High-voltage accumulator for motor vehicle and high-voltage accumulator

Abstract

The invention relates to a high-voltage accumulator (1) for a motor vehicle, comprising a battery element (2) which comprises a plurality of series-connected cell stacks (3), each of which has a plurality of solid-state cells (4), the solid-state cells (4) each comprise a cathode (5) of one bipolar electrode (6) and an anode (7) of the other bipolar electrode (6) and a solid electrolyte (8) is arranged between the two bipolar electrodes (6), and the solid-state cells (4) of the respective cell stack (3) are connected in parallel to one another and at least two of the cell stacks (3) are enclosed together in a soft envelope (9), wherein a voltage tap element (10) is arranged on the respective cell stack (3), which voltage tap element is connected in each case to a control device (11) arranged within the soft envelope (9) and forms, with the control device, a cell management system (12), by means of which at least one cell voltage of the respective solid-state cell (4) can be detected, the voltage tapping element (10) and the control device (11) are arranged entirely in the soft envelope (9) in common. The invention further relates to a motor vehicle.

Description

Technical Field

[0001] The invention relates to a high-pressure accumulator for a motor vehicle and to a motor vehicle. Background Art

[0002] Batteries, in particular lithium-ion batteries, can be used to drive motor vehicles that can be driven at least partially electrically. In order to achieve the voltage required for this purpose, the individual battery cells are connected to one another in a combination of multiple parallel connections and one series connection. In this way, a cell stack is formed from the individual battery cells, which is connected in a modular manner in a high-voltage storage device. The individual cells are monitored by an external battery management system, which are connected to one another via a cell contact system.

[0003] Solid-state batteries (ASSB for short) are a further development of lithium-ion batteries. In this case, the porous, liquid-soaked separator is replaced by a solid electrolyte. The solid electrolyte can include ceramics and / or solid polymers, which can contain sulfides and / or oxides, and the solid polymer can also be present as a gel. In addition, the solid electrolyte can also be integrated into the electrode in order to ensure lithium-ion conductivity, especially within the electrode. In this case, the solid electrolyte has the following properties, as its name implies, namely, the solid electrolyte is not flowable.

[0004] Current high-voltage storage devices or batteries have the problem that the cells are individually encapsulated, which results in a particularly low energy density. In addition, a complex design is required, which allows low integration. In the case of external circuit connections of the cells, the cables additionally take up structural space in the high-voltage storage device and thus reduce the size of the storage device and thus the range of the vehicle. In addition, the control of the modularity of the cell blocks has not yet been solved in the battery management system.

[0005] Furthermore, DE 10 2019 131 127 A1 shows a solid-state battery having two or more individual stacks stacked one above the other. Summary of the invention

[0006] The object of the present invention is to provide a high-voltage storage device and a motor vehicle in which the battery elements of the high-voltage storage device are each designed to save particularly large installation space in order to achieve a particularly high energy density and also to provide advantageous cell monitoring.

[0007] According to the invention, this object is achieved by the subject matter of the independent claims. Advantageous embodiments and further developments of the invention are given in the dependent claims as well as in the description and in the drawings.

[0008] A first aspect of the invention relates to a high-voltage storage device for a motor vehicle. The high-voltage storage device according to the invention has a battery element, which includes a plurality of, namely at least two, cell stacks connected in series, in particular in bipolar series, each of which has a plurality of, namely at least two solid-state cells, each of which includes a cathode or a cathode part of a bipolar electrode and an anode or an anode part of another bipolar electrode, and a solid electrolyte is arranged between the two bipolar electrodes, the solid-state cells of the respective cell stacks are connected in parallel with each other, and the cell stacks or at least two of the cell stacks are enclosed together in a soft envelope, wherein voltage tapping elements are arranged on the respective cell stacks, the voltage tapping elements are respectively connected to a control device arranged in the soft envelope and form a battery management system with the control device, by means of which at least one cell voltage of the respective cell stack can be detected, wherein the voltage tapping elements are arranged together with the control device, in particular completely in the soft envelope.

[0009] In other words, a battery element for a high-voltage storage device is proposed, which has solid-state cells in a bipolar arrangement structure, wherein a plurality of solid-state cells in the solid-state cells are connected to form a stack in a parallel arrangement structure. At least two cell stacks of the cell stack, in particular all the existing cell stacks, are then connected in series bipolar circuits. In the case of a cell voltage of about 2 volts, it is possible, for example, to connect 100 cells in parallel and 12 of the cell stacks in series or in series bipolarly, so as to obtain a voltage below 60 volts, for example. In this case, the voltage taps are collected on the cell stack plane and connected to a microchip - a cell battery management system - within a soft envelope.

