Cell connector and method for producing a cell connector

Abstract

To create a cell connector for electrically connecting at least one first cell terminal of a first electrochemical cell and at least one second cell terminal of a second electrochemical cell, comprising at least one first contact area for electrically connecting the cell connector to the at least one first cell terminal, at least one second contact area for electrically connecting the cell connector to the at least one second cell terminal, and at least one elastically and / or plastically deformable connection area, which is arranged in the current path between the at least one first contact area and the at least one second contact area, which requires little installation space and allows a small distance between the electrochemical cells electrically connected to each other by the cell connector, it is proposed thatthat the connection area is at least partially formed from a cold-worked metallic material.

Description

[0001] The present invention relates to a cell connector for electrically connecting at least one first cell terminal of a first electrochemical cell and at least one second cell terminal of a second electrochemical cell, comprising at least one first contact area for electrically connecting the cell connector to the at least one first cell terminal, at least one second contact area for electrically connecting the cell connector to the at least one second cell terminal and at least one elastically and / or plastically deformable connection area, which is arranged in the current path between the at least one first contact area and the at least one second contact area.

[0002] Cell connectors for electrically connecting cell terminals of electrochemical cells of an electrochemical device have long been used and are designed, for example, as aluminum rails, copper rails, bond wires or cables.

[0003] The elastically and / or plastically deformable connection area of ​​a cell connector can include a mechanical compensation element. Such a compensation element can, for example, be designed as a wave, a bead, or a half-bead.

[0004] The at least one compensation element of the connection area can compensate for relative displacements of the cell terminals of the electrochemical cells electrically connected to each other by the cell connector, so that the forces acting on the cell terminals and the screw or joining connections by means of which the cell terminals are connected to the cell connector due to the relative displacements do not become too large.

[0005] The at least one compensation element must be as flexible as possible, but also capable of withstanding as many load cycles as possible, i.e., it must have high operational strength.

[0006] The relative movements of the cell terminals, which are to be compensated by at least one connection area, can result from operational loads such as shock, vibration or swelling of the electrochemical cells due to aging (so-called "swelling").

[0007] The at least one compensation element can, in addition to compensating for operating loads, also serve during the manufacture of the electrochemical device to press the at least one first contact area or the at least one second contact area against the respective associated first cell terminal or the respective associated second cell terminal, in order to establish an electrically conductive connection at the respective cell terminal in this held-down position of the cell connector, in particular by a welding process, for example a laser welding process. Manufacturing tolerances are thereby compensated for with minimal holding force.

[0008] In addition to providing the necessary mechanical flexibility, the cell connector must conduct the current between the electrochemical cells electrically connected by the cell connector, for which the cell connector should have the lowest possible ohmic resistance, low power loss and consequently a low temperature.

[0009] In known cell connectors for electrically connecting cell terminals of electrochemical devices, the compensating elements, for example a bead or a wave, are designed to be as tall as possible (i.e., with a large extent along the contact direction or Z-direction of the electrochemical device), as long as possible (especially with a long plateau between two half-beads), and with large bending radii (to achieve the lowest possible mechanical stresses). This requires a large installation space for the cell connector and thus a large distance between the electrochemical cells, resulting in a low energy density of the electrochemical device.

[0010] Furthermore, a large number of compensation elements (for example, waves, beads or half-beads) are often used in the same connection area.

[0011] The present invention is based on the objective of creating a cell connector of the type mentioned above which requires a small installation space and allows a small distance between the electrochemical cells electrically connected to each other by the cell connector.

[0012] This problem is solved according to the invention in a cell connector with the features of the preamble of claim 1 by the fact that the connection area is at least partially formed from a cold-worked metallic material.

[0013] Cold working of the metallic material allows for a reduction in material thickness without a corresponding decrease in the modulus of elasticity. This results in increased flexibility or reduced stiffness of the joint area.

[0014] The increased flexibility resulting from the cold working of the metallic material used reduces the forces acting on the connection point between each cell terminal and the cell connector, thereby increasing the service life of the connection point.

[0015] Furthermore, the cold working of the metallic material leads to increased strength in terms of tensile strength and fatigue strength. This has a positive effect on the operational reliability of the cell connector.

[0016] Due to the higher fatigue strength in the area formed from the cold-worked metallic material, the at least one compensation element of the connection area, for example a shaft, a bead or a half-bead, can be designed with a lower height (i.e. with a smaller extent in the contacting direction or Z-direction of the electrochemical device) and / or with a smaller extent perpendicular to the contacting direction or Z-direction of the electrochemical device (for example with shorter plateaus between two half-beads).

[0017] Alternatively or additionally, the bending radii of at least one compensation element can be made smaller.

[0018] Each of the properties described above leads to a reduction in the installation space required for the arrangement of the cell connector.

[0019] Preferably, at least one compensation element of the connection area is formed at least partially from a cold-worked metallic material.

[0020] It is particularly advantageous if at least one compensation element of at least one connection area of ​​the cell connector is made entirely of a cold-worked metallic material.

[0021] If the cell connector comprises several connection areas, it is preferably provided that all connection areas of the cell connector are at least partially formed from a cold-worked metallic material.

[0022] In particular, it may be provided that all connection areas of the cell connector each comprise at least one contact element which is at least partially formed from a cold-worked metallic material.

