CN112332015A

CN112332015A - Energy storage system

Info

Publication number: CN112332015A
Application number: CN202010744974.6A
Authority: CN
Inventors: 圭多·霍夫
Original assignee: Lisa Draexlmaier GmbH
Current assignee: Lisa Draexlmaier GmbH
Priority date: 2019-07-30
Filing date: 2020-07-29
Publication date: 2021-02-05
Anticipated expiration: 2040-07-29
Also published as: CN112332015B; DE102019120498A1

Abstract

The invention relates to an energy storage system (100) comprising at least one module (7, 8) having a plurality of electrochemical cells, wherein the module (7, 8) has a module wall (7', 8') which surrounds a cell (13) of the module (7, 8), wherein the module (7, 8) has an energy storage housing, wherein at least one energy storage housing subregion (1) is designed such that it forms at least two channels (4, 5), in particular at least one inflow channel and at least one return channel, by means of a cooperation with the module wall (7', 8'), for guiding a heat exchange medium (M), in particular a heat exchange liquid, in order to provide a structurally simple and effective cooling for the energy storage system.

Description

Energy storage system

Technical Field

The present invention relates to an energy storage system, in particular for driving a vehicle.

Background

In the case of electrochemical energy storage systems, such as batteries, the desired voltage level is provided by cascading individual electrochemical cells. Multiple units may be combined into a single module. The desired voltage is typically generated by aligning a corresponding module with a corresponding number of cells.

A common field of use of such energy storage systems is electric vehicles, in particular electric vehicles, but their use is not limited thereto. During acceleration, the electric motor for driving the vehicle consumes a large amount of electrical power, which is provided by the energy storage system or by the electrochemical units of the energy storage.

When energy is extracted from an energy storage system or electrochemical cell, it is converted into heat because the sum of all resistances (e.g., cell internal resistance, contact resistance, wire resistance, etc.) forms the power loss within the cell according to the current intensity. The lost power heats the energy storage system or cells such that this thermal energy, if not discharged, overheats the energy storage system or cells of the energy storage. This similarly applies to feeding energy back into the energy storage system.

Therefore, it is necessary to provide the energy storage system with a cooling device or heat exchanger to prevent overheating of the unit or module or the energy storage.

In particular, dynamic driving patterns, such as those found in sport-type and highly mobile vehicles, lead to an increase in the load on the energy storage system. Such an increase in the load of the energy storage system occurs, on the one hand, when corresponding electrical power is called up in the case of a vehicle requiring power, and, on the other hand, when energy is recovered and fed back into the energy storage system.

Particularly efficient cooling of the energy storage system is required if strong load changes occur frequently. This applies in particular to a power-assisted battery which additionally supports an internal combustion engine, for example of a sports vehicle. These power-assisted batteries are often driven to their electrical power limits due to short-term high electrical power demands.

Therefore, an efficient or high performance cooling system is needed to prevent overheating of the unit. Efficient cooling can be achieved by direct thermal connection of the cells to a cooling liquid, with as little additional thermal resistance as possible, for example gap fillers, thermally conductive pastes or electrically insulating intermediate layers. Thus, it is suitable for direct exposure to the coolant, especially for cells with a circular cross-section. For this, it is a prerequisite that the cooling liquid is not electrically conductive. This is for example met by transformer oil or special liquids (e.g. Novec).

Furthermore, it must be taken into account that the cells do not develop excessive temperature differences. Small temperature differences are therefore particularly advantageous, since the cells age at different rates depending on the respective temperature load. The higher the cell temperature, the faster the cell ages. Thus, as uniform an aging of the units as possible should be achieved by small temperature differences between the units to avoid premature failure or significant degradation of the individual units.

The small temperature difference is achieved in particular by the same flow of coolant first flowing through the cell in a first direction and then in the opposite direction to the first direction. This is also known as the counter-flow principle. Thereby taking into account the temperature difference between the units and the cooling liquid and resulting in a heat exchange behavior that maintains a low temperature difference between the units to each other.

