EP4154346A1

EP4154346A1 - Energy storage device having a battery cell module and a cooling device, preferably for an at least partially electrically driven vehicle, and method for producing the energy storage device

Info

Publication number: EP4154346A1
Application number: EP21726876.2A
Authority: EP
Inventors: Simon Bucher; Michael Klauke
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: 2023-03-29
Also published as: DE102020121498A1; CN115606038A; WO2021233778A1

Abstract

The invention relates to an energy storage device for storing electrical energy, preferably for an at least partially electrically driven vehicle. The invention further relates to a method for producing an energy storage device and to a vehicle, preferably a utility vehicle, or to a stationary device having such an energy storage device. The energy storage device (1) has a plurality of storage cells (3, 4, 5) arranged next to one another in a stack-like manner and a cooling device (6) for cooling the storage cells (3, 4, 5). The cooling device (6) has a cooling plate (7) through which a coolant can flow and which is arranged laterally, preferably on the bottom side, with respect to the storage cells (3, 4, 5). The invention is distinguished in that the cooling device further has at least one heat sink (8) through which the coolant can flow and which is arranged between two adjacent storage cells (3, 4, 5) for cooling side surfaces of the storage cells (3, 4, 5), is fluidically connected to the cooling plate (7) and is designed as a heat sink (8) with an elastic shell (9).

Description

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

description

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 a vehicle, preferably a utility vehicle, or a stationary device with such an energy storage device.

Vehicle batteries known from practice, such as those used, for. B. be used as an energy store or as a traction battery in hybrid vehicles or electric vehicles, typically have a battery pack in which several stacked battery storage cells are arranged. The battery storage cells can be combined into modules or built directly into a battery pack as part of what is known as cell-to-pack, CTP technology. In order to ensure proper operation and to avoid damage to such a vehicle battery and to achieve the longest possible service life, it must be operated in a defined temperature range. Here it is known from the prior art, for example, to arrange a cooling plate below the battery cells, optionally with a thermal paste applied to it, through which a cooling fluid flows in order to cool the battery cells. In these known solutions, the substantially smaller surface area of the storage cells facing the cooling plate is typically cooled, while the substantially larger surface area of the storage cells remains uncooled. The disadvantageous result is a highly inhomogeneous temperature distribution within the memory cells and z. B. within the battery cell modules.

It is also known from the prior art that the dissipation of heat generated in the battery cells can be improved by means of cooling fins. For example, the laid-open specification DE 10 2012 218 764 A1 suggests thermally coupling a cooling fin to the side of a battery storage cell via a flat base body, the base body having a cooling channel. The performance of this solution is disadvantageously limited by the heat transfer or the heat transfer coefficient of the contact surface between the cooling fin and the base body. Furthermore, the Cooling fins merely passively cool the storage cells, which disadvantageously results in a time delay when heat is introduced and dissipated, an inhomogeneous temperature distribution and a low cooling capacity.

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

These objects are achieved by devices and methods 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 partial reference to the figures.

A basic idea of the invention is to provide additional heat sinks in the space between the side by side arranged battery cells that are actively cooled and for this purpose with the cooling plate, which is laterally, for. B. is arranged on the bottom side with respect to the battery cells, are fluidically connected. This offers the advantage of particularly effective cooling, which results in the most homogeneous temperature distribution possible within the battery cell. Furthermore, these heat sinks are designed with an elastic cover, i.e. the heat sinks can be designed as so-called foil heat sinks or pouch heat sinks. This has the additional advantage that the heat sinks adapt particularly well to changing surface forms of the battery cells, e.g. B. due to so-called. Swelling effects, adjust. In addition, the elastic heat sinks can compensate for assembly and component tolerances, among other things.

Accordingly, according to a first general aspect of the invention, an energy storage device for storing electrical energy is provided. It is preferably an energy storage device for an at least partially electrically powered vehicle. In other words, the energy storage device can be designed in a manner known per se to store electrical energy that is used in corresponding drive components of the vehicle, eg. B. in an electric machine, can be converted into drive energy. In other words, the energy storage device can be designed to temporarily absorb traction energy. The energy storage device has a plurality of storage cells arranged next to one another in a stack-like manner. The storage cells can also be combined to form a module (battery cell module) and preferably pre-grouped. In addition to the storage cell assembly, the battery cell module can optionally also include other components that are necessary and known per se for storing electrical energy, such as circuit boards, circuits, relays, lines, base or end plate plates, bus bars, terminals, deck - or side covers, plastic sheets and / or circuit boards etc.

Alternatively, the storage cells can also be built directly into a battery pack using what is known as cell-to-pack technology. The cells are not pre-grouped using a battery module and the storage cells are installed directly in the battery pack. Cell-to-pack technologies have recently been used more and more to increase the mass energy density, to improve the efficiency of the volume utilization and to reduce the number of parts for battery packs - compared to conventional battery packs made from pre-grouped Cell modules assembled battery packs.

The memory cells can be connected to one another in parallel and / or in series and have individual memory cells combined to form a cell network. The memory cells can, for. B. be designed as a lithium-ion battery. The cells can preferably be spaced apart from one another with a gap of 0.5 to 1.5 mm.

Furthermore, the energy storage device has a cooling device for cooling the storage cells. The term cooling is preferably, but not exclusively, to be understood as meaning the heat from the storage cells. It is namely also conceivable that the invention - in particular at low temperatures or when starting the vehicle cold - is used to warm or preheat the storage cells, for example to bring the storage cells to operating temperature or to keep them. The cooling device can thus generally serve as a temperature control device for the storage cells.

