Cell connectors for electrically conductive connection of cell terminals

Abstract

To create a cell connector for electrically connecting at least one first cell terminal and at least one second cell terminal, comprising at least one first contact area for connecting the cell connector to the first cell terminal and at least one second contact area for connecting the cell connector to the second cell terminal, wherein the cell connector comprises at least one connection area which is deformable such that the first contact area and the second contact area are movable relative to each other, wherein the connection area comprises at least one compensation section which includes at least one wave crest and / or at least one wave trough, and wherein the cell connector has a cross-sectionally reduced area in which the electrically conductive cross-section of the cell connector is reduced by one or more recesses,To increase the positional tolerance between the cell terminals and / or reduce the reaction forces acting on a joint between the cell connector and each cell terminal without excessively reducing the current-carrying capacity of the cell connector, it is proposed that at least one of the recesses extends through at least one crest and / or at least one trough of the compensation section and that the cell connector is multi-layered.

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, wherein the cell connector comprises at least one first contact region for electrically connecting the cell connector to the first cell terminal and at least one second contact region for electrically connecting the cell connector to the second cell terminal, wherein the cell connector comprises at least one connecting region which is elastically and / or plastically deformable such that the first contact region and the second contact region are movable relative to one another, wherein the connecting region comprises at least one compensation section which comprises at least one wave crest and / or at least one wave trough, and wherein the cell connector has at least one cross-section-reduced region in the current path between the first contact region and the second contact region, in which the electrically conductive cross-section of the cell connector is reduced by one or more recesses.

[0002] Known cell connectors of this type are used in battery modules, which comprise a large number of electrochemical cells that are connected in series and / or parallel.

[0003] In order to compensate for the positional tolerances of the cell terminals, which are connected to one another by means of a cell connector, which are caused by an age-related expansion of the electrochemical cells (“swelling”) and / or by an expansion of the electrochemical cells that occurs periodically during operation of the electrochemical cells (“breathing”) and / or by vibration of a vehicle, the cell connector is provided with the elastically and / or plastically deformable connection area.

[0004] In order to be able to transmit a specified maximum current via such a cell connector and not to exceed a maximum electrical resistance between the interconnected electrochemical cells, it is necessary to use a cell connector with a specified electrically conductive cross-section.

[0005] The cell connector is often formed by forming a starting material, which can be an aluminum sheet, for example.

[0006] Such an aluminum sheet can have a thickness of, for example, 1 mm.

[0007] Due to the limited height of the installation space available in a battery module, the at least one wave trough and / or the at least one wave crest of the compensation section of the connection area can only be formed with a limited amplitude. However, the design of the compensation section of the cell connector has a significant influence on the maximum positional tolerance between the cell terminals of the electrochemical cells connected by the cell connector, which can be compensated for by a maximum permissible force acting on the joint between the cell connector and each of the cell terminals connected by the cell connector.

[0008] If the material thickness of the cell connector is high, only a limited positional tolerance and / or a high reaction force on the joining connection between the cell connector and a cell terminal can be realized with a given low installation space height in a battery module.

[0009] The object of the present invention is to increase the maximum positional tolerance between the cell terminals electrically connected to one another by the cell connector, which occurs due to swelling and / or breathing of the electrochemical cells and / or vibration of a vehicle and can be compensated by the deformation region, and / or to reduce the reaction forces, without excessively reducing the current-carrying capacity of the cell connector.

[0010] This object is achieved according to the invention in a cell connector for electrically conductively connecting a first cell terminal of a first electrochemical cell and a second cell terminal of a second electrochemical cell having the features of the preamble of claim 1 in that at least one of the recesses extends along a longitudinal direction which is oriented transversely to the transverse direction of the cell connector, through at least one wave crest and / or through at least one wave trough of the compensation section and in that the cell connector is designed in multiple layers and comprises at least one first cell connector layer and a second cell connector layer at least in the compensation section.

[0011] To achieve essentially the same current-carrying capacity of the cell connector as with a cell connector made from a single cell connector layer with a material thickness of 1 mm, two cell connector layers with a material thickness of 0.5 mm each can be used. Alternatively, four cell connector layers with a material thickness of 0.25 mm each can be used, or three cell connector layers with a material thickness of 1 / 3 mm each.

