Energy storage unit

Abstract

To provide an energy storage unit capable of adapting the volume change of an electrode separator / electrolyte unit according to a purpose and a manufacturing method for the same.SOLUTION: An energy storage unit (10) includes an electrode separator / electrolyte unit. The electrode separator / electrolyte unit is configured to receive and / or release electrical energy. The electrode separator / electrolyte unit further includes at least one first boundary element (18) that at least partially forms an outer surface (16) of the electrode separator / electrolyte unit. The energy storage unit (10) has a connection unit (20). The connection unit (20) is disposed on the first boundary element. The connection unit (20) is further configured to follow the volume change of the electrode separator / electrolyte unit.SELECTED DRAWING: Figure 1a

Description

[Technical Field]

[0001] The present invention relates to an energy storage unit, a method for manufacturing an energy storage unit, a vehicle and a battery storage system.

[0002] Today, there are many different solutions for building battery cells and storage systems. With the increasing number of storage systems due to the mobility transformation and increasing performance demands, there is an increasing demand for technological innovations that make storage systems more robust.

[0003] Continuing weight reductions in vehicle construction to reduce fuel consumption and increasing competitiveness create cost pressures, resulting in an ever-increasing demand for lower cost, more efficient vehicle components.

[0004] Disclosure of the Invention According to embodiments of the invention, an improved energy storage unit can be advantageously provided. The invention is defined in the respective independent claims. Advantageous developments of the invention can be seen from the respective dependent claims and the following description.

[0005] An advantage of an energy storage unit having the features of claim 1 is that the adapted casing allows for targeted adaptation to changes in the volume of the electrode separator / electrolyte unit. A further advantage is that the volume expansion of the individual cells can be compensated for by the cell casing, so that the expanded state of the cell stack in the module does not require any additional space. For example, the extension length of the electrode separator / electrolyte unit can change depending on its state of charge. The connection unit of the energy storage unit allows for the volume or volume change to be compensated for or adapted accordingly.

[0006] The above is achieved according to the present invention by the energy storage unit comprising an electrode separator / electrolyte unit configured to receive and / or release electrical energy, the electrode separator / electrolyte unit having at least one first boundary element that at least partially forms an outer surface of the electrode separator / electrolyte unit, the energy storage unit having a connection unit disposed on the first boundary element, and the connection unit further configured to follow volumetric changes of the electrode separator / electrolyte unit.

[0007] In other words, the electrode separator / electrolyte unit may change its volume based on a state of charge, an aging process, or the like. To enable the electrode separator / electrolyte unit to adapt to its volume change, the energy storage unit may have a connection unit, e.g., a film-like element, configured to follow the volume change of the electrode separator / electrolyte unit by virtue of its elasticity and / or flexibility. The adaptation of the energy storage unit using the connection unit preferably includes both a volume increase and a volume decrease, or the like. Preferably, the energy storage unit may be disposable within a casing. Advantageously, the sequence of volume changes may in particular be compensation for the volume change by the connection unit.

[0008] For example, the electrode separator / electrolyte unit or the electrode separator stack disposed therein may undergo significant thickness changes during charging or discharging. More preferably, the electrode separator / electrolyte unit may also undergo a continuous thickness increase over its lifetime. In this case, the thickness change may be at least 5% of the original thickness of the electrode separator / electrolyte unit, more preferably 10% and / or even 15% or more. Such thickness changes may occur particularly in lithium cells having a graphite electrode with more than 15% silicon doping on the anode side, and also equipped with silicon electrodes, lithium metal foil electrodes, and / or the like. This may occur in cell chemistries including liquid electrolytes ("lithium-ion cells") and cell chemistries including passivated or solid electrolytes ("solid-state cells").

[0009] More preferably, the electrode-separator / electrolyte unit or the electrode-separator stack arranged therein can be compressed in a predetermined orientation or similar conditions. Here, it is possible to distinguish between effective compression that supports the charge / discharge process, e.g., to avoid mechanical degradation of the active material with subsequent loss in electronic applications. Furthermore, compression may be necessary to ensure constant mechanical contact between the electrode and the separator / electrolyte, e.g., in the event of electrode dissolution in solid-state cells.

[0010] More preferably, ineffective compaction may occur, but this is distinguished from ineffective compaction in that lithium does not separate in a defined manner in or on the anode during charging, which may result in dendritic growth. Many intermediate states between effective and ineffective compaction may occur, depending, inter alia, on both the cell chemistry and the battery management operating strategy. More preferably, effective compaction in the range of 50 kPa to 100 kPa is required for cells with liquid electrolytes, and values well above 100 kPa may be required when solid electrolytes are used to reliably regulate ionic conduction through the electrolyte.