[0023] It is particularly advantageous if all connection areas of the cell connector each include at least one compensation element which is made entirely of a cold-worked metallic material.

[0024] In a preferred embodiment of the invention, it is provided that all contact elements of all connection areas of the cell connector are at least partially formed from a cold-worked metallic material.

[0025] It is particularly advantageous if all compensation elements of all connection areas of the cell connector are made entirely of a cold-worked metallic material.

[0026] The cell connector according to the invention comprises at least one first contact area for electrically connecting the cell connector to a first cell terminal and at least one second contact area for electrically connecting the cell connector to a second cell terminal.

[0027] In principle, the cell connector can include any number of first contact areas for electrically connecting the cell connector to a corresponding number of first cell terminals at a first electrical potential and any number of second contact areas for electrically connecting the cell connector to a corresponding number of second cell terminals at a second electrochemical potential.

[0028] In this way, any number of first cell terminals can be electrically connected in series with a corresponding number of second cell terminals.

[0029] Preferably, each first contact area and / or each second contact area of ​​the cell connector is assigned an elastically and / or plastically deformable connection area.

[0030] In particular, it may be provided that the cell connector comprises a web area which is connected via one or more connection areas to a corresponding number of first contact areas of the cell connector, and via one or more connection areas to a corresponding number of second contact areas of the cell connector.

[0031] In principle, the cold-worked metallic material can be any material that has a specific electrical conductivity sufficient for the required current-carrying capacity of the cell connector.

[0032] For example, the cold-worked metallic material may be a copper material. Such a copper material preferably consists of more than 50% copper by weight.

[0033] In a preferred embodiment of the invention, however, the cold-worked metallic material is an aluminum material.

[0034] Preferably the aluminium material contains more than 50% aluminium by weight, particularly preferably more than 99.0% aluminium by weight.

[0035] Cold working of the metallic material is preferably achieved by mechanical cold forming of a starting material.

[0036] If the connection area of ​​the cell connector is formed from a preferably flat starting material by a forming process, the cold working of the material can, in principle, take place before the forming process, during the forming process or after the forming process.

[0037] In order to obtain the most homogeneous cold forming and thus the most homogeneous cold working of the metallic material, it is advantageous if the cold working takes place before the forming process of the connection area.

[0038] Cold working is preferably achieved by reducing the material thickness of a metallic starting material.

[0039] A measure of the cold working of the starting material is the degree of deformation ε, with ε = (h0 - h1) / h0, where h0 denotes the material thickness of the starting material before cold working and h1 denotes the material thickness of the cold-worked metallic material after cold working.

[0040] Preferably the degree of deformation ε of the cold-worked metallic material is at least 10%, in particular at least 20%, and especially preferably more than 30%, for example more than 60%.

[0041] Furthermore, it is preferably provided that the degree of deformation ε of the cold-worked metallic material is less than 80%.

[0042] Cold-worked metallic aluminium materials are named according to the American standard ANSI H35.1, the international ISO standard 2107 and the European standard AUF 515 with designations that begin with the letter H and are followed by two or three digits.

[0043] The cold working conditions H12 (1 / 4-hard), H14 (1 / 2-hard), H16 (3 / 4-hard) and H18 (hard) according to the aforementioned standards are particularly suitable as cold-worked aluminium materials for the connection area of ​​the cell connector.

[0044] For the operational strength of the cell connector, it is particularly advantageous if the tensile strength R m of the cold-worked metallic material more than 90 N / mm 2 , preferably more than 100 N / mm 2 , especially more than 120 N / mm 2 , especially preferably more than 140 N / mm 2 , amounts.

[0045] Furthermore, it has proven advantageous for the manufacturability of the connection area by a forming process if the tensile strength R m of the cold-worked metallic material less than 160 N / mm 2 amounts.

[0046] The cold-worked metallic material has preferably been worked by a mechanical cold forming process.

[0047] In particular, it may be provided that the cold-worked metallic material is cold-worked by a cold rolling process, an embossing process or a forming process with local reduction of the material thickness.

[0048] Before the cold working process, the cold-worked material may have been annealed.

[0049] The cell connector can, in principle, comprise one layer, two layers, or more than two layers in the connection area.

[0050] In a preferred embodiment of the invention, the cell connector is designed to be single-layered, at least in the connection area.

[0051] Preferably, the connection area is formed essentially entirely from the cold-worked metallic material.

[0052] The connection area preferably has at least one elastically and / or plastically deformable compensation element. The compensation element is preferably made of the cold-worked material.

[0053] Such a compensation element can, for example, be designed as a wave, a bead or a half-bead.

[0054] In preferred embodiments of the invention, the connection area comprises at least one wave, one step, one plateau and / or one half-bead.

[0055] A wave, a step or a half-bead can extend out of the plane spanned by the connection direction and the transverse direction of the cell connector or be essentially flat and confined to the plane spanned by the connection direction and the transverse direction of the cell connector.

[0056] To reduce the thermal conductivity of the cell connector, it can be provided that the cell connector has at least one cross-section-reduced area in the current path between the at least one first contact area and the at least one second contact area, in which the electrically conductive cross-section of the cell connector is reduced by at least one recess.