The cooling device also has a cooling plate through which a coolant can flow. The cooling plate can, for. B. have corresponding fluid guide channels in their inner volume. The cooling plate is arranged laterally, preferably on the bottom, with respect to the memory cells. If storage cells are arranged to form a battery cell module, the cooling plate can be arranged on a side surface of the battery cell module. The side surface can be the bottom surface (lower side surface) of the battery cell module. In other words, the cooling plate is designed to, for. B. by the memory cells absorb radiated heat and dissipate the heat via the coolant flowing through the cooling plate or give off heat to the storage cell.

According to the invention, the cooling device also has at least one heat sink, which is arranged between tween two adjacent storage cells for side surface cooling of the storage cells, is fluidically connected to the cooling plate and is designed as a heat sink with an elastic cover's rule. Each of the at least one heat sink can thus also be flowed through with the coolant and can for this purpose, for. B. also have corre sponding fluid ducts in its inner volume. The heat sink is arranged between two adjacent storage cells for side surface cooling of the storage cells. The heat sinks preferably lie flat against the facing side surfaces of adjacent storage cells, so that heat can be exchanged between the storage cells and the heat sink. For this purpose, the heat sink can be designed, for example, to absorb the heat given off by the storage cells and to dissipate it via the coolant flowing through the cooling plate. Coolant can pass from the cooling plate into the cooling body and from this back into the cooling plate. For this purpose, the heat sink can have, for example, one or more coolant inlets and one or more coolant outlets, via which coolant can flow from the cooling plate into the heat sink and from this back into the cooling plate.

It was stated above that the heat sink is designed as a heat sink with an elastic cover. The term "elastic", as it is understood in the sense of the present invention, indicates that the material of the shell is deformable (pliable) and / or flexible. The shell can accordingly be made of elastic material in order to be able to adapt as best as possible to the temperature-dependent variable volume and geometry of the storage cell.

The proposed energy storage device has several advantages over the known solutions. The proposed fluidic connection between the at least one cooling body and the cooling plate enables a particularly high cooling capacity to be achieved in the space between storage cells. Furthermore, the heat sinks with elastic sheaths enable an adaptive, flat, shape-corresponding contact of the heat sinks on the side surfaces of the storage cells, which enables particularly good heat transfer between the storage cells and the heat sinks, which is achieved through the elastic sheath even when the storage cells expand or contract can be sustained. Furthermore, thanks to their elastic sheath, the heat sinks can optionally perform the function of compression layers (so-called “compression” or “compression layers”) that are arranged between the storage cells in practice “swelling” pads), which in practice are arranged between the storage cells in order to compensate for thermal expansion and contraction of the storage cells and to guarantee constant surface pressure between the storage cells. In addition, the heat sinks can take on the function of thermal insulation pads and at least partially replace them. This can advantageously be omitted. This has advantages in terms of cost, weight and packaging. Furthermore, it is advantageous that an expansion of the storage cells does not lead to a progressive increase in the surface pressure or this is at least reduced. Within the energy storage device, a pressure that is as constant as possible is effected by the coolant pressure. Furthermore, the cooling of the storage cell spaces results in a high heat capacity and a delay time for thermal aging and damage effects.

According to a particularly advantageous embodiment, the elastic shell of the cooling body can include an aluminum foil with or without a plastic coating or plastic film. It is conceivable that z. B. is a commercially available aluminum foil with a plastic coating, as is common, for example, in the packaging industry. Advantageously, there is a particularly good heat transfer between the heat sink and the storage cell and, at the same time, a particularly hard-wearing and resistant cover for the heat sink.

As an alternative or in addition, the heat sink of the energy storage device can be a foil heat sink and / or pouch heat sink. The term pouch heat sink is used in analogy to the pouch battery cell, also pouch bag cell or coffee bag cell, which is widespread in battery technology, and is intended to include any type of flexible outer covering of the heat sink. The wall thickness of the shell can be in a range between 0.05 mm to 0.2 mm, particularly preferably around 0.1 mm, by way of example. It is advantageous that the heat sink can compensate for thermally induced expansion or compression movements of the storage cell particularly well, so that a particularly good heat transfer or heat dissipation conditions between the storage cell and the heat sink is always guaranteed. The gap between two storage cells can only be in the range of approx. 1 mm by way of example.

It has already been stated above that the energy storage device comprises at least one, that is to say one or more, heat sinks. 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 in this respect comprise a plurality of heat sinks, with between all storage cells a heat sink for side surface cooling of the storage cells is arranged in each case. In other words, heat sinks and storage cells can follow one another in an alternating sequence within the energy storage device. It is conceivable that this is a regularly alternating sequence of heat sinks and storage cells. This guarantees a homogeneous heat dissipation or temperature distribution within the energy storage device and further increases the efficiency of the cooling of the energy storage device. In an alternative variant, it is also possible that the sequence of heat sinks and storage cells is irregular. In other words, it is alternatively conceivable, for example, that a cooling body is provided in each case only in every second, third, or fourth, etc. intermediate space between adjacent storage cells.

Furthermore, a cooling body with an elastic cover can be arranged on the outside of the outer storage cells for side surface cooling. This means that such a heat sink can optionally also be arranged on the end sides of the battery cell module and thus form the first and the last element of the alternating sequence of heat sinks and storage cells in the energy storage device. This advantageously reduces the heat radiation of the energy storage device with respect to neighboring components.

In a further embodiment, the cooling body can have at least one fold or embossing which is designed to subdivide an interior space of the cooling body into subspaces that are fluidically interconnected. In the first subspace there is a coolant inlet for coolant from the cooling plate and in the last subspace there is the coolant outlet of the heat sink, from which the coolant is directed back to the cooling plate.

