CN115606038A

CN115606038A - Energy storage device, preferably for an at least partially electrically driven vehicle, having a battery cell module and a cooling device, and method for producing an energy storage device

Info

Publication number: CN115606038A
Application number: CN202180035628.3A
Authority: CN
Inventors: 西蒙·巴彻; 迈克尔·克鲁克
Original assignee: MAN Truck and Bus SE
Current assignee: MAN Truck and Bus SE
Priority date: 2020-05-19
Filing date: 2021-05-14
Publication date: 2023-01-13
Also published as: WO2021233778A1; DE102020121498A1; EP4154346A1

Abstract

The invention relates to an energy storage device (1) for storing electrical energy, preferably for an at least partially electrically driven vehicle. The invention also relates to a method for producing an energy storage device and to a vehicle, preferably a commercial vehicle, or a fastening device having such an energy storage device. The energy storage device (1) has a plurality of storage units (3, 4, 5) arranged side by side in a stacked manner and a cooling device (6) for cooling the storage units (3, 4, 5). The cooling device (6) comprises a cooling plate (7) through which a coolant can flow, the cooling plate (7) being arranged on a side, preferably on the bottom side, of the storage unit (3, 4, 5). The invention is characterized in that the cooling device also comprises at least one cooling body (8) which can be flowed through by the coolant, is arranged between two adjacent storage units (3, 4, 5) in order to cool the sides of the storage units (3, 4, 5), is in fluid connection with the cooling plate (7), and is designed as a cooling body (8) with an elastic jacket (9).

Description

Energy storage device, preferably for an at least partially electrically driven vehicle, having a battery cell module and a cooling device, and method for producing an energy storage device

Technical Field

The invention relates to an energy storage device for storing electrical energy, preferably for an at least partially electrically driven vehicle. The invention also relates to a method for producing an energy storage device and to a vehicle, preferably a commercial vehicle, or to a fastening device having such an energy storage device.

Background

Vehicle batteries known from practice, which are used, for example, as energy stores or traction batteries in hybrid or electric vehicles, typically have a battery pack in which a plurality of battery storage cells arranged in a stack are arranged. These battery storage units may be combined into modules or mounted directly into a battery pack in the category of so-called battery-to-pack (CTP) technology. In order to ensure proper operation and avoid damage to such vehicle batteries and to achieve the longest possible service life, the vehicle batteries must be operated within a defined temperature range. Here, it is known, for example from the prior art, to arrange a cooling plate, optionally with a thermally conductive paste applied to the cooling plate, under the battery cells, through which a cooling fluid flows to cool the battery cells. In these known solutions, the storage unit is generally of significantly smaller area and the underside of the unit facing the cooling plate is cooled, while the side of the storage unit of significantly larger area remains uncooled. This disadvantageously produces an extremely uneven temperature distribution within the storage unit and, for example, within the battery cell module.

It is also known from the prior art that the dissipation of the heat generated in the battery cell can be improved by means of a heat sink. Thus, for example, the publication DE 10 2012 218 764 A1 proposes thermally coupling heat sinks to the sides of the battery storage cells via a flat base body, in each case, the base body having cooling channels. The performance of this solution is disadvantageously limited by the heat transfer or the heat transfer coefficient of the contact surface between the heat sink and the substrate. Furthermore, the heat sink can only achieve passive cooling of the storage unit, which disadvantageously leads to a time delay in the introduction and removal of heat, an uneven temperature distribution and a low cooling capacity.

Disclosure of Invention

The object of the present invention is to provide a technique for temperature control, in particular cooling, of such an energy storage device, with which the disadvantages of the known solutions for temperature control, in particular for cooling, can be avoided. The object of the invention is to improve the known energy storage device in particular with regard to the cooling performance of the storage unit.

These objects are solved by a device and a method having the features of the independent claims. Advantageous embodiments and applications of the invention emerge from the dependent claims and are explained in more detail in the following description with reference in part to the drawings.

One basic idea of the invention is to provide an additional cooling body in the interspace between the battery cells arranged next to one another, which are actively cooled and for this purpose are in fluid connection with a cooling plate arranged on the side, for example on the bottom side, of the battery cells. This provides the advantage of a particularly effective cooling, which results in a temperature distribution within the battery cell that is as uniform as possible. Furthermore, these cooling bodies are configured with an elastic jacket, i.e. they can be configured as so-called foil cooling bodies or bag cooling bodies. This provides the additional advantage that the cooling body can be adapted particularly well to the changing surface shape of the battery cell, which is caused, for example, by the so-called swelling effect. Furthermore, the elastic cooling body can compensate, in particular, for assembly and component tolerances.

Thus, according to a first general aspect of the present invention there is provided an energy storage device for storing electrical energy. It is preferably an energy storage device for an at least partially electrically driven vehicle. In other words, the energy storage device can be designed in a manner known per se to store electrical energy, which can be converted into drive energy in a corresponding drive assembly of the vehicle (for example in an electric machine). In other words, the energy storage device may be configured for temporarily accommodating tractive energy.

The energy storage device has a plurality of storage cells arranged side by side in a stacked manner. These storage units may also be combined into one module (battery cell module) and preferably grouped beforehand. In addition to the storage cell assembly itself, the battery cell module may optionally additionally comprise further components which are required for storing electrical energy and are known per se, such as circuit boards, circuits, relays, lines, base or end plates, busbars, terminals, top or side covers, plastic plates and/or circuit boards, etc.

Alternatively, the storage unit can also be installed directly into the battery pack in the category of the so-called battery-to-battery technology. In this case, the pre-grouping of the battery cells by the battery module is abandoned, and the storage unit is directly mounted in the battery pack. Battery-to-battery technology has recently been increasingly used to increase mass energy density, improve volumetric utilization efficiency, and reduce the number of components of a battery pack, as compared to a conventional battery pack composed of pre-grouped battery cell modules.

The memory cells may be connected in parallel and/or in series with each other and have individual memory cells combined into a cell complex. The storage unit can be designed, for example, as a lithium-ion battery. The cells may preferably be spaced from each other by a gap of 0.5 to 1.5 mm.

