Cell contact system for an electrical energy storage device and electrical energy storage device with the cell contact system

Abstract

The invention relates to a cell contacting system (25) for an electrical energy storage device (10) and an electrical energy storage device (10), wherein the cell contacting system (25) has a hold-down device (40), a flexible circuit board (45) and a sensor (50) arranged on the flexible circuit board (45), wherein the hold-down device (40) has a holding section (55), a spring section (60) and a fastening section (65), wherein the holding section (55) bears against the flexible circuit board (45) with a first contact surface (70), wherein the fastening section (65) is arranged offset to the holding section (55) and the spring section (60) mechanically connects the fastening section (65) to the holding section (55), wherein the hold-down device (40) has a sensor (50) extending over the fastening section (65),the spring portion (60) and the holding portion (55) extending first material layer (90) and a second material layer (95) extending at least over the fastening portion (65) and connected to the first material layer (90), wherein the hold-down device (40) is designed to provide a spring force (FF) for pressing the holding portion (55) against the flexible printed circuit board (45).

Description

[0001] The invention relates to a cell contacting system according to claim 1 and an electrical energy storage device according to claim 11.

[0002] Electrical energy storage devices, in particular traction batteries for an electrically powered vehicle, are known, comprising a battery cell arrangement and a cell contact system. A temperature sensor is attached to a battery cell of the battery cell arrangement.

[0003] The object of the invention is to provide an improved cell contacting system and an improved electrical energy storage device.

[0004] This object is achieved by means of a cell contacting system according to claim 1 and by means of an electrical energy storage device according to claim 11. Advantageous embodiments are specified in the dependent claims.

[0005] It has been recognized that an improved cell contacting system for an electrical energy storage device can be provided by having the cell contacting system comprise a holding device, a flexible circuit board, and a sensor arranged on the flexible circuit board. The holding device comprises a holding portion, a spring portion, and a fastening portion, wherein the holding portion bears against the flexible circuit board with a first contact surface. The fastening portion is arranged offset from the holding portion, and the spring portion mechanically connects the fastening portion to the holding portion.

[0006] The hold-down device has a first material layer extending over the fastening section, the spring section and the holding section and a second material layer extending at least over the fastening section and connected to the first material layer, wherein the hold-down device is designed to provide a spring force for pressing the holding section against the flexible printed circuit board.

[0007] This design has the advantage that the first material layer can be made particularly thin, while the second material layer can be used to stiffen the first layer. The materials used for the first and second layers can be optimally adapted to the specific conditions of use.

[0008] In a further embodiment, the cell contacting system has at least one cell connector arrangement with at least one cell connector. The cell connector can be electrically connected to a terminal pole of an electrical energy storage cell of the electrical energy storage device. The first material layer has an electrically conductive first material, wherein the fastening section rests against the cell connector with the first material layer and is connected to the cell connector. The second material layer has a second material that is different from the first material. This configuration has the advantage that, for example, the second material can be selected to be electrically insulating, so that the second material layer electrically insulates the first material layer from its surroundings, in particular from unwanted contact.

[0009] In a further embodiment, the first material layer extends from a first end of the hold-down device over the spring portion and the holding portion in a longitudinal direction to a second end of the hold-down device. The first end is arranged on the fastening portion. The first material layer is formed in one piece and from a single material. For example, the first material layer can be produced from sheet metal using a stamping and bending process, making the first material layer easy to manufacture and form.

[0010] Starting from the first end, the second material layer is shorter in the longitudinal direction than the first material layer, and the second material layer covers a first partial section of the first material layer, preferably on a side facing away from the cell connector. This configuration has the advantage that the first material layer is uncovered in a second partial section, allowing a tool, for example for resistance welding or soldering, to be applied to the first material layer. For example, the first material layer can be connected to a first conductor track of the flexible printed circuit board by means of a soldering or welding process in the region of the holding section through the exposed second partial section.In the first section, the hold-down device can be influenced via the second material layer in such a way that the hold-down device is stiffened by the second material layer and thus a particularly large spring force can be provided for pressing the holding section onto the flexible circuit board and thus for pressing the flexible circuit board onto the electrical energy storage device.