It is conceivable that the heat sink has a fold or embossing or several folds or embossing conditions. The fold or the embossing can be applied, for example, by reshaping, kinking, folding and / or heating. The embossing preferably has a thickness of approximately 0.1 to 0.2 mm. The at least one fold or the embossing can be designed to guide coolant in an arc-shaped, U-shaped or meandering shape from a coolant inlet of the heat sink to a coolant outlet of the heat sink. A directed flow is advantageously produced in the heat sink, which further increases the overall cooling effect.

According to a further variant of this embodiment, the heat sink can have exactly one fold or embossing, for example arranged in a central area, which is formed to divide an interior of the heat sink into two fluidically interconnected sub-spaces in order to guide coolant in an arcuate and / or U-shaped manner from the Kühlmittelein passage of the heat sink to the coolant outlet of the heat sink.

According to a further aspect, the cooling plate can have a first wall facing the storage cells, which has a slot structure for holding the at least one cooling body. This first wall can be designed as a separate component in the form of a plate with a slot structure. The slots of the slot structure can each have a width that corresponds to the width of the heat sink. An end region of the cooling body having a coolant inlet and a coolant outlet can furthermore be held in one of the slots. In other words, the heat sinks can be perpendicular to the cooling plate z. B. be placed like a sail one behind the other on the slots of the cooling plate. The slots can serve in an advantageous manner on the one hand to hold the heat sink and on the other hand the fluidic connection between the heat sink and the cooling plate.

According to a development of the last-mentioned aspect, the end region of the cooling body can have a sealing lip for fluidically sealing the slot and thus the fluidic connection point between the cooling plate and the cooling body (s). Preferably, the sealing lip as an elastomer sealing lip, for. B. be designed as an elastomer injection. It is conceivable that the sealing lip is already attached to the heat sink in the delivery state of the heat sink. Alternatively, it is conceivable that the sealing lip is only applied by overmolding the heat sink during assembly. For fluidic sealing of the slot, the sealing lip can for example have an approximately double-T-shaped cross section which is pressed into the slot and overlaps the slot in all spatial directions. A simple and effective fluidic sealing of the slots or the fluidic connection between the cooling body and the cooling plate is advantageous.

According to a development of the aspect of the sealing lip, this sealing lip can have a nose which engages in a shape-corresponding notch or undercut of the first wall to produce a form fit between the sealing lip and the cooling plate. This advantageously increases the stability of the connection between the heat sink and the cooling plate, which reduces the risk that a holder of the heat sink is pressed out of the respective slot and leaks under a fluid pressure of the coolant in the cooling plate. According to a further aspect, the cooling plate can have a second, z. B. half-shell, include wall. This second wall can have embossments which are designed to guide coolant inside the cooling plate into a coolant flow and a coolant return. In other words, through the embossing z. B. channels or tracks for the coolant to conduct the coolant are delimited. The embossings can preferably also have depressions for holding the at least one cooling body. The troughs can, for example, be designed to correspond to the position and dimensions of the fold of the heat sink. The embossing can thus develop a double function: fluid guidance and holding of the heat sink. A particularly simple and cost-saving possibility of guiding the fluid within the cooling plate and of holding the cooling body on the cooling plate advantageously results. The cooling plate can thus be composed of a first plate with a slot structure (first wall) and a second plate with an embossed structure (second wall).

According to a further embodiment, the cooling plate can be designed in such a way that the coolant flow within the cooling plate has a coolant channel arranged on an edge region of the cooling plate with a plurality of orthogonally arranged side branches and the coolant return has a coolant channel arranged on an edge region opposite to the coolant flow with a A plurality of orthogonally arranged sides has branches. In addition, the side branches of the coolant flow and the side branches of the coolant return can be interlaced in such a way that a side branch of the coolant flow is always arranged immediately adjacent to a side branch of the coolant return. In other words, an alternating sequence of side branches of the coolant flow and coolant return can result within the cooling plate. For example, the coolant flow and coolant return can be designed in the form of two letters “n” pushed one inside the other, more preferably two letters “E” pushed one inside the other. This further increases the performance of the cooling device via improved heat transfer.

According to a further development of the last-mentioned aspect, the side branches of the coolant flow and the side branches of the coolant return of the cooling plate can be fluidly connected to one another via the heat sink. In this way, a particularly long cooling section is implemented within the battery cell module.

In a further embodiment, the heat sink can be at least partially surrounded by a frame which is arranged between adjacent storage cells and is used for receiving is formed by forces between adjacent storage cells, preferably to take on pressing forces between adjacent storage cells. Such a printing frame is therefore hereinafter referred to as a printing frame. Preferably the print frame is a plastic print frame. It is possible that the print frame z. B. is adapted in its structure and shape to the design of the memory cell module and its connection in the battery pack. It is advantageous that the forces of pressing the battery cell modules are diverted via the pressure frames and not the heat sinks, which increases the service life of the energy storage device. Due to the compressive strength of the printing frame, tensioning of the storage cells is also possible, particularly in the case of prismatic storage cells.

According to a further aspect, the pressure frame can be fastened to an edge of the heat sink. The printing frame can preferably be attached to an outer edge embossing or edge fold of the cooling body by means of an extrusion coating. This case of injection molding from the heat sink to the pressure frame is preferably only used when the pressure frame is assembled together with the heat sinks, and not when the battery cells are pressed in the module production. Here, a separate component can be attached to the heat sink as a pressure frame through the extrusion coating, or the extrusion coating itself can form the printing frame.

As an alternative to attaching the pressure frame to the edge of the heat sink, the pressure frame can rest loosely against the heat sink and be held in position by pressing the adjacent memory cells. In other words, the pressure frame can, for example, have no mechanical connection to the cooling body and can stand freely downwards, i.e. in the direction of the cooling plate. It is conceivable that the printing frame is inserted during the assembly of the battery cells or that it is part of the grouping of the storage cells, e.g. B. part of the battery cell module is. This represents a particularly simple and inexpensive arrangement of the printing frame. Furthermore, the previously common assembly process of known battery cell modules or known cell-to-pack battery packs can also be used for the battery cell module or cell-to-pack proposed here due to the printing frame -Battery packs are accepted.