Furthermore, the energy storage device has a cooling device for cooling the storage unit. The term "cooling" is preferably, but not exclusively, understood to mean the heat that is discharged from the storage unit. It is therefore also conceivable for the invention, in particular at low temperatures or during cold start of the vehicle, to heat or preheat the storage unit, for example to bring or maintain the storage unit at operating temperature. Therefore, the cooling device may be generally used as a temperature control device for the storage unit.

The cooling device also has a cooling plate through which a coolant can flow. The cooling plate can have for this purpose, for example, in its inner volume, corresponding fluid-conducting channels. The cooling plate is arranged on a side face, preferably on the bottom side, of the storage unit. If the storage cells are arranged as one battery cell module, the cooling plate may be arranged on the side of the battery cell module. The side surface may be a bottom surface (lower side surface) of the battery cell module. In other words, the cooling plate is designed, for example, to absorb heat radiated by the storage unit and to dissipate said heat to the storage unit or to output it to the storage unit by means of a coolant flowing through the cooling plate.

According to the invention, the cooling device also has at least one cooling body which is arranged between two adjacent storage units for cooling the sides of the storage units, is in fluid communication with the cooling plate and is configured as a cooling body with an elastic jacket. Each of the at least one cooling body can therefore also be flowed through by a coolant and for this purpose can have a corresponding fluid conducting channel, for example also in its inner volume. The cooling body is disposed between two adjacent storage units for cooling the sides of the storage units. The heat sinks preferably lie flat on the sides of adjacent storage units facing one another, so that heat can be exchanged between the storage units and the heat sinks. For this purpose, the heat sink can be designed, for example, to absorb heat emitted by the storage unit and to dissipate said heat by means of a coolant flowing through the cooling plate. Coolant may enter the cold body from the cold plate and then return from the cold body to the cold plate. For this purpose, the cooling body can have, for example, one or more coolant inlets and one or more coolant outlets, through which coolant can flow from the cooling plate into the cooling body and from the cooling body back into the cooling plate.

It has been determined above that the cooling body is designed as a cooling body with an elastic jacket. The term "elastic" is understood in the sense of the present invention to mean that the material of the sheath is deformable (bendable) and/or flexible. The sheath can therefore be made of an elastic material in order to be able to adapt as well as possible to the temperature-variable volume and geometry of the storage unit.

The proposed energy storage device has a number of advantages over known solutions. The fluid connection provided between the at least one cooling body and the cooling plate makes it possible to achieve a particularly high cooling capacity in the intermediate space between the storage units. Furthermore, the heat sink with the elastic jacket makes it possible to mount the heat sink on the side of the storage unit in a self-adapting, flat, form-fitting manner, whereby a particularly good heat transfer between the storage unit and the heat sink is achieved, which heat transfer can be maintained by the elastic jacket even when the storage unit expands or contracts. Furthermore, the cooling bodies can optionally take over the function of compression layers (so-called "compression" or "expansion" cushions) which are arranged in practice between the storage units, by means of their elastic sheathing, which are arranged in practice between the storage units in order to compensate for thermal expansion and contraction of the storage units and to ensure a constant surface pressure between the storage units. Additionally, the cooling body can take over the function of and at least partially replace an insulation mat (so-called "thermal insulation pads"). Advantageously, this makes it possible to dispense with an insulating mat. This has cost, weight and packaging advantages. Furthermore, it is advantageously provided that the expansion of the storage unit does not lead to a gradual increase in the surface pressure, or at least to a reduction in said surface pressure. In the energy storage device, a pressure which is as constant as possible is achieved by the coolant pressure. Furthermore, cooling of the memory cell voids results in high thermal capacity and delay times for thermal aging and damage effects.

According to a particularly advantageous embodiment, the elastic jacket of the cooling body can comprise an aluminum foil or a plastic foil with or without a plastic coating. It is conceivable that this is a commercially available aluminium foil with a plastic coating, which is common for example in the packaging industry. A particularly good heat transfer between the heat sink and the storage unit advantageously takes place, while at the same time providing the heat sink with a particularly wear-resistant and resistant jacket.

Alternatively or additionally, the cooling body of the energy storage device may be a foil cooling body and/or a bag cooling body. The term "pouch-type cooling body" is here similar to the pouch-type battery cells, pouch-type battery cells or coffee pouch battery cells widely used in battery technology and shall include any type of flexible housing of a cooling body. Here, by way of example only, the wall thickness of the sheath may be in the range between 0.05mm and 0.2mm, particularly preferably approximately 0.1mm. Advantageously, the heat sink can compensate particularly well for thermally induced expansion or compression movements of the storage unit, so that particularly good heat transfer or heat dissipation conditions between the storage unit and the heat sink are always ensured. For example only, the gap between two storage units may be in the range of about 1mm.

It has been stated above that the energy storage device comprises at least one, i.e. one or more, cooling bodies. A particularly preferred embodiment is described below, according to which the energy storage device comprises a plurality of cooling bodies. According to this particularly preferred embodiment, the at least one heat sink can comprise a plurality of heat sinks in this respect, wherein in each case one heat sink is arranged between all storage units for cooling a side of the storage units. In other words, the cooling body and the storage unit may follow each other in an alternating sequence within the energy storage device. It is conceivable that this is a regular alternating sequence of cooling bodies and storage units. This ensures even heat dissipation or temperature distribution in the energy storage device and further improves the cooling efficiency of the energy storage device. In an alternative variant, an irregular sequence of cooling bodies and storage cells is also possible. In other words, it is alternatively conceivable, for example, to provide cooling bodies only in every 2, every 3, every 4, etc. spaces between adjacent memory cells, respectively.

Furthermore, cooling bodies with an elastic jacket can be arranged in each case on the outer side of the external storage unit for cooling the side faces. That is to say, such cooling bodies can also optionally be arranged on the terminal side of the battery cell module and thus form the first and last element of an alternating sequence of cooling bodies and storage cells in the energy storage device. This advantageously reduces the heat radiation of the energy storage device compared to the component adjacency.

In a further embodiment, the cooling body can have at least one corrugation or embossing which is configured to divide the interior space of the cooling body into subspaces which are fluidically connected to one another. In the first subspace, there is a coolant inlet for the coolant from the cooling plate, and in the last subspace there is a coolant outlet for the cooling body, from which coolant returns to the cooling plate.