[0011] In a further embodiment, the hold-down device has a third material layer, which is arranged on the second material layer on a side facing away from the first material layer and is connected to the second material layer. The third material layer can, for example, further stiffen the hold-down device in the area of ​​the fastening section, thus preventing unwanted bending or flexion of the fastening section. This can prevent shear stress on the connection between the hold-down device and the cell connector.

[0012] In a further embodiment, the third material layer can be shorter in the longitudinal direction, starting from the first end, than the first material layer and / or the second material layer. This allows the spring force to be further adapted by means of the third material layer and, for example, the stiffness of the spring section of the hold-down device to be defined. This results in a stepped design of the hold-down device.

[0013] In a further embodiment, the first material layer has a first thickness of 0.1 mm to 0.3 mm inclusive. The second material layer has a second thickness of 0.1 mm to 0.5 mm inclusive, in particular 0.3 mm to 0.5 mm inclusive.

[0014] In a further embodiment, the first material layer comprises at least one of the following first materials and / or the second material layer comprises at least one of the following second materials: aluminum, steel, spring steel, nickel, an electrically conductive material, metal, an electrically non-conductive material, a plastic, a material with a continuous temperature resistance of greater than 125 °C, a thermoset, a thermoplastic.By means of the electrically conductive first materials, an electrical connection between the fastening section and the holding section via the spring section is possible, so that in addition to pressing the flexible circuit board against the battery side surface and thus an indirect temperature measurement, an electrical connection can also be provided via the cell connector to the connection pole, so that two operating states of the electrical energy storage cell can also be detected and transmitted via the circuit board.

[0015] The second material is particularly well-suited for stiffening the hold-down device. Additionally, the electrically non-conductive second material can ensure electrical insulation of the hold-down device, especially the first material layer. This can provide protection against accidental contact.

[0016] In a further embodiment, the second material of the second material layer is different from the first material of the first material layer. Alternatively, the second material of the second material layer can be identical to the first material of the first material layer.

[0017] In a further embodiment, the first material layer is connected, preferably mechanically and electrically, to the cell connector by means of a welded joint, in particular by means of an ultrasonic welded joint and / or a resistance welded joint, and / or a riveted joint and / or a clinched joint and / or a sintered joint. The second material layer is connected to the first material layer by means of an adhesive bond. This configuration can be manufactured particularly easily and cost-effectively, allowing the layers to be connected to one another and ensuring a secure connection of the first material layer to the hold-down device.

[0018] An improved electrical energy storage device can be provided in that the electrical energy storage device has a cell contacting system and an energy storage cell arrangement with at least one electrical energy storage cell with a connection pole and a storage cell side surface. The cell contacting system is designed as described above, wherein the cell connector is electrically connected to the connection pole. The flexible printed circuit board rests against the storage cell side surface in some areas. The hold-down device presses the flexible printed circuit board against the storage cell side surface using spring force. This makes it possible to provide an electrical energy storage device that is particularly easy to install. Furthermore, the hold-down device ensures reliable measurement, for example of a temperature of the energy storage cell, so that the energy storage cell arrangement can be operated reliably within its permissible operating parameters.

[0019] The invention is explained below with reference to the figures. These show: Fig. 1 a schematic representation of an electrical energy storage device with a hold-down device according to a first embodiment; Fig. 2 a perspective view of the Fig. 1 shown hold-down device; and Fig. 3 a schematic representation of the hold-down device in the pressed installed state.

[0020] For ease of understanding, the following figures refer to a coordinate system. The coordinate system has, for example, an x-axis (longitudinal direction), a y-axis (transverse direction), and a z-axis (height direction). The coordinate system can, for example, be designed as a right-hand system.

[0021] Fig. 1 shows a schematic representation of an electrical energy storage device 10 with a hold-down device 40 according to a first embodiment.

[0022] The electrical energy storage device 10 can be designed, for example, as a traction battery for an electrically powered vehicle, in particular a fully electrically powered vehicle or a hybrid vehicle. Fig. 1 only a part of the electrical energy storage device 10 is shown.

