Energy storage system with at least one energy storage cell for storing electrical energy

Abstract

Energy storage system (1) with at least one energy storage cell (2) for storing electrical energy, wherein the energy storage system (1) has a housing (3) with at least two receiving areas separated at least partially or partially by one or more housing walls or housing wall areas for receiving the at least one energy storage cell (2), wherein the at least one energy storage cell (2) is associated with a receiving frame (4) in which an end area of ​​the energy storage cell (2) is at least partially or partially received or can be received, wherein the receiving frame (4) is received in one of the receiving areas of the housing (3) and is connected there to at least one bottom area of ​​the receiving area via a material-bonded connection, in particular an adhesive connection (5), and wherein at least in a state in which the end area of ​​the energy storage cell (2) is received at least partially or partially in the receiving frame (4),The receiving frame (4) forms a degassing channel system, wherein the receiving frame (4) associated with the at least one energy storage cell (2) is designed such that, in a state in which the end region of the energy storage cell (2) is received in the receiving frame (4), a first degassing channel section (8) is formed between a lower surface, in particular an end face, of the end region of the energy storage cell (2) and an inner surface of a bottom region (6) of the receiving frame (4), which is fluidly connected to a second degassing channel section (9) formed between a side wall region of the end region of the energy storage cell (2) and a side wall region (7) of the receiving frame (4).

Description

[0001] The present invention relates to an energy storage system with at least one energy storage cell for storing electrical energy.

[0002] Energy storage systems of the type considered herein are used in many fields of technology. The present invention relates in particular to the field of energy storage systems for vehicles, wherein these are aircraft or watercraft, track-guided vehicles, or preferably road vehicles. Road vehicles are understood to include, in particular, passenger cars, trucks, buses, or motorhomes.

[0003] As part of optimizing the energy balance of vehicles, especially road vehicles, and particularly to reduce fuel consumption, existing vehicle batteries are being integrated into various concepts, for example in start / stop systems or energy recuperation during braking. Vehicles are also increasingly equipped with in-vehicle systems that require an electrical power supply.

[0004] Lead-acid batteries are typically used as starter batteries, but their low energy density makes them quite heavy. Lithium-ion batteries, on the other hand, have a relatively high energy density. Furthermore, compared to conventional lead-acid batteries, lithium-ion batteries offer advantages such as a longer lifespan, lower self-discharge, improved fast-charging capability, and shorter maintenance intervals.

[0005] Overall, new requirements are being placed on energy storage systems, particularly batteries, that go beyond the previous requirement of being suitable for starting an internal combustion engine. At the same time, modern energy storage systems that meet these new requirements should ideally have the same installation space as existing batteries; that is, they should not require any additional installation space, and the external dimensions should remain largely unchanged. In general, and especially due to the increasing number of energy consumers, ever higher demands are being placed on the performance, weight, reliability, and manufacturing costs of energy storage systems in vehicles.

[0006] Energy storage cells, such as lithium-ion cells, age both when not in use (also known as calendar aging) and when in use (known as cyclic aging). This aging process alters the technical properties of the energy storage cell. Depending on the cell chemistry used, this aging often leads to internal gas evolution through gas formation reactions. This results in an increase in internal pressure and / or a change in the shape of the energy storage cell.

[0007] It is known from the prior art to take into account a pressure increase or a change in shape of an energy storage cell in the cell and battery design.

[0008] Document US 2024 / 0222800A1 relates to an energy storage system for a vehicle with multiple energy storage cells for storing electrical energy. The energy storage system has a housing in which several receiving areas for the corresponding energy storage cells are formed. A degassing channel system is also provided in the housing when the cells are installed.

[0009] Energy storage systems for various applications typically consist of many individual energy storage cells connected in series and / or parallel. These energy storage cells are usually grouped into cell blocks, also called modules, each containing a certain number of energy storage cells and their mechanical fixings, such as end plates, to absorb the clamping force. Within the individual cells, pressure increases due to gas evolution during aging.

[0010] Within the module, the cells can only expand to a certain extent due to mechanical fixation. Beyond this point, only the tension within the module can increase, partly due to compression of the released gas. This tension continues to increase until the end of the battery's lifespan. This necessitates additional module stiffening measures, which require more material and are heavier. Furthermore, the energy density of the battery system is reduced, which has a detrimental effect.

