housing or the lid of the battery cell. The direction of gas flow 15, i.e., the path that gas can take within the battery cell 1 through the gas channels 13, is illustrated by arrows, whereby the direction of flow 15 can also be reversed, for example.

[0112] Fig. 4a shows a schematic side view of a battery cell according to one embodiment and Fig. 4b shows a schematic perspective view of the battery cell from Fig. 4a.

[0113] Battery cell 1 is a prismatic battery cell and can, for example, be battery cell 1 from Figs. 2a-2p and Fig. 3b. Battery cell 1 comprises housing 2 in which electrode stacks (e.g., 6, Figs. 2a-2p, 3b) are arranged. Housing 2 is closed on both sides (x-direction) with covers 4. A pressure relief valve 5, through which gas can escape from the battery cell, is also arranged in housing 2.

[0114] Both covers 4 of the battery cell 1 contain a connection arrangement 3. Alternatively, the connection arrangement 3 can be located only in the left or only in the right cover 4. The connection arrangements 3 are, for example, one of the connection arrangements 3 shown in Figures 2a-3b, whereby the two connection arrangements 3 in the two covers 4 can be configured differently. The electrode stack, current collector, contact areas, and absorption element are located inside the housing 2 and are not visible. Alternatively, a battery cell 1 can be provided with only one cover 4, in which the connection arrangement 3 can be located. The pressure relief valve 5 can, for example, also be located in the cover 4.

[0115] Consequently, battery cell 1 is optimized for crush / crash resistance with respect to the absorption element of the connection arrangement 3, and also for contact efficiency with respect to the contact areas of the connection arrangement 3. Furthermore, as described above, battery cell 1 is also optimized with respect to the reduction in installation space of the connection arrangement 3 and the associated improved volumetric energy density.

[0116] Reference symbol

[0117] Battery cell a Battery cell without absorption element

[0118] Housing

[0119] Connection arrangement a Connection arrangement without absorption element

[0120] Lid

[0121] Overpressure valve

[0122] Electrode stack

[0123] power collector

[0124] poor

[0125] Intrusion zone 0 Absorption element 0a Intermediate element 0b Side of the absorption element facing the electrode stack 1 Contact area 2 Bridge 3 Gas channel 5 Direction of gas flow 6 Rounded corners

Claims

Patent claims 1. A connection arrangement (3) of a battery cell (1) for electrically connecting the battery cell (1) to a circuit, comprising a contact area (11) for electrically connecting a current collector (7) of the battery cell (1) to the connection arrangement (3), and an absorption element (10) for receiving a load acting on an electrode stack (6) via the connection arrangement (3), wherein the absorption element (10) is configured to distribute the load over the surface of the absorption element (10) and / or to deform in order to absorb mechanical energy.

2. Connection arrangement (3) according to claim 1, wherein the absorption element (10) comprises a hollow profile with an open or closed cross-section.

3. Connection arrangement (3) according to claim 2, wherein the hollow profile is designed as a gas channel for draining gas within the battery cell (1).

4. Connection arrangement (3) according to one of the preceding claims, wherein the absorption element (10) comprises a U-shaped element.

5. Connection arrangement (3) according to one of the preceding claims, wherein the contacting area (11) is arranged on the absorption element (10).

6. Connection arrangement (3) according to one of the preceding claims, wherein the absorption element (10) is electrically conductive.

7. Connection arrangement (3) according to one of the preceding claims, wherein the connection arrangement (3) is arranged on a lid (4) for closing a housing (2) of the battery cell (1), and the contact area (11) and the absorption element (10) are arranged on an inside of the lid (4).

8. Connection arrangement (3) according to one of the preceding claims, wherein the absorption element (10) is formed as a flat surface on a side facing the electrode stack (6).

9. Connection arrangement (3) according to one of the preceding claims, wherein the absorption element is formed from thin-walled metal that is suitable to deform under a load.

10. Connection arrangement (3) according to one of the preceding claims, wherein the absorption element (10) is designed as a plastic insert.

11. A battery cell comprising an electrode stack (6), a housing (2) in which the electrode stack (6) is arranged, a cover (4) for closing the housing (2), the connection arrangement (3) according to one of the preceding claims, and a current collector (7) for electrically connecting the electrode stack (6) to the connection arrangement (3).

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