[0023] The electrical energy storage device 10 has an energy storage cell arrangement 15 which is arranged in Fig. 1 is indicated schematically. The energy storage cell arrangement 15 can have at least one electrical energy storage cell 20.

[0024] The electrical energy storage cell 20 can be configured, for example, as a lithium-ion cell, a lithium iron phosphate cell, and / or a pouch cell. Furthermore, the electrical energy storage device 10 has a cell contact system 25.

[0025] The electrical energy storage cell 20 has a storage cell side surface 35. The storage cell side surface 35 can, for example, be flat and extend, for example, in an xy plane. The storage cell side surface 35 is preferably arranged on a side of the electrical energy storage cell 20 facing the cell contact system 25.

[0026] The cell contacting system 25 comprises at least one cell connector arrangement 30, the hold-down device 40 according to the first embodiment, at least one flexible printed circuit board 45 and at least one sensor 50.

[0027] In the embodiment, the sensor 50 is designed, for example, as a temperature sensor. In the embodiment as a temperature sensor, the sensor 50 can be designed, for example, as an NTC sensor.

[0028] The flexible printed circuit board 45 has a flexible carrier material on which at least one first conductor track arrangement 145 (in Fig. 1 not shown). The first conductor track arrangement 145 can, for example, be electrically connected to the sensor 50, in particular the temperature sensor. Due to the flexible carrier material of the flexible printed circuit board 45, the flexible printed circuit board 45 can be bent reversibly and non-destructively by at least 30° up to and including 300° at least 100 times with little effort. In particular, the flexible printed circuit board 45 is particularly well suited to conform to the memory cell side surface 35. The sensor 50 is designed to detect a temperature of the memory cell side surface 35 and to provide information about the temperature at the first conductor track arrangement 145 of the flexible printed circuit board 45.

[0029] During operation of the electrical energy storage device 10, for example during charging or discharging with electrical energy, an operating parameter, in particular a temperature, of the electrical energy storage cell 20 changes. For example, during a rapid charging process, the electrical energy storage cell 20 can heat up considerably. Likewise, during the rapid charging process, in particular at the beginning of the rapid charging process, it is necessary to detect the current temperature of the electrical energy storage cell 20 in order to optimally charge the electrical energy storage cell 20 and not charge it with excessive electrical power. This can prevent damage to and / or destruction of the electrical energy storage cell 20.

[0030] When the temperature of the energy storage cell 20 changes, a spatial extent of the energy storage cell 20 changes. In particular, the energy storage cell 20 can expand, for example, in the y- and / or z-direction or contract when cooled.

[0031] In particular, the operating parameter, in particular the temperature, of the electrical energy storage cell 20 must be maintained within its operating data in order, for example, to minimize the risk of fire in the electrical energy storage cell 20. In order to detect a change in the operating parameter, in particular in the temperature of the energy storage cell 20, particularly quickly, Fig. 1, the flexible printed circuit board 45 is pressed against the storage cell side surface 35 with a spring force FF by the hold-down device 40 in order to ensure a good thermal connection between the storage cell side surface 35 of the energy storage cell 20 and the sensor 50. The storage cell side surface 35 acts against the spring force FF with a counterforce FG.

[0032] By pressing the flexible circuit board 45 with the sensor 50 onto the storage cell side surface 35, a reliable contact of the sensor 50 with the storage cell side surface 35 is ensured even in the event of a thermal expansion change of the energy storage cell 20.

[0033] In the embodiment, the hold-down device 40 has a holding portion 55, a spring portion 60, and a fastening portion 65. The holding portion 55 has a first contact surface 70, which is arranged on the holding portion 55 on a side facing the flexible printed circuit board 45 and against which the holding portion 55 rests against the flexible printed circuit board 45.

[0034] The flexible printed circuit board 45 has a second contact surface 75. The second contact surface 75 faces away from the hold-down device 40 and rests against the memory cell side surface 35, preferably in a flat manner.

[0035] In the z-direction, opposite the second contact surface 75, the flexible printed circuit board 45 has a printed circuit board side surface 80. The printed circuit board side surface 80 can be substantially planar and follows a contour of the second contact surface 75. Thus, the printed circuit board side surface 80 can be aligned substantially parallel to the memory cell side surface 35.