[0010] A number of advantages are obtained by the high-voltage storage device according to the present invention. On the one hand, the battery element is particularly compactly constructed and a highly integrated structural type can be achieved at the same time. In addition, the simplification of the high-voltage storage device and the cable harness can be achieved. In addition, the increased energy density of the high-voltage storage device can be achieved based on the saving of structural space. Here, based on the use of solid monomers, it is possible, for example, to form a particularly thick monomer, so that other peripheral devices, such as additional voltage tapping elements, can be saved. In addition, it is advantageous that a particularly flexible monomer design can be achieved, whereby, for example, the thickness of each layer in the construction of the battery element can be freely selected. In addition, the monomer complex, that is, the battery element, can be formed as a "smart component", which is basically completely embedded in the soft film except for the contact element or the pole connection end, because the battery element has a control device, which forms at least a simple battery management system. A certain modularity is obtained, so that the high-voltage storage device can be flexibly formed by a plurality of battery elements, for example. Based on the saving of materials, especially copper and / or aluminum and / or the reduction of production costs, the high-voltage storage device can also be provided at a particularly low cost. Another advantage is the reduction of heat loss, because simple monomer contact connection and material reduction reduce heat loss.

[0011] Furthermore, three spatial arrangements of the voltage tapping element and thus advantageous designs of the battery element are described below.

[0012] In an advantageous embodiment of the invention, the respective voltage tapping element is led from the respective cell stack to a surface of the cell stack located outside, on which the soft coating rests and which is different from the lead-out surface, i.e. the side of the battery element leading out the contact elements and the poles, and the respective voltage tapping element meets a collection section there or is connected to the collection section, which connects the respective voltage tapping element to a control device, which is also arranged between the surface and the soft coating, wherein the voltage tapping element is arranged substantially transversely to the longitudinal extension direction of the battery element. The collection section is, for example, a cable or a cable bundle. “Substantially transversely to the longitudinal extension direction” means that a deviation from the longitudinal extension direction of, for example, up to 30 degrees and in particular up to 10 degrees can be achieved. In other words, the voltage tap is led transversely to the longitudinal extension direction, for example upwards, connected there and connected, for example, by means of a thin flexible printed circuit board to a control device, in particular in the form of a chip. This results in the following advantage, namely, in a particularly advantageous manner, the geometric requirements of the battery element or the high-voltage storage device can be responded to by suitable guidance of the voltage tap.

[0013] In another advantageous structural form of the present invention, the corresponding voltage tapping element is guided from the corresponding cell stack on the side of the corresponding cell stack and encounters another collection section there, which connects each voltage tapping element to a control device, which is arranged on the top side or lead-out surface of the battery element. The side is, for example, one of the faces of the corresponding cell stack, which is transverse to the longitudinal extension direction of the cell stack and is also particularly on the short side and therefore does not correspond to the face introduced previously. In other words, the voltage tapping element is collected on one side of the battery element. In particular, the collection section, which is configured as a cable bundle or electrical contact for connection to the control device, is oriented along the longitudinal extension direction toward the top side, that is, the side where the pole of the battery element is led out from the soft coating. The control device is arranged on this top side. The following advantage is obtained, that is, in a particularly advantageous manner, the requirements determined by the geometry or structural space of the high-voltage storage can be responded to.

[0014] In another advantageous embodiment of the invention, the respective voltage tapping element is led from the respective cell stack to a surface of the cell stack located outside, on which the soft coating rests and which is different from the lead-out surface or the top side, and the respective voltage tapping element meets a collection section there or is connected to the collection section, which connects the voltage tapping element to a control device, which is arranged on the top side, wherein the voltage tapping element is arranged substantially along the longitudinal extension direction of the battery element, wherein the voltage tapping element is arranged substantially along the longitudinal extension direction of the battery element. In other words, the voltage taps converge at the edge and are led from there to the control device on the head of the battery by means of a thin collection section. "Substantially along the longitudinal extension direction" means that a deviation of up to 30 degrees, and in particular a deviation of up to 10 degrees, can be achieved. The described orientation of the voltage tapping element and the control device also results in the advantage that the structural space adaptation of the battery element can be achieved in a particularly advantageous manner.