It is conceivable for the cooling body to have a corrugation or an embossment or a plurality of corrugations or embossings. The corrugation or embossing may be applied, for example, by forming, bending, folding and/or heating. The embossings preferably have a thickness of about 0.1 to 0.2 mm. The at least one corrugation or embossment may be configured to direct coolant from a coolant inlet of the cooling body to a coolant outlet of the cooling body in an arc, U-shape, or serpentine shape. Advantageously, a directed flow in the cooling body is generated, which further increases the overall cooling effect.

According to a further variant of this embodiment, the cooling body can have exactly one fold or embossment

For example in the central region, which is designed to divide the interior of the heat sink into two fluidically connected partial spaces in order to conduct the coolant in a bent and/or U-shaped manner from a coolant inlet of the heat sink to a coolant outlet of the heat sink.

According to another aspect, the cooling plate may have a first wall facing the storage unit, the first wall having a slit structure for holding at least one cooling body. The first wall may be designed as a separate part in the form of a plate with a slit structure. The slots of the slot arrangement may each have a width corresponding to the width of the cooling body. The end region of the cooling body having the coolant inlet and the coolant outlet can also be held in one of the slots. In other words, the cooling bodies can be arranged perpendicular to the cooling plates, for example, one after the other like sails, on the slots of the cooling plates. These slots can thus advantageously be used for holding the cooling body on the one hand and for holding the fluid connection between the cooling body and the cooling plate on the other hand.

According to a development of the latter aspect, the end region of the cooling body can have a sealing lip for the fluid-tight sealing of the gap and thus of the connection between the cooling plate and the cooling body(s). Preferably, the sealing lip can be designed as an elastomer sealing lip, for example as an elastomer injection molding. It is conceivable that the sealing lip is already applied to the cooling body in the delivery state of the cooling body. Alternatively, it is conceivable that the sealing lip is applied during installation by overmoulding the cooling body. For the fluid-tight sealing of the gap, the sealing lip can have, for example, an approximately double-T-shaped cross section which is pressed into the gap and overlaps the gap in all spatial directions. Advantageously, a simple and effective fluid seal of the gap or of the fluid connection between the cooling body and the cooling plate is produced.

According to a development of an aspect of the sealing lip, the sealing lip can have a projection which engages into a correspondingly shaped recess or undercut of the first wall in order to produce a form fit between the sealing lip and the cooling plate. This advantageously increases the stability of the connection between the cooling body and the cooling plate, which reduces the risk that the carrier of the cooling body is pressed out of the respective gap and becomes unsealed under the fluid pressure of the coolant present in the cooling plate.

According to another aspect, the cooling plate may comprise a second wall, e.g. a half shell wall, facing away from the storage unit. The second wall may have embossments configured to direct coolant within the cooling plate to the coolant supply and the coolant return. In other words, the embossing can delimit channels or paths for the coolant for conducting the coolant. Preferably, the embossing can also have grooves for holding at least one cooling body. The recesses can be configured, for example, corresponding to the position and size of the folds of the cooling body. Embossing thus can serve a dual function: fluid direction and cooling body retention. The fluid guide in the cooling plate and the holding of the cooling body on the cooling plate are advantageously made particularly simple and cost-effective. The cooling plate may thus consist of a first plate (first wall) having a slit structure and a second plate (second wall) having an embossed structure.

According to a further embodiment, the cooling plate can be designed such that the coolant supply within the cooling plate has a coolant channel arranged at an edge region of the cooling plate, which coolant channel has a plurality of side branches arranged orthogonally to the edge region, and the coolant return has a coolant channel arranged in the edge region opposite the coolant supply, which coolant channel has a plurality of side branches arranged orthogonally to the edge region. Further, the coolant supply and return side branches may be interwoven with one another such that the coolant supply side branch is always directly adjacent to the coolant return side branch. In other words, an alternating sequence of side branches of the coolant supply and the coolant return can be generated within the cooling plate. For example, the coolant supply portion and the coolant return portion may be configured in the form of two letters "n" pushed into each other, more preferably in the form of two letters "E" pushed into each other. This further increases the efficiency of the cooling device by improved heat transfer.

According to a development of the latter aspect, a side branch of the coolant supply and a side branch of the coolant return of the cooling plate can be fluidly connected to each other via the cooling body. In this way, a particularly long cooling path is achieved within the battery cell module.

In a further embodiment, the cooling body can be at least partially surrounded by a frame arranged between adjacent storage units, which frame is configured to absorb forces, preferably compressive forces, between adjacent storage units. Such a pressure frame is therefore referred to hereinafter as pressure frame. Preferably, the pressure frame is a plastic pressure frame. The pressure frame can be adapted, for example, in terms of its structure and shape, to the design of the storage cell module and its connection in the battery pack. Advantageously, it results that the pressing force of the battery cell module is dissipated via the pressure frame instead of via the cooling body, which increases the service life of the energy storage device. Due to the compressive strength of the pressure frame, the storage unit can also be tensioned, in particular in the case of prismatic storage units.

According to another aspect, the pressure frame may be fixed at an edge of the cooling body. Preferably, the pressure frame may be fixed at the outer edge embossing or edge corrugation of the cooling body by overmolding. Such a case of overmolding the cooling body to the pressure frame is preferably used only when the pressure frame is mounted with the cooling body, not when the battery cell is pressed during module manufacturing. In this case, the separate component can be fixed as a pressure frame on the heat sink by overmoulding, or the overmoulding itself can form the pressure frame.

Instead of fixing the pressure frame at the edge of the cooling body, the pressure frame can rest loosely on the cooling body and be held in place by pressing against the adjacent storage unit. In other words, the pressure frame may, for example, have no mechanical connection to the cooling body and be free from constraints in the downward direction, i.e. in the direction of the cooling plate. It is conceivable that the pressure frame is inserted during installation of the battery unit or is already part of a storage unit grouping in the delivery state, for example part of a battery unit module. This represents a particularly simple and cost-effective arrangement of the pressure frame. Furthermore, the hitherto familiar mounting process of known battery cell modules or known batteries to battery pack-packs can also be used for the battery cell modules or battery to battery pack-packs proposed here, due to the pressure frame.