[0036] The spring portion 60 is arranged in the longitudinal direction (x-direction) between the holding portion 55 and the fastening portion 65 and connects the holding portion 55 to the fastening portion 65. The hold-down device 40 preferably has a Z-shaped configuration, at least in the relaxed state, so that the spring portion 60 is arranged at a first obtuse angle α to the holding portion 55 and a second obtuse angle β to the fastening portion 65. The first angle α and the second angle β can be identical.

[0037] In the embodiment, the hold-down device 40 is multi-layered and has at least a first material layer 90 and at least a second material layer 95. In Fig. In Figure 1, the first material layer 90 and the second material layer 95 are shown exaggeratedly thick for illustrative purposes. Additionally, the hold-down device 40 may have a third material layer 100 and, if appropriate, a fourth material layer 105.

[0038] In relation to the longitudinal direction, the hold-down device 40 extends from a first end 110 to a second end 115. The first end 110 is arranged, for example, on the fastening section 65 on a side facing the cell connector 85. The hold-down device 40 extends via the fastening section 65, the spring section 60, and the holding section 55 to the second end 115. The second end 115 is arranged, for example, on the holding section 55 on a side facing away from the fastening section 65 in the longitudinal direction.

[0039] Fig. 2 shows a perspective view of the Fig. 1 shown hold-down device 40.

[0040] The first material layer 90 extends from the first end 110 to the second end 115 over the fastening section 65, the spring section 60 and the holding section 55. The first material layer 90 is preferably formed in one piece and from the same material.

[0041] Preferably, the first material layer 90 comprises at least one of the following first materials: aluminum, steel, spring steel, nickel, an electrically conductive material, metal, an electrically non-conductive material, a plastic, a material with a continuous temperature resistance of greater than 125°C, a thermoset, a thermoplastic.

[0042] Preferably, the first material layer 90 has a first thickness (in the z-direction) of 0.1 mm to 0.5 mm inclusive. In particular, the first material layer 90 has a first thickness of 0.1 mm to 0.3 mm inclusive.

[0043] The first material layer 90 can be produced, for example, using a punching and bending process. It is advantageous, for example, if the first material layer 90 comprises the same material as the cell connector 85. It would also be possible for the first material layer 90 to comprise a material that lies in an electrochemical series between a material of the cell connector 85 and the conductor track of the second conductor track arrangement 140 of the flexible printed circuit board 45.

[0044] The first material layer 90 is electrically and mechanically connected to one of the associated cell connectors 85 on the side facing the cell connector assembly 30. For example, the first material layer 90 can be connected to the cell connector 85 by means of a welded connection, in particular an ultrasonic welded connection and / or a resistance welded connection. The cell connector 85 is preferably arranged on the underside of the side of the first material layer 90 facing the energy storage cell assembly 15.

[0045] As an alternative to the welded connection explained above, it is also possible for the first material layer 90 to be connected to the associated cell connector 85 in a form-fitting and / or force-fitting manner, for example by means of a riveted connection and / or a clinch connection. A sintered connection is also possible in order to connect the first material layer 90 to the associated cell connector 85 both electrically and mechanically.

[0046] The second material layer 95 is arranged on the first material layer 90 on a side facing away from the cell connector 85 and the energy storage cell arrangement 15. In the longitudinal direction, starting from the first end 110 and extending to the second end 115, the second material layer 95 is shorter than the first material layer 90. Since the second material layer 95 and the first material layer 90 each begin at the first end 110, the second material layer 95 ends at a distance from the second end 115. Thus, the second material layer 95 covers only a first partial section of the first material layer 90 on a side of the first material layer 90 facing away from the energy storage cell arrangement 15 of the flexible printed circuit board 45. Between the second end 115 and the second material layer 95, the top side of the first material layer 90 is uncovered, for example.

[0047] The second material layer 95 comprises a second material that is different from the first material of the first material layer 90. In particular, it is possible, for example, for the second material layer 95 to comprise at least one of the following second materials: an electrically non-conductive material, a plastic, a material with a continuous temperature resistance of greater than 125°C, a thermoset, a thermoplastic, aluminum, steel, spring steel, nickel, an electrically conductive material, or metal.