As mentioned above, such energy storage systems are typically constructed to be modular; i.e. a certain number of modules with cells are arranged in series to obtain a certain voltage. If the cooling is carried out with only a single medium flow for all modules, the unit temperatures of the modules arranged one after the other in the flow direction also differ. Thus, for example, for the cells of the first module, the temperature difference between the cell temperature and the medium temperature in the flow direction is, for example, greater than the temperature difference between the cell temperature and the medium temperature of the last module in the flow direction.

For this reason, it is known to provide the same inlet temperature for the modules in parallel with the heat exchange medium. In this way, a high cooling capacity can be provided, so that the temperature difference between the units within the respective modules is low, and also so that the temperature difference between the modules of the energy storage system is low. However, for such a parallel supply of heat exchange medium to the modules, a very costly lead-in and lead-out system comprising a large number of components to be installed is required.

Disclosure of Invention

It is therefore an object of the present invention to provide a structurally simpler and more efficient cooling of an energy storage system.

This object is solved by the subject matter of the independent claims. Advantageous developments of the invention are given in the dependent claims, the description and the drawings.

The energy storage system according to the invention comprises: at least one module with a plurality of electrochemical cells, wherein the module has module walls which surround the cells of the module, with an energy storage housing, wherein at least one subregion of the energy storage housing is designed such that it forms two channels, in particular at least one inflow channel and at least one return channel, by cooperation with the module walls, for conducting a heat exchange medium, in particular a heat exchange fluid.

The module generally comprises a certain number of electrochemical cells, which can have essentially any type and shape. The energy storage system may include a plurality of adjacent modules with corresponding cells. The modules may also be interconnected, for example by a slot-spring mechanism, so that the modules are positionally stable relative to each other. The module walls of the module surround the cells such that the module walls form an outer peripheral surface around the cells. The module walls may, but need not, be closed on all sides of the module. The module wall can be designed in one piece or in multiple pieces.

The energy storage system has an energy storage housing. The energy storage housing houses at least one module or a plurality of modules. The sub-areas of the energy storage housing, for example the floor of the energy storage housing, have a structure which is suitable for forming channels together with the module walls when the modules are placed in the corresponding sub-areas. These structures must be adapted and designed to guide the heat exchange medium by co-action with the module walls.

The partial regions of the energy storage device housing with the corresponding structures for forming the channels can be designed in one piece or in multiple pieces. In one possible embodiment, the partial regions of the energy storage housing are designed as the base plate of a one-piece injection-molded housing, which comprises corresponding structures or devices for forming channels together with the module walls. The energy accumulator housing sub-region can have a supply opening and a discharge opening, through which the heat exchange medium can be supplied to or discharged from a corresponding structure of the energy accumulator housing sub-region.

The channel formed by the energy storage housing sub-region and the module wall is referred to as an inflow channel here, which serves to convey the heat exchange medium to the module, so that it can be used to cool the units of the module. Here, a passage for discharging the heated or cooled medium from the module after heat exchange with the unit of the module is referred to as a return passage. The return channel is also formed by the energy store housing sub-region and the module wall.

A liquid medium, in particular a non-conductive liquid, such as transformer oil or another suitable medium, can be selected as heat exchange medium. Gaseous media may also be used if desired.

The structure for forming the channel is integrated in a subregion of the energy storage housing. It is only necessary to mount at least one module as part of the energy storage system in order to bring the channel into a state in which the heat transfer medium can be conducted by cooperation, in particular by resting on the existing structure of the sub-region of the energy storage housing.

The energy storage system according to the invention makes it possible to dispense with costly pipe systems, a large number of separate seals and other components for supplying the heat exchange medium in parallel to at least one module or a plurality of modules. Thereby eliminating the cost of components of the cooling system (e.g., piping, seals, fasteners). Furthermore, the installation costs of the cooling system piping and additional components are eliminated. The weight and susceptibility to error of the energy storage system is also reduced.

In principle, the invention can be used not only to cool the unit, but also, if desired, to heat it, in particular at low external temperatures, by means of the invention. It is important that the invention is generally used for cooling purposes, i.e. heat exchange from the unit to the heat exchange medium and vice versa.