[0011] In this case, if too low a compaction pressure is used, for example less than 100 kPa for a liquid electrolyte, or less than 1 MPa for a solid electrolyte, ineffective compaction may occur.

[0012] Preferably, the energy storage unit can be provided with a flexible casing using the connection unit, which casing can follow reversible thickness changes of more than 10% of the electrode separator / electrolyte unit, in which case the cell casing can abut the flexible casing face-wise against the electrode separator stack, thus applying a defined force.

[0013] For example, the connection unit can be more elastically deformed, and this elastic deformation can follow the expansion or volume reduction of the electrode separator / electrolyte unit. Preferably, the connection unit can be formed as a type of film that can be formed from elastomer, thermoplastic resin, metal and / or thermoplastic resin-metal composite or the like.

[0014] The respective dependent claims indicate preferred developments of the invention.

[0015] Preferably, the connection unit has at least one material and / or shape configured to follow the volume changes of the electrode separator / electrolyte unit, wherein the material is an elastomer, plastic and / or metal, and / or the shape is a bellows, trampoline and / or folding bellows configured to follow the volume changes of the electrode separator / electrolyte unit.

[0016] An advantage of this embodiment is that the material and / or contour or shape of the connection unit can be adapted to follow changes in the volume of the electrode separator / electrolyte unit, thereby maintaining a constant required structural space. Preferably, for example, a first part of the connection unit can be arranged on the first boundary element, and a second part of the connection unit can be arranged on the casing of the energy storage unit. A further advantage is that an even compression across the surface of the electrode separator / electrolyte unit can be ensured. For example, a typical maximum value is up to 20%, preferably up to 10%.

[0017] More preferably, the connection unit is configured to connect the first boundary element to a casing of the energy storage unit.

[0018] An advantage of this embodiment is that the connection unit can be arranged on the casing and the boundary element, allowing the electrode separator / electrolyte unit to be subsequently inserted into the energy storage unit. This configuration allows cell production based on the production of prismatic cells. The electrode separator / electrolyte unit is preferably introduced into the cell casing and electrically connected to the cell connections. The casing is then preferably welded. Therefore, the above-described embodiment of the cell casing can be relatively easily integrated into the existing production of prismatic cells.

[0019] More preferably, the electrode separator / electrolyte unit has a second boundary element at least partially forming an outer surface of the electrode separator / electrolyte unit, wherein the connecting unit is connected to the first boundary element and the second boundary element to follow volumetric changes of the electrode separator / electrolyte unit.

[0020] An advantage of this embodiment is that it can accommodate volume changes of the electrode separator / electrolyte unit in two dimensions, for example along the axis. For example, the connection unit can be formed as a kind of folding bellows or the like, which interconnects the first boundary element and the second boundary element, so as to accommodate volume changes of the electrode separator / electrolyte unit. Preferably, the connection unit can apply a mechanical force that moves the boundary element towards the electrode separator / electrolyte unit. The boundary element is preferably pressed against the electrode separator / electrolyte unit.

[0021] More preferably, the energy storage unit further comprises a stress unit, which is configured to apply a preset force to the first boundary element.

[0022] An advantage of this embodiment is that the stress unit can be used to purposefully follow or adjust, in particular suppress, volume changes of the electrode separator / electrolyte unit. Preferably, the stress unit can be configured to follow volume changes of the electrode separator / electrolyte unit and / or to generate a predetermined pressure on the electrode separator / electrolyte unit. In this case, the stress unit can abut the electrode separator / electrolyte unit and thus apply a force to at least one outer surface of the electrode separator / electrolyte unit. Here, for example, the electrode separator / electrolyte unit can have an edge layer or the like, against which the stress unit can apply the predetermined force.

[0023] More preferably, the stress unit is configured to apply a predetermined force, the applied predetermined force being configured to adjust the height of the electrode separator / electrolyte unit.

[0024] An advantage of this embodiment is that the predetermined force can be adapted to suit the ageing state of the electrode separator / electrolyte unit, e.g., the electrode separator / electrolyte unit may have different volume zones and / or depletions in its operation, and the adapted predetermined force can take these volume zones and / or depletions into account by the stress unit.

[0025] More preferably, the stress unit is configured to apply a predetermined force substantially uniformly to the outer surface of the electrode separator / electrolyte unit.

[0026] An advantage of this embodiment is that the mechanical or hydraulic force that can be generated by the stress unit can be distributed as evenly as possible over the entire outer surface of the electrode separator / electrolyte unit. For example, the electrode separator / electrolyte unit has a cover and / or a base, and the stress unit is adjusted to apply the predetermined force substantially completely to this cover and / or base. In this context, substantially completely may mean, in particular, that the force is applied by the stress unit to at least 80% of the area of the outer surface of the electrode separator / electrolyte unit, including tolerances due to manufacturing, in particular.

