Energy storage unit for a motor-driven vehicle

Abstract

The invention relates to an energy storage unit for an electromotorized vehicle, in particular for an electromotorized monocycle or two-wheeled vehicle, having a partial housing in which at least two cell stacks are received for each receiving at least two electrochemical energy storage cells, according to the invention, the energy storage cells are designed as round cells, each energy storage cell having two electrical cell poles, and the electrical cell poles of at least two energy storage cells are electrically conductively connected to each other in a series and / or parallel circuit via at least one cell connector. According to the invention, the at least two cell stacks are arranged adjacent to each other in such a way that, in the assembled state of the energy storage unit, a pressing device of the energy storage unit connects the cell connector to the electrical cell pole of the energy storage cell in a non-material-tight force-fitting manner, the pulling force of the pressing device can be adjusted outside the sub-shell.

Description

Technical Field

[0001] The present invention relates to an energy storage unit for an electric motor-driven vehicle, in particular for an electric motor-driven one-wheel vehicle or two-wheel vehicle, and an electric motor-driven vehicle, the electric motor-driven vehicle having an electrochemical energy storage unit which can be detachably connected to the electric motor-driven vehicle or can be firmly integrated in the electric motor-driven vehicle. Background Art

[0002] Many electric motor-driven vehicles are operated with rechargeable energy storage units, which are discharged by the electric motor-driven vehicle and can be recharged with the help of a charging device. This type of energy storage unit includes a plurality of electrochemical energy storage cells interconnected in series and / or in parallel to achieve the required battery voltage or voltage capacity. If the energy storage cell is configured as a lithium-ion cell (lithium-ion), for example, very high power density and energy density can be achieved particularly advantageously. Usually, this type of energy storage unit has an outer shell, in which at least two so-called cell stacks are received, for receiving at least two energy storage cells, respectively, the energy storage cells being configured as round cells. Each energy storage cell has two electric cell poles, wherein the electric cell poles of at least two energy storage cells are electrically conductively connected to each other via at least one cell connector to achieve a series circuit and / or a parallel circuit.

[0003] A rechargeable energy storage unit for an electric motor-driven vehicle is known from WO 2021 / 048028 A1, wherein a plurality of electrochemical energy storage cells are electrically connected via two cell connector devices, the energy storage cell being configured as a round cell, the cell connector device being arranged on the end of the end side of the round cell. The cell connector device is configured as a circuit board having an opening and a spring-elastic contact element arranged in the opening, the contact element being able to be connected to the cell pole of the end side of the round cell by force locking. In order to ensure the force-locking connection between the cell pole and the contact element, a plurality of threaded rods are provided, the threaded rods passing through the two circuit boards and fixing the two circuit boards by nuts screwed on both sides. Alternatively, the fixing of the cell connector device is realized via a projection, the projection being arranged in the outer housing of the energy storage unit.

[0004] A rechargeable energy storage unit for an electric motor-driven vehicle is known from DE 10 2021 206 819 A1, wherein for each cell stack, a plurality of electrochemical energy storage cells are electrically connected in a series circuit and / or a parallel circuit via two cell connectors, the energy storage cells being configured as round cells, the cell connectors being arranged on the end of the end side of the round cells. The electrical connection between the cell connector and the round cell is implemented in such a way that the cell poles of the energy storage cells each have a material-locked welded connection with at least one contact element of the cell connector. Although the material-locked connection provides a very reliable and durable electrical contact on the one hand, it hinders the removal or replacement of the following individual energy storage cells on the other hand: the maximum capacitance of the energy storage cell has been strongly reduced over time or the energy storage cell has a fault. The removal of the energy storage unit to be recycled is also hindered in the following manner: the individual energy storage cells can only be separated from the cell connector with relatively great effort. Summary of the invention

[0005] The object of the present invention is to provide an energy storage unit which is improved compared to the prior art and which allows a simplified replacement of energy storage cells, in particular by maintenance personnel, in combination with safe operation and more flexible adaptability of the cell connector device to the required battery voltage or battery capacity of the energy storage cell.

[0006] In order to solve this task, it is provided that at least two single cell stacks are arranged adjacent to each other so that in the assembled state of the energy storage unit, the pressing device of the energy storage unit connects the single cell connector to the electric single cell pole of the energy storage unit without material locking, wherein the tension of the pressing device can be adjusted outside the sub-housing. The sub-housing is particularly to be understood as a partial housing, which brings together the individual single cell stacks and is arranged in the outer housing of the energy storage unit. Particularly advantageously, the present invention can realize the simplified replacement of the following single energy storage cell: the maximum capacitance of the energy storage cell has been strongly reduced over time or the energy storage cell has a fault. In addition, the tolerance compensation in the longitudinal extension dimension of the energy storage cell can be realized in a simple manner so that the force-locked connection between the single cell pole and the single cell connector can be adapted by the pressing device.

[0007] The electric motor-driven vehicle can be designed, for example, as an electric bicycle (e.g. EPAC - Electrically Power Assisted Cycle, electric bicycle, electric moped, electric cargo bicycle, etc.), electric motorcycle, one-wheeled or two-wheeled electric scooter (e-Scooter), electric moped or the like. The invention can also be applied to other applications in the field of micromobility applications, such as electric kick scooters (e-kick-Scooter), mono-wheels or other non-type-approved vehicles, which have a battery pack that is fixedly installed in the vehicle or can be replaced. Therefore, an electric motor-driven vehicle is also to be understood as a vehicle that has a drive unit for supporting the driver or is partially driven by an electric motor.

[0008] The energy storage unit can be firmly integrated in the electric motor-driven vehicle or constructed as a replaceable battery pack that can be disassembled without tools. In addition, in the case of a replaceable battery pack, it can be provided that the replaceable battery pack can be charged not only in a state connected to the electric motor-driven vehicle, but also in a state separated from the electric motor-driven vehicle. The battery voltage of the energy storage unit is usually a multiple of the voltage of a single energy storage cell of the energy storage unit, and is derived from the interconnection (parallel / or series) of each energy storage cell. Preferably, the energy storage cell is constructed as a lithium-based energy storage cell, such as lithium ion, lithium polymer, lithium metal, sodium ion or the like. However, the present invention can also be applied to energy storage units with nickel-cadmium cells, nickel-hydrogen cells or other suitable cell types. In the case of a common lithium-ion energy storage cell with a cell voltage of 3.6V, nominal battery voltages such as 3.6V, 18V, 36V, and 54V are obtained as an example. However, the present invention is independent of the type and structure of the energy storage cells and energy storage units used, but can be applied to any electrochemical energy storage units and energy storage cells with a battery voltage of 36 V, 48 V, 52 V, for example, in addition to round cells, it can also be applied to pouch cells (Pouchzellen) or the like.

[0009] Another embodiment of the present invention provides that the clamping device is configured as at least one rod, which extends through the sub-housing, the rod having at least one threaded section arranged on the end side, and the tension can be adjusted via a nut, which can be tightened with the threaded section. Advantageously, the tension of the clamping device can be changed very simply and reproducibly in order to ensure reliable electrical contact between the cell pole of the energy storage cell and the cell connector during a long operating period of the energy storage unit on the one hand, and to enable simple replacement of individual energy storage cells on the other hand. Particularly advantageously, the nut can be configured as a self-locking nut.

[0010] The energy storage unit has at least one cell connector device, which has a carrier layer, wherein at least one cell connector is arranged on the carrier layer and, in the assembled state of the energy storage unit, the pressing device presses at least one of the electric cell poles of the energy storage cell in the direction of the carrier layer against a spring-elastic contact element of the cell connector.