[0012] The multi-layered nature of the cell connector significantly reduces the force exerted on the joints between the cell connector and the first cell terminal or the second cell terminal during a relative displacement of the cell terminals connected to one another by the cell connector. At these joints, preferably at least one cell connector layer of the cell connector is firmly bonded to the respective cell terminal, in particular by welding, particularly preferably by laser welding.

[0013] Preferably, at least two cell connector layers of the cell connector are connected to one another in a materially bonded manner, in particular by welding, preferably by laser welding.

[0014] Alternatively or additionally, it can also be provided that at least two cell connector layers of the cell connector are mechanically connected to one another, for example by positive locking and / or frictional locking.

[0015] The use of a multilayer cell connector increases the flexibility of the cell connector, particularly in the connection area, preferably in the compensation section of the connection area. The electrically conductive cross-section of the cell connector can be the same size as in the case of a single-layer cell connector.

[0016] Due to the recesses arranged in the connection region of the cell connector, in particular in the compensation section, the thermal conductivity of the cell connector is significantly reduced, while the electrical resistance of the cell connector is only slightly increased, so that thermal propagation across the cell connector is reduced without impairing the usability of the cell connector for establishing an electrically conductive connection between the first electrochemical cell and the second electrochemical cell.

[0017] This prevents a sudden increase in the temperature of an electrochemical cell in a battery module (so-called "thermal runaway"), which can be caused, for example, by overcharging the electrochemical cell or by damage to the electrochemical cell, from being transferred to a neighboring electrochemical cell by heat transfer via the cell connector and thereby also triggering such a "thermal runaway" in the neighboring electrochemical cell, which could lead to a chain reaction in the entire battery module.

[0018] Preferably, in the cross-section-reduced region of the cell connector, several layers, in particular all layers, of the cell connector are each provided with at least one recess.

[0019] However, the recesses of different layers may have a different shape and / or size.

[0020] In a preferred embodiment of the cell connector according to the invention, it is provided that the compensation section comprises at least one wave crest and at least one wave trough and at least one of the recesses extends along the longitudinal direction through the at least one wave crest and through the at least one wave trough.

[0021] The longitudinal direction of the cell connector is preferably aligned perpendicular to the transverse direction of the cell connector.

[0022] It has proven particularly advantageous if the compensation section comprises at least one wave crest and at least one wave trough, preferably at least two wave troughs, and at least one recess extends along the longitudinal direction of the cell connector through the at least one wave crest and through the at least one wave trough, preferably through the at least two wave troughs.

[0023] Preferably, all recesses of the reduced-cross-section region of the cell connector extend through the at least one wave crest and through the at least one wave trough, preferably the at least two wave troughs.

[0024] The at least one wave crest and / or the at least one wave trough preferably extend along a transverse direction of the cell connector.

[0025] A wave formed in the compensation section can extend out of the plane spanned by the connection direction and the transverse direction of the cell connector or can also be substantially planar and limited to the plane spanned by the connection direction and the transverse direction of the cell connector.

[0026] At least one of the recesses, preferably all of the recesses, of the reduced-cross-section region of the cell connector preferably extend into at least one substantially planar region of at least one contact region of the cell connector.

[0027] In a particularly preferred embodiment of the invention, it is provided that at least one of the recesses, preferably all of the recesses, of the reduced-cross-section region extend into a planar region of both contact regions of the cell connector.

[0028] The reduced-cross-section region of the cell connector preferably has at least two recesses, in particular at least three recesses, particularly preferably at least four recesses.

[0029] A material thickness of at least one of the cell connector layers of the cell connector is preferably less than 1 mm, in particular less than 0.9 mm, particularly preferably less than 0.5 mm, for example less than 0.3 mm, at least in the compensation section of the cell connector.

[0030] It is particularly advantageous if the material thickness of all cell connector layers of the cell connector, at least in the compensation section, is less than 1 mm, in particular less than 0.9 mm, particularly preferably less than 0.5 mm, for example less than 0.3 mm.