[0015] In another advantageous construction form of the present invention, at least one of the voltage tapping element and / or the control device and / or the collection section is at least partially formed by a flexible printed circuit board. In other words, a material that can be electrically applied is used, and the material can be at least bent in its shape. For example, there is a PCB that is printed on an elastic material, such as a plastic film, and can be deformed at least in certain areas. If each voltage tapping element and / or at least one of the voltage tapping elements, the control device and / or the collection section are formed as wireless, the following advantage is produced, that is, the structural space of the battery element can be particularly compact. In this way, a particularly flexible adaptation to geometric requirements and / or a particularly high energy density can also be achieved.

[0016] In a further advantageous embodiment, the control device has a communication device which can be operated wired and / or wirelessly, in particular by radio. In other words, the control device has a communication port which is an interface for exchanging data, for example, with a control device of a motor vehicle. The data exchange can be carried out wired by means of at least one wire. Additionally or alternatively, the data exchange can be carried out wirelessly and / or wire-free by radio, for example by means of WLAN, Bluetooth, RFID or the like. This results in the advantage that a particularly advantageous monitoring of the high-voltage storage device can be achieved.

[0017] In another advantageous embodiment of the present invention, the corresponding solid-state cells are square and / or prismatic. In other words, the corresponding solid-state cells have the shape of a cuboid or a prism. This results in the advantage that a space-saving construction of the battery element can be achieved in a particularly advantageous manner.

[0018] In another advantageous embodiment of the invention, the lead-out surface or the corresponding top side is arranged on the weld seam of the soft film, on which the connection element or the pole is led out of the soft film. In other words, the connection element or the contact is formed directly on the weld seam, so that, for example, when welding two film halves, the connection element or the contact is located between the two film halves and thus forms a lead-out from the soft film. This results in the following advantages, namely, for example, no external openings need to be provided in the soft film, so that the battery element can be designed to be particularly robust, for example.

[0019] In another advantageous structural form of the present invention, at least one of the solid-state cells is configured as a double-sided cell. Here, the other cathode or anode in particular forms a part of another adjacent solid-state cell respectively. This is possible, for example, based on the structural form of the corresponding electrode as a bipolar electrode. In this way, a plurality of solid-state cells can be connected in parallel in a particularly advantageous manner, in particular based on the characteristics of the bipolar electrode in combination with a solid electrolyte without the need for each of the corresponding solid-state cells to be coated. Additionally or alternatively, the corresponding bipolar electrode here can have not only an anode but also a cathode, for example, for series connection, so that series connection can be achieved particularly advantageously. This results in the advantage that the battery can be constructed in a particularly space-saving manner.

[0020] A second aspect of the invention relates to a motor vehicle. The motor vehicle according to the invention comprises a high-voltage accumulator according to the first aspect of the invention.

[0021] In this case, advantageous embodiments and further developments of the first aspect of the invention may be regarded as advantageous embodiments and further developments of the second aspect of the invention, and vice versa.

[0022] Further features of the invention are apparent from the claims, the drawings and the description of the drawings. The features and feature combinations mentioned above in the description and the features and feature combinations mentioned below in the description of the drawings and / or shown only in the drawings can be used not only in the respectively indicated combination but also in other combinations or alone. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will now be described in more detail with the aid of preferred embodiments and with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram shows a cell stack of a battery element for a high-voltage storage device of a motor vehicle;

[0025] Figure 2 A schematic diagram showing another embodiment of a cell stack;

[0026] Figure 3 A schematic diagram showing an embodiment of a battery element of a high-voltage storage device having a battery management system;

[0027] Figure 4 A schematic diagram showing a second specific embodiment of a battery element of a high-voltage storage device having a battery management system; and

[0028] Figure 5 A schematic diagram shows a third specific embodiment of a battery element of a high-voltage storage device having a battery management system. DETAILED DESCRIPTION

[0029] High-voltage storage devices are used to drive motor vehicles that are at least partially electrically driven. In particular, lithium-ion batteries are used here. A further development of lithium-ion batteries is the so-called solid-state battery, in which a solid electrolyte can be combined with bipolar electrodes, for example. This allows the possibility of a so-called bipolar circuit connection, in which the individual monomer units can be connected in series and must be individually sealed in the circuit connection.