[0048] The second material layer 95 can, for example, be formed by means of a Fig. 1. Another connection of the second material layer 95 to the first material layer 90 would also be possible. For example, the first material layer 90 and the second material layer 95 can also be connected by means of a sintered layer or a mechanical connection, for example, a clinch connection.

[0049] In the embodiment, the second material layer 95 is designed, for example, in the longitudinal direction such that the second material layer 95 extends completely over the fastening section 65 and at least partially over the spring section 60. An arrangement of the second material layer 95 on the holding section 55 is omitted in the embodiment.

[0050] The second material layer 95 has a second thickness in the z-direction. The second thickness can, for example, be from 0.1 mm up to and including 0.5 mm. In particular, the second material layer can have a second material thickness of from 0.3 mm up to and including 0.5 mm. Preferably, the second material layer 95 is formed thicker in the z-direction than the first material layer 90. It is particularly advantageous, for example, if the first material of the first material layer 90 is different from the second material of the second material layer 95.

[0051] The optionally provided third material layer 100 and the fourth material layer 105 begin, for example, at the first end 110 of the first material layer 90, so that all of the material layers 90, 95, 100, 105 are arranged in a stack at the first end 110. In the embodiment, the third material layer 100 and the fourth material layer 105 are of equal width in the longitudinal direction.

[0052] Furthermore, the third material layer 100 is formed to be shorter in the longitudinal direction than the second material layer 95, so that, analogously to the first material layer 90, the second material layer 95 is covered by the third material layer 100 in a third partial section and, in a fourth partial section facing the third section in the direction of the second end 115, the second material layer 95 is not covered on the upper side on the side facing away from the energy storage cell arrangement 15.

[0053] The third material layer 100 comprises one of the following third materials: an electrically non-conductive material, a plastic, a material with a continuous temperature resistance of greater than 125 °C, a thermoset, a thermoplastic, aluminum, steel, spring steel, nickel, an electrically conductive material, metal.

[0054] The third material can be chosen differently from the first material and / or the second material.

[0055] Furthermore, a third thickness (in the z-direction) of the third material layer 100 can be different from the first thickness of the first material layer 90 and from the second thickness of the second material layer 95. For example, the third thickness of the third material layer 100 can be 0.1 mm to 0.5 mm inclusive. In particular, the third thickness can be 0.2 mm to 0.5 mm inclusive.

[0056] Analogous to the third material layer 100, the fourth material layer 105 is arranged on the third material layer 100 on a side facing away from the first and second material layers 90, 95.

[0057] The fourth material layer 105 comprises one of the following fourth materials: an electrically non-conductive material, a plastic, a material with a continuous temperature resistance of greater than 125 °C, a thermoset, a thermoplastic, aluminum, steel, spring steel, nickel, an electrically conductive material, metal.

[0058] Furthermore, a fourth thickness (in the z-direction) of the fourth material layer 105 can be different from the first thickness of the first material layer 90 and / or the second thickness of the second material layer 95 and / or the third thickness of the third material layer 100. For example, the fourth thickness of the fourth material layer 105 can be 0.1 mm to 0.5 mm inclusive. In particular, the fourth thickness can be 0.2 mm to 0.5 mm inclusive.

[0059] In a further embodiment, the fourth material layer 105 and / or the fourth material layer 105 and the third material layer 100 can also be omitted.

[0060] In the holding section 55, a through-opening 125 can additionally be arranged in the first material layer 90. The through-opening 125 is, for example, circumferentially enclosed by the holding section 55. The through-opening 125 extends completely in the z-direction through the first material layer 90.

[0061] On the circumference, at least in the holding section 55 on the first contact surface 70 facing the flexible printed circuit board 45, the holding section 55, in particular the first material layer 90, can be electrically connected to a second conductor track arrangement 140 of the flexible printed circuit board 45 by means of an electrically conductive second connection 135. The electrical connection can be used, for example, to detect an electrical cell voltage of the energy storage cell 20 and to evaluate it by a battery management system electrically connected to the conductor track 140.