[0027] More preferably, the connection unit and the stress unit are configured to adjust a predetermined pressure on the electrode separator / electrolyte unit. Preferably, the stress unit is switchable, i.e., the force is variably adjustable. Here, a greater force is adjusted, for example, when the cell is discharged, which can cause a pressing force on the separator / electrolyte layer, for example, when the metal anode dissolves. During charging, the force on the stress unit can be reduced, so that the anode can be tailored, in particular preventing dendritic growth.

[0028] An advantage of this embodiment is that a synergistic effect can be created between the connection unit and the stress unit, since the first boundary element has the necessary strength to receive and evenly distribute the predetermined force of the stress unit, and the connection unit can accommodate displacements between the preferably rigid first boundary element and the casing of the energy storage unit. For example, the connection unit can generate elastic deformation to accommodate expansion or volumetric reduction of the electrode separator / electrolyte unit. This allows the connection unit to simultaneously at least partially perform the function of the stress unit, where the connection unit attracts the boundary element toward the electrode separator / electrolyte unit with a tensile force, while the stress unit presses the boundary element toward the battery unit with a compressive force. Thus, depending on the mechanical requirements, the compression function can be performed exclusively by the connection unit, and an additional stress unit can be completely omitted.

[0029] Preferably, the stress unit and the first boundary element are integrally formed.

[0030] An advantage of this embodiment is that the stress unit and the first boundary element can be formed in one step using a metal molding or the like, which further reduces production costs.More preferably, the stress unit can be formed as a form, in particular a metal molding, which is attached to the first boundary element and is therefore formed integrally therewith.Preferably, the metal molding can be elastically deformable.

[0031] Preferably, the stress unit comprises a spring unit, which is adapted to generate a predetermined force by changing its shape.

[0032] The advantage of this embodiment is that the spring unit not only has a particularly long operating period but also requires a particularly small construction space, in particular because the spring unit can abut against the outer surface of the electrode separator / electrolyte unit as well as at reference or installation points, thereby generating a predetermined force.

[0033] More preferably, the spring unit comprises a disc spring and / or a wave spring, which generates a predetermined force by changing its shape.

[0034] An advantage of this embodiment is that both disc springs and wave springs have low manufacturing costs and high availability, which can further reduce the overall cost of the energy storage unit.

[0035] More preferably, the first boundary element comprises a plurality of spring elements, the plurality of spring elements being disposed on the first boundary element and having a curvature towards the first boundary element, the curvature of the plurality of spring elements being configured to generate a predetermined force.

[0036] An advantage of this embodiment is that the spring elements can be formed integrally with the first boundary element, so that the first boundary element and the stress unit can be formed, for example, by an extrusion process. Preferably, for example, an aluminum forming part is considered, which on the one hand forms a planar surface, which forms the first boundary element and further has a plurality of spring elements that can form the spring unit. Even more preferably, the first boundary element and the plurality of spring elements are formed integrally, so that the plurality of spring elements are formed in one forming part of the first boundary element.

[0037] An advantage of this embodiment is that the first boundary element comprising multiple spring elements can be easily and flexibly adapted to different lengths of electrode separator / electrolyte units, since the first boundary element can be adapted by cutting an endless extruded profile to the length of each electrode separator / electrolyte unit.

[0038] Preferably, the stress unit comprises a hydraulic unit, in which case the hydraulic unit is configured to release a predetermined force by displacement of a hydraulic element.

[0039] An advantage of this embodiment is that the hydraulic unit can adapt the displacement of the hydraulic element so that a predetermined force is formed over the operating period of the energy storage unit in order to be able to follow any age-related defects that may occur.

[0040] Further preferably, the connection unit is configured to form a hollow chamber between the first boundary element and the connection unit, and in this case the hydraulic unit is configured to fill the hollow chamber with a fluid to create the predetermined force.

[0041] An advantage of this embodiment is that the connection unit can be formed as a tube, cushion, or the like, for example, by rolling over and sealing a film, and the hydraulic unit can introduce a fluid into the tube or cavity, thereby forming the stress unit. It is also advantageous to simultaneously use the hydraulic medium as a cooling medium for the cell. For this purpose, the hydraulic medium can flow through the connection unit. Gas-pressure-activated connection units are also conceivable. A medium-filled stress unit preferably easily implements a switching function, i.e., the force is variably adjustable. In this case, for example, during cell discharge, a greater force can be applied by increasing the internal pressure of the connection unit, which can press against the separator / electrolyte layer, for example, if the metal anode were to dissolve. During charge, the internal pressure can be reduced, thereby reducing the force on the stress unit, which allows the anode to be tailored and, in particular, prevents dendritic growth.