[0031] In preferred embodiments of the cell connector, it is provided that at least one of the cell connector layers is integrally connected to at least one further cell connector layer.

[0032] In particular, it can be provided that at least one of the cell connector layers is connected to at least one further cell connector layer by welding, particularly preferably by laser welding.

[0033] It is particularly advantageous if all cell connector layers of the cell connector are firmly connected to one another, in particular by welding, particularly preferably by laser welding.

[0034] It is advantageous if the at least one of the cell connector layers is integrally connected to the at least one further cell connector layer of the cell connector outside the compensation section of the cell connector.

[0035] In principle, it can be provided that at least one of the cell connector layers in the compensation section lies flat against at least one other of the cell connector layers, at least in some areas.

[0036] However, it is more advantageous if at least one of the cell connector layers does not lie flat against any other cell connector layer, at least in the compensation section.

[0037] It is particularly advantageous if all cell connector layers of the cell connector, at least in the compensation section, do not lie flat against any adjacent further cell connector layer of the cell connector.

[0038] In principle, it can be provided that at least one, preferably each, of the recesses is formed symmetrically with respect to a plane running perpendicular to the transverse direction of the cell connector.

[0039] In a preferred embodiment of the invention, however, it is provided that at least one of the recesses is formed asymmetrically with respect to each plane running perpendicular to the transverse direction of the cell connector.

[0040] It is preferably provided that all recesses of the reduced-cross-section region of the cell connector are formed asymmetrically with respect to each plane running perpendicular to the transverse direction of the cell connector.

[0041] For example, it can be provided that at least one of the recesses comprises a first end region facing the first contact region of the cell connector, a second end region facing the second contact region of the cell connector and a central region lying between the first end region and the second end region, wherein the central region is connected to the first end region or to the second end region via a respective constriction region and wherein the respective recess in the constriction region has a respective minimum width (b) which is smaller than a maximum width (B1) of the recess in the first end region, smaller than a maximum width (B2) of the recess in the second end region and / or smaller than a maximum width (B m ) of the recess in the central region of the recess.

[0042] It is particularly advantageous if all recesses of the reduced-cross-section area of ​​the cell connector are designed in the manner described above.

[0043] The cell connector according to the invention is particularly suitable for use as a component of an electrochemical device which comprises a first electrochemical cell having a first cell terminal, a second electrochemical cell having a second cell terminal, and a cell connector according to the invention, wherein the cell connector electrically connects the first cell terminal of the first electrochemical cell and the second cell terminal of the second electrochemical cell to one another.

[0044] The electrochemical cells can, for example, be designed as lithium-ion battery cells.

[0045] The electrochemical device may, for example, be designed as a battery module or comprise one or more battery modules.

[0046] The electrochemical device can be used, for example, in a vehicle, in particular an automobile, or in a stationary energy storage device.

[0047] Further features and advantages of the invention are the subject of the following description and the drawing of an embodiment.

[0048] 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 region for electrically connecting the cell connector to the first cell terminal and a second contact region for electrically connecting the cell connector to the second cell terminal, as well as a connection region which is elastically and / or plastically deformable such that the first contact region and the second contact region are movable relative to one another, wherein the connecting region comprises at least one compensation section which comprises at least one wave crest and / or at least one wave trough extending along a transverse direction of the cell connector, and wherein the cell connector has at least one cross-section-reduced region in the current path between the first contact region and the second contact region, in which the electrically conductive cross-section of the cell connector is reduced by one or more recesses in the form of through-openings, wherein at least one of the recesses extends along a longitudinal direction which is oriented transversely to the transverse direction of the cell connector, through at least one wave crest and / or through at least one wave trough of the compensation section and wherein the cell connector is formed in multiple layers and comprises at least a first cell connector layer and a second cell connector layer at least in the compensation section, with the view towards the top side of the cell connector facing away from the cell terminals of the electrochemical cells to be connected to one another when the cell connector is in the assembled state; Fig. 2 another perspective view of the cell connector from Fig. 1, with the view towards the underside of the cell connector facing the cell terminals of the electrochemical cells to be connected to one another in the assembled state of the cell connector; Fig. 3 a schematic side view of the cell connector from the Fig. 1 and Fig. 2, the first cell terminal, the second cell terminal, the first electrochemical cell and the second electrochemical cell, looking in the direction of arrow 3 in Fig. 1; Fig. 4 a top view of the cell connector from the Fig. 1 to 3; Fig. 5 a bottom view of the cell connector from the Fig. 1 to 3; Fig. 6 a cross-section through the cell connector from the Fig. 1 to 5, along the line 6 - 6 in Fig. 4; and Fig. 7 an enlarged view of area I from Fig. 3.