[0011] In order to avoid such module stiffening measures, it is also known to provide a degassing opening in the housing of an energy storage system that is flow-connected or connectable to the outside atmosphere.

[0012] This degassing opening is usually equipped with a pressure relief valve, which allows a flow connection between the outside atmosphere and the interior of the housing at a certain critical overpressure inside the housing.

[0013] Such degassing openings in the housing of the energy storage system can equalize the overpressure that builds up inside the housing due to gas development in the energy storage cells. However, this approach requires further measures, namely to allow the gas to escape from the individual energy storage cells into the interior of the housing.

[0014] Undoubtedly, it is generally conceivable, for example, to provide a degassing opening on an end face of each energy storage cell, which allows degassing from the energy storage cell into the interior of the housing of the energy storage system. However, with this approach, care must be taken to ensure that the degassing openings of the energy storage cells are not covered during the assembly and fixing of the individual energy storage cells in the housing of the energy storage system and thus cannot or can no longer fully fulfill their actual function.

[0015] The invention is therefore based on the objective of providing a way in which energy storage cells can be securely fixed in the housing of an energy storage system in an easy-to-implement yet effective manner, without blocking a degassing opening provided on an end face of the energy storage cells.

[0016] This problem is solved in particular by the subject matter of independent claim 1, which relates to an energy storage system with at least one energy storage cell for storing electrical energy. Advantageous embodiments of the energy storage system according to the invention are specified in the dependent claims.

[0017] Accordingly, the invention relates in particular to an energy storage system with at least one energy storage cell for storing electrical energy, wherein the energy storage system has a housing with at least two receiving areas for receiving the at least one energy storage cell, which are at least partially or partially separated by one or more housing walls or housing wall areas.

[0018] Each energy storage cell is associated with a mounting frame in which at least one end region of the energy storage cell is at least partially or partially received or can be received. The mounting frame is received in one of the receiving areas of the housing of the energy storage system and is connected there to at least one bottom region of the receiving area of ​​the housing of the energy storage system via a material-bonded connection, in particular an adhesive bond.

[0019] According to the invention, it is particularly provided that, at least in a state in which the end region of the energy storage cell is at least partially or partially received in the receiving frame, the receiving frame forms a degassing channel system.

[0020] The advantages achievable with the solution according to the invention are obvious: by providing a suitable mounting frame, the energy storage cell can be securely fixed in the receiving area of ​​the housing of the energy storage system. Specifically, an end section of the energy storage cell is preferably positively engaged by the mounting frame, and the mounting frame is then bonded to the base of the receiving area of ​​the housing of the energy storage system.

[0021] In order to nevertheless provide an effective degassing option for the energy storage cell, the mounting frame is designed to form a degassing channel system.

[0022] This measure enables simple yet effective manufacturing of the energy storage system. In particular, complete automation of the energy storage system's manufacturing process is achievable without the need for additional measures such as stiffening structures in the housing.

[0023] An advantage is that the degassing channel system opens into an interior space of the energy storage system housing and a degassing opening connects at least one energy storage cell to the interior of the housing. The housing of the energy storage system itself has a degassing opening that is or can be connected to the outside atmosphere.

[0024] It is advisable that the degassing opening of at least one energy storage cell and / or the degassing opening of the housing of the energy storage system has a pressure relief valve.

[0025] According to implementations of the energy storage system according to the invention, the receiving frame is designed to be at least partially or partially complementary to the end region of the energy storage cell such that the end region of the energy storage cell is received or received in the receiving frame in a form-fitting manner, at least substantially. In other words, the energy storage cell is preferably held in the receiving frame by a form-fitting connection.

[0026] This connection is preferably designed as a plug connection, which allows for simplified assembly of the energy storage system and, in particular, simplified mounting of the energy storage cell in the corresponding mounting frame.

[0027] According to embodiments of the energy storage system according to the invention, the receiving frame has a preferably cylindrical and in particular pot-shaped or pot-like base body with a bottom area via which the receiving frame is materially connected to the bottom area of ​​the receiving area of ​​the housing, and with a wall area connected to the bottom area of ​​the base body and surrounding the bottom area of ​​the base body.

[0028] In the energy storage system according to the invention, the receiving frame associated with the at least one energy storage cell is designed such that, in a state in which the end region of the energy storage cell is received in the receiving frame, a first degassing channel section is formed between a lower surface, in particular an end face, of the end region of the energy storage cell and an inner bottom region of the receiving frame, which is fluidly connected to a second degassing channel section formed between a side wall region of the end region of the energy storage cell and a side wall region of the receiving frame.