In a first embodiment of the energy storage system, the energy storage housing sub-region has a cross-sectional profile with a plurality of sunken sub-regions and a plurality of raised sub-regions, wherein the module walls cooperate with the raised sub-regions to form the channel. The sunken and raised sub-regions may have different shapes. In a possible variant, the sunken partial region can be designed in cross section as a V, U or trough. Other shapes are also contemplated. The plurality of sunken sub-regions can be dimensioned such that a desired minimum volume flow can be achieved by means of the formed channel or channels in order to efficiently discharge heat. The raised partial regions can be dimensioned, in particular over their width, in such a way that a media-tight, in particular liquid-tight, closure between two lowered partial regions can be ensured and, in addition, the weight of the module supported thereon can be absorbed.

In a further possible development of the energy storage system, an elastic seal, in particular a foam seal, is present or arranged between at least the first raised subregion and the module wall, said elastic seal being designed to prevent the heat exchange medium from passing between the module wall and the raised subregion. For example, a window glass adhesive, a foam seal or a body seal may be used as the elastic seal. For foam seals, a liquid or thixotropic paste-like sealant is usually prepared in a machine and applied to the raised subareas by caterpillar-shaped nozzles. The sealant material is then treated, dried or cross-linked to achieve a soft, compressible seal. The advantages of foam sealing are mainly that foam sealing can be achieved simply and inexpensively by automated machine processes.

In a further possible development of the energy storage system, an elastic seal is arranged between each raised subregion forming the channel and the module wall. It is thereby ensured that all channels formed are rendered medium-tight, in particular liquid-tight.

In a further possible development of the energy storage system, the raised partial region extends over substantially the entire partial region of the energy storage housing in a meandering manner. The elastic seal, in particular the foam seal, extends substantially over the entire length of the raised sub-region. In particular, the meander can be formed in one piece from the raised partial region. For raised sub-regions, sharp edges and corners can be avoided by the meandering shape. Furthermore, the width and length dimensions of the channel can be determined in a simple manner by the form or characteristics of the meander. Furthermore, such a meandering shape can be easily achieved by a casting process. In particular, the characteristics of the meander may follow the module width, such that the width of the module walls of the module corresponds to the width of two adjacent channels formed by the meander. The heat exchange medium for cooling the module can then be obtained, for example, from the first channel. The medium heated by the units of the module may be discharged into the second channel. The module walls of the module thus extend at least partially over the two channels. The module wall can also be designed in multiple parts and have multiple wall elements. The foam seal can be applied mechanically, automatically and without interruption over the entire zigzag-shaped raised subregion. This makes it possible to provide the meandering partial region on which the foam seal is arranged particularly cost-effectively and precisely.

In a further possible development of the energy storage system, at least one inflow channel and at least one return channel, in particular adjacent to the constricted inflow channel, are formed by the zigzag-shaped raised partial regions by cooperation with the module walls. The inflow channel and the return channel are each laterally delimited by raised sub-areas. If the incoming flow channel and the return flow channel are directly adjacent, the incoming flow channel and the return flow channel are separated by a common raised subregion delimiting the respective channels. In terms of module arrangement, this is a particularly simple form of realising the incoming flow channels and the return flow channels, from which the modules can be supplied with heat exchange medium.

In a further embodiment variant of the energy storage system, there is a first opening of the module wall, through which a heat exchange medium can be supplied to the cells of the module from a first channel (in particular, an inflow channel) formed by the module wall and a subregion of the energy storage housing. Furthermore, there is a second opening of the module wall, through which the medium supplied to the unit can be discharged into a second channel formed by the module wall and a subregion of the energy store housing, in particular a return channel. Typically, the first opening (which may also be referred to as inlet opening) and the second opening (which may also be referred to as outlet opening) are arranged at different positions on the module wall. The first opening may comprise a plurality of openings through which the heat exchange medium enters the cells of the module. These openings may advantageously be arranged in the longitudinal direction on the same incoming flow channel. Furthermore, the second opening may also comprise a plurality of openings, through which the heat exchange medium leaves the module. These openings can advantageously be arranged longitudinally on the same return channel. The first and second openings may be arranged on the same side of the module, or may for example also be arranged on opposite sides. This may depend, for example, on whether the counterflow principle should be used for the heat exchange medium. The supply and discharge of heat exchange medium into and out of the module is relatively insensitive to tolerances if the widths of the incoming flow channel and the adjacent return flow channel are chosen correspondingly. This is especially true if the width of the incoming flow channel is configured such that it significantly overlaps one or more inlets of the module wall. This is also true if the width of the return channel is configured such that it significantly overlaps one or more outlets of the module wall. Thus, by suitable positioning of the modules on the corresponding raised partial regions of the energy store housing and thus on the corresponding channels, a simple and tolerance-insensitive supply and discharge of the heat exchange medium into and out of the module can be ensured. This is a considerable advantage compared to systems in which pipes have to be used to connect the modules individually to the inlet openings of the modules.

