Electrical Energy Storage

Abstract

The invention relates to an electrical energy store for incorporation into a motor vehicle, comprising at least two housing parts: a first housing part that does not contain a storage cell and a second housing part that contains a storage cell; the first housing part is provided as an upper housing part for incorporation into a motor vehicle and the second housing part is provided as a lower housing part for incorporation into a motor vehicle; the first housing part can be closed by a removable first cover, The second housing part is formed as a capsule closed by a second cover which cannot be removed again. It relates to electrical energy storage.

Description

[Technical Field]

[0001] The present invention relates to a method for assembling lithium ion batteries for installation in vehicles, such as those known as on-board batteries, high voltage storage or traction batteries, and further to electrical energy storage devices, in particular lithium ion batteries, for motor vehicles, hereinafter referred to as energy storage devices for short. [Background technology]

[0002] Patent document 1 discloses, for example, an energy store (in the form of a lithium-ion battery) with a store assembly space having two compartments (or housing parts) separated by a horizontal plane, in which a partition wall is formed as a horizontal cooling plate, and in the lower assembly space, a cell assembly is suspended and connected to the cooling plate in a manner that allows good heat transfer, with the cell contacts and hazard openings of each cell facing downwards.

[0003] Tesla's "Battery-Day" on September 22, 2020 (recorded live at https: / / www.youtube.com / embed / l6T9xIeZTds) showcased energy storage (in the form of lithium-ion batteries) that is lost; while the storage is highly rigid due to the cells being firmly bonded to the housing, the cell assembly cannot be repaired in the event of a failure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] German Patent Application Publication No. 102019110007 Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to improve energy storage devices for motor vehicles, in particular lithium-ion batteries for motor vehicles, as economically as possible. [Means for solving the problem]

[0006] This problem is solved by the features of the independent claims. The dependent claims are advantageous developments of the invention.

[0007] The present invention relates to an electrical energy store for incorporation into a motor vehicle, comprising at least two housing parts, a first housing part that does not contain a storage cell and a second housing part that contains a storage cell, the first housing part is provided as an upper housing part for incorporation into a motor vehicle and the second housing part is provided as a lower housing part for incorporation into a motor vehicle; the first housing part can be closed by a removable first cover, The second housing part is formed as a capsule that is closed by a second cover that cannot be removed again.

[0008] In an advantageous embodiment of the invention, a central housing part is arranged between the two housing parts, which separates the two housing parts in a horizontal plane and contains an intermediate space for the cooling liquid to flow through.

[0009] In a further advantageous embodiment of the invention, the first housing part is adapted to accommodate the reservoir electronics and is provided with outwardly projecting electrical connections.

[0010] In a further advantageous embodiment of the invention, the storage electronics in the first housing section and the storage cells in the second housing section are electrically connected by an electrical connection (e.g. a wiring bundle), the penetration(s) of which through the central housing section are provided with a sealing body(s).

[0011] In a further advantageous embodiment of the invention, the sealing body is adapted to withstand burst pressure.

[0012] In a further advantageous embodiment of the present invention, the second housing portion contains a cell pack having storage cells whose cases are aligned vertically in the assembled state, and the second housing portion further contains a frame disposed below the cell pack.

[0013] In a further advantageous embodiment of the invention, the downwardly facing frame (in the assembled state) is provided with support members which act as force-bearing casing extensions for the cells.

[0014] In a further advantageous embodiment of the invention, the support member is formed as a separate carrier below the cell casing, or as an extension of the cell casing, or as a support tube that completely surrounds the cell and further comprises a cavity.

[0015] In a further advantageous embodiment of the invention, the second cover is locally provided with at least one material thinning which acts as a breaking point in the event of a critical overpressure in the reservoir.

[0016] In a further advantageous embodiment of the invention, the cell pack is protected from damage in lateral and longitudinal collisions by an intermediate space up to the outer boundary of the second housing part, the intermediate space being at least partially reinforced by a plastic-elastic material filling the intermediate space.

[0017] The present invention is based on the following considerations:

[0018] The present invention is intended to contribute to reducing the cost of energy storage (for example in the form of lithium ion batteries, often abbreviated as "LiB") Based on the generally known state of the art, and in addition to this known state of the art, it proposes an energy storage having the following characteristics: Crash safety and bollard safety (Pollersicherheit) - Hermetically sealed cell installation space Self-destruction at the cell level (i.e., prevention of propagation at the cell level) - Cooling, maintenance and replacement of storage electronic components possible

[0019] The drawback of the generally known technology is that the energy storage requires very high costs for crash and bollard safety, protection against moisture and heat propagation, and reliability and hazard resistance of the electronic components. The solution of these problems is the subject of the present invention.