[0042] Further preferably, the electrode separator / electrolyte unit has at least one shaping element, the shaping element being configured to adapt its height, and the stress unit being configured to change the height of the shaping element by a predetermined force.

[0043] An advantage of this embodiment is that the shaping element can be configured to maintain the movement of the electrode separator / electrolyte unit at different volumes. Preferably, the shaping element can maintain a substantially constant spacing between different layers of the electrode separator / electrolyte unit at different heights of the electrode separator / electrolyte unit. To this end, the shaping element can include a mechanism configured to increase the volume of the electrode separator / electrolyte unit when a predetermined force in the stress unit is minimized.

[0044] Preferably, the molding element has a first layer and a second layer, wherein the first layer has disposed thereon at least one web element configured to space the first layer from the second layer.

[0045] The advantage of this embodiment is that using a web element and two layers, the two layers can be positioned apart from each other by the positioning function of the web element.

[0046] More preferably, the web element is deflectable and / or foldable relative to the first layer about a deflection point of the first layer.

[0047] An advantage of this embodiment is that when the stress unit reduces the height or volume of the electrode separator / electrolyte unit with a predetermined force, the first layer approaches the second layer, causing the web element to fold about the deflection point, thereby reducing the spacing between the first and second layers. As the volume of the electrode separator / electrolyte unit increases, particularly when the predetermined force of the stress unit is reduced or minimized, the web element begins to move the first layer away from the second layer.

[0048] More preferably, the molding element has a third layer, wherein the first layer has on one side another web element arranged opposite the web element, the other web element spacing the third layer from the first layer.

[0049] An advantage of this embodiment is that it simplifies the attachment of various layers to one another. In other words, a first layer may have a first web element on a first side and a second or another web element on a second side, whereby the web elements are located on opposite sides of one another. In this regard, a web element may be used on the first side to separate the second layer from the first layer, and another web element may be used on the second layer to separate the third layer.

[0050] Another aspect of the present invention relates to a method of manufacturing an energy storage unit as described above and below, said method comprising: - providing a casing for an electrode separator / electrolyte unit; - placing a first boundary element on a casing of the energy storage unit by means of a connection unit; - introducing the electrode separator / electrolyte unit into the energy storage unit, whereby the connection unit follows the volume change of the electrode separator / electrolyte unit; Includes:

[0051] More preferably, the method further comprises: - placing a cover on the casing such that a substantially fluid-tight space is formed around the electrode separator / electrolyte unit in the energy storage unit; Includes:

[0052] More preferably, the method further comprises: forming a contact connection between the electrode separator / electrolyte unit and the cover to form an electrical connection between the electrode separator / electrolyte unit and the cover; Includes:

[0053] More preferably, the cover has at least two contact elements, and energy is supplied to the two contact elements by means of an electrical connection.

[0054] More preferably, the method further comprises: - placing a stress unit on the first boundary element, whereby the stress unit is able to create a predetermined force on the first boundary element; Includes:

[0055] Another aspect of the invention relates to a vehicle having an energy storage unit as described above and below.

[0056] Another aspect of the invention relates to a battery storage system for stationary use to receive and discharge electrical energy, the battery storage system having a plurality of the energy storage units described above and below.

[0057] It should be noted that the term "unit" in this specification should be understood broadly and includes both an integrated configuration and a multi-part configuration of each unit, and each part unit is not limited to a single location within the vehicle, but may be distributed throughout the vehicle.

[0058] All disclosures made above and below with respect to one aspect of the invention apply equally to all other aspects of the invention.

[0059] An embodiment of the present invention will now be described with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0060] [Figure 1a] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 1b] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 1c] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 2a] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 2b] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 2c] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 3a] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 3b] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 3c] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 4] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 5a] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 5b] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 6a] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 6b] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 7a] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 7b] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 8] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 9] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 10] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 11] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 12] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 13] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 14] FIG. 1 illustrates an energy storage unit according to one embodiment. [Figure 15] 1 is a flowchart illustrating steps of a method for manufacturing an energy storage unit, according to one embodiment. [Figure 16] 1 illustrates a vehicle 200 according to one embodiment. [Figure 17] FIG. 3 illustrates a battery storage system 300 according to one embodiment.

[0061] Embodiments of the invention The figures are only schematic and are not drawn to scale, and in the figures, identical, similarly acting or similar elements have been provided with the same reference numerals.