[0011] In an extended embodiment, the cell connector device is arranged between two cell stacks, wherein at least one cell connector is arranged on two opposite end sides of the carrier layer along the longitudinal axis of the energy storage unit in such a way that in the assembled state of the energy storage unit, the pressing device presses the electric cell poles of two energy storage cells adjacent along the longitudinal axis of the two cell stacks in the direction of the carrier layer respectively against the contact elements of the cell connector. By means of this type of symmetrical preassembly of the cell connector device, a parallel or series interconnection of the energy storage cells can be achieved in a simple manner without the need for an additional material-locked connection process. For this purpose, it is further provided that at least two cell connectors arranged on the end sides of the carrier layer are constructed as a one-piece conductor plate, which wraps around the carrier layer in order to electrically connect the electric cell poles of at least some of the energy storage cells of the energy storage cells of the two cell stacks to each other. This type of conductor plate enables a particularly simple assembly of the cell connector device, since it is almost only necessary to push the conductor plate onto the carrier layer along the end sides of the carrier layer.

[0012] In order to support the effect of the spring-elastic contact element, at least one single cell connector device has at least one elastic spring component, which is arranged between the carrier layer and at least one contact element of the at least one single cell connector so that in the assembled state of the energy storage unit, the pressing device presses at least one of the electric single cell poles of the energy storage cell toward the at least one contact element in the direction of the carrier layer against the elastic force, and the elastic force is generated / synthesized by the first elastic force of the contact element and the other elastic force of the at least one spring component. In this way, the possible length tolerance of the energy storage cell can also be better compensated. In addition, the spring component can form a limited stop for the corresponding contact element when the energy storage unit is pressed by the pressing device. In addition, the possible reduction of the spring elastic effect of the contact element can be preventively offset.

[0013] In order to avoid radial displacement of individual energy storage cells, for example in the event of a fall of the energy storage unit or a collision of an electric motor-driven vehicle, it is further provided that in the assembled state of the energy storage unit the spring element achieves frictionally adhesive contact with the energy storage cell in the region of its cell poles.

[0014] The spring element can be made of an elastomer and / or a synthetic polymer, the elastomer being in particular a thermoplastic elastomer (TPE), a foam, the foam being in particular a polyurethane foam (Poron), the synthetic polymer being in particular a silicone. Advantageously, the carrier layer of the cell connector device is made of polyamide or of polypropylene. The cell connector can in turn be made of an electrically conductive metal, for example nickel, copper, steel, aluminum or Hilumin (diffusion annealed strip steel with an electrolytic nickel coating).

[0015] Another embodiment of the invention provides that each cell stack has a plurality of hollow cylindrical holes for receiving a respective energy storage cell, wherein a longitudinal gap is provided in the hole along the longitudinal axis of the energy storage unit in such a way that at least one longitudinal web of the hole, which is adjacent to the longitudinal gap and is resiliently supported, enables radial fixation of the round cell, and the inner diameter of the hole without the longitudinal web is larger than the outer diameter of the round cell respectively received in the hole. In this way, the individual energy storage cells can be very easily pushed into the cell stack in the direction of their longitudinal extension and fixed in the radial direction against displacement relative to the contact elements of the cell connector connected to the cell poles of the energy storage cells.

[0016] In order to prevent the cell connector device and the cell stack from moving relative to each other, the carrier layer of the cell connector device and the cell stack each have a plurality of form-locking elements for mechanically connecting the carrier layer and the cell stack to each other. At the same time, via the form-locking elements, it is possible to achieve a Poka-Yoke solution. ) enables a clear and unique assembly of the cell connector device on the cell stack in order to avoid, for example, a reverse polarity of the energy storage cells during assembly.

[0017] In order to achieve the task mentioned at the outset, it can be provided that the energy storage unit has at least one cell connector device, which has a carrier layer, on which at least one cell connector is arranged in such a way that in the assembled state of the energy storage unit, at least one of the electric cell poles of the energy storage cell is pressed in the direction of the carrier layer against an electrical contact element of the cell connector in order to connect the contact element to the electric cell pole in a non-positively locking, in particular non-materially locking, manner. This results in the advantage of a higher contact safety compared to the prior art, since the carrier layer forms a defined stop for the contact element. Furthermore, by means of the separate construction of the carrier layer and the cell connector, the cell connector device can be adapted in a simple manner to the required battery voltage or battery capacitance of the energy storage unit by corresponding modifications to the cell connector.

[0018] Another configuration of the present invention is that the carrier layer has two opposite end sides, and at least one single cell connector is arranged on each end side, and the single cell connector has at least one contact element. Along the longitudinal axis, the energy storage unit has at least two single cell stacks for receiving at least two energy storage cells respectively. The single cell connector device is arranged between two adjacent single cell stacks, and has at least one single cell connector on two opposite end sides of the carrier layer, so that in the assembled state of the energy storage unit, the electric single cell poles of the two energy storage cells adjacent along the longitudinal axis of the two single cell stacks are pressed toward the contact elements of the single cell connector in the direction of the carrier layer. By this type of symmetrical preassembly of the single cell connector device, the parallel or series interconnection of the energy storage cells can be realized in a simple manner without the need for an additional material-locked connection process.

[0019] Furthermore, it is provided that at least two cell connectors arranged on the end side of the carrier layer are designed as one-piece conductor plates, which surround the carrier layer in order to electrically connect the electrical cell poles of at least some of the energy storage cells of the energy storage cells of the two cell stacks to one another. Such a conductor plate enables particularly simple assembly of the cell connector device, since it is almost only necessary to push the conductor plate onto the carrier layer along the end side of the carrier layer.

[0020] In order to achieve the object defined at the outset, it is further provided that the cell connector has at least one main contact element, which is materially connected to the cell pole of the energy storage cell, and the cell connector for at least one of the main contact elements has at least one redundant contact element, which in the initial state of the assembled energy storage unit is not materially connected to the electric cell pole of the energy storage cell. Particularly advantageously, despite the materially connected connection, the present invention still enables simple removal of energy storage cells whose maximum capacitance has greatly decreased over time or which have a fault. For this purpose, the energy storage cell to be removed can be easily separated from the cell connector together with the main contact element materially connected thereto.

[0021] In one embodiment of the invention, it is provided that at least one redundant contact element is used in the case of maintenance to be connected in a materially bonded manner to an electric cell pole of a replacement energy storage cell for an energy storage cell connected to the primary contact element. Thus, after the energy storage cell to be replaced has been removed, the replacement energy storage cell can be connected in a very simple manner in a materially bonded manner to the redundant contact element of the cell connector.

[0022] At least one redundant contact element is arranged adjacent to the main contact element so that the outer contour of the main contact element and the at least one redundant contact element does not exceed the outer periphery of the connected energy storage cell. Therefore, a compact structural form of the cell connector can be achieved in a particularly advantageous manner. Then, at least one redundant contact element is placed, for example, only force-locked on the cell pole of the energy storage cell, which is connected to the main contact element. In addition, in order to replace the energy storage cell, the cell connector can remain unchanged at the same position in the energy storage unit.

[0023] In an alternative or supplementary configuration, it is provided that at least one redundant contact element is arranged adjacent to the main contact element so that the redundant contact element can be brought to the position of the main contact element by flipping. Particularly advantageously, in this way, the same, optimal position on the cell pole can also be used to replace the energy storage cell for the material-locked connection with the redundant contact element of the cell connector. In addition, the cell pole of the energy storage cell can have a small electrical contact surface in order to avoid possible leakage currents and short circuits.