The pressure frame is preferably adapted to the outer contour of the heat sink. According to a further aspect, the print frame can be in the form of the letters “M”, that is to say M-shaped, or ok

"N" be trained. These shapes are only to be understood as examples. The printing frame can also have other shapes and its shape depends on the shape of the battery or can be adapted to it.

The memory cells can be so-called pouch memory cells or prismatic memory cells. If the storage cells are combined to form a battery cell module, for example, the battery cell module can have prismatic storage cells or pouch storage cells. If, as an alternative, the storage cells are built directly into a battery pack using what is known as cell-to-pack technology, the storage cells can also be designed here as prismatic storage cells or as pouch storage cells.

The term prismatic memory cells as used in the context of this document is intended to include, in particular, those memory cells that have a solid prism-shaped or cuboid housing, eg. B. made of a dimensionally stable plastic. In contrast, the term pouch memory cells as used in the context of this document is intended to include, in particular, memory cells that are enclosed by a flexible outer film. In addition, reference is made to the differences in the internal structure of the prismatic and pouch storage cells, which are well known in battery technology. With regard to prismatic storage cells and pouch storage cells, the additional active side cooling according to the invention results in improved heat dissipation and, in particular, the advantages of a more homogeneous storage cell temperature distribution, a more constant storage cell temperature level, a longer storage cell life and a more targeted temperature Conditioning of the storage cell (including during the charging process).

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 powered. The vehicle is preferably a motor vehicle, for example a passenger car or a utility vehicle. In the latter case, the vehicle can, in other words, be a motor vehicle which, by virtue of its design and device, is designed for the transport of people, for the transport of goods or for pulling trailers. For example, the vehicle can be a truck, a bus and / or an articulated truck that is at least partially electrically powered. However, it is also conceivable that the vehicle is a rail vehicle or an airplane. Furthermore, it is also conceivable that the invention is designed as a stationary energy storage device or battery storage device or that the energy storage device is part of a stationary, that is, non-mobile, device. An example of this would be a permanently installed energy storage device, for example in combination with a solar or wind power plant.

According to a second general aspect of the invention, a method for manufacturing the energy storage device is also provided. To produce an energy storage device according to the embodiment described above, in which the cooling plate has a first wall facing the battery cell module with a slot structure for holding the heat sinks, the method is characterized by the following step for arranging the heat sinks on the cooling plate:

The at least one heat sink is attached to the cooling plate by pushing the heat sink through a slot in the slot structure until the end region of the heat sink that has the coolant inlet and coolant outlet is positioned and / or rests against the slot.

In this case, one heat sink can be pushed through a slot by means of a mounting sword, onto which the heat sink is slipped before being pushed through and which is pulled out again after the heat sink has been pushed through and fastened to the cooling plate. This has the advantage that the cooling body with the elastic cover is prevented from collapsing during the manufacture of the energy storage device and simple assembly is made possible.

When the storage cells are grouped as a battery cell module with prismatic storage cells, the battery cell module is then placed on the at least one inserted heat sink. It is also conceivable to first put on the battery cell module and then to position the heat sinks from below by pushing them through the slot structure in the spaces between the storage cells.

If pouch cells are used, they are placed separately on the cooling plate and then combined to form a cell module.

In the variant as a cell-to-pack battery module, the storage cells are placed separately on the cooling plate as part of the cell-to-pack, CTP, process, for example placed individually. The proposed method can also optionally include the application of a heat-conducting paste (so-called “gap filler”) to the cooling plate.

The proposed method and its developments can be used both on prismatic storage cells and on pouch storage cells.

The preferred embodiments and features of the invention described above can be combined with one another as desired. To avoid repetition, features disclosed purely according to the device should also apply as disclosed according to the method and be claimable. The aforementioned aspects and features according to the invention, in particular with regard to the design of the cooling body and cooling plate and their arrangement with respect to one another, thus also apply to the method.

Details and advantages of the invention are described below with reference to the accompanying drawing. Show it:

Figure 1 shows a cooling device of the energy storage device according to an embodiment of the invention;

Figure 2 shows an energy storage device according to an embodiment in the exploded view;

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

FIG. 4 shows a heat sink of the cooling device in a side view according to one embodiment of the invention;

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

FIG. 6 shows a heat sink of the cooling device with a pressure frame according to a further embodiment of the invention;

FIG. 7 shows a detailed view of FIG. 6 to illustrate the holder or fluidic connection of a cooling body on or with the cooling plate;

FIG. 8 shows a heat sink of the 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 holder or fluidic connection of a cooling body on or with the cooling plate;

FIG. 10 shows an energy storage device with an enlarged detail to illustrate the mounting and fluidic connection of a cooling body to the cooling plate according to a further embodiment;

FIG. 11 shows a supplementary view of the positioning of a pouch storage cell between two heat sinks arranged on a cooling plate according to a further embodiment;

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

FIG. 13 additional schematic representations of the method steps from FIG. 12.

Identical or functionally equivalent elements are denoted by the same reference characters in all figures and some are not described separately.

Figures 1, 2, 3, 4 and 5 show a first, Figures 6 and 7 a second, Figures 8 and 9 a third, Figure 10 a fourth and Figure 11 a fifth embodiment of the proposed energy storage device 1, the Some of the figures only serve to better illustrate the characteristic partial aspect of the respective embodiment. In this respect, components that are not essential for these characteristic partial aspects have been omitted for better visibility of this characteristic aspect.