The pressure frame is preferably adapted to the outer contour of the cooling body. According to another aspect, the pressure frame may be configured in the form of the letter "M", i.e., M-shaped or "n". These shapes are to be understood as examples only. The pressure frame may also have other shapes and its shape may depend on or be adapted to the shape of the battery.

The storage cells may be so-called pocket storage cells or prismatic storage cells. For example, if the memory cells are combined into a battery cell module, the battery cell module may have prismatic memory cells or pouch type memory cells. Alternatively, the storage cells can also be designed here as prismatic storage cells or pocket-type storage cells if they are installed directly in the battery pack in the category of the so-called battery-to-battery technology.

The term "prismatic storage unit" used in the sense of this document shall in particular include storage units having a fixed prismatic or rectangular parallelepiped housing, for example made of a shape-stable plastic. In contrast, the term "pocket-type storage unit" as used in the sense of this document shall in particular include a storage unit surrounded by a flexible outer foil. Furthermore, reference is made to the differences in the internal structure of prismatic and pouch-type memory cells, which are well known in the battery technology. For prismatic storage cells and pocket storage cells, improved heat dissipation is achieved by the additional active-side cooling according to the invention, and in particular the advantages of a more uniform storage cell temperature distribution, a more constant storage cell temperature level, a longer storage cell service life and a more targeted storage cell temperature regulation (in particular also during charging) are achieved.

The invention also relates to a vehicle having an energy storage device as described in this document. The vehicle is preferably at least partially electrically driven. The vehicle is preferably a motor vehicle, such as a passenger car or a commercial vehicle. In the latter case, the vehicle may in other words be a motor vehicle, which, due to its design and equipment, is designed for transporting people, transporting goods or for towing trailers. For example, the vehicle may be an at least partially electrically driven truck, a bus and/or an articulated truck. However, it is also conceivable that the vehicle is a rail vehicle or an aircraft.

Furthermore, it is likewise conceivable for the invention to be constructed as a stationary energy storage device or as a battery storage means, or for the energy storage device to be stationary, i.e. not part of a mobile device. An example of this is a fixedly mounted energy storage device, for example in combination with a solar installation or a wind installation.

According to a second general aspect of the invention, there is also provided a method for manufacturing an energy storage device. In order to manufacture an energy storage device according to the above-described embodiment, wherein the cooling plate has a first wall facing the battery cell module, the first wall having a slit structure for holding the cooling body, the method is characterized by the following steps for arranging the cooling body on the cooling plate:

at least one cooling body is fixed to the cooling plate by pushing the cooling body through the slot of the slot arrangement until an end region of the cooling body having a coolant inlet and a coolant outlet is positioned and/or rests on the slot.

In this case, the cooling body can be inserted through the slots by means of the mounting tongues, the cooling body being attached to the mounting tongues before insertion and being pulled out again after the cooling body has been inserted through and fixed to the cooling plate. This has the advantage that the cooling body and the elastic sheath are prevented from collapsing during the production of the energy storage device and that a simple installation is possible.

When the storage cells are grouped into battery cell modules with prismatic storage cells, the battery cell modules are then placed on at least one through-going cooling body. It is also conceivable to first place the battery cell modules and then position the cooling body in the interspaces between the storage cells from below by passing the cooling body through the slot structure.

If the pouch type battery cells are used, the pouch type battery cells are separately mounted to the cooling plate and then combined into one battery cell module.

In the embodiment variant as a battery-to-battery pack/battery module, the storage cells are individually mounted, for example individually, on a cooling plate in the context of the battery-to-battery pack CTP method.

The proposed method may also optionally comprise applying a thermally conductive paste (so-called "gap filler") onto the cooling plate.

The proposed method and its extensions can be applied to both prismatic and pocket memory cells.

The above-described preferred embodiments and features of the invention can be combined with one another as desired. To avoid repetition, features disclosed purely in terms of apparatus should also be applicable and claimable as disclosed in terms of the method. The above-described aspects and features according to the invention, in particular with regard to the configuration of the cooling body and the cooling plate and their arrangement relative to one another, are therefore also applicable to the method.

Drawings

The details and advantages of the invention are described below in conjunction with the following figures.

FIG. 1 illustrates a cooling device of an energy storage device according to an embodiment of the present invention;

FIG. 2 illustrates an exploded view of an energy storage device according to one embodiment;

FIG. 3 shows a lower wall of a cooling plate of a cooling device according to an embodiment of the invention to illustrate coolant guiding within the cooling device;

fig. 4 shows a side view of a cooling body of a cooling device according to an embodiment of the invention;

fig. 5 shows the heat sink in fig. 4 in a perspective view;

fig. 6 shows a cooling body of a cooling device with a pressure frame according to another embodiment of the invention;

FIG. 7 shows a detailed view of FIG. 6 to illustrate the holding of the cooling body on the cooling plate or the fluid connection of the cooling body to the cooling plate;

fig. 8 shows a cooling body of a cooling device with a pressure frame according to a further embodiment of the invention;

FIG. 9 shows a detailed view of FIG. 8 to illustrate the holding of the cooling body on the cooling plate or the fluid connection of the cooling body to the cooling plate;

FIG. 10 shows an energy storage device with enlarged details to illustrate retention and fluid connection of a cooling body to a cooling plate, according to another embodiment;

FIG. 11 shows a supplementary view of the positioning of a bag-type storage unit disposed between two cooling bodies on a cooling plate, according to another embodiment;

FIG. 12 shows a schematic flow diagram of a method for manufacturing an energy storage device; and

fig. 13 shows a supplementary schematic of the method steps in fig. 12.

Identical or functionally equivalent elements are denoted by the same reference numerals throughout the figures and are in part not separately described.

Detailed Description

Fig. 1, 2, 3, 4 and 5 show a first embodiment of the proposed energy storage device 1, fig. 6 and 7 show a second embodiment, fig. 8 and 9 show a third embodiment, fig. 10 shows a fourth embodiment and fig. 11 shows a fifth embodiment, wherein some of the figures are only intended to better illustrate various characteristic sub-aspects of the respective embodiments. Components that are not important to these characteristic sub-aspects are not shown to enhance visibility of the characteristic aspects.