[0057] Such a recess can in particular be designed as a passage opening which completely penetrates a base body of the cell connector from a first outer side of the cell connector to a second side of the cell connector.

[0058] It is particularly advantageous if the at least one cross-sectionally reduced area is arranged in at least one connection area of ​​the cell connector, which is at least partially made of a cold-worked metallic material.

[0059] For example, it may be provided that the cross-section-reduced area is arranged on a compensation element of such a connection area.

[0060] The area of ​​the cell connector, which is formed from the cold-worked metallic material, can extend into the at least one first contact area and / or into the at least one second contact area, since contact areas with a lower material thickness are easier to weld.

[0061] In preferred embodiments of the invention, it is therefore provided that the at least one first contact area and / or the at least one second contact area of ​​the cell connector are at least partially formed from a cold-worked metallic material.

[0062] In particular, it may be provided that the cell connector is essentially made entirely of a cold-worked metallic material.

[0063] The cell connector according to the invention is particularly suitable for use as a component of a cell contacting system for an electrochemical device comprising several electrochemical cells, wherein the cell contacting system comprises at least one cell connector according to the invention.

[0064] Such a cell contacting system according to the invention is particularly suitable for use as a component of an electrochemical device comprising several electrochemical cells and a cell contacting system according to the invention.

[0065] Such an electrochemical device can be designed in particular as an energy storage device, for example for an electric vehicle or for a stationary storage application.

[0066] The electrochemical cells can be designed in particular as lithium-ion battery cells.

[0067] The present invention further relates to a method for manufacturing a cell connector for electrically connecting at least one first cell terminal of a first electrochemical cell and at least one second cell terminal of a second electrochemical cell, wherein the cell connector comprising at least one first contact area for electrically connecting the cell connector to the at least one first cell terminal, at least one second contact area for electrically connecting the cell connector to the at least one second cell terminal and at least one elastically and / or plastically deformable connection area, which is arranged in the current path between the at least one first contact area and the at least one second contact area.

[0068] The present invention is based on the further objective of creating a method for manufacturing a cell connector which creates a cell connector that requires a small installation space and allows a small distance between the electrochemical cells electrically connected to each other by the cell connector.

[0069] This problem is solved by a method for producing a cell connector of the type mentioned above, the method comprising the following: - Providing a metallic starting material; - Cold working of at least a portion of the metallic starting material to form a cold-worked metallic material; and - Formation of at least one connection area of ​​the cell connector by forming the cold-worked metallic material or in the course of the cold-working of the metallic starting material to the cold-worked metallic material.

[0070] Preferably, the at least one connection area is formed by forming the metallic material which has already been work-hardened before the forming process.

[0071] It has proven particularly advantageous to anneal the metallic starting material before cold working.

[0072] Specific embodiments of the inventive method for producing a cell connector have already been explained above in connection with specific embodiments of the inventive cell connector for electrically conductive connection of cell terminals.

[0073] The inventive method for producing a cell connector is particularly suitable for producing the cell connector according to the invention.

[0074] The cell connector according to the invention is preferably produced by the inventive method for producing a cell connector.

[0075] Further features and advantages of the invention are the subject of the following description and the graphic representation of exemplary embodiments.

[0076] The drawings show: Fig. 1 a perspective view of a cell connector for electrically connecting a first cell terminal of a first electrochemical cell and a second cell terminal of a second electrochemical cell, wherein the cell connector comprises a first contact area for electrically connecting the cell connector to the first cell terminal, a second contact area for electrically connecting the cell connector to the second cell terminal and an elastically and / or plastically deformable connection area which is arranged in the current path between the first contact area and the second contact area, wherein the connection area is formed from a cold-worked metallic material; Fig. 2 a longitudinal section through the cell connector from Fig. 1; Fig. 3 a diagram showing the course of the 0.2% yield strength (R p 0,2 ), the course of the tensile strength (R m) and the course of the elongation at break (A 10 ) of aluminium as a function of the degree of deformation or cold rolling degree (ε); Fig. 4 a perspective view of a contact area and a connection area of ​​a cell connector formed from a cold-worked metallic material, and of a web area of ​​the cell connector formed from a non-cold-worked metallic material; Fig. 5 a longitudinal section through the contact area, the deformation area and the web area of ​​the cell connector Fig. 4; Fig. 6 a longitudinal section through a first contact area, a connection area and a second contact area of ​​a cell connector, wherein the connection area comprises a wave as a compensation element; Fig. 7 a longitudinal section through a first contact area, a connection area and a second contact area of ​​a cell connector, wherein the connection area comprises a step or half-bead as a compensation element; Fig. 8 a longitudinal section through a first contact area, a connection area and a second contact area of ​​a cell connector, wherein the connection area comprises two (differently high) half-beads as compensation elements; Fig. 9 a longitudinal section through a first contact area, a connection area and a second contact area of ​​a cell connector, wherein the connection area comprises four half-beads as compensation elements; Fig. 10 a longitudinal section through a first contact area, a connection area and a second contact area of ​​a cell connector, wherein the connection area comprises two half-beads and a plateau arranged between the half-beads as elastically and / or plastically deformable compensation elements; Fig. 11 a longitudinal section through a first contact area, a connection area and a second contact area of ​​a cell connector, wherein the connection area comprises two half-beads as elastically and / or plastically deformable compensation elements and further a plateau arranged between the half-beads, wherein the plateau has a greater length along a connection direction of the cell connector pointing from the first contact area to the second contact area than the plateau of the cell connector made of Fig. 10; and Fig. 12 a longitudinal section through a first contact area, a connection area and a second contact area of ​​a cell connector, wherein the connection area comprises two half-ribs as elastically and / or plastically deformable compensation elements and furthermore a plateau arranged between the half-ribs, wherein the heights of the half-ribs in a contacting direction of the cell connector oriented perpendicular to the connection direction of the cell connector have greater heights than the half-ribs of the Fig. 10 cell connectors shown.