[0062] In addition, the sensor 50 can be arranged in the through-opening 125, which can be thermally connected to the electrical energy storage cell 20 via the flexible printed circuit board 45 by means of the hold-down device 40 and the spring force FF provided by the hold-down device 40.

[0063] The sensor 50 is electrically connected to the battery management system via the first conductor track arrangement 145 and is designed to provide information about a temperature of the respectively assigned energy storage cell 20 to the battery management system.

[0064] In the transverse direction, the first material layer 90 has a first side surface 150 and a second side surface 155 arranged transversely to the first side surface 150. The first and second side surfaces 150, 155 can, for example, be arranged parallel to one another. In the embodiment, the first side surface 150 and the second side surface 155 each extend in an xz plane over the holding section 55, the spring section 60, and the fastening section 65.

[0065] In the embodiment, the second material layer 95 and / or the third material layer 100 and / or the fourth material layer 105 has the same extension in the transverse direction as the first material layer 90, so that the second material layer 95 and / or the third material layer 100 and / or the fourth material layer 105 end flush with the first side surface 150 and / or flush with the second side surface 155.

[0066] As already explained above, the second material layer 95 ends on the side facing away from the first end 110, for example in the region of the spring section 60, and the third material layer 100 and / or the fourth material layer 105 ends in the region of the fastening section 65.

[0067] The second to fourth material layers 95, 100, 105 in the region of the fastening section 65 result in a particularly rigid design in the fastening region 65. As a result, a shear load on the connection between the hold-down device 40 and the cell connector 85 can be avoided even with a large spring force FF, which is to be supported on the cell connector 85.

[0068] This stepped configuration of at least the second material layer 95 and, if provided, the third and / or fourth material layer 100, 105 means that the spring force FF provided by the hold-down device 40 can be structurally defined in the spring section 60 by means of the arrangement of the second material layer 95 and optionally the third material layer 100 and / or the fourth material layer 105. The second material layer 95 stiffens the spring section 60 in the region of the spring section 60, so that the flexural rigidity of the hold-down device 40 and thus the spring force FF can be adjusted by adapting the second material layer 95 and / or the third material layer 95 and / or the fourth material layer 105 through the geometric configuration of the hold-down device 40.

[0069] Furthermore, by selecting the appropriate material for the second and / or third material and / or fourth material, the deflection behavior of the spring section 60 and the support of the spring force FF via the fastening section 65 can be optimized in a defined manner.

[0070] Furthermore, by means of the second material layer 95 and / or the third material layer 100 and / or the fourth material layer 105, in particular in the region of the fastening section 65 when using an electrically non-conductive second and / or third and / or fourth material, a reliable electrical insulation of at least the fastening section 65 and optionally also the spring section 60 of the first material layer 90 can be provided.

[0071] Fig. 3 shows a schematic representation of the hold-down device 40 in the pressed, installed state.

[0072] In the installed pressed state, the hold-down device 40 can essentially have a flat design, so that the Fig. 1 and Fig. 2 is at least partially or completely eliminated. Even in the assembled state in the electrical energy storage device 10, the hold-down device 40 presses the flexible printed circuit board 45 against the storage cell side surface 35, thus ensuring the thermal connection of the sensor 50 to the storage cell side surface 35.

[0073] The individual material layers 90, 95, 100, 105 can form a step-like configuration of the hold-down device 40 between the first end 110 and the second end 115.

[0074] In the following, a second to fifth embodiment of the hold-down device 40 of the electrical energy storage device 10 will be discussed. Structurally, in the second to fifth embodiments, the hold-down device 40 is essentially identical to the one shown in the Fig. 1 to 2 is formed according to the first embodiment. In the following, the differences between the hold-down device 40 of the respective embodiment and the one shown in the Fig. The first embodiment of the hold-down device 40 shown in Figures 1 to 2 will be discussed.

[0075] In a second embodiment of the hold-down device 40, the first material layer 90 comprises, for example, spring steel as the first material. For example, the first material layer 90 can have a first thickness of 0.1 mm to 0.2 mm, in particular 0.1 mm.

[0076] The second to fourth material layers 95, 100, 105 can each have spring steel as the second to fourth material. The third and / or fourth material layers 100, 105 can be omitted.