In the following, reference is first made to FIGS. 1, 2, 3, 4 and 5. 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 can be designed to take up electrical energy, preferably traction energy, temporarily. The energy storage device 1 has, in a manner known per se, a plurality of storage cells 3 arranged next to one another in a stack-like manner. B. be designed as a lithium-ion battery. The memory cells 3 are combined to form a battery cell module 2 and are connected to one another in parallel and / or in series. In FIG. 1, the memory cells 3 are shown as prismatic cells 5. Alternatively, the storage cells 3 can also be designed as pouch storage cells 4 (cf. FIG. 11). Above it has already been established that as an alternative to using battery cell modules, so-called cell-to-pack processes can also be used, in which the storage cells are built directly into a battery pack and thus the costs for the module components are skipped as an intermediate step can.

In addition to the storage cell assembly, the battery cell module 2 also includes other components that are known per se and required for storing electrical energy, such as base or end plate plates 33, circuit boards or busbars 35 and circuit boards 36, top or side covers 31, 32, protective plates 34 etc. fall, some of which are shown by way of example in FIG.

Heat loss occurs in the storage cells 3 during operation. At a low ambient temperature, heat can also be absorbed, that is to say the energy storage device can be heated. In order to ensure proper operation and to avoid damage to the memory cells 3 and to achieve the longest possible service life, they must be operated in a defined temperature range.

For this purpose, the energy storage device 1 has a cooling device 6 for temperature control, in particular for cooling, of the storage cells 3, which is shown in FIG. The cooling device 6 has a coolant through which a coolant can flow and is arranged on a side surface, here on a bottom surface, of the battery cell module 2 and is designed for bottom cooling of the battery cell module 2. For this purpose, the cooling plate 7 z. B. have a coolant connection 37 through which the coolant can flow into the cooling plate 7 and have a coolant outflow 38 through which the coolant can flow out of the cooling plate 7. The cooling plate 7 can be fluidically connected to a cooling circuit of the motor vehicle, the other components of which are not shown here.

Furthermore, in the exemplary embodiment shown in FIG. 1, the cooling device has a plurality of cooling bodies per 8 (42 pieces here, merely by way of example). The heat sinks 8 have an elastic outer shell. Such heat sinks 8 can therefore also be referred to as foil heat sinks or pouch heat sinks. The term pouch heat sink will therefore also be used in the following. The elastic sheath can, for. B. have an aluminum foil and a plastic coating. The pouch heat sinks 8 are arranged in a row next to and behind one another on the cooling plate, corresponding to the arrangement of the storage cells, so that a pouch heat sink 8 is arranged in the space between two adjacent storage cells. For the sake of clarity, not all cooling bodies 8 are provided with reference symbols in FIGS. 1, 2, 10 and 11 without exception.

In Fig. 2, the positioning of the heat sink 8 between the storage cells 3, 5 of the energy storage device 1 of this first embodiment is clear. Part of the energy storage device 1 is shown in the (partial) exploded view.

In this embodiment, a heat sink 8 is arranged between all adjacent storage cells 3 for side surface cooling of the storage cells 3. In the exemplary embodiment shown, storage cells 3 and heat sinks 8 follow one another in an alternating sequence in the energy storage device 1. As an alternative or in addition, it is conceivable that in each case a pouch heat sink 8 is arranged on the outer surfaces of the outer storage cells 10 for side surface cooling (not shown here).

The heat sinks 8 rest on the side surfaces of the storage cells 3, 5. As a result of the relatively large contact surface, in particular in comparison to the exclusive floor cooling, a comparatively large amount of heat from the storage cells 3, 5 is transferred to the heat sinks 8. To this extent, a relatively large amount of heat is withdrawn from the storage cells 3, 5.

The heat sinks 8 are fluidly connected to the cooling plate 7 and are medium with the coolant through ström bar. The heat absorbed by the heat sink 8 is transferred to the coolant and is transported away.

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

In Fig. 3 it can be seen that the second wall 18 has embossments 23 which are designed to conduct coolant within the cooling plate 7 into a coolant flow and a coolant return. The embossments 23 of the second wall 18 for their part preferably have troughs 24 for holding the heat sink 8.

3 illustrates the coolant routing within the cooling device 6. The coolant flow has a coolant channel 25, which is arranged on an edge region of the cooling plate 7, and has a A plurality of side branches 26 arranged orthogonally thereto. The coolant return has a coolant channel 27, which is arranged on an edge region opposite to the coolant flow, and has a plurality of side branches 28 arranged orthogonally thereto. The side branches 26 of the coolant flow and the side branches 28 of the coolant return are interlocked in such a way that a side branch 26 of the coolant flow is always arranged immediately adjacent to a side branch 28 of the coolant return. In other words, in this embodiment there is an alternating sequence of side branches 26 of the coolant flow and side branches 28 of the coolant return. In other words, the coolant flow and the coolant return in the plan view have the shape of two letters “E” pushed one inside the other, this coolant flow being merely an example.

The side branches 26 of the coolant flow and the side branches 28 of the coolant return of the cooling plate 7 are fluidically connected to one another via the cooling body 8. For this purpose, a coolant inlet 15 of the heat sink 8 is fluidically connected to a side branch 26 of the coolant supply, while a coolant outlet 16 of the heat sink 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 via the coolant connection 37 and flows into the coolant flow and the orthogonally arranged side branches 26. The coolant then enters the heat sink 8 via the coolant inlet of the heat sink 15, absorbs the heat from the storage cells 8 and flows heated via the coolant outlet 16 of the heat sink 8 into the coolant return of the cooling plate 7. The coolant return feeds the heated coolant via the coolant outlet 38 to a cooling circuit (not shown) of the motor vehicle. In this respect, the storage cells 3 are actively tempered or cooled in the cooling mode.