[0062] 1a illustrates an energy storage unit 10 according to one embodiment. The energy storage unit 10 includes an electrode separator / electrolyte unit 12 configured to receive and / or release electrical energy, at least one first boundary element 18 that at least partially forms an outer surface 16 of the electrode separator / electrolyte unit 12, and a connection unit 20 disposed on the first boundary element 18 and configured to follow volumetric changes of the electrolyte unit 12. Preferably, a casing 22 can be made from a frame. The shape of the casing 22 or frame preferably corresponds to the shape of the electrode separator / electrolyte unit 12.

[0063] Preferably, the casing 22 can be a cell casing made or constructed from a frame or the like. The shape of the frame or cell casing here corresponds to the casing 22 of the electrode separator / electrolyte unit 12. Preferably, the frame can be made of metal, preferably aluminum, and / or nickel-coated steel for cells subjected to high mechanical loads. More preferably, the frame can be manufactured from a plastic, such as PPS. Preferably, the casing 22 or frame has a lateral opening through which the connection unit 20 can be placed. More preferably, the electrode separator / electrolyte unit 12 can be inserted through the opening in the side of the frame, which can then be closed or welded with a cover module.

[0064] More preferably, the connection unit 20 can be formed from a type of film that can be produced using elastomers or the like, for example, EPDM-based elastomers, especially in connection with a liquid electrolyte in the electrode separator / electrolyte unit 12. More preferably, elastomers can also be used in the case of a solid electrode separator / electrolyte unit 12.

[0065] More preferably, the electrode separator / electrolyte unit 12 expands together with the electrode separator stack during the charging process, thereby deflecting the connection unit 20 or film outward. Here, in particular, the connection unit 20 can accommodate the volumetric changes of the electrode separator / electrolyte unit 12 as it reduces in thickness during the discharging process. The use of an elastomeric material within the connection unit 20 can ensure that the electrode separator / electrolyte unit 12 remains in mechanical contact with the connection unit 20 or the boundary element 18 in virtually all cases. More preferably, the elasticity of the connection unit 20 can contribute to applying a defined mechanical force to the electrode separator / electrolyte unit 12. Furthermore, the connection unit 20 can contribute to an elastic force that particularly assists in reducing the thickness of the electrode separator / electrolyte unit 12.

[0066] Figure 1b shows the energy storage unit 10 of Figure 1a in a cross-sectional view. Preferably, the connection unit 20 is arranged either in the first boundary element 18 of the energy storage unit 10 or in the casing 22. Figure 1b shows the energy storage unit 10 in a discharged state.

[0067] Figure 1c shows the energy storage unit of Figures 1a and 1b in a charged state. As can be seen from a comparison of Figures 1b and 1c, the volume of the electrode separator / electrolyte unit 12 increases in the charged state. Here, the connection unit can accommodate the increased volume due to elastic deformation.

[0068] 2a shows an energy storage unit 10 according to one embodiment, which in this case has a connection unit 20 with a sort of folding bellows-like profile that allows the first boundary element 18 to be deflected relative to the casing 22, in particular to be able to follow volume changes of the electrode separator / electrolyte unit 12.

[0069] More preferably, the energy storage unit 10 can have a frame with laterally attached flexible cover elements or connection units 20. The cover elements preferably consist of fixed lateral portions and flexible deformation elements. The cover elements or connection units 20 preferably protect the electrode separator stack from mechanical damage and distribute externally applied mechanical forces evenly over their surface. The cover elements or connection units 20 can be made of metal, plastic, or reinforced elastomer. If metal, the cover elements can be configured to be electrically insulating, at least on the inner surface of one or more of the connection units 20.

[0070] The flexible deformation element or the connection unit 20 may comprise an elastomer. Preferably, the deformation of the flexible deformation element is achieved by the elasticity of the material. The flexible deformation element may be made of metal or elastomer. In this case, the deformation of the flexible deformation element can be achieved by a shape change of the material or by a shape change of the material and the elasticity of the material. The flexible deformation element can contribute to applying a defined mechanical force to the electrode separator stack. The flexible deformation element can contribute to actively assisting in reducing the thickness of the electrode separator stack.

[0071] Figure 2b shows a cross-sectional view of the energy storage unit of Figure 2a. As can be seen from Figure 2b, the connection unit 20 has a substantially folding bellows or bellows-like structure. Figure 2b shows the energy storage unit 10 or electrode separator / electrolyte unit 12 in a discharged state.

[0072] Figure 2c shows the energy storage unit 10 of Figures 2a and 2b. As can be seen from Figure 2c, the connection unit 20 is biased by the folding bellows, particularly relative to the casing 22, which allows it to follow the volume changes of the electrode separator / electrolyte unit 12.