[0077] Identical or functionally equivalent elements are designated with the same reference symbols in all figures.

[0078] One in the Fig. 1 and Fig. The cell connector 100 shown serves to electrically connect a first cell terminal 102 of a first electrochemical cell 104 and a second cell terminal 106 of a second electrochemical cell 108 (see figure). Fig. 2).

[0079] The electrochemical cells 104 and 108 form components of a battery module 110 of an electrochemical device designated as a whole by 112, which can comprise several battery modules 110, each of which in turn comprises several electrochemical cells 104, 108.

[0080] The electrochemical device 112 can in particular be designed as an accumulator, especially as a lithium-ion accumulator.

[0081] The electrochemical cells 104, 108 of the electrochemical modules can accordingly be designed as accumulator cells, in particular as lithium-ion accumulator cells.

[0082] The first cell terminal 102 can have positive or negative polarity; the second cell terminal 106 then has the opposite polarity, for example negative polarity or positive polarity.

[0083] The cell connector 100 comprises a base body 114, which in turn has a first contact area 116, which in the assembled state of the cell connector 100 is electrically connected to the first cell terminal 102 of the first electrochemical cell 104, and a second contact area 118, which in the assembled state of the cell connector 100 is electrically connected to the second cell terminal 106 of the second electrochemical cell 108.

[0084] The base body 114 of the cell connector 100 is preferably manufactured as a stamped and bent part.

[0085] The basic body 114 of the cell connector 100 is located in the Fig. 1 and Fig. 2. The embodiment shown is made entirely from a cold-worked metallic material.

[0086] The cold-worked metallic material is preferably an aluminum material.

[0087] In particular, it may be stipulated that the cold-worked metallic material contains more than 99.0% aluminum by weight.

[0088] The degree of deformation ε of the cold-worked metallic material is preferably at least 10%, particularly at least 20%, and especially preferably more than 30%, for example approximately 50%.

[0089] Furthermore, the degree of deformation ε of the work-hardening metallic material is preferably less than 80%, and in particular less than 60%.

[0090] In the diagram of Fig. Figure 3 shows the curve of the 0.2% yield strength (R). p 0,2 ), the tensile strength (R m ) and the elongation at break (A 10 ) of cold-worked pure aluminum as a function of the degree of deformation or cold rolling degree ε.

[0091] The degree of deformation ε results from the original material thickness h0 of the still unworked material and the material thickness difference Δh, by which the material thickness is reduced by the cold working, to ε = Δh / h0.

[0092] The cold working of the metallic starting material, especially aluminium, can be carried out, for example, by a cold rolling process or by an embossing process.

[0093] As from Fig. As can be seen in section 3, the tensile strength R m of the metallic material becomes monotonically increasing with increasing degree of deformation or cold rolling degree ε.

[0094] If a soft-annealed aluminum sheet, whose condition is designated H111, is used as the metallic starting material, it is in a soft initial state with a tensile strength of approximately 80 N / mm² before cold working (i.e., at ε = 0). 2 .

[0095] If this starting material is cold-worked to a degree of deformation of 10%, it reaches the H12 (1 / 4-hard) state, with an increased tensile strength of approximately 100 N / mm². 2 .

[0096] If the soft-annealed starting material is cold-worked to a degree of hardening of 20%, it reaches the H14 (1 / 2-hard) state, in which the tensile strength is slightly over 110 N / mm². 2 lies.

[0097] If the starting material is cold-worked to a degree of deformation of approximately 36%, it reaches the H16 state (3 / 4-hard), in which the tensile strength increases to approximately 125 N / mm². 2 has increased.

[0098] If the starting material is cold-worked to a degree of deformation of approximately 62%, it reaches the H18 (hard) state, in which the tensile strength is approximately 145 N / mm². 2 amounts.

[0099] If the starting material is cold-worked to a degree of deformation of approximately 86%, it reaches the H19 (extra hard) state, in which the tensile strength is approximately 172 N / mm². 2 amounts.

[0100] At the preferred degree of deformation of ε = 50%, the cold-worked aluminum material lies between states H16 and H18, with a tensile strength of approximately 136 N / mm². 2 .

[0101] Such cold-worked aluminum material exhibits particularly high flexibility and fatigue strength, which is advantageous for the formation of elastically and / or plastically deformable structures, especially in the case of a stamped and bent part.

[0102] The first contact area 116 and the second contact area 118 of the cell connector 100 are connected to the respective cell terminal 102 or 106 by screwing or preferably by material bonding when the cell connector 100 is assembled.