[0024] In order to be able to replace a plurality of energy storage cells identically in one working step, the cell connector has a main extension plane which extends in particular transversely to the longitudinal axis of the energy storage unit, wherein at least one redundant contact element is arranged adjacent to the main contact element in such a way that the redundant contact element can be brought into the position of the main contact element by displacing the cell connector along the main extension plane.

[0025] Furthermore, in order to avoid short circuits, it is provided that at least one redundant contact element is electrically insulated in the initial state of the assembled energy storage cell, in particular by means of an insulating foil. Furthermore, inadvertent activation processes of the redundant contact element can be avoided in this way.

[0026] In order to further simplify the maintenance or removal of the energy storage unit, the main contact element and / or at least one redundant contact element has a desired breaking point for mechanically separating from the cell connector. The desired breaking point needs to be designed in such a way that it is subjected to normal loads and is therefore sufficiently robust during the intended service life of the energy storage unit with respect to external mechanical influences on the energy storage unit, for example in the case of a fall, blows or strong vibrations.

[0027] In addition, the main contact element and / or at least one redundant contact element can have a guide geometry for separation at the desired breaking point. In this way, the separation can be simplified with the aid of a suitable auxiliary tool (e.g., a separation pliers or a lever tool) which is placed on the guide geometry. In addition, the guide geometry can be designed in such a way that it enables replacement of the energy storage cell or manipulation of the cell connector to be detected.

[0028] It is expected that the fracture site is arranged in the direct environment of the connection point between the main contact element or at least one redundant contact element and the electric cell pole. Therefore, the geometry of the so-called welding pit of the contact element can be configured so that the geometry is easy to break under certain movements. In particular, it is expected that the fracture site can be disassembled by pulling, pressing and / or twisting or shearing movement. As a result, the fracture site continues to remain robust relative to the normal load mentioned above. It is also conceivable that the welding pit itself is designed to be sensitive to torsion. Therefore, the welding pit can be separated from the cell pole by a simple rotation of the energy storage cell to be replaced around its longitudinal axis.

[0029] In order to be able to replace energy storage cells multiple times at the same position in the energy storage unit if necessary, the cell connector for the main contact element has at least two redundant contact elements. It can also be provided that the cell connector for each main contact element has at least one redundant contact element. Thus, in the case of maintenance, all energy storage cells of the energy storage unit can be replaced in the same way.

[0030] Another task of the present invention is to provide a cell connector for energy storage units that is improved relative to the prior art, and the cell connector can be universally used for different topologies of energy storage units. In order to solve this task, the cell connector has at least one processing area, by means of which the contact elements of the battery poles of at least two different energy storage cells can be mechanically and / or electrically separated from each other. Particularly advantageously, the present invention can realize the applicability of this type of universal cell connector for energy storage units of different voltage ranges and / or energy capacities. Therefore, the cell connector according to the present invention is designed so that the cell connector is suitable for the maximum variant of the energy storage unit and can be modified for smaller voltage ranges and / or energy capacity variants in a simple manner by the electromechanical separation of the corresponding contact elements.

[0031] In order to further simplify adaptability, at least one processing area can be configured as an expected fracture site, especially a constriction and / or a perforation. In addition or alternatively, the contact element of the single cell connector that is connected to the electric cell pole of the energy storage cell in a material-locked manner has an expected fracture site for mechanically separating from the single cell connector. Here, the expected fracture site needs to be configured so that the expected fracture site is subjected to normal loads, and therefore is sufficiently robust to external mechanical influences on the energy storage unit during the set service life of the energy storage unit, for example, in the case of falling, hitting or strong vibration. In particular, the expected fracture site can be disassembled by pulling, pressing and / or twisting or shearing motion. Thus, the expected fracture site continues to remain robust relative to the normal load mentioned.

[0032] In addition, a guiding geometry is provided for separating the at least two contact elements at the desired breaking point of the cell connector. In this way, the separation can be simplified with the aid of a suitable auxiliary tool (e.g., a separating pliers or a lever tool) which is placed on the guiding geometry. It is also conceivable that the desired breaking point itself has a corresponding guiding geometry, for example in the form of a specially configured perforation.

[0033] In another embodiment, it is provided that at least one processing region has a marking. This advantageously makes it easier to identify and / or process the processing region. It is particularly advantageous if the processing regions that are separated and that are electrically meaningful have markings of the same configuration. This facilitates the processing of the cell connector for the intended use in the energy storage unit starting from the largest possible variant of the cell connector.

[0034] At least one mechanical indicator is provided on the cell connector, in particular on its edge region, for identifying modifications made on the cell connector. Thus, in the event of repairs, it can be easily recognized that the corresponding cell connector is no longer in the initial state for the maximum variant of the energy storage unit.

[0035] The invention further relates to an energy storage unit having a plurality of electrochemical energy storage cells, which are designed as round cells, and having at least two cell connectors according to the invention, which are used for connecting at least two of the energy storage cells in series and / or in parallel, wherein the at least two cell connectors are identical in their initial state. Prior to final assembly of the energy storage unit, at least one of the at least two cell connectors can be processed in such a way that at least two contact elements of the processed cell connector are mechanically and / or electrically separated from one another. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In the following, according to Figures 1 to 20 The present invention is explained by way of example only, wherein the same reference numerals in the figures represent the same components having the same function.

[0037] The accompanying drawings show:

[0038] Figure 1 : A schematic diagram of a motor-driven vehicle in a first variant, which is designed as a two-wheeled electric bicycle,

[0039] Figure 2 : A schematic diagram of a motor-driven vehicle in a second variant, the vehicle being designed as a two-wheeled electric bicycle,

[0040] Figure 3 :Used according to Figure 1 or 2 , a perspective view of a first exemplary embodiment of an energy storage unit for an electric motor-driven vehicle,

[0041] Figure 4 :according to Figure 3 A cross section of an energy storage unit along its longitudinal axis,

[0042] Figure 5: According to Figure 3 and 4A perspective view of a single cell connector device of an energy storage unit of an embodiment of the invention ( Figure 5a ) and Section View ( Figure 5b ),

[0043] Figure 6 : A sectional view of a further embodiment of a single-cell connector device along the longitudinal axis of the energy storage unit,

[0044] Figure 7 :according to Figure 6 A perspective view of an embodiment of

[0045] Figure 8 : A sectional view of a further embodiment of a single-cell connector device along the longitudinal axis of the energy storage unit,

[0046] Fig. 9 : A single cell stack of energy storage units together with two Figure 6 An exploded schematic diagram of the arrangement of the single-cell connector device on the end side,

[0047] Figure 10: Before processing ( Fig.10a ) and after processing ( Fig.10b ) A further embodiment of a single cell connector of the single cell connector device configured as a conductor plate,

[0048] Fig.11 : A further embodiment of a cell connector having two main contact elements and two redundant contact elements for one energy storage cell,

[0049] Fig.12 : A further embodiment of a cell connector having two main contact elements and two redundant contact elements for two energy storage cells,

[0050] Fig.13 : A further embodiment of a cell connector having one main contact element and three redundant contact elements for one energy storage cell,

[0051] FIG. 14 : A further embodiment of a single-cell connector having at least one processing area for a primary contact element and a redundant contact element ( Fig.14a ) and different configurations of the processing areas for the two main contact elements ( Fig.14b , 14c , 14d),