[0049] Identical or functionally equivalent elements are designated by the same reference numerals in all figures.

[0050] One in the Fig. The cell connector 100 shown in Figures 1 to 7 serves for the electrically conductive connection of a first cell terminal 102 of a first electrochemical cell 104 and a second cell terminal 106 of a second electrochemical cell 108 (see in particular the Fig. 3).

[0051] The electrochemical cells 104 and 108 form components of a battery module 109 of an electrochemical device designated as a whole by 111, which may comprise a plurality of battery modules 109, each of which in turn comprises a plurality of electrochemical cells 104, 108.

[0052] The electrochemical device 111 can be designed in particular as an accumulator, in particular as a lithium-ion accumulator.

[0053] The electrochemical cells 104, 108 of the electrochemical battery modules 109 can be designed accordingly as accumulator cells, in particular as lithium-ion accumulator cells.

[0054] The first cell terminal 102 can have positive or negative polarity; the second cell terminal 106 then has the opposite polarity, for example, the negative polarity or the positive polarity.

[0055] The cell connector 100 comprises a base body 110, which in turn has a first contact region 112, which in the assembled state of the cell connector 100 is electrically conductively connected to the first cell terminal 102 of the first electrochemical cell 104, and a second contact region 114, which in the assembled state of the cell connector 100 is electrically conductively connected to the second cell terminal 106 of the second electrochemical cell 108.

[0056] The base body 110 of the cell connector 100 comprises several, for example two, three or more, cell connector layers, which are preferably each manufactured as a stamped and bent part.

[0057] In the exemplary embodiment shown in the drawing, the base body 110 of the cell connector 100 comprises a first cell connector layer 113 facing the cell terminals 102, 106 in the assembled state of the cell connector 100 and a second cell connector layer 115 facing away from the cell terminals 102, 106.

[0058] The cell connector layers 113, 115 of the cell connector 100 can be formed in particular from aluminum, copper, tin, zinc, iron, gold or silver or from an alloy of one or more of the aforementioned metals.

[0059] Furthermore, the cell connector layers 113, 115 of the cell connector 100 can also be formed from another metal or another metallic alloy.

[0060] In addition, the cell connector layers 113, 115 of the cell connector 100 can in principle also be formed from a conductive plastic material and / or from a conductive carbon material.

[0061] In the assembled state of the cell connector 100, the first contact region 112 and the second contact region 114 of the cell connector 100 are connected by screwing or preferably by a material fit to the respectively assigned cell terminal 102 or 106.

[0062] Such a material connection can be produced in particular by welding, in particular laser welding, or by soldering.

[0063] In order to enable direct access, for example for measuring purposes, to the cell terminals 102 and 106, respectively, even after the material-to-material connection of the cell connector 100 to the cell terminals 102 and 106, the first contact region 112 can be provided with a, for example substantially circular, through-opening 116 and / or the second contact region 114 of the base body 110 can be provided with a, for example substantially circular, through-opening 118.

[0064] The passage openings 116 and 118 preferably extend through all cell connector layers 113, 115 of the cell connector 100.

[0065] During operation of the electrochemical device 111, due to different temperatures and / or different thermal expansion coefficients 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, a difference can occur between a longitudinal expansion of the cell connector 100 on the one hand and a change in the distance between the longitudinal axis 120 of the first cell terminal 102 and the longitudinal axis 122 of the second cell terminal 106 on the other hand. A change in temperature changes the relative positions of the cell terminals 102, 106 connected to one another by the cell connector 100 in a connection direction 126 oriented perpendicular to the axial direction 124 of the cell terminals 102, 106 and / or in a transverse direction 128 oriented perpendicular to the axial direction 124 of the cell terminals 102, 106 and perpendicular to the connection direction 126.