[0029] In particular, it is provided that the degassing opening of the energy storage cell is located on the front face of the end region of the energy storage cell, which is received in the mounting frame.

[0030] According to exemplary embodiments of the invention, the inner bottom area of ​​the receiving frame has a recess, arranged centrally, particularly with regard to the inner bottom area, which, in a state in which the end area of ​​the energy storage cell is received in the receiving frame, forms at least partially or partially the first degassing chamber section with the lower end face of the end area of ​​the energy storage cell.

[0031] Alternatively or additionally, it is conceivable that the inner bottom area of ​​the receiving frame has at least one channel-, groove- or trough-shaped depression extending radially to a peripheral area of ​​the inner bottom area of ​​the receiving frame, which, in a state in which the end area of ​​the energy storage cell is received in the receiving frame, forms at least partially or partially the first degassing channel section with the, in particular, lower end face of the end area of ​​the energy storage cell.

[0032] Alternatively or additionally, it may also be provided that at least one channel-, groove- or trough-shaped depression extending in the longitudinal direction of the side wall area of ​​the receiving frame is formed, which, in a state in which the end area of ​​the energy storage cell is received in the receiving frame, forms at least partially or partially the second degassing channel section with the side wall area of ​​the end area of ​​the energy storage cell.

[0033] In particular, a supercapacitor (Supercap) or an ultracapacitor (Ultracap) is used as an energy storage cell.

[0034] Such energy storage cells are characterized by excellent properties, especially with regard to cycle stability, life expectancy, temperature range, power density, energy efficiency, vibration resistance, resistance to acceleration forces, maintenance-free operation and environmentally friendly materials.

[0035] Of course, the invention is not limited to use on such energy storage cells, but also relates to embodiments in which the at least one energy storage cell is designed as an electrochemical accumulator. These are, in particular, lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, or nickel-metal hydride batteries.

[0036] The present disclosure further relates to an (unclaimed) method for manufacturing an energy storage system of the aforementioned inventive type.

[0037] In the manufacturing process, a housing with at least two receiving areas, separated at least partially or in some sections by one or more housing walls or housing wall sections, is provided. Likewise, at least one energy storage cell and a receiving frame are provided, wherein the receiving frame is designed to be at least partially or in some sections complementary to an end section of the energy storage cell such that the end section of the energy storage cell can be received in the receiving frame in a form-fitting manner, at least substantially.

[0038] The end section of the energy storage cell is then inserted into the receiving frame.

[0039] After an adhesive material has been introduced into one of the receiving areas of the housing, the receiving frame with the energy storage cell, which is at least partially or partially received in the receiving frame via its end area, is inserted into the receiving area of ​​the housing provided with the adhesive material.

[0040] The method specifically provides that, at least in a state in which the end region of the energy storage cell is at least partially or partially received in the receiving frame, the receiving frame forms a corresponding degassing channel system.

[0041] The invention is described in more detail below with reference to the accompanying drawings.

[0042] They show: Fig. 1 schematically and in an isometric view a part of an exemplary embodiment of an at least partially assembled energy storage system according to the invention; Fig. 2 schematically and in an isometric view an embodiment of a receiving frame and a (lower) end region of an energy storage cell, before the lower end region of the energy storage cell is received in the receiving frame; Fig. 3 schematically and in an isometric view an area of ​​the housing of the energy storage system, wherein an adhesive material is applied in the receiving areas of the housing; Fig. 4 schematically and in an isometric view and a partially cutaway isometric view the housing of the energy storage system according to Fig. 3. after applying the adhesive material to the receiving areas of the housing and then inserting the receiving frame with the energy storage cell, which is at least partially or partially received in the receiving frame over its end area, into the receiving area of ​​the housing provided with the adhesive material; and Fig. 5 schematically and in a sectional view the recording frame according to Fig. 4 with the energy storage cell which is at least partially or partially received in the receiving frame via its end area after the receiving frame has been inserted into the receiving area of ​​the housing which is provided with the adhesive material.

[0043] The exemplary embodiment of the energy storage system 1 according to the invention, shown in the drawings, has several energy storage cells 2 for storing electrical energy. The energy storage cells 2 are so-called supercapacitor cells.