[0052] FIG. 15 : Removable connection of the contact element on the cell connector as a closed eyelet ( Fig.15a ), as a single-sided open eyelet ( Fig.15b ) and as a plug-in connection ( Fig.15c ),

[0053] Fig.16 : Embodiment for a detachable connection of four contact elements on a cell connector by means of a single screw connection,

[0054] Fig.17 : Embodiment for a detachable connection of a contact element to a single cell connector designed as a rail system,

[0055] Fig.18 : A further embodiment for a detachable connection of a contact element to a single cell connector designed as a rail system,

[0056] Fig.19 :according to Fig.15c sectional view of a reversible plug connection for a single cell connector device having single cell connectors arranged on both sides,

[0057] Fig. 20 : Embodiment of a reversible connection between a cell connector device or a cell connector and a circuit board of an energy storage unit. DETAILED DESCRIPTION

[0058] exist Figure 1 1 shows a schematic diagram of a vehicle 10 driven by an electric motor, which is designed as a two-wheeled electric bicycle 12. The electric bicycle 12 can be supplied with energy via an energy storage unit 16 designed as a replaceable battery pack 14 and can be designed, for example, as an electric assisted vehicle, as an electric bicycle (e-Bike) or the like. The electric bicycle 12 has a housing in the form of a frame 18, which has two wheels 20 supported in the frame 18. The replaceable battery pack 14 is connected in a detachable manner via a connecting device 22 arranged on the frame 18, which cooperates electromechanically with an interface (not shown in more detail) mounted on an outer housing 24 of the replaceable battery pack 14.

[0059] In addition, the electric bicycle 12 has a drive unit 26, which includes an electric motor 28, which is preferably configured as an EC motor or a BLDC motor, which is in the form of an intermediate motor. Instead of the intermediate motor, a hub motor in one of the two wheels 20 can also be used. The drive unit 26 is also supplied with energy via the replaceable battery pack 14 and includes an electronic device unit (not shown), which is used to control or regulate the electric bicycle 12, especially the electric motor 28. In addition, the electronic device unit is connected to a sensor unit (also not shown), which includes a plurality of sensor elements, such as torque sensors, motion sensors (for example in the form of acceleration sensors) and magnetic sensors. In addition, a pedal crank 30 with a pedal crank shaft 32 is provided on the electric bicycle 12, via which the driver can perform pedaling movements for driving the rear wheel 20 in the sense of conventional bicycle operation. The electronic device unit, the drive unit 26 with the electric motor 28 and the pedal crank shaft 32 are arranged in a drive housing 34 connected to the frame 18.

[0060] Preferably, the drive movement of the electric motor 28 is transmitted to the pedal crankshaft 32 via a transmission (not shown), wherein the intensity of the support provided by the drive unit 26 is controlled or adjusted by means of an electronic device unit. The electronic device unit is designed to control the drive unit 26 in such a way that the driver of the electric bicycle 12 is supported when pedaling. Preferably, the electronic device unit is designed to be operable by the driver, so that the driver can adjust the degree of support.

[0061] The electric bicycle 12 includes an onboard computer 36, which is arranged on the handlebars 38 of the electric bicycle 12. For example, the onboard computer 36 is constructed in a manner that can be detached from the electric bicycle 12 and includes a human-machine interface (HMI) for displaying information and for controlling the onboard computer 36 and / or the electric bicycle 12 or the drive unit 26. For example, the HMI is constructed as a touch screen or the like. The onboard computer 36 is connected to the drive unit 26 for exchanging information and instructions. For example, the speed determined by the electronic device unit of the drive unit 26 with the help of the sensor unit, the adjusted support of the electric motor 28, the route information of the navigation unit integrated in the onboard computer 36, and the charging state of the replaceable battery pack 14 can be displayed via the HMI.

[0062] Figure 2 An alternative embodiment of the electric bicycle 12 is shown. Figure 1Different, the energy storage unit 16 is fully integrated in the frame 18 of the electric bicycle 12 together with its electromechanical interface, and the electromechanical interface is used for energy transmission and / or data transmission between the electric bicycle 12 and the energy storage unit 16. However, in order to replace the energy storage unit 16 more simply, the energy storage unit also has an outer shell 24. In addition, a charging and / or discharging interface 40 is provided in the frame 18 of the electric bicycle 12 in a manner accessible from the outside, for charging or discharging the energy storage unit 16. The charging and / or discharging interface is configured as a USB-C interface for example. However, other interfaces for wired or wireless energy transmission and / or data transmission can also be considered. In addition, multiple interfaces 40 of this type can also be provided on the electric bicycle 12.

[0063] exist Figure 3 and 4 , an embodiment of the internal structure of an energy storage unit 16 is shown in a perspective view or in a section along the longitudinal axis L of the energy storage unit 16. In the outer housing 24 (not shown) of the energy storage unit 16, a subhousing 44 is provided, which consists of at least two end-side end caps 42. By way of example, the energy storage unit 16 consists of five cell stacks 46, which are arranged adjacent to each other with their end sides along the longitudinal axis L of the energy storage unit 16. The geometry of the energy storage unit 16 is largely determined by the arrangement of the cell stacks 46 relative to each other.

[0064] By way of example, each cell stack 46 has a total of eight hollow cylindrical holes 48 for receiving a respective energy storage cell 52, which is designed as a round cell 50. Each hollow cylindrical hole 48 in turn has a cylindrical wall 54, which surrounds the round cell 50 along its side surface. The holes 80 each have a radial center axis, which essentially corresponds to the radial center axis of the round cell 40 and extends parallel to the longitudinal axis L of the energy storage unit 16. The wall 54 of the cell stack 46 is designed in such a way that it is assigned to two different holes 48 between two round cells 50 adjacent in the radial direction. In order to make it easier to push the round cell 50 into the hole 48 along the longitudinal axis L of the energy storage unit 16 or to push it out again accordingly in the case of maintenance, the inner diameter D of each hole 48 is 1.2 mm. B at least greater than the outer diameter D of the round single cell 50 respectively received in the hole C Preferably, the wall 54 or the cell stack 46 is constructed in one piece from a thermoplastic material or a similar material. Figure 3 and 4 In the illustration, for the sake of clarity, only a single hole 48 is filled with a round cell 50 . Typically, a fully assembled energy storage unit 16 is completely occupied by an energy storage cell 52 .

[0065] A total of 40 round batteries 50 are interconnected via cell connectors 56 in a series circuit and / or in a parallel circuit, wherein the series circuit defines a battery voltage U acting on an electromechanical interface (not shown) of the energy storage unit 16. Batt , and the parallel circuit of each round cell 50 mainly increases the capacitance of the energy storage unit 16. The cell connector 56 is made of conductive metal, such as nickel, copper, steel, aluminum or Hilumin. Each round cell 50 has a positive or negative electric cell pole 58 on its two end sides, which is used to contact with at least one spring-elastic contact element 60 of the cell connector 56 configured as a conductor plate 62 in an electromechanical manner. Therefore, the contact element 60 extends substantially parallel to the cell pole 58 of the round cell 50, wherein the cell pole 58 is substantially perpendicular to the longitudinal axis L of the energy storage unit 16. In this context, "substantially" should be understood as not having to have an exactly parallel or perpendicular direction, but can also be slightly different from the exactly parallel or perpendicular direction due to tolerance reasons. Each contact element 60 can also realize a non-material-locked force-locked connection of the cell connector 56 with the corresponding cell pole 58 of the round cell 50. However, instead of a purely force-locked connection, a material-locked connection between the cell pole 58 and the contact element 60 can also be considered, for example in the form of a resistance welded connection, an ultrasonic welded connection or a laser welded connection. Likewise, a soldered connection is also possible, wherein it is necessary to pay attention to the possible increased heat input into the energy storage cell. In addition, the cell connector 56 is used for single cell monitoring (Single Cell Monitoring - SCM) in conjunction with a microprocessor (not shown in more detail) of the electronics unit of the energy storage unit 16. For this purpose, the cell connector 56 is connected to the circuit board 66 (see the contact metal ferrule of the conductor plate 62) via an electrical contact 64, in particular via the contact metal ferrule of the conductor plate 62. Fig. 20 ) is connected to the electronic device unit together with the microprocessor on the circuit board. Since the electronic device unit and the microprocessor and their arrangement on the corresponding circuit board in the energy storage unit 16 are not important for the present invention, this point will not be discussed further. For a person skilled in the art, corresponding devices for monitoring or controlling or regulating the energy storage cell 52 are known.