In an advantageous possible variant, the first opening and the second opening are circular voids. However, the first opening or the second opening may have different shapes of voids. Furthermore, it can be provided that the first openings have a smaller passage area for the heat exchange medium than the second openings, in particular a smaller diameter in the case of circular recesses. If the first opening comprises a plurality of openings and the second opening comprises a plurality of openings, such a size of the passage area of the first opening and the second opening may be provided for all corresponding openings. In particular, the first opening can be provided in the edge region of the module wall, so that a common first opening or a plurality of common first openings or inlet openings are formed, for example, by the cooperation of the recesses of the module walls of two modules arranged adjacent to one another.

In a further exemplary refinement, the energy storage system comprises a first module with a first module wall and a second module with a second module wall, wherein the first module wall and the second module wall each enclose a cell comprised by the first module and the second module, wherein the first module and the second module each have at least one open end face, wherein the open end faces of the first module and the second module directly adjoin one another, wherein the first module and the second module each have a cell holder for positioning the cell within the respective module, wherein the cell holders of the first module and the second module, the cells of the first module and the second module and the first module and the second module are arranged such that they form a medium-tight intermediate module channel for guiding a heat exchange medium, and wherein the first opening is formed by at least one recess of the first module wall and the second module wall adjoining one another, through which a heat exchange medium can be supplied to the intermediate module channel. These module faces, which are generally perpendicular to the module walls, are referred to as end faces. The end faces are open, i.e. not closed by the module walls. Thus, cavities are formed between the modules by the abutting end faces, which cavities can receive a heat exchange medium. With this possible development of the invention, the modules with their originally present components (for example, the cells, cell holders and module walls) are additionally used to produce intermediate module channels arranged between the modules for conducting the heat exchange medium. No additional, costly components for guiding the medium are required. While ensuring efficient heat exchange over the unit.

In a further exemplary development of the energy storage system, the cells of the module are designed cylindrically, and at least a first sealing element and a second sealing element are arranged on each cell of the module, wherein the first sealing element seals, in particular liquid-seals, between the cell and the cell holder in the radial direction, and the second sealing element seals, in particular liquid-seals, between the cell holder and the cell in the axial direction of the cell. Cylindrical cells are sometimes referred to as circular cells due to the circular cross-section perpendicular to the axial direction. The unit together with the sealing element arranged thereon forms a media-tight, in particular liquid-tight, structure which enables the formation of the intermediate module channel without the need for additional structures for the module. The intermediate module channel therefore has at least one inlet opening through which the heat exchange medium reaches into the intermediate module channel. The medium is thus guided in a structured manner in a defined direction and in this case flows around at least one subregion of the unit to be cooled.