[0073] FIG. 3a shows an embodiment of an energy storage unit 10. The energy storage unit 10 has a first boundary element 18 and a second boundary element 24. The connection unit 20 can be arranged between the first boundary element 18 and the second boundary element 24. More preferably, the first boundary element 18 and / or the second boundary element 24 can be arranged in a casing 22 of the energy storage unit 10. More preferably, the connection unit 20 can arrange the first boundary element 18 and / or the second boundary element 24 in the casing 22. Preferably, the casing 22 has two rectangular half shells, which are connected to each other by a flexible deformation element or connection unit 20. Each half shell preferably protects the electrode separator stack or the electrode separator / electrolyte unit 12 from mechanical damage and distributes externally applied mechanical forces evenly across its surface. The casing can also preferably comprise metal, plastic, and / or reinforced elastomer. Electrical connections can be integrated into one of the half-shells. A flexible deformation element or connection unit 20 can contribute to applying a defined mechanical force to the electrode-separator stack. The flexible deformation element can contribute to actively assisting the reduction of the thickness of the electrode-separator stack.

[0074] Figure 3b shows a cross-sectional view of the energy storage unit 10 of Figure 3a. The energy storage unit 10 is shown in Figure 3b in a discharged state, so that the first boundary element 18 and the second boundary element 24 have minimal deflection.

[0075] Figure 3c shows the energy storage unit 10 of Figures 3a and 3b in a charged state. As shown in Figure 3c, due to the expansion of the electrode separator / electrolyte unit 12, the second boundary element 24 can be deflected relative to the casing 22, and in this case the connection unit 20 can follow the deflection by means of a folding bellows or the like.

[0076] FIG. 4 shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has a casing 22, in which a first boundary element 18 is arranged by means of a connection unit 20. A stressing unit 14 is preferably arranged on the first boundary element 18, and the stressing unit 14 is configured to apply a predetermined force to the first boundary element 18. In this case, in particular, the stressing unit 14 can be configured to apply the predetermined force, where the applied predetermined force is configured to adjust the height 13 of the electrode separator / electrolyte unit 12. More preferably, the connection unit 20 and the stressing unit 14 are configured to adjust a predetermined pressure within the electrode separator / electrolyte unit 12. More preferably, the stressing unit 14 can be formed as a type of foam, in particular a metal foam or the like, that is injection-molded integrally with the first boundary element 18. In this case, the stressing unit is preferably fixedly connected to the cover element and thus to the casing 22. 4 shows the spring elements distributed in multiple configurations across the energy storage unit 10. Preferably, the spring characteristics of the stress unit 14 allow the force and spring stroke to be adjusted.

[0077] Figure 5a shows an energy storage unit 10 according to one embodiment. As can be seen from Figure 5a, two energy storage units 10 are arranged adjacent to each other. More preferably, the two energy storage units 10 share one stress unit 14. For example, the stress unit 14 may abut the first boundary element 18 of the first energy storage unit 10 and the second boundary element 24 of the second energy storage unit 10. In this case, the energy storage units 10 are shown in a discharged state in Figure 5a.

[0078] Figure 5b shows the energy storage unit 10 of Figure 5a in a charged state. As can be seen from Figure 5b, the electrode separator / electrolyte unit 12 of the energy storage unit 10 has expanded, thereby reducing the extension length of the stress unit 14. Preferably, the extension length can be compensated for or followed via the connection unit 20 between the casing 22 and the first boundary element 18 or the second boundary element 24.

[0079] 6a shows an embodiment of the energy storage unit 10. The energy storage unit 10 here has a first boundary element 18 on which a stress unit 14 is arranged. Furthermore, the stress unit 14 includes a spring unit 26. As shown in FIG. 6a, the spring unit 26 is formed by a disc spring 28.

[0080] 6b shows an embodiment of the energy storage unit 10. The energy storage unit 10 in this case has a first boundary element 18 on which a stress unit 14 is arranged. The stress unit 14 comprises a spring unit 26 which comprises at least one wave spring 30.

[0081] 7a shows an embodiment of the energy storage unit 10. The energy storage unit 10 comprises a stress unit 14 formed by a plurality of spring elements 34 arranged on a first boundary element 18. In this case, the plurality of spring elements 34 and the first boundary element 18 can in particular be formed integrally. More preferably, the predetermined force of the stress unit 14 can be formed in particular by the curvature of the plurality of spring elements 34.

[0082] Figure 7b shows an embodiment of the energy storage unit 10. As shown in Figure 7b, the first boundary element 18 and the plurality of spring elements 34 are integrally molded, so that the plurality of spring elements 34 are formed in a molded portion 35 of the first boundary element 18.