[0066] In the common case of a nominal cell voltage U of 3.6 V, Cell In the case of a lithium-ion round cell 50, a battery voltage U of n·3.6 V acts on the corresponding electrical contacts of the electromechanical interface. Batt , wherein n defines the number of circular cells 50 connected in series. So-called cell clusters consisting of circular cells 50 connected in parallel can also be connected in series via cell connectors 56 in order to achieve a certain battery voltage U while increasing the capacitance. BattIn the case of other electrochemical energy storage cells 52, the nominal cell voltage U Cell It can be different, so that depending on the type and application of the energy storage unit 16, battery voltages of 18V to 70V and above are possible. Depending on the number of energy storage cells 52 connected in parallel in the cell cluster, the capacitance of commercially available high-power energy storage cells 16 can be as high as 14Ah and above, so that, for example, more than 750Wh can be achieved in the field of electric bicycles. However, the present invention is independent of the type, structure, voltage, power supply capacity, etc. of the energy storage cell 52 used, but can be applied to a plurality of different energy storage cells 16.

[0067] Figure 4 It is explained that the five cell stacks 46 of the energy storage unit 16 are arranged adjacent to each other along the longitudinal axis L so that the clamping device 68 connects the cell connector 56 to the electric cell pole 58 of the round cell 50 in a force-locking manner without material connection in the assembled state of the energy storage unit 16. Since the round cell 50 does not always have exactly the same longitudinal extension in terms of production technology, this can be achieved in a very simple way in combination with the spring-elastic contact element 60 of the cell connector 56. In the illustrated embodiment, the clamping device 68 consists of four rods 70, which penetrate the subhousing 44 and the cell stack 46 and have a threaded section 72 at least on one end. Therefore, the tensile force F acting on the subhousing 44, the cell stack 46 and the cell connector 56 is T In order to ensure a reliable electrical contact between the cell poles 58 of the round cell 50 and the cell connector 56 during a long operating period of the energy storage unit 16, a nut 74 of the clamping device 68 can be adjusted in a simple manner outside the subhousing 44, which nut can be tightened with the threaded section 72. In addition, the energy storage unit 16 can be disassembled to be able to replace individual round cells 50 whose maximum capacitance has greatly decreased over time or which have a defect. The nut can be designed particularly advantageously as a self-locking nut.

[0068] The cell stacks 56 arranged on the end sides of the cell stacks 46 are each part of a cell connector device 76. The cell connector devices 76 are not only arranged between the cell stacks 46, but also on the two outer end sides of the structural unit composed of the cell stacks 46, so that the two end covers 42 of the sub-housing 44 also form a cell connector device 76. Figure 5a5a (perspective view) and 5b (section view), each cell connector device 76 has a carrier layer 78, on which the cell connector 56 is arranged with its spring-elastic contact element 60, which is designed as a conductor plate 62. For example, the carrier layer 78 can be made of polyamide, polypropylene or a similar material with corresponding electrically insulating properties. Likewise, a carrier layer 78 made of epoxy resin or the like is conceivable. To illustrate the construction of the cell connector device 76, the round cell 50 is shown in FIG. Figure 5a The inner portion of the groove 44 is not completely pushed into the hole 48. Figure 5b The inserted state of the round cell 50 is shown in the enlarged detail on the cell pole 58 of the round cell. In the assembled state of the energy storage unit 16, the electric cell pole 58 is pressed against the spring-elastic contact element 60 of the cell connector 56 in the direction of the carrier layer 78 by the pressing device 68. Since the carrier layer 78 forms a defined stop for the contact element 60, the advantage of high contact safety between the cell pole 58 and the contact element 60 is obtained. In addition, by the separate design of the carrier layer 78 and the cell connector 56, it is possible to adapt the cell connector device 76 to the required battery voltage or battery capacitance of the energy storage unit 16 in a simple manner by corresponding modifications on the cell connector 56.

[0069] Along the longitudinal axis L of the energy storage unit 16, a longitudinal gap 80 is arranged in the hole 48 of the cell stack 46 such that at least one longitudinal web 82 of the hole 48, which is adjacent to the longitudinal gap 80 and is resiliently supported, enables radial fixing of the round cell 50 by virtue of the fact that the longitudinal web is axially spaced relative to the outer diameter D of the round cell 50. C Reduce the inner diameter D of the hole 48 B In this way, the round cell 50 can be fixed in the hole 48 without play along the longitudinal axis L in combination with easy pushing in or pulling out in the axial direction. Preferably, the longitudinal web 82 is integrally provided with the wall 54 of the hole 46. However, it is also conceivable that the longitudinal web 82 is connected to the wall 54 by means of an adhesive connection or the like.

[0070] Figure 6A further embodiment of an energy storage unit 16 is shown in a greatly simplified sectional view along the longitudinal axis L, which has two adjacent cell stacks 46 and round cells 50 inserted therein. In the case of the middle cell connector device of the three cell connector devices 76, at least one cell connector 56 is arranged at two opposite end sides of the carrier layer 78 along the longitudinal axis L in each case so that in the assembled state of the energy storage unit 16, a pressing device 68 (not shown) presses the electric cell poles 58 of the round cells 50 adjacent along the longitudinal axis L of the two cell stacks 46 against the contact elements 60 of the cell connectors 56 in each case in the direction of the carrier layer 78. For this purpose, it is provided that the cell connectors 56 arranged at each end side of the carrier layer 78 are each designed as a one-piece conductor plate 62, which surrounds the carrier layer 78 at one edge in order to electrically connect the electric cell poles 58 of the round cells 50 of the two adjacent cell stacks 46 to one another. Therefore, the cell connector 56 or the conductor plate 62 and the carrier layer 78 have a sandwich-type construction. The enveloping of the carrier layer 78 can be realized in particular by means of an electrical contact 64 for connection to the circuit board 66. In addition, a conductor plate 62 of this type enables a particularly simple assembly of the cell connector device 76, since it is almost only necessary to push the conductor plate onto the carrier layer 78 along the end side of the carrier layer. By means of this type of symmetrical preassembly of the cell connector device 76, the parallel or series interconnection of the round cells 50 can be realized in a simple manner without the need for an additional material-locked connection process.