[0077] Preferably, the second thickness and / or the third thickness and / or the fourth thickness is identical to the first thickness, so that, for example, the first and / or the second and / or the third and / or the fourth material layer 90, 95, 100, 105 can be made of the same sheet material before they are joined together.

[0078] In a third embodiment of the hold-down device 40, the first material layer 90 comprises, for example, predominantly aluminum, at least 50 percent by mass, as the first material.

[0079] For example, the first material layer 90 can have the first thickness of 0.25 mm to 0.35 mm, in particular 0.3 mm. The aluminum can provide an electrical connection between the second conductor track arrangement 140 and the cell connector 85.

[0080] The second thickness of the second material layer 95 is increased compared to the second embodiment in order to substantially compensate for the lower stiffness of the aluminum compared to the spring steel of the first material layer 90 in the second embodiment.

[0081] The second material layer comprises at least one electrically non-conductive second material, for example a plastic, such as polyethylene (PE) and / or polypropylene (PP). The second thickness can be, for example, 0.2 mm to 0.3 mm inclusive.

[0082] The second to fourth material layers 95, 100, 105 can also each contain different plastics.

[0083] In a fourth embodiment of the hold-down device 40, the first material layer 90 comprises, for example, predominantly aluminum as the first material, comprising at least 50 percent by mass. For example, the first material layer 90 can have a first thickness of 0.25 mm to 0.35 mm, in particular 0.3 mm. The aluminum can be used to establish an electrical connection between the second conductor track arrangement 140 and the cell connector 85.

[0084] Preferably, the first material layer 90 is nickel-plated and / or tin-plated. The nickel-plating and / or tin-plating can be formed as a thin layer.

[0085] The second material layer 95 preferably comprises predominantly nickel, in particular at least 50 percent by mass.

[0086] The second thickness can be, for example, 0.15 mm to 0.25 mm, in particular 0.2 mm.

[0087] The third and / or fourth material layer 100, 105 can be omitted, or the third and / or fourth material layer can, for example, comprise the electrically non-conductive third and / or fourth material, for example, plastic. The tinned and / or nickel-plated first material layer 90 prevents corrosion of the aluminum and prevents corrosion at the connection to the first conductor track arrangement 145, which is made of copper, for example.

[0088] In a fourth embodiment of the hold-down device 40, the first material layer 90 comprises, for example, steel as the first material. For example, the first material layer 90 can have a first thickness of 0.08 mm to 0.15 mm, in particular 0.1 mm. It is advantageous if the steel of the first material layer 90 is nickel-plated.

[0089] The second material layer 95 preferably comprises predominantly aluminum as the second material, at least 50 percent by mass. The second thickness can be, for example, 0.15 mm to 0.25 mm, in particular 0.2 mm. Nickel plating of the steel of the first material layer 90 prevents corrosion on the second material layer 95, which is made of aluminum.

[0090] The third material layer 100 preferably comprises predominantly aluminum as the third material. The third thickness can be, for example, 0.15 mm to 0.25 mm, in particular 0.2 mm.

[0091] The fourth material layer 105 can be omitted or the fourth material layer 105 comprises an electrically non-conductive fourth material, for example plastic. List of reference symbols 10 electrical energy storage 15 Energy storage cell arrangement 20 electrical energy storage cell 25 Cell contact system 30 cell connector arrangement 35 memory cell side surface 40 hold-down clamps 45 flexible circuit board 50 sensors 55 stopping section 60 spring section 65 fastening section 70 first investment area 75 second contact surface 80 PCB side surface 85 cell connectors 86 connection pole 90 first layer of material 95 second layer of material 100 third layer of material 105 fourth layer of material 110 first end 115 second end 120 first electrical connection 125 passage opening 130 connection area 135 second electrically conductive connection 140 second conductor track arrangement 145 first conductor track arrangement 150 first side surface 155 second side surface FF spring force FG counterforce α first angle β second angle