[0066] The connection direction 126 lies in a plane containing the longitudinal axes 120, 122 of the cell terminals 102 and 106 and runs parallel to a longitudinal direction 130 of the cell connector 100.

[0067] In particular, the connection direction 126 runs through a center 132 of the through-opening 116 in the first contact region 112 and through a center 134 of the through-opening 118 in the second contact region 114 of the cell connector 100.

[0068] Furthermore, due to different longitudinal expansions of the electrochemical cells 104 and 108 connected to one another by the cell connector 100, a change in the relative positions between the interconnected cell terminals 102 and 106 along the axial direction 124 of the cell terminals 102, 106 may occur.

[0069] In order to be able to compensate for such relative movements between the interconnected cell terminals 102, 106 and thus between the first contact region 112 and the second contact region 114 of the cell connector 100 in the longitudinal direction 130 of the cell connector 100, in the transverse direction 128 of the cell connector 100 and / or in a contact direction 136 of the cell connector 100 oriented perpendicular to the longitudinal direction 130 and perpendicular to the transverse direction 128, the base body 110 of the cell connector 100 comprises an elastically and / or plastically deformable connecting region 138, which is arranged between the first contact region 112 and the second contact region 118 in the current path of the cell connector 100 and connects the two contact regions 112 and 114 to one another.

[0070] In the embodiment of a cell connector 100 shown in the drawing, the deformable connection region 138 comprises a compensation section 140, which comprises a central wave crest 166 and two wave troughs 168 arranged laterally next to the wave crest 166.

[0071] The wave crest 166 and the wave troughs 168 preferably extend substantially parallel to the transverse direction 128 of the cell connector 100.

[0072] Furthermore, the cell connector 100 comprises at least one cross-section-reduced region 142 in the current path between the first contact region 112 and the second contact region 114, 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 four, recesses 144.

[0073] The recesses 144 are preferably formed as through-openings 152 in the base body 110 of the cell connector 100 and extend from a bottom side 154 of the cell connector 100 facing the cell terminals 102, 106 to be connected to one another in the assembled state of the cell connector 100 to a top side 156 of the cell connector 100 facing away from the cell terminals 102 and 106 to be connected to one another in the assembled state of the cell connector 100, through all cell connector layers 113, 115 of the cell connector 100.

[0074] Preferably, the cross-sectionally reduced region 142 comprises a plurality of such passage openings 152, in particular at least three such passage openings 152, particularly preferably at least four such passage openings 152, as in the exemplary embodiment shown in the drawing.

[0075] The passage openings 152 follow one another along the transverse direction 128 of the cell connector 100 and are each separated from an adjacent other passage opening 152 or from an outer edge 148 of the cell connector 100 by a constriction 158 of the reduced-cross-section region 142.

[0076] The extension of at least one constriction 158 along the transverse direction 128 is preferably greater than the extension of at least one of the passage openings 152 adjacent to the constriction 158 along the transverse direction 128.

[0077] Preferably, at least one of the passage openings 152 of the reduced-cross-section region 142 is formed as an elongated hole 160.

[0078] Particularly preferably, all passage openings 152 of the reduced-cross-section region 142 are each designed as an elongated hole 160.

[0079] The electrically conductive cross section of each reduced-cross-section region 142 is preferably less than 90%, in particular less than 70%, particularly preferably less than 60%, of the electrically conductive cross section that the respective reduced-cross-section region 142 would have without the presence of the recesses 144.

[0080] The cell connector layers 113, 115 of the cell connector 100 are preferably formed from a material having a thermal conductivity of at least 200 W / mK and / or a specific heat capacity of at least 800 J / kgK.

[0081] Such a material can in particular be an aluminum alloy.

[0082] Each of the reduced-cross-section regions 142 forms a chain of recesses 144 along the current path from the first contact region 112 to the second contact region 114.