[0030] A high-voltage storage device 1 which can be used for operating a motor vehicle will be described below with reference to the drawings. The high-voltage storage device comprises a battery element 2 which comprises a plurality of, namely at least two, bipolarly connected cell stacks 3 in series. Figure 1A first embodiment of such a cell stack 3 is shown in a schematic diagram. Here, the cell stack 3 has a plurality of or at least two solid-state cells 4, each of which includes a cathode 5 of a bipolar electrode 6 and an anode 7 of another bipolar electrode 6, wherein the other bipolar electrode is separated from the bipolar electrode 6 by a solid electrolyte 8, wherein the solid-state cells 4 of the corresponding cell stack 3 are connected in parallel. Here, at least two of the cell stacks 3 are enclosed together in a soft film 9, wherein a voltage tapping element 10 is provided on the corresponding cell stack 3, wherein the voltage tapping element is respectively connected to a control device 11 provided in the soft film 9 and forms a battery management system 12 with the control device, through which at least one cell voltage of the corresponding cell stack 3 can be detected, wherein the voltage element 10 and the control device 11 are completely provided in the soft film 9 together.

[0031] The solid electrolyte 8 itself forms a separator, for example, or is at least partially arranged in a separator. The respective bipolar electrode 6 can have an electrical conductor 19 which is arranged between the two anodes 7 or cathodes 5 or, in an alternative embodiment, between the anode 7 and the cathode 5 .

[0032] Figure 1 A possible embodiment of a corresponding cell stack 3 is thus shown.

[0033] Figure 1 The embodiment of FIG. 4 shows a possible structural form of a monomer stack 3, which in the embodiment is composed of, for example, two solid monomers 4. Figure 1 The embodiment of the monomer stack 3 is applied in accordance with Figure 3 and 4 Two embodiments of the present invention.

[0034] Figure 2 A similar design of a cell stack 3 is shown, however in an alternative geometrical arrangement, which is used for a cell stack according to Figure 5 The structural form of the embodiment.

[0035] By using bipolar electrodes 6 , the respective cathode 5 and / or anode 7 of the respective solid-state cell 4 can be designed to be double-sided.

[0036] Figures 3 to 5 The corresponding battery elements 2 of each include two connecting elements 13, one of which forms the positive pole of the cell stack 3 connected in series, in particular in series bipolar connection, and the other connecting element forms the negative pole, wherein the circuit connection is represented by the connecting line between the cell stacks 3. In this case, the connecting elements 13 are particularly away from the soft film 9 in opposite directions, which is suitable for Figures 3 to 5In this case, the corresponding region can be formed as the lead-out surface 14 at which the connecting element 13 leaves the monomer.

[0037] Here, in Figure 3 The first exemplary embodiment shown in FIG. 1 is designed such that the respective voltage tapping element 10 is led from the respective cell stack 3 to a surface 15 of the cell stack 3 located outside, against which the soft coating 9 rests and which is different from the lead-out surface 14, and there encounters a collection section 16 which connects the voltage tapping element 10 to a control device 11 which is likewise arranged between the surface 15 and the soft coating 9, wherein the voltage tapping element 10 is arranged essentially transversely to the longitudinal extension direction of the battery element 2.

[0038] In contrast, Figure 4 A second exemplary embodiment of a battery element 2 is shown in a schematic diagram, in which a respective voltage tapping element 10 is guided from a respective cell stack 3 on an edge of the respective cell stack 3 and meets a further collection section 16 which connects the voltage tapping element 10 to a control device 11, wherein the control device 11 is arranged on the top side of the battery element 2, i.e. on the positive pole.

[0039] Alternative here, Figure 5 A third embodiment is shown, in which the Figure 2 1 , wherein the respective voltage tapping element 10 is led from the respective cell stack 3 to the surface of the cell stack 3 located outside, against which the soft covering film 9 rests and which is different from the lead-out surface 14, and there encounters a collection section 16, which connects the voltage tapping element 10 to a control device 11, which is arranged on the top side, wherein the voltage tapping element 10 is arranged substantially along the longitudinal extension direction of the battery element 2. The longitudinal extension direction is the direction in which the battery element 2 has the longest extension dimension, in particular in a substantially cuboid design with a length, a width and a height, wherein the length coincides with the longitudinal extension direction.

[0040] Advantageously, the at least one voltage tapping element 10 and / or the control device 11 and / or the collection section 16 are at least partially formed by a flexible printed circuit board. It is also advantageous if the corresponding solid-state cell 4 is square and / or prismatic. Advantageously, the corresponding control device 11 has a communication device or is designed to have the communication device for wired and / or wireless communication, so that, for example, a communication port 17 is provided.

[0041] For a particularly stable design, in which the connecting element 13 is led out of the top side and / or the lead-out surface 14 of the casing 9 , the connecting element 13 is arranged on a weld seam 18 of the casing 9 .

[0042] Furthermore, a motor vehicle is described which comprises a high-pressure storage device 1 according to the embodiment shown.