[0020] The energy storage device according to the present invention is divided into an electronics installation space facing the interior of the vehicle and a hermetically sealed cell installation space facing the exterior of the vehicle. Hermetically sealing the cell installation space allows for the elimination of seals and devices for venting and / or draining condensate. Furthermore, exposure of the cell pack elements to moisture and corrosion is eliminated, preventing battery leakage from entering the interior of the vehicle in the event of a crash. The hermetically sealed connection increases the rigidity of the structure. Functionally, excess pressure is released via a break in the wall of the cell installation space at the exterior of the vehicle. Protection of the cell pack in the event of a side or frontal collision is enhanced by a force-dispersing plastic-elastic material. The plastic-elastic material deflects the incoming force laterally, as if hydraulically, by diverting it around the cell pack or between the cells, which not only allows more material to participate in absorbing the impact, but also converts the force at least partially from compression to tension and applies it to the walls of the cell installation space in this way, resulting in better material exhaustion. In addition, the hydraulically-like distribution of the force allows the cells to be evenly pressurized from all sides, which reduces the risk of cell damage in an impact. The plastic-elastic material here may have the property of expanding to support cell-by-cell containment. The protection of the cell pack in the event of a bollard collision is achieved by directing forces from the road-facing wall of the cell pack through the intermediate member in the cell contact area between the cells or through the cell wall, and then through the cell wall to the wall of the cell pack facing the interior of the vehicle, which serves to transmit forces onto the vehicle's body structure and also functions to cool the cells. The intermediate member also reduces the impact of cell failure by separating the venting spaces of the individual cells, thereby providing increased protection against heat propagation. Separating the electronics pack from the cell pack protects the electronics pack in the event of a battery compromise and ensures that their functionality is maintained thereafter.The placement of the electronics installation space inside the vehicle allows protection from high mechanical loads, elevated temperatures, and moisture using the measures used in vehicle construction, for example, for infotainment electronics. Furthermore, it allows for the maintenance of electronic components without opening the cell installation space. A partition wall between both installation spaces is used to cool the cell pack and the electronics.

[0021] The figures show an embodiment of the invention. [Brief explanation of the drawings]

[0022] [Figure 1] 1 shows an advantageous overall structure of an energy store according to the invention; [Figure 2a] 1 shows a first possible form of support member forming a frame according to the invention; FIG. [Figure 2b] 10A and 10B show a second possible form of support member forming a frame according to the invention; [Figure 3] 1A-1C illustrate an exemplary method for manufacturing this energy storage structure. DETAILED DESCRIPTION OF THE INVENTION

[0023] FIG. 1 shows an energy store LiB, which consists of a central housing part 1, which horizontally separates the two housing parts 2, 3 of the energy store LiB and contains an intermediate space for a flowing coolant 4, which can be connected to an external cooling channel via a connection port 5. The first housing part 2 faces towards the interior of the vehicle (i.e., upwards when installed) and is preferably used to accommodate the store electronics 6 and has electrical connections 7 facing outwards. The second housing part 3 faces towards the exterior of the vehicle (i.e., downwards towards the road when installed) and is used to accommodate storage cells 17 (also called cells for short), which are in particular made as cell packs 8. The cells 17 can be, for example, circular or prismatic cells. The store electronics 6 and the cell packs 8 are electrically connected, for example, to an electrical connection 9, the penetration of which through the central housing part 1 is preferably provided with a gas-tight seal 10 resistant to burst pressure. The first housing part 2 is provided with a repeatedly removable cover 11 attached and sealed to the central housing part 1 to allow maintenance of the electronic components.

[0024] The second housing part 3 is provided with a cover 12 that is non-removable, e.g., welded, crimped or glued, so as to provide an airtight seal to the central housing part 1. In other words, the second housing part 3 is formed by the central housing part 1 and the non-removable cover 12 as a closed capsule.