[0071] In order to support the effect of the spring-elastic contact element 60, the cell connector device 76 has at least one elastic spring element 84, which is arranged between the carrier layer 78 and the contact element 60 of the cell connector 56 in such a way that, in the assembled state of the energy storage unit 16, the electric cell pole 58 of the round cell 50 overcomes the spring force F in particular by the holding-down device 69. S The contact element 60 is pressed in the direction of the carrier layer 78 , said spring force being generated by a first spring force of the contact element 60 and a further spring force of the at least one spring element 84 . Figure 7 In with Figure 5a This is illustrated in a similar view, but with a round cell 50 that has not yet been completely inserted. In this way, possible length tolerances of the round cell 50 can also be better compensated. In addition, the spring component 84 can form a limit stop for the corresponding contact element 60 when the energy storage unit 16 is pressed. In addition, a possible reduction in the spring elastic effect of the contact element 60 can be preventively offset. Preferably, the spring component 84 is produced from an elastomer and / or a synthetic polymer, the elastomer is especially a thermoplastic elastomer (TPE), a foam, the foam is especially a polyurethane foam, and the synthetic polymer is especially silicone. That is, composite materials composed of the mentioned materials are also conceivable.

[0072] exist Figure 8 1 shows a further embodiment of an energy storage cell 16 or of a cell connector device 76 in a section along the longitudinal axis L of the energy storage cell 16. In order to prevent radial displacement of the round cell 50, for example in the event of a fall of the energy storage cell 16 or a collision of the electric motor-driven vehicle 10, in the assembled state of the energy storage cell 16, the spring element 84 realizes a frictionally locking adhesive contact with the round cell 50 in the region of the cell pole 58 of the round cell.

[0073] exist Fig. 9 4 shows an exploded schematic view of a cell stack 46. The cell stack consists of two cell supports 86, which form a grid structure for a total of eight hollow cylindrical holes 48 with their cylindrical walls 54. In addition, each hole 48 - as already described Figure 6 As described, along the longitudinal axis L of the energy storage unit 16, there is a longitudinal gap 80 and at least one longitudinal web 82, which is adjacent to the longitudinal gap and is supported in an elastic manner. On the end sides of the cell stack 46 composed of two cell supports 86, a cell connector device 76 is arranged respectively for electrically interconnecting the round cells 50 (not shown) inserted into the holes 48. Here, each cell connector device 76 has two cell connectors 56, which are configured as a one-piece conductor plate 62, which encloses the carrier layer 78 on one edge, so as to electrically connect the electric cell poles 58 of the round cells 50 of two adjacent cell stacks 46 in a series circuit and / or a parallel circuit. Therefore, the two conductor plates 62 and the carrier layer 78 are implemented in a sandwich-type construction. In order to prevent the cell connector device 76 and the cell holder 86 of the cell stack 46 from moving relative to each other, the carrier layer 78 of the cell connector device 76 and the cell holder 86 respectively have a plurality of form-locking elements 88 for mechanically connecting the carrier layer and the cell holder to each other. The form-locking elements 88 can be configured in very different ways, for example, as triangular, pin-shaped and / or circular protrusions, which are embedded in the corresponding complementary recesses of the parts to be connected. In addition, via the form-locking elements 88, it is possible to realize a clear and unique assembly of the cell connector device 76 on the cell stack 46 or the cell holder 86 in the sense of a mistake-proof solution, so as to avoid the reverse polarity (Verpolung) of the inserted round cell 50 in particular when assembling the energy storage unit 16. It should be mentioned that the cell stack 46 can also be configured as a single cell holder 86 or the cell holder 86 can correspond to the cell stack 46 in terms of its working principle.

[0074] FIG. 10 shows in a top view a further embodiment of a cell connector 56 for a cell stack 46, which is designed as a conductor plate 62 and has a total of ten energy storage cells 52. The cell connector 56 has a plurality of processing areas 90, by means of which the contact elements 60 to be connected for the battery poles 58 of different energy storage cells 52 can be mechanically and / or electrically separated from one another. Thus, a universal cell connector 56 can be provided for energy storage units 16 of different voltage ranges and / or energy capacities. Fig.10a , the single cell connector 56 is designed in such a way that it is suitable for the maximum variant of the energy storage unit 16 and can be modified accordingly in a simple manner for the variant of a smaller voltage range and / or energy capacity by means of the electromechanical separation of the corresponding contact element by means of the processing area 90. In order to further simplify the adaptability, the processing area 90 can be configured as a desired breaking point 92, for example in the form of a narrowing and / or a perforated portion. Here, the desired breaking point 92 needs to be configured in such a way that it withstands normal loads and is therefore sufficiently robust to external mechanical influences on the energy storage unit 16 during the set use cycle of the energy storage unit, for example, in the case of a fall, a blow or a strong vibration. In particular, the desired breaking point 92 can be disassembled by pulling, pressing and / or twisting or shearing movement. As a result, the desired breaking point continues to remain robust relative to the normal load mentioned.

[0075] In order to simplify the separation on the processing area 90 of the cell connector 56 with the aid of suitable auxiliary tools (e.g., separation pliers, lever tools), the cell connector 56 has a guide geometry 94 in the surroundings of the processing area 90, to which the auxiliary tool can be attached. It is also conceivable that the desired breaking point 92 itself has a corresponding guide geometry, for example in the form of a specially configured perforation.

[0076] Furthermore, it is easier to identify and / or process the processing region 90 if the processing region has a marking 96. The marking 96 can be designed so that the processing regions 90 that are separated in an electrically meaningful manner have identically designed markings 96. This facilitates the processing of the cell connector 56 for the intended use in the energy storage unit 16, starting from the maximum variant of the cell connector.

[0077] exist Fig.10b In the example, the dashed line shows Fig.10a The single cell connector 56 in the embodiment is disassembled into two separate conductor plates 62. To this end, two processing areas in a total of nine processing areas 90 are separated by means of suitable separation tools at the corresponding markings 96 or according to Fig.10aThe two conductor plates 62 can thus form two cell clusters within the cell stack 46 via their contact elements 60, which are still electromechanically connected to one another. Depending on the orientation of the energy storage cells 52 in the associated holes 48 of the cell stack 46, a parallel circuit or a series circuit for the corresponding cell clusters can thus be realized. In addition, it is possible to interconnect the energy storage cells 52 of adjacent cell stacks 46 in a parallel circuit and / or a series circuit, depending on the requirements for the energy storage unit 16, with the aid of conductor plates 62, whose contact elements 60 are electromechanically connected to one another via contact pieces 64, which are arranged accordingly on both sides of the carrier layer 78 of the cell connector device 76.

[0078] A mechanical indicator 98 is provided on the cell connector 56, in particular on the edge region of the cell connector 56, for identifying modifications made to the cell connector 56. Fig.10b After the single pool connector 56 in Fig.10a The projections visible in the figure are removed by means of a separating tool. Thus, in the case of repairs, it can be easily recognized that the corresponding cell connector is no longer in the initial state of the maximum variant for the energy storage unit 16.