[0083] The recesses 144 are preferably separated from the base body 110 after the formation of the same, for example punched out, or cut out, preferably by means of a laser.

[0084] The recesses 144 preferably have a rounded edge 164 to prevent tearing of the base body 110 after the recesses 144 have been formed in the base body 110.

[0085] Preferably, the extent of each recess 144 of a reduced-cross-section region 142 along the longitudinal direction 130 or along the connecting direction 126 of the cell connector 100 is greater than the extent of the same recess 144 along the transverse direction 128 of the cell connector 100.

[0086] The thermal conductivity of the cell connector 100 is greatly reduced by the cross-sectional reduction in the area of ​​the cross-sectionally reduced regions 142 of the cell connector.

[0087] The mechanical properties of the connecting region 138 of the cell connector 100, which serve to compensate for positional tolerances between the first contact region 112 and the second contact region 140, are retained or improved.

[0088] Despite the high current density, the constrictions 158 in the cross-section-reduced regions 142 dissipate heat well due to the immediately adjacent large areas of the regions 162 of the cell connector 100 adjoining the cross-section-reduced regions 142.

[0089] The operating principle of the cross-section-reduced areas 142 is similar to that of so-called heat traps on electrical conductor tracks.

[0090] The increase in the electrical resistance of the cell connector 100 due to the presence of the reduced-cross-section region 142 is only slight, preferably less than 10%.

[0091] However, the reduction in cross-section in the reduced-cross-section regions 142 represents a significant obstacle to the transfer of heat, so that the thermal resistance of the cell connector 100 in the longitudinal direction 130 or in the connection direction 126 increases by preferably at least 200%.

[0092] Due to this significant increase in the thermal resistance of the cell connector 100, the propagation of a temperature increase from the first electrochemical cell 104 to the second electrochemical cell 108 is significantly delayed, preferably by at least 10 seconds, in particular by at least 15 seconds, particularly preferably by at least 20 seconds.

[0093] Thus, it can be prevented that in the event of a “thermal runaway” of the first electrochemical cell 104 due to heat transfer via the cell connector 100, a “thermal runaway” of the second electrochemical cell 108 is also triggered.

[0094] This delay in thermal propagation between the first electrochemical cell 104 and the second electrochemical cell 108 is particularly effective when thermal insulation is arranged between a first cell housing of the first electrochemical cell 104 and a second cell housing of the second electrochemical cell 108, wherein the thermal resistance of the thermal insulation is preferably greater than a quarter, in particular greater than a third, particularly preferably greater than half, for example greater than two-thirds, of the thermal resistance of the cell connector 100.

[0095] This can be achieved, for example, by the thermal insulation arranged between the cell housings of the electrochemical cells 104 and 108 comprising an air layer and / or a thermal insulation layer made of a solid material.

[0096] The layer of heat-insulating solid material may, for example, comprise mica.

[0097] The thickness of the layer of heat-insulating solid material is preferably at least 0.5 mm, in particular at least 1 mm.

[0098] The thickness of the air layer of the thermal insulation is preferably at least 0.5 mm, in particular at least 1 mm.

[0099] Preferably, the constrictions 158 of the reduced-cross-section region 142 are arranged substantially equidistant from one another along the transverse direction 128 of the cell connector 100.

[0100] The bottlenecks 158 are preferably dimensioned such that, in the case of peak currents being called from the electrochemical device 111 in the respective application, they always operate well below the tripping threshold of fuses present in the circuit.

[0101] The reduced-cross-section region 142, in particular the recesses 144 and the constrictions 158, is preferably formed mirror-symmetrically to a transverse center plane 170 of the cell connector 100, which is aligned parallel to the transverse direction 128 and perpendicular to the contact regions 112, 114 of the cell connector 100.

[0102] The recesses 144 of the cross-section-reduced region 142 extend along the longitudinal direction 130 of the cell connector 100, which is oriented transversely, preferably perpendicularly, to the transverse direction 128 of the cell connector 100, through the wave crest 166 and the two wave troughs 168 of the compensation section 140 into the flat regions 172 of the first contact region 112 and the second contact region 114, respectively, adjacent to the wave troughs 168.