[0025] Preferably, the central housing part 1 consists of two deep-drawn, stamped, for example welded plates 1a, 1b with flats 1c, 1d, which form the thermal contact surfaces between the reservoir electronics 6 and the cell pack 8. The first plate 1a has through-holes 1e, 1f for the attachment of the connection ports 5 and 7, as well as a flange for attaching a first cover 11. The second plate 1b has a flange or edge for attaching a second cover 12. These plates 1a, 1b, 12 may here consist of metal, plastic or a plastic-metal multilayer composite and may at least partly be provided with an electrical insulator, for example a film.

[0026] The cell pack 8 preferably comprises the frame 13 (in its assembled state) facing downwards, the cell contacts 14, the terminals of the cell sensing part 15, the electrical terminals 16 on the cell pack side of the electrical connection 9, the cells 17, an adhesive or filler 19 between the cells 17, and a potting 20 around the cell contacts 14 and the cell sensing part 15. The filler 19, made of the same material as the potting 20, can be introduced together with the potting. In a preferred embodiment, it consists of hard paraffin. The cell contacts 14, the cell sensing part 15, and the terminals 16 are at least partially preassembled in the frame 13 to form an assembly 21, which can be firmly connected to the second cover 12 and central housing part 1 in the first replacement part 18a or to the cell 17 and central housing part 1 in the second replacement part 18b. This connection can be made here, for example, by means of a spread adhesive, by means of a double-sided adhesive film, preferably with good thermal conductivity, by pre-application to one of the elements to be connected, or by welding.

[0027] Furthermore, a holder 21 is provided which serves to fix the position of the cells 17. This holder 21 may, in known manner, for example, be provided with spikes in the intermediate spaces of the storage cells 17 if the holder is made as a round cell.

[0028] The frame 13 may be made as part of the holding body 21 and may also serve as an element for transmitting forces from the second cover 12 to the central housing part 1 or to the cell wall 17a. It is used to direct the force of a bollard crash towards the central housing part 1, and also to shield the vent spaces 22 provided for the individual cells 17 from each other, and to direct gases and particles released from the cells 17 to protect adjacent cells 17 in the event of a fault.

[0029] In a particularly advantageous embodiment of the invention, the frame 13 is supported by support members 30, which serve as force-bearing extensions of the cell 17 case. The support members 30 may be formed as separate carriers beneath the cell case (FIG. 2a), as extensions of the cell case, or as support tubes completely surrounding the cell and further comprising a cavity H (FIG. 2b). The support members 30 preferably have integrated electrical connections forming terminals for the cell contacts 14 and / or the cell sensing element 15, and / or the electrical connection 16 on the cell pack side of the electrical connection 9. Furthermore, the support members 30 may be part of the holder 21.

[0030] The second cover 12 includes, at least in one area, at least one material thinning 12a, which acts as a breaking point in the event of a critical overpressure in the reservoir and limits the overpressure in a controlled manner. Preferably, multiple material thinnings 12a are formed on the front, rear and / or underside of the second cover 12. In yet another embodiment, there is a material thinning 12a below each venting space 22. In yet another embodiment, the breaking point is realized by locally weakening the hermetically sealed connection 12b of the central housing part 1 and the second cover 12.

[0031] The cell pack 8 is preferably also protected from damage in lateral and longitudinal collisions by an intermediate space 23 extending up to the outer boundary of the second housing part 3. In a preferred embodiment, this protection is at least partially reinforced by a plastic-elastic material 24 filling the intermediate space 23, which spreads locally acting forces over a larger area and deflects them like a fluid, thereby allowing the entire reservoir assembly to participate in absorbing the impact energy. In a possible embodiment, the plastic-elastic material 24 is made of a lightweight, barely compressible plastic granule, inorganic filler, sand, cork, sawdust, wax, fluid, or a combination thereof, which fills the intermediate space 23. In an advantageous embodiment, the plastic-elastic material has expanding properties. The plastic-elastic material 24 may here be packed in a tube or the like. In yet another embodiment, the plastic-elastic material 24 is made of a preformed profile. In yet another configuration, the adhesive or filler 19, the elastomeric material 24, and optionally the potting 20, are made of the same material and are introduced in the same manufacturing process.

[0032] The storage electronics 6 preferably incorporates a cell monitor 6a, a protection circuit device 6b, a battery management system 6c, and an optional converter 6d for providing further voltage levels in the vehicle, a converter 6e for connecting to a supply voltage and circuit devices external to the vehicle, and a filter 6f for the vehicle's electrical consumers. These elements of the storage electronics 6 are connected at least in part to the cell pack 8 via the electronics side of the electrical connection 9 and to the connection 7 by a further electrical connection 25. In an advantageous configuration, the connection 7 and the further connection 25 are combined in one component, for example a pigtail.