FIG. 4 shows an individual heat sink 8 of the energy storage device according to the first embodiment from FIG. 1 in a side view. FIG. 5 serves as a supplementary view in a perspective illustration of the cooling body 8.

As mentioned above, the pouch heat sink 8 is formed with an elastic sleeve 9. In the exemplary embodiment shown, the wall thickness of the elastic sleeve is approximately 0.1 mm. For this reason, the pouch heat sink can attach itself particularly well to the side wall of a storage cell 3, 4, 5 (not shown in FIG. 4) - even in the event that the storage cell 3, 4, 5 expands due to thermal conditions or contracts. In the embodiment shown, the heat sink 8 has a fold 11 in the central region of its surface. In further embodiments not shown here, the cooling body 8 can also have a plurality of folds 11.

The fold 11 divides the interior of the cooling body 8 into fluidically interconnected partial spaces 13, 14. In other words, the fold 11 does not extend over the entire height of the cooling body 8, so that coolant above the fold 11 from the first partial space 13 into the second partial space 14 can kick.

The fold 11 is designed to guide coolant in a U-shape from the coolant inlet 15 of the heat sink 8 to the coolant outlet 16 of the heat sink 8 (see also FIG. 3). In other embodiments, not shown here, several folds can be provided in order to guide coolant in a meandering shape from the coolant inlet 15 of the heat sink 8 to the coolant outlet 16 of the heat sink 8.

The pouch cooling body 8 also has an edge fold 12 which seals the inner volume of the cooling body 8. Fold 11 and edge fold 12 have been applied in the present case by folding with heating. In further embodiments, however, the fold 11 and the edge fold 12 can also be applied, for example, by deformation, kinking, folding and / or heating.

Fig. 6 shows a heat sink 8 of the energy storage device 1 according to a second embodiment.

In this embodiment, the heat sink 8 is partially surrounded by a pressure frame 29 arranged between adjacent storage cells 3, 4, 5. The print frame 29 is designed as a plastic print frame 29 in front of it.

If the battery cell module 2 is pressed in this embodiment to increase the rigidity during manufacture, the pressing forces are not absorbed by the heat sinks 8 arranged between the storage cells 3, 4, 5, but rather by the plastic pressure frame 29. The heat sinks 8 are protected from damage and their flow cross-section is kept open.

7 shows a detailed view of FIG. 6, in particular of the lower left area of FIG. 6 marked with a dashed circle, to illustrate the mounting of the pouch heat sink 8 on the cooling plate and the fluidic connection. In the present case, the plastic pressure frame 29 is attached to the edge fold 12 of the cooling body 8 by an extrusion coating. For this purpose, the pressure frame 29 sits in the embodiment shown on a sealing lip 20, which will be described in detail later and which in turn is positively connected to the first wall 17 of the cooling plate 7.

Fig. 8 shows a heat sink 8 of the energy storage device 1 according to a third embodiment.

The difference to the second embodiment is essentially to be seen in the fact that the pressure frame 29 rests loosely on or on the heat sink 8 and is held in position by pressing the adjacent storage cells 3.

Furthermore, the print frame 29 in the present case has the shape of the letter “M”. This form is only an example. The way in which the pressure is absorbed by the printing frame can depend on the internal structure of the storage cells, among other things. The design of the print frame, in particular its shape, can depend on where the points of the print transfer to the outside are arranged merely as an example. Furthermore, the design of the pressure frame can depend on the rigidity of the plastic housing of the prismatic battery cell.

9 serves to additionally clarify the embodiment. The pressure frame 29 has no mechanical connection to the edge fold 12 of the cooling body 8 and is only held in position by pressing the storage cells (not shown).

FIG. 10 shows a cooling device and storage cells 3 of the energy storage device 1 according to a fourth embodiment with an enlarged detail of the cooling plate 7, the sealing lip 20 and a cooling body 8 shown in the lower illustration of FIG. 10.

In accordance with an 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 the slot structure 19 shown at the top in FIG. 13.

The slots of the slot structure 19 each have a width corresponding to the width of the heat sink (in the depth direction of the plane of the drawing). The end region of the heat sink 8 having the coolant inlet 15 and coolant outlet 16 is inserted into the slots of the slot Structure 19 supported. For the fluidic sealing of the slot, the end region of the cooling body has the sealing lip 20 shown in FIG. 10. In the present case, the sealing lip 20 is an elastomer sealing lip 20. The sealing lip 20 overlaps the slots in the first wall 17 both on the side facing and facing away from the battery cell module, so that the sealing lip and thus the heat sink are held on the first wall 17 of the cooling plate .

Between first wall 17 and second wall 18, coolant flows over coolant level 7a and enters coolant channel 8a of pouch heat sink 8, which is open at the bottom, via coolant inlet 15 (see FIG. 3) at the end region of pouch heat sink 8.

The cooling body 8 implemented with the elastic sheath 9 is exposed to loads as a result of the fluid pressure present. In order to prevent the cooling body 8 from collapsing in the lower region under the fluid pressure, the sealing lip 20 optionally has a nose 21. The nose 21 engages in a shape-corresponding undercut 22 (indicated by dashed lines) of the first wall 17. This form fit between sealing lip 20 and cooling plate 7 counteracts the horizontal fluid pressure. The heat sink 8 is prevented from collapsing.

The described embodiments can be used both for pouch memory cells 4 or as prismatic memory cells 5.

11 shows a supplementary view of the positioning of a pouch storage cell between two heat sinks arranged on a cooling plate according to a fifth embodiment. Instead of a pouch storage cell, this positioning can also take place in an analogous manner with another storage cell, in particular a prismatic storage cell, which is built in as part of a cell-to-pack, CTP, battery design.