[0103] Such a material-bonded connection is preferably produced by welding, in particular laser welding, or by soldering.

[0104] In order to allow direct access to the cell terminals 102 and 106, for example for measuring purposes, even after the cell connector has been materially joined to the cell terminals 102 and 106, the first contact area 112 can be provided with a passage opening 120, for example substantially rectangular, and / or the second contact area 118 of the base body 114 can be provided with a passage opening 122, for example substantially rectangular.

[0105] During operation of the electrochemical device 112, differences in temperature and / or different coefficients of thermal expansion of the cell connector 100 on the one hand and a (not shown) receiving device for the electrochemical cells 104, 108 on the other hand can lead to a difference between the longitudinal expansion of the cell connector 100 on the one hand and a change in the distance between the longitudinal axis 124 of the first cell terminal 102 and the longitudinal axis 126 of the second cell terminal 106 on the other. A temperature change alters the relative positions of the cell terminals 102, 106 connected by the cell connector 100 in a connection direction 130 perpendicular to the axial direction or contact direction 128 and / or in a transverse direction 132 perpendicular to both the contact direction 128 and the connection direction 130.

[0106] The connection direction 130 lies in a plane which contains the longitudinal axes 124, 126 of the cell terminals 102 and 106, and runs parallel to a longitudinal direction 134 of the cell connector 100.

[0107] In particular, the connection direction 130 runs through a center of the passage opening 120 in the first contact area 116 and through a center of the passage opening 122 in the second contact area 118 of the cell connector 100.

[0108] Furthermore, due to different longitudinal expansions of the electrochemical cells 104 and 108 connected to each other by the cell connector 100, a change in the relative positions between the connected cell terminals 102 and 106 along the contact direction 128 of the cell terminals 102, 106 can occur.

[0109] In order to compensate for such relative movements between the interconnected cell terminals 102, 106 and thus between the first contact area 116 and the second contact area 118 of the cell connector 100 in the longitudinal direction 134 of the cell connector 100, in the transverse direction 132 of the cell connector 100 and / or in the contact direction 128 of the cell connector 100 aligned parallel to the contact direction 128 of the cell terminals 102, 106, the base body 114 of the cell connector 100 comprises an elastically and / or plastically deformable connection area 136, which is arranged between the first contact area 116 and the second contact area 118 in the current path of the cell connector 100 and connects the two contact areas 116 and 118 together.

[0110] During the Fig. 1 and Fig. In the embodiment of a cell connector 100 shown in Figure 2, the deformable connection area 136 comprises a shaft 140 as an elastically and / or plastically deformable compensation element 138, the shaft crest 142 of which extends parallel to the transverse direction 132 of the cell connector 100.

[0111] Furthermore, the cell connector in the current path between the first contact area 112 and the second contact area 114 preferably comprises at least one, more preferably several, in the illustrated embodiment two, cross-section-reduced areas 144 in which the electrically conductive cross-section of the cell connector 100 is reduced by at least one or preferably by several, in the illustrated embodiment by eleven, recesses 146.

[0112] The recesses 146 are preferably designed as passage openings 148 in the base body 114 of the cell connector 100 and extend from a bottom surface 150 of the base body 114 facing the cell terminals 102, 106 to be connected in the assembled state of the cell connector 100 to a top surface 152 of the base body 114 facing away from the cell terminals 102, 106 to be connected in the assembled state of the cell connector 100 through the entire base body 114 of the cell connector 100.

[0113] The recesses 146 or passage openings 148 follow one another along a perforation line 154 of the respective cross-sectionally reduced area 144 and are separated from an adjacent recess 146 or passage opening 148 or from an edge of the base body 114 of the cell connector 100 by a constriction of the cross-sectionally reduced area 144.

[0114] Preferably, at least one of the passage openings 148 of the cross-sectionally reduced area 144 is designed as a circular hole 156.

[0115] Particularly preferably, all passage openings 148 of the cross-sectionally reduced area 144 are designed as a circular hole 156.

[0116] In principle, the passage openings 148 of the cross-sectionally reduced area 144 can also have a different shape, for example the shape of an elongated hole.

[0117] However, a passage opening 148 designed as a circular hole 156 is less prone to tearing out under a mechanical alternating load on the cell connector 100 than a passage opening designed as an elongated hole.

[0118] The electrically conductive cross-section of each cross-section-reduced area 144 is preferably less than half, in particular less than one third, and especially preferably less than one quarter, of the electrically conductive cross-section that the cross-section-reduced area 144 in question would have without the presence of the recesses 146.

[0119] Furthermore, the electrically conductive cross-section of each cross-section-reduced area 144 of the cell connector 100 is preferably less than half, in particular less than one third, and especially preferably less than one quarter, of the electrically conductive cross-section of an area 158 of the cell connector 100 which adjoins the respective cross-section-reduced area 144 in the current path between the first contact area 116 and the second contact area 118 of the cell connector 100.

[0120] During the Fig. 1 and Fig. In the embodiment of a cell connector 100 shown in Figure 2, the cell connector 100 has several, for example two, cross-section-reduced areas 144 spaced apart from each other in the longitudinal direction 134 of the cell connector 100 in the current path between the first contact area 116 and the second contact area 118 of the cell connector 100.