[0044] Instead of such energy storage cells 2, it is also conceivable to use energy storage cells 2 that are designed, for example, as lithium-ion batteries.

[0045] In particular the presentation in Fig. 3 can be seen that the energy storage system 1 has a housing 3 with several receiving areas for receiving the energy storage cells 2, at least partially or partially separated by one or more housing walls or housing wall areas.

[0046] The energy storage system 1 according to the invention is characterized in particular by the fact that each energy storage cell 2 is assigned a receiving frame 4 in which - as in Fig. 2 indicated - an end area of ​​the energy storage cell 2 is at least partially or partially absorbable.

[0047] The representations in Fig. 4 and Fig. Figure 5 shows that the receiving frame 4, with the energy storage cell 2 being at least partially or partially received in the receiving frame 4 via its end region, is inserted into a receiving area of ​​the housing 3 provided with adhesive material 5. This connects the receiving frame 4 to at least one bottom region of the receiving area of ​​the housing 3 via a material-bonded connection, in particular an adhesive connection.

[0048] The sectional view of the Fig. It can also be inferred from paragraph 5 that at least in a state in which the end region of the energy storage cell 2 is at least partially or partially received into the receiving frame 4, the receiving frame 4 forms a degassing channel system.

[0049] The degassing channel system, which is formed by the mounting frame 4, opens into an interior space of the housing 3 of the energy storage system 1. A degassing opening of the energy storage cell 2 (not shown in the drawings) is flow-wise connected to the interior space of the housing 3.

[0050] The drawings also do not show that the housing 3 of the energy storage system 1 has a degassing opening that is or can be connected to the outside atmosphere in terms of airflow.

[0051] The degassing opening of the energy storage cell 2 and the degassing opening of the housing 3 of the energy storage system 1 can each have a pressure release valve.

[0052] As in Fig. 2 indicated and in the section view according to Fig. As can be seen in Figure 5, the receiving frame 4 is designed to be at least partially or partially complementary to the end region of the energy storage cell 2 in such a way that the end region of the energy storage cell 2 can be received or received in the receiving frame 4 at least essentially in a form-fitting manner via a plug connection.

[0053] In detail, the receiving frame 4 has a preferably cylindrical and, in particular, a cup-shaped or pot-like base body. The base body has a bottom area 6, via which the receiving frame 4 is materially connected to the bottom area of ​​the receiving area of ​​the housing 3 of the energy storage system 1.

[0054] The base body of the mounting frame 4 further has a side wall area 7 which is connected to the bottom area 6 of the base body and surrounds the bottom area 6 of the base body.

[0055] This is - as in Fig. 5 shown - the receiving frame 4 associated with the energy storage cell 2 is designed such that, in a state in which the end region of the energy storage cell 2 is received in the receiving frame 4, a first degassing channel section 8 is formed between a lower surface, in particular end face, of the end region of the energy storage cell 2 and an inner bottom region 6 of the receiving frame 4, which is fluidly connected to a second degassing channel section 9 formed between a side wall region of the end region of the energy storage cell 2 and a side wall region 7 of the receiving frame 4.

[0056] According to the section view Fig. It can be seen from Figure 5 that the inner bottom area 6 of the receiving frame 4 has a depression which, in a state in which the end area of ​​the energy storage cell 2 is received in the receiving frame 4, forms at least partially or partially with the lower end face of the end area of ​​the energy storage cell 2 the first degassing channel section 8.

[0057] Alternatively or additionally, it is also conceivable that the inner bottom area 6 of the receiving frame 4 has at least one channel-, groove- or trough-shaped depression extending radially to a peripheral area of ​​the inner bottom area 6 of the receiving frame 4, which, in a state in which the end area of ​​the energy storage cell 2 is received in the receiving frame 4, forms at least partially or partially the first degassing channel section 8 with the lower end face of the end area of ​​the energy storage cell 2.