Reference is first made below to fig. 1, 2, 3, 4 and 5. Fig. 2 shows an energy storage device 1 for storing electrical energy for an at least partially electrically driven motor vehicle (not shown). The energy storage device 1 may be configured to temporarily contain electrical energy, preferably traction energy. The energy storage device 1 has, in a manner known per se, a plurality of storage units 3 arranged side by side in a stacked manner. These storage cells can be designed, for example, as lithium-ion accumulators. The storage units 3 are combined into the battery cell modules 2 and connected in parallel and/or series with each other. The storage cells 3 are shown in FIG. 1 as prismatic cells 5. Alternatively, the storage unit 3 can also be designed as a bag storage unit 4 (see fig. 11). It has been determined above that instead of using battery cell modules, it is also possible to use the so-called battery-to-battery method, in which the storage cells are mounted directly into the battery and therefore the cost of the module assembly as an intermediate step can be skipped.

In addition to the storage cell assembly itself, the battery cell module 2 additionally comprises components known per se and required for storing electrical energy, such as a base plate or end plate 33, a metal plate or busbar 35 and a circuit board 36, top or side covers 31, 32, a protective plate 34, etc., which are partially illustrated in fig. 2 by way of example.

Heat loss occurs in the storage unit 3 during operation. When the ambient temperature is low, the heat can be absorbed, i.e. the energy storage device can be heated. In order to ensure proper operation and avoid damage to the storage unit 3 and to achieve as long a service life as possible, the storage unit must operate within a defined temperature range.

For this purpose, the energy storage device 1 has a cooling device 6 for temperature control of the storage unit 3, in particular for cooling the storage unit 3, which cooling device is shown in fig. 1. The cooling device 6 has a cooling plate 7 through which a coolant can flow, which is arranged on a side face, here on the bottom face, of the battery cell module 2 and is designed to cool the bottom of the battery cell module 2. For this purpose, the cooling plate 7 has, for example, a coolant connection 37, through which coolant can flow into the cooling plate 7, and a coolant outflow 38, through which coolant can flow out of the cooling plate 7. The cooling plate 7 may be in fluid connection with a cooling circuit of a motor vehicle, other components of which are not shown here.

Furthermore, the cooling device in the embodiment shown in fig. 1 has a plurality of cooling bodies 8 (here, only 42 blocks are taken as an example). The cooling body 8 has an elastic outer jacket. Such a cooling body 8 may therefore also be referred to as a foil cooling body or a bag cooling body. Therefore, the term "pocket cooler" is also used below. The elastic sheath may for example have an aluminium foil and a plastic coating.

The pocket coolers 8 are arranged in rows next to one another and one behind the other on the cooling plate in accordance with the arrangement of the storage units, so that one pocket cooler 8 is arranged in each case in the intermediate space between two adjacent storage units. For greater clarity, not all cooling bodies 8 are provided with reference numerals in fig. 1, 2, 10 and 11.

In fig. 2, the positioning of the cooling body 8 between the storage units 3, 5 of the energy storage device 1 of this first embodiment is clear. A part of the energy storage device 1 is shown in (partially) exploded view.

In this embodiment, one cooling body 8 is arranged between all adjacent storage units 3 in each case for cooling the side faces of the storage units 3. In the exemplary embodiment shown, the storage cells 3 and the heat sink 8 therefore follow one another in an alternating sequence in the energy storage device 1. Alternatively or additionally, it is conceivable to arrange a respective pocket-type cooling body 8 on the outer surface of the external storage unit 10 for lateral cooling (not shown here).

The heat sink 8 rests on the side of the storage units 3, 5. Due to the relatively large contact surface, in particular compared to sole plate cooling, a comparatively large amount of heat of the storage units 3, 5 is transferred to the heat sink 8. In this respect, relatively large amounts of heat are discharged from the storage units 3, 5.

The cooling body 8 is in fluid connection with the cooling plate 7 and can be flowed through by a coolant. The heat absorbed by the cooling body 8 is transferred to the coolant and transported away.

For this purpose, the cooling plate 7 comprises a first wall 17 (see, for example, fig. 7) facing the battery cell module 2 and a half-shell-shaped second wall 18 (see, for example, fig. 3) facing away from the battery cell module 2.

As can be seen in fig. 3, the second wall 18 has embossments 23, which embossments 23 are configured to guide the coolant in the cooling plate 7 into the coolant supply and the coolant return. The embossing 23 of the second wall 18 itself preferably has a recess 24 for holding the cooling body 8.

Fig. 3 shows the coolant guidance in the cooling device 6. The coolant supply has a coolant channel 25 arranged at the edge region of the cooling plate 7, which has a plurality of side branches 26 arranged orthogonally to the edge region. The coolant return has a coolant channel 27, which coolant channel 27 is arranged on the edge region opposite the coolant supply and has a plurality of side branches 28 arranged orthogonally to the edge region. The coolant supply and return

coolant side branches

26, 28 are interwoven such that the coolant supply side branch 26 is always disposed directly adjacent the coolant return side branch 28. In other words, in this embodiment an alternating sequence of coolant supply side branches 26 and coolant return side branches 28 is produced. In other words, the coolant supply and the coolant return have the shape of two letters "E" pushed into one another in plan view, wherein the coolant guidance is merely exemplary.

The side branch 26 of the coolant supply part and the side branch 28 of the coolant return part of the cooling plate 7 are fluidly connected to each other by the cooling body 8. For this purpose, the coolant inlet 15 of the cooling body 8 is fluidly connected to a side branch 26 of the coolant supply, while the coolant outlet 16 of the cooling body 8 is fluidly connected to a side branch 28 of the coolant return of the cooling plate 7.

In other words, coolant enters the cooling plate 7 through the coolant connection 37 and flows into the coolant supply and the orthogonally arranged side branch 26. The coolant then enters the cooling body 8 via the coolant inlet of the cooling body 15, absorbs the heat of the storage unit 8 and flows heated via the coolant outlet 16 of the cooling body 8 into the coolant return of the cooling plate 7. The coolant return directs the heated coolant to a cooling circuit (not shown) of the motor vehicle via the coolant outflow end 38. In this regard, the storage unit 3 is actively temperature controlled or cooled in a cooling mode.