[0121] In particular, it may be provided that a first cross-sectionally reduced area 144a is arranged in a first flank 160a of the compensation element 138 of the connection area 136, for example designed as a shaft 140, which faces the first contact area 112 of the cell connector 100, and / or a second cross-sectionally reduced area 144b is arranged in a second flank 160b of the compensation element 138 of the connection area 136, for example designed as a shaft 140, which faces the second contact area 118 of the cell connector 100.

[0122] The base body 114 of the cell connector 100 is preferably made of a material that has a thermal conductivity of at least 200 W / mK and / or a specific heat capacity of at least 800 J / kgK.

[0123] The cold-worked aluminum materials described above exhibit these properties.

[0124] The base body 114 of the cell connector 100 is preferably separated from a flat starting material, for example by punching or cutting, for example by laser cutting.

[0125] The starting material is then brought into the final shape of the base body 114 by a forming process, for example a deep drawing process and / or an embossing process, whereby the at least one compensation element 138 of the connection area 136 is formed by forming.

[0126] The cold working of the metallic starting material of the cell connector 100 can in principle be carried out before, during or after the forming process by which the at least one compensation element 138 of the connection area 136 is formed.

[0127] Likewise, the removal of the passage openings 148 of the cross-sectionally reduced areas 144 can in principle take place before or after the forming process by which the at least one compensation element 138 of the connection area 136 is formed.

[0128] The passage openings 148 are preferably separated from the material of the base body 114, for example by punching or, preferably by means of a laser, by cutting out.

[0129] The recesses 146 or passage openings 148 preferably have a rounded edge to prevent the base body 114 from tearing after the recesses 146 or passage openings 148 have been made in the base body 114.

[0130] Due to the small extent of the recesses 146 or passage openings 148 in the longitudinal direction 134 or in the connection direction 130 of the cell connector 100, the electrical resistance of the current path of the cell connector 100 from the first contact area 116 to the second contact area 118 is only slightly increased by the cross-sectionally reduced areas 144.

[0131] However, the thermal conductivity of the cell connector 100 is greatly reduced by the cross-sectional reduction in the area of ​​the cross-sectionally reduced areas 144 of the cell connector 100.

[0132] The mechanical properties of the connection area 136 of the cell connector 100, which serve to compensate for positional tolerances between the first contact area 116 and the second contact area 118, are retained.

[0133] Because the strong cross-sectional reduction in the cross-sectionally reduced areas 144 only has an effect over a very short distance along the connection direction 130 for the electric current flowing between the first contact area 116 and the second contact area 118 of the cell connector 100, the increase in the electrical resistance of the cell connector 100 is only slight, preferably less than 10%.

[0134] However, the reduction in cross-section in the cross-section-reduced areas 144 represents a significant obstacle to the transfer of heat, so that the thermal resistance of the cell connector 100 in the longitudinal direction 134 or in the connection direction 130 is preferably increased by at least 200%.

[0135] This significant increase in the thermal resistance of the cell connector 100 significantly delays the propagation of a temperature increase from the first electrochemical cell 104 to the second electrochemical cell 108, preferably by at least 10 seconds, particularly by at least 15 seconds, and most preferably by at least 20 seconds.

[0136] This prevents a “thermal runaway” (heating due to a malfunction of an electrochemical cell) of the first electrochemical cell 104 from also triggering a “thermal runaway” of the second electrochemical cell 108 due to heat transfer via the cell connector 100.

[0137] The work hardening of the material in the area of ​​the at least one compensation element 138 of the connection area 136 of the cell connector 100 results in a lower material thickness, in particular a lower sheet thickness of the starting material, being used while maintaining the same modulus of elasticity.

[0138] This leads to a higher flexibility of the at least one compensation element 138 in the connection area 136 and to a lower stiffness of the same.

[0139] The increased flexibility of the connection area 136 resulting from the material used to form the at least one compensation element 138 reduces the forces acting on the connection point, for example a weld seam, between each cell terminal 102, 106 on the one hand and the cell connector 100 on the other hand during operation of the electrochemical device, thereby increasing the service life of the connection point.

[0140] Furthermore, the cold-worked material from which the at least one compensation element 138 is formed exhibits increased tensile strength and increased fatigue strength.

[0141] This has a positive effect on the operational reliability of the connection area 136 of the cell connector 100 during operation of the electrochemical device 112.

[0142] As already mentioned, the starting material for the production of the cold-worked metallic material is preferably a soft-annealed sheet (in state H111), which is selectively worked to one of the states H12, H14, H16 or H18 by the cold-working process, for example a cold rolling process or a stamping process.

[0143] Since at least one compensation element 138 made of the cold-worked material has a higher fatigue strength, the shape and number of the compensation elements 138 can be adjusted accordingly.

[0144] If the connection area 136 includes several waves 140 as compensation elements 138, the number of waves can be reduced.

[0145] If the connection area 136 has at least one shaft 140 and / or at least one half-bead as a compensation element 138, the height of the shaft 140 or the half-bead, i.e. its extension along the contacting direction 128 of the cell connector 100, can be reduced, which leads to a reduction of the required installation space for the cell contacting system in the contacting direction 128.