In a further exemplary embodiment variant, at least one third opening is present after the last cell of the module in the flow direction of the intermediate module channel, through which the heat exchange medium can be guided into the interior of the first module and/or the second module. A module interior space channel can be formed by the cells, the cell holders and the module walls, wherein after the last cell of the module, a second opening is arranged in the flow direction opposite to the flow direction of the intermediate module channel, through which second opening the heat exchange medium can be conducted out into a return channel formed by the first or second module wall and a subregion of the energy store housing. By providing a third opening for transferring the medium from the normally medium-tight intermediate module duct into the module interior duct, a return flow of the medium is achieved in a module interior duct different from the intermediate module duct. The third opening, which may also be referred to as a transfer opening, may likewise comprise a plurality of openings. In one possible configuration, the third opening is present after the last cell respectively between two adjacent parallel-lying cells of the module in the flow direction of the middle module channel. The module internal channels are designed to be medium-sealed with respect to the middle module channel or with respect to the middle module channels present on both sides by means of corresponding radial and axial sealing elements on the units. By this arrangement the counter-flow principle can be achieved, since a first part of the units can be cooled first in the flow direction of the middle module channel and after passing the third opening further parts of these units can be cooled in the opposite direction in the module inner channel. This allows minimizing the temperature differences of the units of the module. Like the intermediate module duct, the module internal duct is realized without additional medium-conducting components.

Drawings

Advantageous embodiments of the invention are explained below with reference to the drawings. The figures are as follows:

fig. 1 shows a plan view of a base plate of an energy storage housing of an embodiment of an energy storage system according to the invention, with zigzag-shaped raised partial regions which are suitable for forming channels for guiding a heat exchange medium,

FIG. 2 shows an enlarged view of a part of the contour diagram of the base plate with raised and lowered sub-regions for guiding the heat exchange medium, and

fig. 3 shows a cross-sectional view through a module arranged on a substrate for illustrating the medium flow.

The figures are only schematic representations and are only intended to explain the invention. Identical or functionally identical elements are provided with the same reference numerals throughout.

Detailed Description

For ease of understanding, reference numerals of the figures are retained in the following description.

Fig. 1 shows a subregion 1 of the energy store housing, also referred to as an energy store housing subregion, in the form of a die-cast base plate of the energy store housing. For operation, the energy storage housing sub-region is screwed to the rest of the energy storage housing to accommodate the modules comprised by the energy storage system.

The base plate 1 shows a zigzag-shaped raised subregion 2 and a lowered subregion 3. Such a zigzag-shaped raised partial region 2 is surrounded by a frame-shaped raised partial region 2. This frame-like raised subregion 2 is arranged around the zigzag-shaped raised subregion 2, so that the two structures together form a channel on the base plate 1. The raised subarea 2 has a constant height above the reference plane of the floor. The raised sub-regions 2 thus form a constant height level, which can cooperate with the module walls of the module. Between the meander-shaped structures forming raised sub-areas 2 there are sunken sub-areas 3, said sub-areas 3 being arranged below the raised sub-areas 2 with respect to a reference plane parallel to the base plate.

The sunken sub-zone 3 receives a heat exchange medium, in particular a cooling liquid. The raised subarea 2 separates different areas of the lowered subarea 3. The sunken sub-zone 3 can be sunken to different depths, which depend in particular on how much volume of cooling liquid should be transported through the respective zone.

The zigzag-shaped raised partial regions 2 extend over substantially the entire base plate 1 of the energy storage housing in order to achieve effective cooling of the module. In addition, due to the zigzag structure of the raised subregion 2, two adjacent sunken regions can act as an inflow channel 4 and a return channel 5. In this case, the width of the incoming flow channel 4 and the width of the return channel 5 are matched to the dimensions of the module, so that the incoming flow channel 4 can supply cooling liquid to the module through the inlet opening, while the adjacent return channel 5 can receive cooling liquid exiting from the outlet opening of the module. This is also set in a corresponding manner for other modules of the same type that may be present.

Fig. 2 shows an enlarged section of the cross-sectional profile of the structure of the base plate 1 of fig. 1. The raised subareas 2 and the lowered subareas 3, as well as the formed inflow channels 4 and return channels 5, are visible. Furthermore, a foam seal is shown, which is not illustrated in fig. 1, and which extends along the raised partial regions 2, i.e. along the zigzag-shaped raised partial regions 2 and the frame-shaped raised partial regions 2. A module, not shown, is placed on this foam seal 6. The sunken sub-region 3 has a different depth of subsidence relative to the reference plane. The flow channel 4 and the return channel 5 are sealed upwards by a not shown module wall to be placed on the foam seal 6. Furthermore, the foam seal 6 is compressed by the self-weight of the module supported thereon, and the seal between the inflow channel 4 and the return channel 5 is reinforced. Thus, the coolant cannot pass from the flow channel 4 into the return channel 5 through the raised sub-region 2 and vice versa.