[0079] Unlike the non-material-locked force-locked connection of the contact element 60 to the cell pole 58, their material-locked connection still provides a reliable and permanent electrical contact, but on the other hand prevents the removal or replacement of individual energy storage cells 52 whose maximum capacitance has greatly decreased over time or which have failed. The removal of the energy storage unit 16 to be recycled is also prevented by the fact that the individual energy storage cells 52 can only be separated from the cell connector 56 with relatively great effort. Therefore, Figure 11 to 1The solution is proposed in such a way that the cell connector 56 has at least one main contact element 60 which is connected in a materially bonded manner to the cell pole 58 of the energy storage cell 52, wherein the cell connector 56 for at least one of the main contact elements 60 has at least one redundant contact element 100 which, in the initial state of the assembled energy storage unit 16, is not connected in a materially bonded manner to the electrical cell pole 58 of the energy storage cell 16. As a result, despite the materially bonded connection between the cell connector 56 and the energy storage cell 52, a simple removal of the energy storage cell 52 is possible. For this purpose, the energy storage cell 52 to be removed can be easily separated from the cell connector 56 together with the main contact element 60 which is connected in a materially bonded manner thereto. The redundant contact element 100 is used in the case of repair to be connected in a materially bonded manner to the electrical cell pole 58 of a replacement energy storage cell 52 for the energy storage cell 52 connected to the main contact element 60. After the energy storage cell 52 to be replaced has been removed, the replacement energy storage cell 52 can be connected in a very simple manner to the redundant contact element 100 of the cell connector 56 in a material-locking manner, for example by resistance welding, ultrasonic welding or laser welding. Figure 11 to 1 4, the point-shaped connection points (depressions) of the contact element 60 welded to the battery pole 58 are marked by small crosses, while the unwelded depressions (dimples) of the redundant contact element 100 are shown as hollow circles. In principle, soldering connections are also conceivable, taking into account the heat input into the replacement energy storage cell 52 that occurs here.

[0080] exist Fig.11 In the embodiment, two redundant contact elements 100 are arranged adjacent to two main contact elements 60 connected to the cell poles 58 of the energy storage cells 52 in a materially bonded manner, so that after replacing the energy storage cell 52 by a corresponding replacement energy storage cell 52 and separating the main contact elements 60, the redundant contact elements can be brought to the position of the main contact elements 60 by turning over on the processing area 102 provided for this purpose, which can be configured as a perforation and / or a marking, for example. Particularly advantageously, in this way, the same, optimal position on the cell pole 58 can also be used for replacing the energy storage cell 52 for materially connecting to the redundant contact elements 100 of the cell connector 56. In addition, the cell pole 58 of the energy storage cell 52 can have a small electrical contact surface, as in particular in the case of a cell pole 58 with a positive voltage potential, in order to avoid possible leakage currents and short circuits. Furthermore, in order to avoid short circuits, it is provided that at least one redundant contact element 100 is electrically insulated in the initial state of the assembled energy storage cell 16 , in particular by means of an insulating foil 104 . Furthermore, inadvertent activation processes of the redundant contact element 100 can be avoided in this way.

[0081] In order to be able to replace a plurality of energy storage cells 52 identically in one operation, according to Fig.12 The cell connector 56 has a main extension plane 106 which extends in particular transversely to the longitudinal axis L of the energy storage cell 16. The redundant contact element 100 is arranged adjacent to the main contact element 60 in such a way that it can be brought into the position of the main contact element 60 by moving the cell connector 56 along the main extension plane 106 (indicated by arrow 108).

[0082] according to Fig.13 , the redundant contact element 100 is arranged adjacent to the main contact element 60 so that the outer contour of the main contact element and the redundant contact element 60, 100 does not exceed the outer periphery of the energy storage cell 52, which is connected to the main contact element 60 and is configured as a round cell 50. Therefore, a compact structural form of the cell connector 56 can be achieved in a particularly advantageous manner. Then, the redundant contact element 100 is placed on the cell pole 58 of the round cell 50, which is connected to the main contact element 60 in a material-locked manner. In addition, in order to replace the round cell 50, the cell connector 56 can remain unchanged at the same position in the energy storage unit 16 or the cell stack 46. In order to replace the round cell 50 at the same position in the energy storage unit 16 multiple times, the cell connector 56 for the main contact element 60 has three redundant contact elements 100. Furthermore, it can be provided that the cell connector 56 for each main contact element 60 has at least one redundant contact element 100. Thus, in the event of maintenance, all energy storage cells 52 of an energy storage unit 16 can be replaced in the same manner.

[0083] In order to further simplify the maintenance or removal of the energy storage unit 16, the processing area 102 of the main contact element and / or at least one redundant contact element 60, 100 according to Figure 14 is respectively constructed as an expected breaking point 110. This allows the energy storage cell 52 to be mechanically separated from the cell connector 56 by a simple break that may be without additional tools. However, the expected breaking point 110 needs to be constructed so that the expected breaking point is subjected to normal loads, and therefore is sufficiently robust to external mechanical influences on the energy storage unit 16 during the set use cycle of the energy storage unit, such as in the case of falling, hitting or strong vibration. In particular, the expected breaking point 110 can be disassembled by pulling, pressing and / or twisting or shearing movement. Thus, the expected breaking point continues to remain robust relative to the normal load mentioned.

[0084] The desired breaking point 110 is arranged in the direct surroundings of a recess between the primary contact element or at least one redundant contact element 60, 100 and the electric cell pole 58 of the energy storage cell 16. The recess itself can also be used as the desired breaking point 110. Here, the geometry of the recess is configured so that it is easy to break under certain movements, in particular, it is designed to be sensitive to torsion. Therefore, the recess can be separated from the cell pole 58 by a simple rotation of the energy storage cell 52 to be replaced around its longitudinal axis.

[0085] In the attached Figures 14a to 14d Different configurations of the desired breaking location element 110 are shown in FIG. Fig.14a The desired breaking point 110 designed as a constriction for the main contact element and the redundant contact element 60 , 100 is shown in each case. Figures 14b to 14d Different variants are shown for the desired breaking points 110 for two main contact elements 60 in each case, with a different number and arrangement of cutouts and notches.

[0086] The main contact element and / or the redundant contact element 60, 100 can each have a guide geometry 112 for separation at the desired breaking point 110. The guide geometry 112 can be formed, for example, directly by the outer contour of the contact element 60, 100. In this way, the separation can be simplified with the help of suitable auxiliary tools (for example, separation pliers or a lever tool), which are placed on the guide geometry 112. In addition, the guide geometry 112 and / or the processing area 102 can be configured in such a way that the guide geometry and / or the processing area enable replacement of the energy storage cell 52 or manipulation on the cell connector 56 to be detected.

[0087] Alternatively or in addition, instead of the desired breaking point 110, it is also possible to provide according to Figures 15 to 18 that the main contact element and / or the redundant contact element 60, 100 have a connection area 114, so as to configure the main contact element and / or the redundant contact element in a reversibly detachable manner with the cell connector 56. Reversible disassembly should be understood as that the electromechanical connection between the contact element 60, 100 and the cell connector 56 can be disassembled and reestablished. Therefore, on the one hand, the main contact element 60 can be disassembled from the cell connector 56 and then connected to the cell connector again, and on the other hand, the main contact element 60 connected to the cell pole 58 of the consumed energy storage cell 52 can be replaced by the contact element 100 connected to the cell pole 58 of the replacement energy storage cell 52. In addition, by pre-assembling the energy storage unit 52 and the contact element 60, the assembly of the energy storage unit 16 can be simplified.

[0088] exist Fig.15aIn FIG. 1 , the connecting region 114 of the contact element 60 is designed as a closed, oval eye 116 . Fig.15b A variant is shown as an eyelet 118 open on one side. Both variants can be connected by means of a screw connection (see Fig.16 ) is connected to the cell connector 56 and ensures a certain tolerance compensation in the radial direction of the round cell 50 due to its elliptical configuration. The closed eyelet 116 provides a better hold for the contact element 60 during assembly, while the open eyelet 118 allows easier assembly by pushing it laterally into the screw connection that has not yet been tightened. In addition, in this way, if necessary, multiple contact elements 60 can be fastened to a common connection point of the cell connector 56. Fig.15c A tool-free connection is shown in which the connection region 114 is designed as a plug connection 120 between the contact element 60 and the cell connector 56 .