[0146] If the connection area 136 has at least one plateau which is arranged between two shafts 140, between two half-beads or between a shaft 140 and a half-bead, the length of the plateau, i.e. its extent in the longitudinal direction 134 of the cell connector 100, can be reduced due to the work hardening of the material from which the connection area 136 is formed.

[0147] If the connection area has 136 bent sections with a bending radius, these bent sections can be made with smaller bending radii due to the work hardening of the material from which these bent sections are formed.

[0148] All of this leads to a reduction in the installation space required for the arrangement of the cell contacting system.

[0149] Preferably, the material thickness of the base body 114 of the cell connector 100 is mechanically reduced in the area of ​​at least one compensation element 138 of the connection area 136, for example by embossing, in order to cold work the material of the compensation element 138 in question.

[0150] The cold-worked compensation element 138 can, for example, be a wave 140, a half-bead or a bead.

[0151] In the first contact area 116 and / or in the second contact area 118 of the cell connector 100, the material of the base body 114 of the cell connector 100 can also be cold-worked at least in sections and therefore have a lower material thickness, since contact areas 116, 118 with a lower material thickness, i.e. with less extension along the contact direction 128, are easier to weld and thus easier to connect to the respective associated cell terminal 102, 106.

[0152] Cold forming, especially embossing, increases the flexibility and fatigue strength of the cell connector 100 while requiring less installation space.

[0153] During the Fig. 1 and Fig. In the embodiment of a cell connector 100 shown in Figure 2, the entire material of the base body 114 is cold-worked.

[0154] The Fig. 4 and Fig. Figure 5 shows a section of a second embodiment of a cell connector 100, in which a first contact area 116 made of a cold-worked material is connected via a connection area 136 made of a cold-worked material to a web area 162 made of a non-cold-worked material.

[0155] At least one (not shown) second contact area 118 is connected to the web area 162 via a further (not shown) connection area 136.

[0156] How best to determine from the longitudinal section through the first contact area 116, the connection area 136 and the web area 162 of the cell connector 100 Fig. 4 in Fig. As can be seen in Figure 5, the material thickness h1 of the base body 114 of the cell connector 100 in the first contact area 116 and in the connection area 136 is significantly less than the material thickness h0 of the base body 114 of the cell connector 100 in the web area 162 of the cell connector 100.

[0157] For example, it may be stipulated that the material thickness h1 is approximately 50% of the material thickness h0.

[0158] The deformation of the material of the first contact area 116 and the connection area 136 to the lower material thickness h1 can take place before, during or after the formation of the compensation element 138 in the connection area 136 by a forming process.

[0159] In the Fig. 4 and Fig. In the embodiment shown in Figure 5, the connection area 136 comprises a shaft 140 as an elastically and / or plastically deformable compensation element 138.

[0160] The connection area 136 could also include a half-rib instead of a shaft 140, or the connection area 136 could include several compensation elements 138, for example several shafts 140, several half-ribs or at least one shaft 140 and at least one half-rib.

[0161] Various embodiments showing how a connection area 136 formed from a cold-worked material can be formed from one or more compensation elements 138 are described in the Fig. 6 to 12 each shown in a longitudinal section along the connection direction 130 through a connection area 136.

[0162] Fig. Figure 6 shows an embodiment of a cell connector 100 in which the connection area 136 arranged between a first contact area 116 and a second contact area 118 comprises a shaft 140 as a compensation element 138.

[0163] Fig. Figure 7 shows an embodiment of a cell connector 100 in which the connection area 136 arranged between a first contact area 116 and a second contact area 118 comprises a half-bead 164 as a compensation element 138.

[0164] The half-rib 164 has an essentially S-shaped or Z-shaped cross-section.

[0165] At the in Fig. In the embodiment of a cell connector 100 shown in Figure 8, the connection area 136 arranged between a first contact area 116 and a second contact area 118 comprises, as compensation elements 138, a first half-rib 164a, which adjoins the first contact area 116, and a second half-rib 164b, which adjoins the second contact area 118.

[0166] At the in Fig. In the embodiment of a cell connector 100 shown in Figure 9, the connection area 136 arranged between a first contact area 116 and a second contact area 118 comprises, as compensation elements 138, a first half-rib 164a, which adjoins the first contact area 116, a second half-rib 164b, which adjoins the first half-rib 164a, a third half-rib 164c, which adjoins the second half-rib 164b, and a fourth half-rib 164d, which adjoins the second contact area 118.

[0167] All four half-ribs 164a to 164d each have an essentially S-shaped or Z-shaped cross-section.

[0168] One in Fig. The embodiment of a cell connector 100 shown in Figure 10 differs from the one shown in Figure 10. Fig. 8 embodiment in which a plateau 166 is arranged between the two half-ribs 164a and 164b, which the connection area 136 comprises as elastically and / or plastically deformable compensation elements 138, and which connects the first half-rib 164a and the second half-rib 164b to each other.

[0169] The plateau 166 is essentially flat and oriented essentially parallel to the first contact area 116 and essentially parallel to the second contact area 118 of the cell connector 100, but offset in the contacting direction 128 both relative to the first contact area 116 and relative to the second contact area 118.

[0170] As from Fig. As can be seen in Figure 10, the plateau 166 between the first half-rib 164a and the second half-rib 164b along the connecting direction 130 has a length l1.