In this embodiment, the heat sinks 8 have a double function.

First, they provide the particularly advantageous cooling of the memory cells already described. Second, in this embodiment they take on the function of compression layers (so-called “compression / swelling pads”). Due to their elastic shell 9, the heat sinks 8 can compensate for thermally induced expansion and compression movements of the pouch storage cell 3, 4 particularly effectively and, if so, replace the compression layers. This embodiment is also applicable to energy storage devices with prismatic cells, which also have a threshold behavior that in the interim space must be compensated, even if the swelling behavior Due to the rigidity of the housing of prismatic storage cells, the swelling behavior can typically be lower than with pouch storage cells.

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

For additional clarification, some of the steps are shown in FIG. 13.

The proposed method is inter alia. the underlying idea is to prevent the cooling body 8 with the elastic sheath 9 from collapsing during the manufacture of the energy storage device 1 by using an assembly sword 30.

The first step S1 of the method initially comprises the optional application of a heat-conducting paste (so-called “gap filler”) to the first wall 17 of the cooling plate 7 (not shown). The thermal paste can, for. B. serve to air-filled gaps, which typically have poor thermal conductivity or an insulating effect, between the cooling plate

7 and memory cells 3, 4, 5 to close. The thermal paste can have a correspondingly high thermal conductivity, so that the heat of the storage cells 3, 4, 5 can be conducted into the cooling plate 7.

In step S2, the heat sinks 8 are slipped onto a mounting sword 30. The mounting sword 30 shown in Fig. 13 can be z. B. have two fins, which from below via the coolant inlet 15 and the coolant outlet 16 into the subspaces 13, 14 of the heat sink

8 can be inserted. The inner volume of the heat sink 8 can be filled or spanned at least approximately completely by the assembly sword 30. Coincidence of the flexible sheath 9 of the heat sink 8 is prevented in this respect.

The third step S3 comprises inserting the cooling body 8 slipped onto the mounting sword 30 from below into the slots of the slot structure 19 of the upper wall 17 of the cooling plate 7. For better visibility, FIG. 13 shows an insertion from above into the slot structure. The heat sinks 8 can, for. B. already have a sealing lip 20 arranged at one end region of the heat sinks 8 in the delivery state, which wedges positively with the slot structure when the heat sinks 8 are inserted, so that the heat sinks 8 are held on the upper wall 17 of the cooling plate 7. The second and third step S3 can preferably be repeated until each slot of the slot structure 19 is occupied by a heat sink 8 slipped onto an assembly sword 30. The repetition of steps S2 and S3 can be replaced by the use of an assembly tool which has several assembly swords, so that instead of repetition of steps S2 and S3, all heat sinks can be introduced into the slot structure in just one work step.

In the fourth step S4, either storage cells 3, 4, 5 or a battery cell module 2 are placed onto the upper wall 17 from above.

Within this step, the cooling bodies 8 sitting on the upper wall 17 are positioned between the storage cells 3, 4, 5, optionally arranged as a battery cell module 2.

This placement of the storage cells on the cooling plate takes place in a variant of the energy storage device in which the storage cells are provided in the form of prefabricated battery cell modules 2 made of prismatic storage cells, 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 variant of step S4.

In the case of a battery cell module that is formed from pouch cells, on the other hand, separate pouch cells are preferably placed on the cooling plate, so that the pouch cells are only then combined to form a cell module. This is illustrated in FIG. 13 by the right-hand variant of step S4.

If, on the other hand, the energy storage device is manufactured using a so-called cell-to-pack process, the storage cells being installed directly in a battery pack and thus the costs for the module components being skipped as an intermediate step, then the storage cells are placed on the Cooling plate by placing separate memory cells, regardless of whether they are designed as prismatic memory cells or pouch memory cells. This is also illustrated in FIG. 13 by the right-hand variant of step S4.

In step S5, the mounting sword 30 is pulled out downwards. Then, in step S6, the second wall 18 of the cooling plate 7 is placed onto the first wall 17 from below. In a manner known per se, the first and second walls 17, 18 are then joined to one another to produce the flow guide plane.

Although the invention has been described with reference to particular exemplary embodiments, it will be apparent to those skilled in the art that various changes can be made and equivalents used as replacements without departing from the scope of the invention. Accordingly, it is intended that the invention not be limited to the disclosed exemplary embodiments, but that it encompass all exemplary embodiments that fall within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and the features of the subclaims independently of the claims referred to.

List of reference symbols

1 energy storage device

2 battery cell module

3 memory cell

4 pouch storage cells

5 prismatic storage cell

6 cooling device

7 cooling plate

7a coolant level

8 heat sinks

8a coolant duct

9 elastic cover

10 Outer storage cell

11 fold

12 edge fold

13 First subspace

14 Second subspace

15 coolant inlet

16 coolant outlet

17 First wall

18 Second wall

19 slot structure

20 sealing lip

21 nose

22 undercut

23 Embossing

24 well

25 Coolant duct of the coolant supply line

26 Side branch of the coolant supply

27 Coolant duct of the coolant return

28 Side branch of the coolant return

29 print frames

30 assembly sword

31 Deck Cover 32 side cover

33 end plate

34 Guard plate

35 busbar 36 printed circuit board

37 Coolant connection

38 Coolant drain

Claims

1. Energy storage device (1) for storing electrical energy, preferably for an at least partially electrically powered vehicle, comprising a plurality of storage cells (3, 4, 5) arranged next to one another in stacks and a cooling device (6) for cooling the storage cells (3, 4, 5), wherein the cooling device (6) comprises:

- A cooling plate (7) through which a coolant can flow and which is arranged laterally, preferably on the bottom side, with respect to the storage cells (3, 4, 5), and

- At least one with the coolant flow ble cooling body (8), which is arranged between two adjacent storage cells (3, 4, 5) for side surface cooling of the storage cells (3, 4, 5), is fluidically connected to the cooling plate (7) and is designed as a heat sink (8) with an elastic sleeve (9).