[0103] The material thickness of at least one of the cell connector layers 113, 115 is, at least in the compensation section 140 of the cell connector 100, less than 1 mm, in particular less than 0.9 mm, particularly preferably less than 0.5 mm, for example less than 0.3 mm.

[0104] It has proven particularly advantageous for the easy deformability of the compensation section 140 if the material thickness of all cell connector layers 113, 115 of the cell connector 100, at least in the compensation section 140 of the cell connector 100, is less than 1 mm, in particular less than 0.9 mm, particularly preferably less than 0.5 mm, for example less than 0.3 mm.

[0105] As best seen from the top view of the underside 154 of the cell connector 100 in Fig. 5, the cell connector layers 113, 115 in the first contact area 112 and in the second contact area 114 of the cell connector 100 are materially connected to one another, preferably by at least one joining line 174 in each case.

[0106] Preferably, the first contact region 112 and / or the second contact region 114 has two or more such joining lines 174.

[0107] The joining lines 174 are preferably aligned substantially parallel to the longitudinal direction 130 of the cell connector 100.

[0108] At the joining lines 174, at least two cell connector layers 113, 115 are connected to one another in a materially bonded manner, preferably by welding, particularly preferably by laser welding.

[0109] Preferably, the cell connector layers 113 and 115 of the cell connector 100 are integrally connected to one another outside the compensation section 140 of the cell connector 100.

[0110] How best to use the Fig. 3, Fig. 6 and Fig. 7, the cell connector layers 113 and 115 lie flat against one another at least in some areas, at least in the compensation section 140 of the cell connector 100.

[0111] However, it can also be provided that the cell connector layers 113 and 115 in the compensation section 140 of the cell connector 100 do not lie flat against one another.

[0112] How best to use the Fig. 4 and Fig. 5, the recesses 144 of the reduced-cross-section region 142 of the cell connector 100 - at least in a relaxed resting state of the cell connector 100 - are formed asymmetrically with respect to each plane running perpendicular to the transverse direction 128 and parallel to the longitudinal direction 130 of the cell connector 100.

[0113] In the embodiment of a cell connector 100 shown in the drawing, it is provided that the recesses 144 each have a first end region 176 facing the first contact region 112 of the cell connector 100, a second end region 178 facing the second contact region 114 of the cell connector 100 and a central region 180 lying between the first end region 176 and the second end region 178.

[0114] The central region 180 is connected to the first end region 176 or to the second end region 178 of the same recess 144 via a respective narrowing region 182 of the respective recess 144.

[0115] The respective recess 144 has in the constriction regions 182 a minimum width b which is smaller than a maximum width B1 of the recess 144 in the first end region, smaller than a maximum width B2 of the recess 144 in the second end region 178 and smaller than a maximum width B m the recess 144 in the central region 180 of the recess 144.

[0116] The width is the extent of the recess 144 parallel to the transverse direction 128 of the cell connector 100.

[0117] By "breathing" and / or "swelling" of the first electrochemical cell 104 and the second electrochemical cell 108, which are connected to one another by the cell connector 100, and / or by vibration and / or by local heating of the cell connector 100 ("thermopulse"), the relative position between the first contact region 112 and the second contact region 114 changes during the operation of the electrochemical device 111 in which the electrochemical cells 104, 108 are arranged, and / or during the accumulated operating time of the first electrochemical cell 104 and the second electrochemical cell 108.

[0118] In particular, the relative position of the first contact region 112 and the second contact region 114 changes along the contact direction 136 of the cell connector 100.

[0119] Because the cell connector 100 is designed in multiple layers, the flexibility and deformability of the compensation section 140 of the cell connector 100 and thus its ability to compensate for positional tolerances of the first contact region 112 and the second contact region 114 of the cell connector 100 is increased compared to a single-layer cell connector 100 with the same overall material thickness.

[0120] Thus, even with a low overall height of the cell connector 100, relatively large displacement paths of the first contact region 112 relative to the second contact region 114 along the contact direction 136 of the cell connector 100 can be achieved.