[0171] Furthermore, the plateau 166 has an offset v1 relative to the first contact area 116 of the cell connector 100 along the contacting direction 128.

[0172] One in Fig. The embodiment of a cell connector 100 shown in Figure 11 differs from the one shown in Figure 11. Fig. 10 illustrated embodiment in that the length l2 of the plateau 166 in the embodiment is made of Fig. 11 is greater than the length l1 of the plateau 166 along the connecting direction 130 at the in Fig. 10 illustrated embodiment.

[0173] The offset v1 of the plateau 166 relative to the first contact area 116 along the contact direction 128 is, however, different in both embodiments according to the Fig. 10 and Fig. 11 are the same size.

[0174] One in Fig. Figure 12 shows a further embodiment of a cell connector 100 that differs from the one shown in Fig. In the embodiment shown in 10, the offset v2 of the plateau 166 relative to the first contact area 116 is increased in the case of the Fig. 12 shown embodiment is greater than the offset v1 of the plateau 166 relative to the first contact area 116 along the contacting direction 128 in the Fig. 10 illustrated embodiment.

[0175] The length l1 of the plateau 166 along the connecting direction 130, however, is in the Fig. In the embodiment of a cell connector 100 shown in Figure 12, the length l1 of the plateau 166 along the connection direction 130 is essentially the same as the length l1 of the plateau 166 along the connection direction 130 in the Fig. 10 illustrated embodiment of a cell connector 100.

[0176] Of course, an embodiment of a cell connector could also be created in which both the offset of the plateau 166 relative to the first contact area 116 along the contacting direction 128 and the length of the plateau 166 along the connection direction 130 differ from the corresponding dimensions of the one in Fig. The 10 cell connectors shown are 100 different.

Claims

[1] Cell connector for electrically connecting at least one first cell terminal (102) of a first electrochemical cell (104) and at least one second cell terminal (106) of a second electrochemical cell (108), comprising at least one first contact area (116) for electrically connecting the cell connector (100) to the at least one first cell terminal (102), at least one second contact area (118) for electrically connecting the cell connector (100) to the at least one second cell terminal (106) and at least one elastically and / or plastically deformable connecting region (136) which is arranged in the current path between the at least one first contact region (116) and the at least one second contact region (118), characterized by , that the connecting region (136) is at least partially formed from a work-hardened metallic material. [2] Cell connector according to claim 1, characterized by that the work-hardened metallic material is an aluminum material or a copper material. [3] Cell connector according to one of claims 1 or 2, characterized by that the degree of deformation (ε) of the work-hardened metallic material is at least 10%. [4] Cell connector according to one of claims 1 to 3, characterized by that the tensile strength (R m ) of the work-hardened metallic material more than 90 N / mm 2 amounts. [5] Cell connector according to one of claims 1 to 4, characterized by that the work-hardened metallic material is work-hardened by a cold rolling process, a stamping process or a forming process with local reduction of the material thickness. [6] Cell connector according to one of claims 1 to 5, characterized by that the cell connector (100) is formed in a single layer at least in the connecting region (136). [7] Cell connector according to one of claims 1 to 6, characterized by that the connecting region (136) is formed substantially entirely from the work-hardened metallic material. [8] Cell connector according to one of claims 1 to 7, characterized by that the connecting region (136) has at least one elastically and / or plastically deformable compensation element (138) made of the work-hardened material. [9] Cell connector according to claim 8, characterized by that the connecting region (136) comprises at least one wave (140), a step, a plateau (166) and / or a half-bead (164). [10] Cell connector according to one of claims 1 to 9, characterized bythat the cell connector (100) has at least one cross-section-reduced region (144) in the current path between the at least one first contact region (116) and the at least one second contact region (118), in which the electrically conductive cross-section of the cell connector (100) is reduced by at least one recess (146). [11] Cell connector according to one of claims 1 to 10, characterized by that the at least one first contact region (116) and / or the at least one second contact region (118) of the cell connector (100) is at least partially formed from a work-hardened metallic material. [12] Cell contacting system for an electrochemical device (112) comprising a plurality of electrochemical cells (104, 108), comprising at least one cell connector (100) according to one of claims 1 to 11. [13] An electrochemical device comprising a plurality of electrochemical cells (104, 108) and a cell contacting system according to claim 12. [14] Method for producing a cell connector (100) for electrically connecting at least one first cell terminal (102) of a first electrochemical cell (104) and at least one second cell terminal (106) of a second electrochemical cell (108), wherein the cell connector (100) at least one first contact area (116) for electrically connecting the cell connector (100) to the at least one first cell terminal (102), at least one second contact area (118) for electrically connecting the cell connector (100) to the at least one second cell terminal (106) and at least one elastically and / or plastically deformable connecting region (136) which is arranged in the current path between the at least one first contact region (116) and the at least one second contact region (118), the method comprising: - Providing a metallic starting material; - work hardening at least a portion of the metallic starting material to form a work hardened metallic material; and - Forming at least the at least one connecting region (136) of the cell connector (100) by forming the work-hardened metallic material or during the work-hardening of the metallic starting material to form the work-hardened metallic material. [15] Method according to claim 14, characterized by that the metallic starting material is soft annealed before work hardening.

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