2. Energy storage device (1) according to claim 1, characterized in that a) that the elastic sleeve (9) of the cooling body (8) comprises an aluminum foil and / or a plastic coating; and / or b) that the heat sink (8) is a foil heat sink and / or pouch heat sink.

3. Energy storage device (1) according to one of the preceding claims, characterized in that a) that the at least one heat sink (8) comprises a plurality of heat sinks (8), with a respective heat sink (8) between all storage cells (3, 4, 5) for Side surface cooling of the storage cells (3, 4, 5) is arranged; and / or b) that in each case a cooling body (8) with an elastic cover (9) is arranged on the outside of the outer storage cells (10) for side surface cooling.

4. Energy storage device (1) according to one of the preceding claims, characterized in that the heat sink (8) has at least one fold (11) or embossing, which is formed, an interior of the heat sink (8) in fluidically interconnected sub-spaces (13, 14) to subdivide coolant in an arc, U-shaped or meandering shape from a coolant inlet (15) of the heat sink (8) to a coolant outlet (16) of the heat sink (8).

5. Energy storage device (1) according to claim 4, characterized in that the cooling body (8) has exactly one or one fold (11) or embossing arranged in a central region, which is designed as an interior of the cooling body (8) in two to subdivide fluidically interconnected sub-spaces (13, 14) in order to guide coolant in an arc-shaped and / or U-shaped manner from the coolant inlet (15) of the heat sink (8) to the coolant outlet (16) of the heat sink (8).

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

7. Energy storage device (1) according to claim 6, characterized in that the end region of the heat sink (8) has a sealing lip (20) for fluidic sealing of the slot, wherein preferably the sealing lip (20) is performed as an elastomer injection.

8. Energy storage device (1) according to claim 7, wherein the sealing lip (20) has a nose (21) which is in a shape-corresponding notch or undercut (22) of the first wall (17) to produce a form fit between the sealing lip (20) and The cooling plate (7) engages.

9. Energy storage device (1) according to one of the preceding claims, characterized in that the cooling plate (7) comprises a second half-shell-shaped wall (18) facing away from the storage cells (3, 4, 5) and having embossments (23) which are formed To direct coolant within the cooling plate (7) into a coolant flow and a Kühlmit telrücklauf and which in turn preferably have troughs (24) for holding the min least one heat sink (8).

10. The energy storage device (1) according to claim 9, characterized in that a) that the coolant supply has a coolant duct (25) with a plurality of orthogonally arranged side branches (26) arranged at an edge region of the cooling plate (7), and b) that the Coolant return has a coolant channel (27) with a plurality of side branches (28) arranged orthogonally thereto and arranged on an edge region opposite to the coolant flow, and c) that the side branches (26) of the coolant flow and the side branches (28) of the coolant return are interlaced in such a way that a side branch (26) of the coolant flow is always arranged immediately adjacent to a side branch (28) of the coolant return.

11. Energy storage device (1) according to claim 10, characterized in that the side branches (26) of the coolant flow and the side branches (28) of the coolant return of the cooling plate (7) are fluidically connected to each other via the heat sink (8).

12. Energy storage device (1) according to one of the preceding claims, characterized in that the heat sink (8) is at least partially supported by a printing frame (29) arranged between adjacent storage cells (3, 4, 5), preferably a plastic printing frame (29) , is surrounded, which is formed to absorb forces, preferably to absorb compression forces, between adjacent storage cells (3, 4, 5).

13. Energy storage device (1) according to claim 12, characterized in that the pressure frame (29) a) is attached to an edge of the heat sink (8), preferably on an outer edge embossing or edge fold (12) of the heat sink (8) by an extrusion coating is attached; or b) rests loosely on the cooling body (8) and is held in position by pressing the adjacent storage cells (3, 4, 5).

14. Energy storage device (1) according to claim 12 or 13, characterized in that the printing frame (29) is designed in the form of the letters “M” or “n”.

15. Energy storage device (1) according to one of the preceding claims, characterized in that the plurality of storage cells (3, 4, 5) a) arranged next to one another in a stack-like manner are combined to form a battery cell module (2) and the cooling plate on a side surface, is preferably arranged on a floor surface of the battery cell module (2); or b) are storage cells of a cell-to-pack, CTL, energy store.

16. Energy storage device (1) according to one of the preceding claims, characterized in that the storage cells (3, 4, 5) are designed as pouch storage cells (4) or as prismatic storage cells (5).

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

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

19. The method for producing the energy storage device (1) according to claim 6, characterized by the step:

Attaching the at least one heat sink (8) to the cooling plate (7) by inserting the heat sink (8) through a slot in the slot structure (19) until the end region of the heat sink (8) having the coolant inlet (15) and coolant outlet (16) is positioned on the slot and / or rests.

20. The method according to claim 19, characterized in that the insertion takes place by means of a mounting sword (30), onto which the cooling element (8) is slipped before insertion and which after insertion and attachment of the cooling element (8) to the cooling plate (7) is pulled out again.

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

Placing the storage cells (3, 4, 5) on the cooling plate, so that one of the inserted heat sinks (8) is positioned between two neighboring battery cells, a) the storage cells being provided as a prefabricated battery cell module the cooling plate is placed on, or b) the storage cells being placed on the cooling plate as loose pouch cells and combined to form a cell module; or c) the storage cells being placed on the cooling plate as part of a cell-to-pack, CTP, process.