[0033] FIG. 3 shows diagrammatically the advantageous steps for assembling an energy store LiB according to the invention: 1. Place the holder 21 having the frame 13. 2. Incorporate cell 17. 3. Place the central housing part 1 on top and glue it in place. 4. Turn the existing structure upside down. 5. Apply adhesive 19 between cells 17 by injecting adhesive. 6. Provide cell contacts 14 on the cells 17 to connect the electrical connections 9. 7. The holder 21 is poured to surround the cell 17 along with the cell contacts 14 and cell sensing portion 15. 8. A plastic elastic material 24 is introduced into the at least one intermediate space 23. 9. The second cover 12 is placed over and permanently joined (eg glued) to the central housing part 1. 10. After bonding, welding or other methods of joining, the energy storage body LiB together with all the above-mentioned parts except the first cover 11 is cured. 11. Turn this energy storage device upside down. 12. Install the reservoir electronics 6. 13. Connect reservoir electronics 6 and electrical connections 25 to electrical communication 9. 14. The removable cover 11 is closed and the resulting overall structure of the energy store LiB is inspected and removed for installation in the vehicle.

Claims

1. An electric energy store (LiB) for integration into a motor vehicle, comprising at least two housing parts (2, 3), - a first housing part (2) that does not contain a storage cell (17) and a second housing part (3) that contains a storage cell (17), the first housing part (2) is provided as an upper housing part whose wall faces the interior of the vehicle when assembled in the vehicle, and the second housing part (3) is provided as a lower housing part (3) whose wall faces the road surface when assembled in the vehicle; - a central housing part (1) is arranged between both said housing parts (2, 3), said central housing part separating the two said housing parts (2, 3) in a horizontal plane; - said first housing part (2) can be closed by a first cover (11) removably attached to said central housing part (1); - said second housing part (3) is formed as a closed capsule hermetically sealed by a second cover (12) which is again permanently attached to said central housing part (1); - in said second housing part (3) there is provided a venting space (22) for said storage cell (17); Electrical energy storage.

2. 2. An electrical energy store (LiB) according to claim 1, characterized in that the central housing part contains an intermediate space for the through-flow of cooling liquid (4).

3. 3. An electric energy store (LiB) according to claim 1 or 2, characterized in that the first housing part (2) is adapted to accommodate the store electronics (6) and is provided with outwardly projecting electrical connections (7).

4. 4. The electric energy store (LiB) according to claim 3, characterized in that the store electronics (6) of the first housing part (2) and the storage cells (17) of the second housing part (3) are electrically connected by an electrical connection (9), the penetration of which through the central housing part (1) is provided with a sealing body (10).

5. 5. An electric energy store (LiB) according to claim 4, characterized in that the sealing body (10) is made to withstand burst pressure.

6. 6. An electric energy storage device (LiB) according to claim 1, wherein the second housing part (3) contains a cell pack (8) comprising the storage cells (17), the cases of which are aligned vertically in the assembled state, and further wherein the second housing part (3) contains a frame (13) arranged below the cell pack (8).

7. 7. An electric energy storage unit (LiB) according to claim 6, characterized in that the downwardly facing frame (13) is supported by a plurality of support members (30), which support members act as case extensions of the cells (17) that receive forces.

8. 8. The electric energy storage element (LiB) according to claim 7, characterized in that the support member (30) is formed as a separate carrier below the cell casing, or as an extension of the cell casing, or as a support tube that completely surrounds the cells (17) and further comprises a cavity.

9. 9. An electric energy store (LiB) according to claim 1, characterized in that the second cover (12) has, in its outer part when installed in the motor vehicle, at least one material reduction (12a) which reduces the wall thickness of the second cover (12) locally and serves as a breaking point in the event of a critical overpressure inside the store.

10. 10. An electric energy store (LiB) according to any one of claims 1 to 9, characterized in that the cell pack (8) is protected from damage in the event of a lateral or longitudinal collision by an intermediate space (23) up to the outer boundary of the second housing part (3), the intermediate space being at least partially reinforced by a plastic-elastic material (24) filling the intermediate space (23).

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