[0089] exist Fig.16 In the embodiment, the connection region 114 of the contact element 60 is constructed according to Fig.15b 18. This allows a simple electromechanical connection of the cell poles 58 of the four round cells 50 shown by means of a single screw connection to the cell connector 56. The cell connector 56 can be designed, for example, as a punched grid 122, which in turn is electromechanically connected to the printed circuit board 66 of the energy storage unit 16.

[0090] Fig.17 An alternative to the embodiment according to FIGS. 15 and 16 is shown in which the connection region 114 is designed as a flat, exposed end of the contact element 60, which in turn is clamped into the cell connector 56 designed as a rail system 124. It is also conceivable that the connection region 114 has a pressed depression and / or a step for easier positioning and / or fixing in the rail system 124. In addition or as an alternative, the connection region 114 can also be provided with at least one soldering eye. Or a material that can be easily soldered in order to permanently ensure electrical contact between the contact element 60 and the cell connector 56 and ensure a fault-free battery management system (BMS). As is known, soldered connections also allow reversible disassembly.

[0091] according to Fig.19 , it should be reiterated that Fig.15c5 , which is used for a cell connector device 76 having a cell connector 56, which is arranged on both sides of a carrier layer 78. As can be seen, the contact element 60 is connected at one end in a materially bonded and irreversible manner via a correspondingly welded recess to the cell pole 58 of the energy storage cell 52, while the contact element has a plug connection 120 at its other end. The plug connection can be reversibly connected to the cell connector 56 in a simple manner, so that the energy storage cell 52 that can no longer be used can be replaced together with the contact element 60 connected to the energy storage cell in a materially bonded manner, preferably without tools.

[0092] exist Fig. 20 In FIG. 1 , a further embodiment of an energy storage unit 16 is shown in a greatly simplified section along the longitudinal axis L of the energy storage unit. The cell connector device 76 will not be discussed again here, since it corresponds essentially to the cell connector device according to FIG. Figures 6 to 9 Important here is the reversible connection of the cell connector device 76 or the cell connector 56 to the printed circuit board 66 of the energy storage unit 16, for example by means of a spring element 130, a plug contact or the like. In this way, the printed circuit board 66 together with the electronic unit for the BMS (not shown) arranged thereon can be replaced very easily in the event of a fault. Accordingly, the cell connector 56 or the cell connector device 76 can also be replaced easily.

[0093] Finally, it should be pointed out that the embodiments shown are not limited to Figures 1 to 20 , nor are they limited to the shown forms, quantities and size ratios of the individual components. These embodiments should be understood as exemplary only.

Claims

1. An energy storage unit (16) for an electric motor-driven vehicle (10), in particular for an electric motor-driven single-wheel vehicle or two-wheel vehicle (12), the energy storage unit having a sub-housing (44), in which at least two cell stacks (46) are received for receiving at least two electrochemical energy storage cells (52), the energy storage cells being designed as round cells (50), wherein: Each energy storage cell (52) has two electric cell poles (58), and the electric cell poles (58) of at least two energy storage cells (52) are electrically conductively connected to one another in a series circuit and / or a parallel circuit via at least one cell connector (56), characterized in that the at least two cell stacks (46) are arranged adjacent to one another so that in the assembled state of the energy storage unit (16), a holding device (68) of the energy storage unit (16) connects the cell connector (56) to the electric cell poles (58) of the energy storage cell (52) in a force-locking manner without a material connection, wherein the tensile force (F) of the holding device (68) is T ) can be adjusted outside the sub-housing (44).

2. The energy storage unit (16) according to claim 1, characterized in that The holding-down device (58) is designed as at least one rod (70) which projects through the housing part (44) and has at least one threaded section (72) arranged at the end, and the tension (F T ) can be adjusted via a nut (74) which can be tightened with the threaded section (72).

3. The energy storage unit (16) according to claim 1, characterized in that The energy storage unit (16) has at least one cell connector device (76) having a carrier layer (78), wherein the at least one cell connector (56) is arranged on the carrier layer (78) in such a way that, in the assembled state of the energy storage unit (16), the pressing device (68) presses at least one of the electric cell poles (58) of the energy storage cell (52) in the direction of the carrier layer (78) against a spring-elastic contact element (60, 100) of the cell connector (56).

4. Energy storage unit (16) according to claim 3, characterized in that The cell connector device (76) is arranged between two cell stacks (46), wherein at least one cell connector (56) is arranged on two opposite end sides of the carrier layer (78) along the longitudinal axis (L) of the energy storage unit (16) in such a way that, in the assembled state of the energy storage unit (16), the pressing device (68) presses the electric cell poles (58) of two energy storage cells (52) of the two cell stacks (46) adjacent along the longitudinal axis (L) in the direction of the carrier layer (78) against the contact elements (60, 100) of the cell connector (56).

5. Energy storage unit (16) according to claim 4, characterized in that At least two cell connectors (56) arranged on the end side of the carrier layer (78) are designed as one-piece conductor plates (62) which surround the carrier layer (78) in order to electrically connect the electrical cell poles (58) of at least some of the energy storage cells (52) of the two cell stacks (46) to one another.

6. Energy storage unit (16) according to any one of the preceding claims 3 to 5, characterized in that The at least one cell connector device (76) has at least one elastic spring element (84) which is arranged between the carrier layer (78) and at least one contact element (60, 100) of the at least one cell connector (56) such that in the assembled state of the energy storage unit (16), the holding-down device (68) counteracts a spring force (F S ) presses at least one of the electric cell poles (58) of the energy storage cell (52) toward the at least one contact element (60, 100) in the direction of the carrier layer (78), the elastic force being generated by a first elastic force of the contact element (60) and a further elastic force of the at least one spring component (84).

7. Energy storage unit (16) according to claim 6, characterized in that In the assembled state of the energy storage unit (16), the spring element (84) realizes a frictionally engaging adhesive contact with the energy storage cell (52) in the region of the cell pole (58) of the energy storage cell.

8. Energy storage unit (16) according to any one of the preceding claims 6 or 7, characterized in that The spring element (84) consists of an elastomer and / or a synthetic polymer, the elastomer being in particular a thermoplastic elastomer, a foam, in particular a polyurethane foam, and the synthetic polymer being in particular silicone.

9. Energy storage unit (16) according to any one of the preceding claims 3 to 8, characterized in that The carrier layer (78) consists of polyamide or polypropylene.

10. The energy storage unit (16) according to claim 1, characterized in that Each cell stack (46) has a plurality of hollow cylindrical holes (48) for receiving a respective round cell (50), wherein a longitudinal gap (80) is arranged in the hole (48) along the longitudinal axis (L) of the energy storage unit (16) in such a way that at least one longitudinal web (82) of the hole (48) adjacent to the longitudinal gap (80) and supported in a resilient manner enables radial fixing of the round cell (50), and the inner diameter (D) of the hole (48) without the longitudinal web (82) is B ) is larger than the outer diameter (D) of the circular single cell (50) respectively received in the hole. C ).

11. The energy storage unit according to any one of the preceding claims 3 to 10, characterized in that The carrier layer (78) of the cell connector device (76) and the cell stack (46) each have a plurality of form-fitting elements (88) for mechanically connecting the carrier layer and the cell stack to one another.

12. An electric motor-driven vehicle (10), in particular an electric motor-driven single-wheel vehicle or two-wheel vehicle (12), having an energy storage unit (16) according to any of the above claims, which can be connected to the electric motor-driven vehicle (10) in a detachable manner or can be firmly integrated in the electric motor-driven vehicle (10).

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