Fig. 3 shows a cross-sectional view of a module of an energy storage system disposed on a substrate. Thus, portions of energy storage system 100 are shown. This part comprises a subregion 1 of the energy store housing in the form of a meander-shaped structured base plate. The base plate 1 has raised subregions 2, which subregions 2 form a meander-shaped structure. Between the raised subareas 2 there are sunken subareas 3.

First of all, the base plate 1 shown in fig. 1 and 2 can be seen again in a sectional view. A continuous foam seal 6 is arranged on the raised subarea 2, said foam seal 6 extending continuously along the raised subarea 2. Thus, the foam seal 6 is present over the entire length of the zigzag-shaped extended sub-regions 2 and of the raised sub-regions 2 of the frame. The raised subareas 2 have a constant height with respect to a reference plane parallel to the base plate 1.

Fig. 3 shows that the inflow channel 4 of the sunken subregion 3 is designed deeper than the return channel 5. Since the inflow channel 4 and the return channel 5 are always adjacent to one another and separated by the raised subregion 2, there is an alternating depth profile in the drawing plane of fig. 3, and the depth profile is perpendicular to the longitudinal extension of the raised subregion 2. Below the less sunk return channel 5 there is also arranged a support, not marked in fig. 3, which compensates for the height difference between the return channel 5 and the incoming flow channel 4. Due to the support, the incoming flow channel 4 and the return flow channel 5 have the same level of position and can be supported downwards on the same face.

Fig. 3 shows three identical modules in cross section, which are placed onto the foam seal 6. Of these three modules, the first module is given the reference number 7 and the second module is given the reference number 8. For the sake of clarity, the third module is not provided with its own reference numeral. The embodiments are similarly applicable to the third module.

The first module 7 and the second module 8 have a two-part module wall 7 'or 8', respectively. These module walls 7 'and 8' accommodate (i.e. enclose) the cylindrical electrochemical cells 13 and cell holders 14 of the

respective module

7 or 8. The module wall 7 'or 8' is designed in two parts and comprises two insertable module part walls. In particular, the module walls or module part walls, respectively, can be designed in one piece with the cell holder 14. In this embodiment, the module wall 7 'or 8' comprises a slot 9 and a spring 10, by means of which slot 9 and spring 10 the first module 7 and the second module 8 can be fixed to each other, marked on the third module for space reasons. This also applies to all further directly adjoining modules. Thus, the individual modules form a module block that is joined together.

In operation of the energy store, the coolant M is guided to the first module 7 via the inflow channel 4. The module wall 7 'directly adjoins the module wall 8' of the second module 8. Both module walls 7 'and 8' have a first opening 11 above the incoming flow channel 4 and at the edge of the module walls 7 'and 8', respectively, which first opening 11 can also be referred to as an inlet opening. In the longitudinal direction of the inflow duct 4, i.e. perpendicular to the sectional plane of fig. 3, preferably in the edge region of the first module wall 7 'or the second module wall 8' a plurality of further first openings 11 or inlet openings 11 are provided. The cooling liquid M enters the intermediate module duct 15 through the first opening 11.

The intermediate module passage 15 includes: a cell 13 of the first module 7 or the second module 8, a cell holder 14 for holding the cell 13 of the first module 7 or the second module 8 in a defined position, and a module wall 7 'or 8'. Here, a first sealing element 16 is provided, which seals the space between the cell holder 14 and the cell 13 in a liquid-tight manner. This first sealing element 16 has a radial sealing function. A first sealing element 16 is present in each cell 13 which together form the intermediate module channel 15 at the side of the first module 7. Furthermore, there is a second sealing element 17 which has an axial sealing function and is also arranged between the cell holder 14 and the cell 13. The second sealing element 17 is provided as a cell 13 and a cell holder 14 on the side of the sealing module 8 which participate in the formation of the intermediate module channel 15. For each cell 13 or cell holder 14 there is also a second sealing element 17, which second sealing elements 17 also together form an intermediate module channel 15 on the second module 8 side. Thus, a liquid-tight intermediate module channel 15 is formed together with the first and second module walls 7', 8' of the first and

second modules

7, 8, wherein the cooling liquid is in contact with and heat-exchanging with the top area of the cells 13 of the first module 7 and the bottom area of the cells 13 of the second module 8.