Claims

[1] Cell contact system (25) for an electrical energy storage device (10), - wherein the cell contacting system (25) comprises a hold-down device (40), a flexible circuit board (45) and a sensor (50) arranged on the flexible circuit board (45), - wherein the hold-down device (40) has a holding section (55), a spring section (60) and a fastening section (65), - wherein the holding section (55) bears against the flexible printed circuit board (45) with a first contact surface (70), - wherein the fastening section (65) is arranged offset from the holding section (55) and the spring section (60) mechanically connects the fastening section (65) to the holding section (55), - wherein the hold-down device (40) has a first material layer (90) extending over the fastening section (65), the spring section (60) and the holding section (55) and a second material layer (95) extending at least over the fastening section (65) and connected to the first material layer (90), - wherein the hold-down device (40) is designed to provide a spring force (FF) for pressing the holding section (55) against the flexible printed circuit board (45). [2] Cell contacting system (25) according to claim 1, - comprising at least one cell connector arrangement (30) with at least one cell connector (85), - wherein the cell connector (85) is electrically connectable to a terminal (86) of an electrical energy storage cell (20) of the electrical energy storage device (10), - wherein the first material layer (90) comprises an electrically conductive first material, - wherein the fastening section (65) rests against the cell connector (85) with the first material layer (90) and is connected to the cell connector (85), - wherein the second material layer (95) has a second material different from the first material. [3] Cell contacting system (25) according to one of the preceding claims, - wherein the first material layer (90) extends from a first end (110) of the hold-down device (40) over the spring section (60) and the holding section (55) in a longitudinal direction (x) to a second end (115) of the hold-down device (40), - wherein the first end (110) is arranged on the fastening section (65), - wherein the first material layer (90) is formed in one piece and of the same material. [4] Cell contacting system (25) according to claim 3, - wherein the second material layer (95) is shorter in the longitudinal direction than the first material layer (90) starting from the first end (110), and the second material layer (95) covers a first partial section of the first material layer (90), preferably on a side facing away from the cell connector. [5] Cell contacting system (25) according to one of the preceding claims, - wherein the hold-down device (40) has a third material layer (100) which is arranged on the second material layer (95) on a side facing away from the first material layer (90) and is connected to the second material layer (95). [6] Cell contacting system (25) according to claim 5, - wherein in the longitudinal direction starting from the first end (110) the third material layer (100) is shorter than the first material layer (90) and / or the second material layer (95). [7] Cell contacting system (25) according to one of the preceding claims, - wherein the first material layer (90) has a first thickness of 0.1 mm to 0.5 mm inclusive, in particular 0.1 mm to 0.3 mm inclusive, - wherein the second material layer (95) has a second thickness of 0.1 mm to 0.5 mm inclusive, in particular 0.3 mm to 0.5 mm inclusive. [8] Cell contacting system (25) according to one of the preceding claims, - wherein the first material layer (90) comprises at least one of the following first materials and / or the second material layer (95) comprises at least one of the following second materials: aluminum, steel, spring steel, nickel, an electrically conductive material, metal, an electrically non-conductive material, a plastic, a material with a continuous temperature resistance of greater than 125 °C, a thermoset, a thermoplastic. [9] Cell contacting system (25) according to claim 8, - wherein the second material of the second material layer (95) is different from the first material of the first material layer (90), or - wherein the second material of the second material layer (95) is identical to the first material of the first material layer (90). [10] Cell contacting system (25) according to one of claims 2 to 9, - wherein the first material layer (90) is connected to the cell connector (85), preferably mechanically and electrically, by means of a welded connection, in particular an ultrasonic welded connection and / or a resistance welded connection, and / or a riveted connection and / or a clinched connection and / or a sintered connection, - wherein the second material layer (95) is connected to the first material layer (90) by means of an adhesive bond. [11] Electrical energy storage (10) - comprising a cell contacting system (25) and an energy storage cell arrangement (15) with at least one electrical energy storage cell (20) with a connection pole (86) and a storage cell side surface (35), - wherein the cell contacting system (25) is designed according to one of the preceding claims, - wherein the cell connector (85) is electrically connected to the terminal (86), - wherein the flexible printed circuit board (45) partially rests against the memory cell side surface (35), - wherein the hold-down device (40) presses the flexible printed circuit board (45) against the memory cell side surface (35) with the spring force (FF).

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