Fig. 4 shows a single heat sink 8 of the energy storage device according to the first embodiment of fig. 1 in a side view. Fig. 5 serves as an additional perspective view of the heat sink 8.

As mentioned above, the bag cooler 8 is constructed with an elastic jacket 9. In the embodiment shown, the wall thickness of the elastic sheath is about 0.1mm. Therefore, even in the case where the storage unit 3, 4, 5 expands or contracts due to heat, the bag-type cooling body can be attached particularly well to the side wall of the storage unit 3, 4, 5 (not shown in fig. 4).

In the embodiment shown, the heat sink 8 has folds 11 in the central region of its side faces. In a further embodiment, which is not shown here, the heat sink 8 can also have a plurality of corrugations 11.

The corrugations 11 divide the interior space of the heat sink 8 into

subspaces

13, 14 which are in fluid connection with one another. In other words, the pleats 11 do not extend over the entire height of the heat sink 8, so that coolant can enter the second subspace 14 from the first subspace 13 above the pleats 11.

The corrugations 11 are configured to guide coolant in a U-shape from a coolant inlet 15 of the cooling body 8 to a coolant outlet 16 of the cooling body 8 (see also fig. 3). In other embodiments, not shown here, a plurality of corrugations can be provided to guide the coolant in a zigzag shape from the coolant inlet 15 of the cooling body 8 to the coolant outlet 16 of the cooling body 8.

The pocket cooler 8 also has an edge fold 12 sealing the inner volume of the cooler 8. The folds 11 and the edge folds 12 are in the present case applied by folding with heating. However, in further embodiments, the pleats 11 and the edge pleats 12 may also be applied, for example, by shaping, bending, folding and/or heating.

Fig. 6 shows a cooling body 8 of the energy storage device 1 of the second embodiment.

In this embodiment, the heat sink 8 is partially surrounded by a pressure frame 29 arranged between adjacent storage units 3, 4, 5. The pressure frame 29 is designed in the present case as a plastic pressure frame 29.

If the cell module 2 is pressed in order to increase the rigidity during the production process in the present exemplary embodiment, the pressing force is not absorbed by the cooling body 8 arranged between the storage cells 3, 4, 5, but by the plastic pressure frame 29. In this respect, the cooling bodies 8 are protected against damage and their flow cross section remains open.

Fig. 7 shows a detailed view of fig. 6, in particular the lower left area of fig. 6 marked with a dashed circle, to illustrate the retention and fluidic connection of the pocket cooler 8 on the cooling plate.

In the present case, the plastic pressure frame 29 is fixed by overmolding at the edge folds 12 of the heat sink 8. For this purpose, in the embodiment shown, the pressure frame 29 is placed on a sealing lip 20, which sealing lip 20 will be described in detail later, which sealing lip 20 is itself connected to the first wall 17 of the cooling plate 7 in a form-fitting manner.

Fig. 8 shows a cooling body 8 of an energy storage device 1 according to a third embodiment.

The difference from the second embodiment is essentially that the pressure frame 29 rests loosely on the cooling body 8 or on the cooling body 8 and is held in place by pressing the adjacent storage unit 3.

Furthermore, the pressure frame 29 has the shape of the letter "M" in the present case. This shape is merely exemplary. The absorption of pressure by the pressure frame depends inter alia on the internal structure of the storage unit. By way of example only, the design of the pressure frame, in particular its shaping, may depend on where the locations of the outward transmission of pressure are arranged. In addition, the design of the pressure frame may depend on the stiffness of the plastic housing of the prismatic battery cell.

Fig. 9 is a supplementary explanation of this embodiment. The pressure frame 29 is not mechanically connected to the edge folds 12 of the heat sink 8 and is held in place only by pressing against the storage unit (not shown).

Fig. 10 shows a cooling device and a storage unit 3 of an energy storage device 1 according to a fourth embodiment, wherein a detailed enlargement of the cooling plate 7, the sealing lip 20 and the cooling body 8 is shown in the lower view of fig. 10.

In line with the embodiment already described, the cooling plate 7 comprises a first wall 17 and a second wall 18. The first wall 17 faces the battery cell module 2, while the second wall 18 faces away from the battery cell module 2. The first wall 17 has a slit structure 19 shown in the upper part of fig. 13.

The slits of the slit structure 19 each have a width (depth direction of the drawing) corresponding to the width of the cooling body. The end region of the heat sink 8 with the coolant inlet 15 and the coolant outlet 16 is held in the slot of the slot arrangement 19. For the fluid-tight sealing of the gap, the end region of the cooling body has a sealing lip 20 as shown in fig. 10. In the present case, the sealing lip 20 is an elastomeric sealing lip 20. The sealing lips 20 overlap the gap of the first wall 17 both on the side facing the battery cell module and on the side facing away from the battery cell module, so that the sealing lips and thus the cooling body are held on the first wall 17 of the cooling plate.

The coolant flows between the first wall 17 and the second wall 18 through the coolant plane 7a and enters the downwardly open coolant channels 8a of the pocket cooler 8 via the coolant inlet 15 (see fig. 3) at the end region of the pocket cooler 8.

The cooling body 8 designed with the elastic jacket 9 is loaded by the applied fluid pressure. In order to prevent the cooling body 8 from collapsing under fluid pressure in the lower region, the sealing lip 20 optionally has a projection 21. The projection 21 engages in a correspondingly shaped undercut 22 (marked by a dashed line) of the first wall 17. This form fit between the sealing lip 20 and the cooling plate 7 counteracts the horizontally applied fluid pressure. Collapse of the cooling body 8 is prevented.

The described embodiments may be applied to a pouch type storage unit 4 or a prismatic storage unit 5.

Fig. 11 shows a supplementary view of the positioning of a bag storage unit according to a fifth embodiment between two cooling bodies arranged on a cooling plate. Instead of a pouch-type storage cell, the positioning can also be carried out analogously to another storage cell, in particular a prismatic storage cell, which is installed in the context of battery-to-battery CTP battery design.