The cooling liquid M flows in the flow direction S in the intermediate module duct and absorbs heat from the cells 13 which are surrounded by it. The cooling liquid M flows around the cells 13 of the first module 7 at a portion of the cylindrical outer peripheral surface of the cells 13, which is not visible in the sectional view of fig. 3.

After the last cell 13 of the first and

second module

7 or 8 in the flow direction S, the cooling liquid M encounters the module wall 7 'or 8'. In order to achieve a return flow of the now warmer cooling liquid M without flowing through the middle module channel again in the opposite direction, at least one third opening 18 is provided. This third opening 18, which may also be referred to as a transfer opening, is a cutout of the cell holder 14 of the first module 7 and the cell holder 14 of the second module 8. Since a plurality of cells are usually placed one after the other perpendicular to the drawing plane of fig. 3, a transfer opening 18 is preferably provided for each cell holder 14 after all these last cells 13 in the flow direction S.

By means of this transfer opening 18, the cooling liquid M can penetrate into the inner closed area of the first module 7 or the inner closed area of the second module 8. Where the cooling liquid M can contact the areas of the units 13 of the first and

second modules

7, 8 that have not been flowed through so far and absorb heat.

Like the intermediate module channel 15, the module internal channel 19, to which the cooling liquid M arrives through the transfer opening 18, is designed to be formed liquid-tightly by the respective first and

second sealing elements

16, 17, the unit holder 14, the unit 13 and the module walls 7 'and 8'.

Thus, the cooling liquid M entering into the module internal channels through the transfer openings 18 flows downwards through the unit 13 in the opposite direction to the flow direction S of the intermediate module channels 15, i.e. in the counterflow direction G. After the last unit in the counterflow direction G, a second opening 12 is provided, which can also be referred to as an outlet opening, via which second opening 12 the now further heated coolant can be discharged from the first module 7 or the second module 8 into the respective return channel 5. Here, a plurality of outlet openings 12 of the module can also be provided along the return channel 5. The coolant M is discharged from the energy storage system 100 through the return passage 5.

This principle is advantageously used for all modules of an energy storage system, wherein the first and last module of a modular block differ in that it has only one directly adjacent module. For the first and last modules, coolant flows into the module internal channels through the intermediate module channels and the second channels formed between the last module and the module block end plates.

The described embodiments of the invention allow in particular an efficient cooling of the modules of the energy storage system, etc. by means of the counterflow principle, without additional complex components and installation of pipes. The modules form their own flow channels. The supply of the cooling liquid is effected in a simple manner by means of a structured base plate, the structure of which forms the inflow channels and the return channels in a simple manner by means of a co-operation with the module walls.

List of reference numerals

100 energy storage system

1 sub-area of the energy storage enclosure: base plate

2 raised sub-area

3 sub-area of sinking

4 incoming flow channel

5 Return channel

6, elastic sealing element: foam seal

7 Module, first Module

8 module, second module

7' Module wall, first Module wall

8' module wall, second module wall

9 groove

10 spring

11 first opening: an inlet opening

12 second opening: outlet opening

13 unit

14 unit holding part

15 intermediate module channel

16 first, radial seal element

17 second sealing element, axial sealing element

18 third opening: transfer opening

19 internal passage of module

M heat exchange medium: cooling liquid

Direction of S flow

G direction of counterflow

Claims

1. An energy storage system (100) comprising at least one module (7, 8) with a plurality of electrochemical cells, wherein the module has a module wall (7', 8'), wherein the module wall (7', 8') surrounds a cell (13) of the module (7, 8), wherein the module has an energy storage housing, wherein at least one energy storage housing subregion (1) is designed such that it forms at least two channels (4, 5), in particular at least one inflow channel and at least one return channel, by means of a cooperation with the module wall (7', 8'), for conducting a heat exchange medium (M), in particular a heat exchange liquid.