[0043] The high-voltage storage device 1 described yields numerous advantages:

[0044] For example, a particularly space-saving design can be realized. In addition, a highly integrated design is obtained. This results in a higher energy density and the battery element 2 or the high-voltage storage device 1 can be particularly advantageously adapted to the required geometric properties. In addition, the battery element 2 can be operated in particular as an intelligent component, which results in a certain modularity. Thus, a particularly advantageous bipolar ASSB soft pack cell is presented here.

[0045] Reference numerals list

[0046] 1 High voltage storage

[0047] 2Battery components

[0048] 3 monomer stack

[0049] 4 solid monomer

[0050] 5 cathode

[0051] 6 Bipolar Electrodes

[0052] 7 Anode

[0053] 8 Solid Electrolyte

[0054] 9 Soft film

[0055] 10 voltage tapping elements

[0056] 11 Control Device

[0057] 12Battery Management System

[0058] 13 Connecting elements

[0059] 14 Lead-out surface

[0060] 15 sides

[0061] 16 Collection Department

[0062] 17 communication ports

[0063] 18 Welds

[0064] 19 Conductors

Claims

1. A high-voltage storage device (1) for a motor vehicle, the high-voltage storage device having a battery element (2), the battery element comprising a plurality of cell stacks (3) connected in series, each of the cell stacks having a plurality of solid-state cells (4), the solid-state cells respectively comprising a cathode (5) of a bipolar electrode (6) and an anode (7) of another bipolar electrode (6), and a solid electrolyte (8) being arranged between the two bipolar electrodes (6), the solid electrolyte separating the two bipolar electrodes (6), and the solid-state cells (4) of the corresponding cell stacks (3) being connected in parallel with each other, and at least two of the cell stacks (3) being enclosed together in a soft envelope (9), wherein: A voltage tapping element (10) is arranged on the corresponding cell stack (3), and the voltage tapping element is respectively connected to a controller device (11) arranged in the soft envelope (9) and forms a battery management system (12) with the controller device, through which at least one cell voltage of the corresponding cell stack (3) can be detected, wherein the voltage tapping element (10) and the control device (11) are completely arranged together in the soft envelope (9).

2. The high-voltage storage device according to claim 1, characterized in that The respective voltage tapping elements (10) are led from the respective cell stacks (3) to a surface (15) of the cell stack (3) located outside, against which the soft coating (9) is in contact and which is different from the lead-out surface (14), and the respective voltage tapping elements are connected there to a collection section (16), which connects the respective voltage tapping elements (10) to a control device (11), which is arranged between the surface (15) and the soft coating (9), wherein the voltage tapping elements (10) are arranged substantially transversely to the longitudinal extension direction of the battery element (2).

3. The high-voltage storage device (1) according to claim 1 or 2, characterized in that The respective voltage tapping element (10) is led to the side of the respective cell stack (3) and meets there a further collection section (16) which connects the respective voltage tapping element (10) to a control device (11) which is arranged on the top side of the battery element (2).

4. The high-voltage storage device (1) according to claim 1, characterized in that The respective voltage tapping elements (10) are led from the respective cell stacks (3) to the surface of the cell stack (3) located outside, the soft coating (9) being in contact with the surface and the surface being different from the lead-out surface (14), and the respective voltage tapping elements are connected there to a collecting section (16), which connects the respective voltage tapping elements (10) to a control device (11), which is arranged on the top side, wherein the voltage tapping elements (10) are arranged substantially along the longitudinal extension direction of the battery element (2).

5. The high-voltage storage device (1) according to claim 1, characterized in that At least one of the voltage tapping element (10) and / or the controller device (11) and / or the collecting section (16) is at least partially formed by a flexible printed circuit board.

6. The high-voltage storage device (1) according to claim 1, characterized in that The control device (11) has a communication device which can be operated wired and / or wirelessly.

7. The high-voltage storage device (1) according to claim 1, characterized in that The respective solid-state cells (4) are of cuboid and / or prismatic design.

8. The high-voltage storage device (1) according to claim 1, characterized in that The top side and / or the lead-out surface (14) are arranged on a weld seam of the soft film (9), and the connecting element (13) is led out from the soft film (9) on the top side and / or the lead-out surface.

9. The high-voltage storage device (1) according to claim 1, characterized in that The cathode (5) and / or the anode (7) of at least one of the solid-state cells (4) is designed to be double-sided.

10. A motor vehicle comprising a high-pressure accumulator (1) according to one of the preceding claims.

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