In the present embodiment, the cooling body 8 performs a double function.

First of all, the cooling body 8 provides the particularly advantageous cooling of the storage unit already described. Next, in the present embodiment, the cooling body 8 functions as a compression layer (so-called "compression/expansion pad"). The cooling bodies 8, due to their elastic jacket 9, can compensate particularly effectively for thermally induced expansion and compression movements of the bag storage units 3, 4 and in this respect replace the compression layer. This embodiment is also suitable for energy storage devices with prismatic battery cells which also have an expansion behavior which has to be compensated for in the interspace, even though the expansion behavior due to the rigidity of the housing of the prismatic storage cells may typically be lower than in the case of pouch-type storage cells.

Fig. 12 shows a schematic flow diagram of a method for producing an energy storage device 1 according to the fourth exemplary embodiment already described.

To supplement the description, these steps are shown in part in fig. 13.

The proposed method is based in particular on the idea of preventing the collapse of the cooling body 8 with the elastic sheath 9 by using the mounting tongue 30 during the manufacture of the energy storage device 1.

The first step S1 of the method comprises first optionally applying a thermally conductive paste (so-called "gap filler") to the first wall 17 of the cooling plate 7 (not shown). The thermally conductive paste can be used, for example, to close air-filled gaps between the cooling plate 7 and the storage units 3, 4, 5, which gaps typically have a poor thermal conductivity or an insulating effect. The thermally conductive paste can have a correspondingly high thermal conductivity, so that the heat of the storage units 3, 4, 5 can be conducted into the cooling plate 7.

In step S2, the heat sink 8 is attached to the mounting tongue 30. The mounting tongue 30 shown in fig. 13 can for this purpose have, for example, two fins which are inserted from below into the

subspaces

13, 14 of the heat sink 8 via the coolant inlet 15 and the coolant outlet 16. The inner volume of the heat sink 8 can be filled or spanned at least approximately completely by the mounting tongue 30. In this respect, a collapse of the flexible jacket 9 of the cooling body 8 is prevented.

The third step S3 consists in inserting the cooling body 8 attached to the mounting tongue 30 from below into the slot of the slot structure 19 of the upper wall 17 of the cooling plate 7. For better visibility, the insertion of the slit structure from above is shown in fig. 13. The heat sink 8 may already have, for example in the delivery state, a sealing lip 20 arranged at the end region of the heat sink 8, which sealing lip wedges in a form-fitting manner with the slot structure when the heat sink 8 is inserted, so that the heat sink 8 is held on the upper wall 17 of the cooling plate 7.

Preferably, the second and third step S3 can be repeated until each slot of the slot structure 19 is occupied by a cooling body 8 mounted on the mounting tongue 30. The repetition of steps S2 and S3 can be replaced by using one mounting tool with a plurality of mounting tongues, so that all cooling bodies can be inserted into the slot structure in only one working step instead of the repetition of steps S2 and S3.

In a fourth step S4, the storage units 3, 4, 5 or the battery cell modules 2 are placed from above onto the top wall 17.

In this respect, within this step, the cooling body 8 on the upper wall 17 is positioned between the storage units 3, 4, 5 optionally arranged as battery cell modules 2.

In one embodiment variant of the energy storage device in which the storage cells are provided in the form of prefabricated battery cell modules 2 made up of prismatic storage cells, the storage cells are placed on the cooling plate in such a way that the entire battery cell module 2 is placed on the cooling plate. This is illustrated in fig. 13 by the left-hand variant of step S4.

In contrast, in the case of a battery cell module formed from pouch-type battery cells, it is preferable to place the individual pouch-type battery cells onto a cooling plate so that the pouch-type battery cells are only then combined into a battery cell module. This is illustrated in fig. 13 by the right-hand variant of step S4.

In contrast, if the energy storage device is manufactured by the so-called battery-to-battery method, in which the storage cells are directly installed into the battery and thus the costs of the module assembly as an intermediate link are skipped, the placement of the storage cells onto the cooling plate is also carried out by placing individual storage cells, whether they are configured as prismatic storage cells or as pocket storage cells. This is also illustrated in fig. 13 by the right-hand variant of step S4.

In step S5, the mounting tongue 30 is pulled out downward.

Then, in step S6, the second wall 18 of the cooling plate 7 is placed onto the first wall 17 from below. The first and

second walls

17, 18 are then joined to each other in a manner known per se to produce the flow-guiding plane.

While the invention has been described with reference to a specific embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the disclosed embodiments, but that the invention will include all embodiments falling within the scope of the appended claims. The invention also claims the subject matter and features of the dependent claims, in particular independently of the cited claims.

List of reference numerals

1. Energy storage device

2. Battery cell module

3. Memory cell

4. Bag type storage unit

5. Prismatic memory cell

6. Cooling device

7. Cooling plate

7a plane of coolant

8. Cooling body

8a Coolant channel

9. Elastic sheath

10. External memory cell

11. Fold (A)

12. Edge puckering

13. A first subspace

14. Second subspace

15. Coolant inlet

16. Coolant outlet

17. A first wall

18. Second wall

19. Gap structure

20. Sealing lip

21. Raised part

22. Undercut

23. Embossing

24. Groove

25. Coolant channel of coolant supply part

26. Side branch of coolant supply part

27. Coolant channel of coolant return

28. Side branch of coolant return

29. Pressure frame

30. Mounting tongue

31. Top cover

32. Side cover

33. End plate

34. Protective plate

35. Bus bar

36. Circuit board

37. Coolant connection

38. Coolant outflow end

Claims

1. An energy storage device (1) for storing electrical energy, preferably for an at least partially electrically driven vehicle, having a plurality of storage units (3, 4, 5) arranged side by side in a stacked manner and a cooling device (6) for cooling the storage units (3, 4, 5), wherein the cooling device (6) comprises:

-a cooling plate (7) that can be flowed through by a coolant, the cooling plate (7) being arranged on a side, preferably on the bottom side, of the storage unit (3, 4, 5), and

-at least one cooling body (8) that can be flowed through by the coolant, which is arranged between two adjacent storage units (3, 4, 5) to cool the sides of the storage units (3, 4, 5), is in fluid connection with the cooling plate (7) and is configured as a cooling body (8) with an elastic jacket (9).