2. The energy storage system according to claim 1, wherein the energy storage housing sub-region (1) has a cross-sectional profile with a plurality of sunken sub-regions (3) and a plurality of raised sub-regions (2), wherein the module walls (7', 8') cooperate with the raised sub-regions (2) for forming the channels (4, 5).

3. Energy storage system according to claim 2, wherein between at least a first raised subregion (2) and the module wall (7', 8') there is an elastic seal (6), in particular a foam seal, designed to avoid the passage of the heat exchange medium (M) between the module wall (7', 8') and the raised subregion (2).

4. Energy storage system according to claim 3, wherein the resilient seal (6), in particular a foam seal, is arranged between each raised sub-region (2) forming the channel (4, 5) and the module wall (7', 8').

5. The energy storage system according to any of claims 2-4, wherein the raised sub-area (2) extends in a meandering shape substantially over the entire energy storage housing subsection (1), in particular over the floor, and the elastic seal (6) extends substantially over the entire length of the raised sub-area (2).

6. The energy storage system as claimed in claim 5, wherein at least one inflow channel (4) and at least one return channel (5), in particular adjacent to the inflow channel (4), are formed by the cooperation with the module walls (7', 8') by means of the zigzag-shaped raised subregion (2).

7. The energy storage system according to any one of the preceding claims, wherein there is a first opening (11) of the module wall (7', 8') through which a heat exchange medium (M) can be supplied from a first channel (4), in particular an incoming flow channel, formed by the module wall (7', 8') and the energy storage housing sub-region (1) to a cell (13) of the module (7, 8), and there is a second opening (12) of the module wall (7', 8') through which the heat exchange medium (M) supplied to the cell (13) can be discharged into a second channel (5), in particular a return flow channel, formed by the module wall (7', 8') and the energy storage housing sub-region (1).

8. The energy storage system according to claim 7, wherein there is a first module (7, 8) with a first module wall (7', 8') and a second module (7, 8) with a second module wall (7', 8'), wherein the first module wall (7', 8') and the second module wall (7', 8') enclose the cells (13) comprised by the first and second module (7, 8), respectively, wherein the first module (7, 8) and second module (7, 8) have at least one open end face, respectively, wherein the open end faces of the first and second module (7, 8) directly adjoin each other, wherein the first and second module (7, 8) have a cell holder (14) for holding a cell (13) of the respective module (7, 8), respectively, wherein, the cell holders (14) of the first and second modules (7, 8), the cells (13) of the first and second modules (7, 8) and the first and second module walls (7', 8') are arranged relative to one another such that they form a medium-tight intermediate module channel (15) for guiding the heat exchange medium (M), and wherein the first opening (11) is formed by at least one indentation of the first and second module walls (7', 8') adjoining one another, through which the heat exchange medium (M) can be fed to the intermediate module channel (15).

9. The energy storage system as claimed in claim 8, wherein the cells (13) of the modules (7, 8) are designed to be cylindrical and at least one first sealing element (16) and a second sealing element (17) are arranged on each cell (13) of the modules (7, 8) participating in the formation of the intermediate module channel (15), wherein the first sealing element (16) leads to a medium seal in the radial direction between the cell (13) and the cell holder (14) and the second sealing element (17) leads to a medium seal in the axial direction of the cell (13) between the cell holder (14) and the cell (13).

10. Energy storage system according to claim 8 or 9, wherein at least one third opening (18) is present after the last cell (13) of the module (7, 8) in an intermediate module channel flow direction (S), through which a heat exchange medium (M) can be guided into the interior space of the first module (7) and/or the second module (8), wherein a module interior channel (19) is formed by the cell (13), the cell holder (14) and the module walls (7', 8'), wherein a second opening (12) is present after the last cell (13) in a counterflow direction (G) with respect to the intermediate module channel flow direction (S), through which the heat exchange medium (M) can be discharged to the interior space defined by the module walls (7 '), 8') and the energy accumulator housing sub-region (1) in a return channel (5).