[0121] Since the cross section of the cell connector 100 available for the electrical current flow (outside the reduced-cross-section region 142) remains unchanged due to the same overall material thickness, the current-carrying capacity of the cell connector 100 is retained even in the case of multi-layer construction.

[0122] Furthermore, the multi-layer nature of the cell connector 100 significantly reduces the force acting on the welding of the cell connector 100 to the first cell terminal 102 or to the second cell terminal 106.

[0123] As already described, the cell connector layers 113 and 115 of the cell connector 100 are also connected to one another in a materially bonded manner, preferably by welding, in particular by laser welding, and / or mechanically.

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 region (112) for electrically connecting the cell connector (100) to the first cell terminal (102) and at least one second contact region (114) for electrically connecting the cell connector (100) to the second cell terminal (106), wherein the cell connector (100) comprises at least one connecting region (138) which is elastically and / or plastically deformable such that the first contact region (112) and the second contact region (114) are movable relative to one another, wherein the connecting region (138) comprises at least one compensation section (140) which comprises at least one wave crest (166) and / or at least one wave trough (168), and wherein the cell connector (100) has at least one cross-section-reduced region (142) in the current path between the first contact region (112) and the second contact region (114), in which the electrically conductive cross-section of the cell connector (100) is reduced by one or more recesses (144), characterized by , that at least one of the recesses (144) extends along a longitudinal direction (130) which is oriented transversely to the transverse direction (128) of the cell connector (100), through at least one wave crest (166) and / or through at least one wave trough (168) of the compensation section (140) and that the cell connector (100) is designed in multiple layers and comprises at least a first cell connector layer (113) and a second cell connector layer (115) at least in the compensation section (140). [2] Cell connector according to claim 1, characterized bythat the compensation section (140) comprises at least one wave crest (166) and at least one wave trough (168) and at least one of the recesses (144) extends along the longitudinal direction (130) through the at least one wave crest (166) and through the at least one wave trough (168). [3] Cell connector according to one of claims 1 or 2, characterized by that the compensation section (140) comprises at least one wave crest (166) and at least one wave trough (168) and at least one recess (144) extends along the longitudinal direction (130) of the cell connector (100) through the at least one wave crest (166) and through the at least one wave trough (168). [4] Cell connector according to one of claims 1 to 3, characterized by that the cross-section-reduced region (142) of the cell connector (100) has at least two recesses (144). [5] Cell connector according to one of claims 1 to 4, characterized bythat a material thickness of at least one of the cell connector layers (113, 115) is less than 1 mm at least in the compensation section (140). [6] Cell connector according to one of claims 1 to 5, characterized by that at least one of the cell connector layers (113, 115) is integrally connected to at least one further cell connector layer (115, 113). [7] Cell connector according to claim 6, characterized by that the at least one of the cell connector layers (113, 115) is integrally connected to the at least one further cell connector layer (115, 113) outside the compensation section (140) of the cell connector (100). [8] Cell connector according to one of claims 1 to 7, characterized by that at least one of the cell connector layers (113, 115) does not lie flat against any other cell connector layer (115, 113), at least in the compensation section (140). [9] Cell connector according to one of claims 1 to 8, characterized bythat at least one of the recesses (144) is formed asymmetrically with respect to each plane running perpendicular to the transverse direction (128) of the cell connector (100). [10] Cell connector according to one of claims 1 to 9, characterized bythat at least one of the recesses (144) comprises at least one first end region (176) facing a first contact region (112) of the cell connector (100), at least one second end region (178) facing a second contact region (114) of the cell connector (100), and at least one central region (180) lying between the first end region (176) and the second end region (178), wherein the central region (180) is connected to the first end region (176) and to the second end region (178) via a respective constriction region (182), and wherein the recess (144) in the constriction region (182) has a respective minimum width (b) which is smaller than a maximum width (B1) of the recess (144) in the first end region (176), smaller than a maximum width (B2) of the recess (144) in the second end region (178) and / or smaller than a maximum width (B m) of the recess (144) in the central region (180) of the recess (144).

Images