[0058] According to the views Fig. 2 and according to Fig. Figure 5 shows that in the side wall area 7 of the receiving frame 4 a channel-shaped depression 10 extending in the longitudinal direction of the side wall area is formed, which in a state in which the end area of ​​the energy storage cell 2 is received in the receiving frame 4, forms at least partially or partially the second degassing channel section 9 with the side wall area of ​​the end area of ​​the energy storage cell 2. Reference symbol list 1 Energy storage system 2 Energy storage cells 3 cases 4 mounting frames 5 Adhesive bond / adhesive material 6. Base area of ​​the mounting frame / base body of the mounting frame 7 Side wall area of ​​the mounting frame / the base body of the mounting frame 8 first degassing channel section 9 second degassing channel section 10 channel / groove / trough-shaped depressions

Claims

[1] Energy storage system (1) with at least one energy storage cell (2) for storing electrical energy, wherein the energy storage system (1) has a housing (3) with at least two receiving areas separated at least partially or partially by one or more housing walls or housing wall areas for receiving the at least one energy storage cell (2), wherein the at least one energy storage cell (2) is associated with a receiving frame (4) in which an end area of ​​the energy storage cell (2) is at least partially or partially received or can be received, wherein the receiving frame (4) is received in one of the receiving areas of the housing (3) and is connected there to at least one bottom area of ​​the receiving area by means of a material-bonded connection, in particular an adhesive connection (5), and wherein at least in one state,in which the end region of the energy storage cell (2) is at least partially or partially received in the receiving frame (4), the receiving frame (4) forms a degassing channel system, wherein the receiving frame (4) associated with the at least one energy storage cell (2) is designed such that, in a state in which the end region of the energy storage cell (2) is received in the receiving frame (4), a first degassing channel section (8) is formed between a lower surface, in particular an end face, of the end region of the energy storage cell (2) and an inner surface of a bottom region (6) of the receiving frame (4), which is fluidly connected to a second degassing channel section (9) formed between a side wall region of the end region of the energy storage cell (2) and a side wall region (7) of the receiving frame (4). [2] Energy storage system (1) according to claim 1, wherein the degassing channel system opens into an interior of the housing (3) of the energy storage system (1) and a degassing opening of the at least one energy storage cell (2) is fluidly connected to the interior of the housing (3), wherein the housing (3) of the energy storage system (1) has a degassing opening that is fluidly connected or connectable to the outside atmosphere. [3] Energy storage system (1) according to claim 2, wherein the degassing opening of the at least one energy storage cell (2) and / or the degassing opening of the housing (3) of the energy storage system (1) has / has a pressure relief valve. [4] Energy storage system (1) according to one of claims 1 to 3, wherein the receiving frame (4) is designed at least partially or partially complementary to the end region of the energy storage cell (2) such that the end region of the energy storage cell (2) is received or received in the receiving frame (4) at least substantially in a form-fitting manner. [5] Energy storage system (1) according to one of claims 1 to 4, wherein the receiving frame (4) has a preferably cylindrical and in particular pot-shaped or pot-like base body with a bottom area (6) via which the receiving frame (4) is connected to the bottom area of ​​the receiving area of ​​the housing (3) in a materially bonded manner, and with a side wall area (7) connected to the bottom area (6) of the base body and surrounding the bottom area (6) of the base body. [6] Energy storage system (1) according to one of claims 1 to 5, wherein the inner surface of the bottom area (6) of the receiving frame (4) has a depression arranged centrally, particularly with regard to the bottom area (6), which, in a state in which the end area of ​​the energy storage cell (2) is received in the receiving frame (4), forms at least partially or partially the first degassing channel section (8) with the lower end face of the end area of ​​the energy storage cell (2). [7] Energy storage system (1) according to one of claims 1 to 6, wherein the inner surface of the bottom region (6) of the receiving frame (4) has at least one channel-, groove- or trough-shaped depression extending radially to a peripheral region of the inner bottom region of the receiving frame (4), which, in a state in which the end region of the energy storage cell (2) is received in the receiving frame (4), forms at least partially or partially the first degassing channel section (8) with the, in particular, lower end face of the end region of the energy storage cell (2). [8] Energy storage system (1) according to one of claims 1 to 7, wherein at least one channel-, groove- or trough-shaped depression (10) extending in the longitudinal direction of the side wall area (7) of the receiving frame (4) is formed, which in a state in which the end area of ​​the energy storage cell (2) is received in the receiving frame (4) forms at least partially or partially the second degassing channel section (9) with a side wall area of ​​the end area of ​​the energy storage cell (2). [9] Energy storage system (1) according to any one of claims 1 to 8, wherein the at least one energy storage cell (2) is designed as a supercapacitor or ultracapacitor; or wherein the at least one energy storage cell (2) is designed as an electrochemical accumulator.

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