[0083] FIG. 8 shows an embodiment of the energy storage unit 10. The energy storage unit 10 has a molding element 36 that can be formed on the first boundary element 18 and / or the second boundary element 25. Preferably, the molding element 36 can be configured to adapt its height 38 with a specifically predetermined force. More preferably, the molding element can be configured to apply a force to the electrode separator / electrolyte unit 12. Preferably, the molding element 36 can function as a stress unit 14. More preferably, the compression element or molding element 36 is fixedly connected to the cell casing or the first boundary element 18. For example, the molding element 36 can be formed as an extruded aluminum part. More preferably, the molding element 36 can at least partially form the first boundary element 18. Advantageously, the molding element 36 can be manufactured inexpensively as a molding.

[0084] 9 shows an embodiment of the energy storage unit 10. The energy storage unit 10 includes at least one shaping element 36, which is configured to adapt its height 38. Preferably, the shaping element 36 has a first layer 40 and a second layer 42. Furthermore, the first layer 40 has at least one web element 44 arranged thereon, which is configured to space the first layer 40 from the second layer 42. Preferably, the web element 44 is deflectable and / or tiltable relative to the first layer 40 about a deflection point 46 of the first layer 40.

[0085] 10 shows an embodiment of the energy storage unit 10. The energy storage unit 10 comprises a shaping element 36. Preferably, the shaping element 36 is able to adapt its height 38 by tilting the web element 24.

[0086] 11 shows one embodiment of the energy storage unit 10. The energy storage unit 10 includes a shaping element 36 configured to adapt the height 38.

[0087] FIG. 12 illustrates an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably includes a molding element 36. The molding element 36 preferably has a first layer 40, a second layer 42, and a third layer 48, and preferably further includes a web element 44 and a further web element 50. In this case, the web element 44 can be disposed on a first side of the first layer 40, and the further web element 50 can be disposed on a second side of the first layer 40. Thus, the further web element 50 can be disposed on the opposite side from the web element 44. Preferably, the first web element 44 is configured to space the second layer 42 from the first layer 40. Preferably, the further web element 50 is configured to space the third layer 48 from the first layer 40.

[0088] One embodiment of the energy storage unit 10 is shown in Figure 13. The energy storage unit 10 can include a shaping element 36 configured to accommodate a height 38. As shown in Figure 13, the contour of the shaping element 36 can be configured to accommodate the height, for example, by protrusions, recesses, or the like.

[0089] 14 shows an embodiment of the energy storage unit 10. Preferably, the electrode separator / electrolyte unit 12 of the energy storage unit 10 is insertable into a casing 22, in which, inter alia, the connection units 20 can be arranged. More preferably, when the electrode separator / electrolyte unit 12 is arranged in the casing 22 between the connection units 20, the casing 22 can be closed by a cover 50.

[0090] 15 shows a flow chart illustrating steps of a method 100 according to one embodiment. The method 100 for manufacturing an energy storage unit 10, as described above and below, includes: a step S1 of providing a casing 22 for the electrode separator / electrolyte unit 12; a step S2 of placing the first boundary element 18 on the casing 22 of the energy storage unit 10 by means of the connection unit 20; a step S3 of introducing the electrode separator / electrolyte unit 12 into the energy storage unit 10, so that the connection unit 20 follows the volume changes of the electrode separator / electrolyte unit 12; More preferably, the method 100 includes the step S4 of placing a cover on the casing 22 to form a substantially fluid-tight space around the electrode separator / electrolyte unit 12 within the energy storage unit 10.

[0091] 16 shows a vehicle 200 according to one embodiment. The vehicle 200 preferably includes an energy storage unit 10 as described above and below.

[0092] 17 illustrates a battery storage system 300 according to one embodiment. The battery storage system 300, which is used in a stationary manner to receive and discharge electrical energy, preferably includes a plurality of energy storage units 10 as described above and below.

Claims

1. An energy storage unit (10), comprising: - Electrode separator / electrolyte unit (12) It has the electrode separator / electrolyte unit (12) is configured to receive and / or emit electrical energy; the electrode separator / electrolyte unit (12) has at least one first boundary element (18), the first boundary element (18) at least partially forming an outer surface (16) of the electrode separator / electrolyte unit (12); the energy storage unit (10) has a connection unit (20), the connection unit (20) is disposed on the first boundary element (18), and the connection unit (20) is further configured to follow volume changes of the electrode separator / electrolyte unit (12); An energy storage unit (10).