2. Energy storage device (1) according to claim 1,

a) The elastic sheath (9) of the cooling body (8) comprises an aluminum foil and/or a plastic coating; and/or

b) The cooling body (8) is a foil cooling body and/or a bag cooling body.

3. Energy storage device (1) according to any of the preceding claims,

a) The at least one heat sink (8) comprises a plurality of heat sinks (8), wherein one heat sink (8) is arranged between all storage units (3, 4, 5) in each case for cooling the sides of the storage units (3, 4, 5); and/or

b) On the outer side of the external storage units (10), cooling bodies (8) having an elastic jacket (9) are arranged in each case for cooling the side surfaces.

4. Energy storage device (1) according to any of the preceding claims, characterized in that the cooling body (8) has at least one corrugation (11) or embossing which is configured to divide an inner space of the cooling body (8) into subspaces (13, 14) which are in fluid connection with each other for guiding coolant from a coolant inlet (15) of the cooling body (8) to a coolant outlet (16) of the cooling body (8) in an arc, U or meander shape.

5. Energy storage device (1) according to claim 4, characterized in that the cooling body (8) has exactly one corrugation (11) or embossing arranged in a central region, which corrugation or embossing is configured to divide an inner space of the cooling body (8) into two fluidically connected subspaces (13, 14) for conducting a coolant from a coolant inlet (15) of the cooling body (8) to a coolant outlet (16) of the cooling body (8) in a meandering and/or U-shaped manner.

6. Energy storage device (1) according to any one of the preceding claims, characterized in that the cooling plate (7) has a first wall (17) facing the storage unit (3, 4, 5) with a slot structure (19) for holding at least one cooling body (8), wherein the slots of the slot structure (19) each have a width corresponding to the cooling body width and an end region of the cooling body (8) with the coolant inlet (15) and the coolant outlet (16) is held in one of the slots.

7. Energy storage device (1) according to claim 6, characterized in that an end region of the cooling body (8) has a sealing lip (20) for fluid-sealing the gap, wherein the sealing lip is preferably designed as an elastomer injection molding.

8. Energy storage device (1) according to claim 7, wherein the sealing lip (20) has a projection (21) which engages into a correspondingly shaped recess or undercut (22) of the first wall (17) to produce a form fit between the sealing lip (20) and the cooling plate (7).

9. Energy storage device (1) according to any of the preceding claims, characterized in that the cooling plate (7) comprises a half-shell shaped second wall (18) facing away from the storage unit (3, 4, 5), which second wall has an embossment (23) configured to guide coolant within the cooling plate (7) to a coolant supply and a coolant return, which embossment itself preferably has a groove (24) for holding the at least one cooling body (8).

10. Energy storage device (1) according to claim 9,

a) The coolant supply has a coolant channel (25) arranged at an edge region of the cooling plate (7), the coolant channel having a plurality of side branches (26) arranged orthogonally to the edge region, and

b) The coolant return has a coolant channel (27) arranged in an edge region opposite the coolant supply, the coolant channel having a plurality of side branches (28) arranged orthogonally to the edge region, and

c) The coolant supply side branch (26) and the coolant return side branch (28) are interwoven with one another such that the coolant supply side branch (26) is always directly adjacent the coolant return side branch (28).

11. Energy storage device (1) according to claim 10, characterized in that a side branch (26) of the coolant supply and a side branch (28) of the coolant return of the cooling plate (7) are fluidly connected to each other via the cooling body (8).

12. Energy storage device (1) according to any one of the preceding claims, characterized in that the cooling body (8) is at least partially surrounded by a pressure frame (29) arranged between adjacent storage cells (3, 4, 5), which is configured to absorb forces, preferably compressive forces, between adjacent storage cells (3, 4, 5), which pressure frame is preferably a plastic pressure frame (29).

13. Energy storage device (1) according to claim 12, characterized in that the pressure frame (29)

a) Is fixed at the edge of the cooling body (8), preferably at the outer edge embossing or edge corrugation (12) of the cooling body (8) by overmoulding; or

b) Rests loosely on the cooling body (8) and is held in place by pressing against the adjacent storage unit (3, 4, 5).

14. Energy storage device (1) according to claim 12 or 13, characterized in that the pressure frame (29) is constructed in the form of the letter "M" or "n".

15. Energy storage device (1) according to any of the preceding claims, characterized by a plurality of storage units (3, 4, 5) arranged side by side in a stacked manner

a) Assembled into a battery cell module (2) and the cooling plate is arranged on a side face of the battery cell module (2), preferably on a bottom face of the battery cell module (2); or

b) Is the storage unit of the battery-to-battery CTL energy storage.

16. Energy storage device (1) according to any of the preceding claims, characterized in that the storage cells (3, 4, 5) are configured as bag-type storage cells (4) or prismatic storage cells (5).

17. Vehicle, preferably a commercial vehicle, having an energy storage device (1) according to any one of the preceding claims.

18. The energy storage device (1) according to any one of claims 1 to 16, which is constructed as a stationary energy storage device or is part of a stationary device.

19. A method for manufacturing an energy storage device (1) according to claim 6, characterized by the steps of:

at least one cooling body (8) is fixed to the cooling plate (7) by pushing the cooling body (8) through a slot of the slot arrangement (19) until an end region of the cooling body (8) having a coolant inlet (15) and a coolant outlet (16) is positioned and/or rests on the slot.

20. Method according to claim 19, characterized in that the passing-through is performed by means of a mounting tongue (30), onto which the cooling body (8) is attached before the passing-through and which is pulled out again after the passing-through and fixing of the cooling body (8) on the cooling plate (7).

21. The method according to claim 19 or 20, further comprising the step of:

the storage units (3, 4, 5) are arranged on the cooling plate such that one of the through-going cooling bodies (8) is respectively positioned between two adjacent storage units,

a) Wherein the storage unit is provided as a prefabricated battery cell module, which is mounted on the cooling plate, or

b) Wherein the storage units are loosely placed as pouch cells onto the cooling plate and combined into a battery cell module; or

c) Wherein the memory cells are disposed onto the cooling plate during a battery-to-battery CTP process.