2. the connection unit (20) has at least one material and / or shape configured to follow the volumetric changes of the electrode separator / electrolyte unit (12); the material is an elastomer, a plastic and / or a metal; and / or the shape is a bellows, trampoline and / or folding bellows configured to follow the volume changes of the electrode separator / electrolyte unit (12); The energy storage unit (10) of claim 1.

3. The energy storage unit (10) according to claim 1 or 2, wherein the connection unit (20) is configured to connect the first boundary element (18) to a casing (22) of the energy storage unit (10).

4. the electrode separator / electrolyte unit (12) has a second boundary element (24) that at least partially defines the outer surface (16) of the electrode separator / electrolyte unit (12); The connection unit (20) is connected to the first boundary element (18) and the second boundary element (24) so as to follow the volume change of the electrode separator / electrolyte unit (12). An energy storage unit (10) according to any one of claims 1 to 3.

5. 5. The energy storage unit (10) of claim 1, further comprising a stress unit (14) configured to apply a predetermined force to the first boundary element (18).

6. the connection unit (20) is configured to create a tensile force on the electrode separator / electrolyte unit (12); The stress unit (14) is configured to create a pressing force on the electrode separator / electrolyte unit (12). The energy storage unit (10) of claim 5.

7. 7. The energy storage unit (10) of claim 6, wherein the stress unit (14) is configured to adapt the predetermined force, and the adapted predetermined force is configured to adjust a height (13) of the electrode separator / electrolyte unit (12).

8. 8. The energy storage unit (10) of claim 5, wherein the stress unit (14) is configured to apply the predetermined force substantially uniformly to the outer surface (16) of the electrode separator / electrolyte unit (12).

9. 9. The energy storage unit (10) of claim 5, wherein the connection unit (20) and the stress unit (14) are configured to adjust a predetermined pressure within the electrode separator / electrolyte unit (12).

10. The energy storage unit (10) according to any one of claims 5 to 9, wherein the stress unit (14) and the first boundary element (18) are formed integrally.

11. 11. The energy storage unit (10) according to any one of claims 5 to 10, wherein the stress unit (14) comprises a spring unit (26) configured to generate the predetermined force by a change in shape.

12. the first boundary element (18) has a plurality of spring elements (34) disposed thereon, the plurality of spring elements (34) having a curved portion directed toward the first boundary element (18); The curvature of the plurality of spring elements (34) is configured to create the predetermined force. An energy storage unit (10) according to any one of claims 5 to 11.

13. 13. The energy storage unit (10) of claim 12, wherein the first boundary element (18) and the plurality of spring elements (34) are integrally molded, whereby the plurality of spring elements (34) are formed in a molded portion (35) of the first boundary element (18).

14. 14. The energy storage unit (10) according to any one of claims 5 to 13, wherein the stress unit (14) comprises a hydraulic unit configured to generate the predetermined force by displacement of a hydraulic element.

15. 15. The energy storage unit (10) according to any one of claims 5 to 14, wherein the stress unit (14) comprises a pneumatic unit configured to generate the predetermined force by displacement of a pneumatic element.

16. the electrode separator / electrolyte unit (12) has at least one shaping element (36), the shaping element (36) being configured to adapt its height (38); The stress unit (14) is configured to change the height (38) of the forming element (36) by the predetermined force. An energy storage unit (10) according to any one of claims 5 to 15.

17. 17. The energy storage unit (10) of claim 16, wherein the shaping element (36) has a first layer (40) and a second layer (42), the first layer (40) having disposed thereon at least one web element (44) configured to space the first layer (40) from the second layer (42).

18. 18. The energy storage unit (10) of claim 17, wherein the web element (44) is deflectable and / or foldable relative to the first layer (40) about a deflection point (46) of the first layer (40).

19. A method (100) for manufacturing an energy storage unit (10) according to any one of claims 1 to 18, comprising the steps of: - a step (S1) of preparing a casing (22) for an electrode separator / electrolyte unit (12); - a step (S2) of placing a first boundary element (18) on the casing (22) of the energy storage unit (10) by means of a connection unit (20); - a step (S3) of introducing the electrode separator / electrolyte unit (12) into the energy storage unit (10), so that the connection unit (20) follows the volume changes of the electrode separator / electrolyte unit (12); A method (100) comprising:

20. The method (100) further comprises: - placing a cover (50) on the casing (22) so as to form a substantially fluid-tight space around the electrode separator / electrolyte unit (12) within the energy storage unit (10); 20. The method (100) of claim 19, comprising:

21. A vehicle (200) equipped with an energy storage unit (10) according to any one of claims 1 to 18.

22. A battery storage system (300) for stationary use to receive and discharge electrical energy, comprising: A plurality of energy storage units according to any one of claims 1 to 18 are provided. A battery storage system (300).

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