Battery system, operating method thereof, and vehicle having such battery system

Abstract

The present invention relates to a battery system, comprising a battery module including a plurality of battery cells, wherein the battery cells are constructed as lithium-ion or lithium-polymer battery cells, and the battery system comprises: a first temperature-control fluid guide device through which a first temperature-control fluid can flow and a first conveying unit for conveying the first temperature-control fluid through the first temperature-control fluid guide device thermally connected to the battery module; a second temperature-control fluid guide device through which a second temperature-control fluid can flow and a second conveying unit for absorbing kinetic energy from the second temperature-control fluid, the second temperature-control fluid guide device having at least one port for fluid-conducting connection to another temperature-control fluid guide device; a heat transfer unit thermally conductive to the first and second temperature-control fluid guide devices, for transferring heat between the first and second temperature-control fluid guide devices, the first and second conveying elements being coupled to each other in a manner capable of transferring mechanical work from the second conveying element to the first conveying element.

Description

Technical Field

[0001] The invention is based on a battery system of the type described in the independent claim.

[0002] Furthermore, the invention relates to a vehicle comprising such a battery system.

[0003] The invention also relates to a method for operating such a battery system. Background Art

[0004] It is known from the prior art that a battery module can be composed of a plurality of individual battery cells which can be electrically conductively connected to one another in series and / or in parallel.

[0005] In particular in electric vehicles (EV), hybrid electric vehicles (HEV) or plug-in hybrid electric vehicles (PHEV), battery modules comprising energy-rich and powerful lithium-ion battery cells or lithium-polymer battery cells are used in order to be able to meet the increasing expectations for driving performance, said battery modules preferably having approximately 100 battery cells.

[0006] Due to chemical conversion processes, lithium-ion battery cells or lithium-polymer battery cells are heated, in particular when releasing or absorbing electrical energy, so that in order to operate such efficient battery cells in a preferred temperature range, it is also known that the battery module can include a temperature control system which, in particular, should ensure that the battery cells do not exceed a predetermined temperature.

[0007] It should be noted that the preferred temperature range for lithium-ion battery cells is approximately between 5° C. and 35° C. Furthermore, the service life decreases continuously from an operating temperature of approximately 40° C., so that in order to meet the requirements for a sufficient service life, the battery cells should be kept in a thermally non-critical state below 40° C. by means of a temperature control system.

[0008] Furthermore, the temperature gradient between different battery cells should not exceed 5 K.

[0009] For this purpose, temperature control systems using a liquid, such as water and / or a glycol mixture, which flows through a cooling plate are known from the prior art, for example.

[0010] Furthermore, it is known from the prior art to arrange a thermal compensation layer, which is referred to in English as “Thermal Interface Material” (TIM), between such a cooling plate of a battery module and the battery cells.

[0011] If, however, the battery cells exceed a predetermined safety-critical temperature, this can lead to a burning out of the battery cells, known as “thermal runaway”, and to a possible associated spread, also known as “propagation”, which results in a significant safety risk. Summary of the invention

[0012] A battery system having the features of the independent claim offers the advantage that a temperature control of a battery module having a plurality of battery cells can be provided which can also be connected in a simple manner and independently to another temperature control system, such as a temperature control system of a vehicle.

[0013] Furthermore, the battery system according to the invention offers the advantage that temperature control can also be carried out by means of the circulation of a temperature control fluid without additional actively driven conveyor elements within the battery system.

[0014] To this end, a battery system is provided, which is in particular a battery system of a vehicle.

[0015] The battery system comprises a battery module having a plurality of battery cells which are designed in particular as lithium-ion battery cells or lithium-polymer battery cells.

[0016] In this case, the battery system has a first temperature-control fluid conducting device.

[0017] The first temperature-control fluid guide device is designed in this case for a first temperature-control fluid to flow through.

[0018] Furthermore, the first temperature-control fluid guiding device has a first conveying unit which is designed to convey the first temperature-control fluid through the first temperature-control fluid guiding device.

[0019] In this case, the first temperature-control fluid guide device is connected in a thermally conductive manner to the battery module.

[0020] In this case, the battery system has a second temperature-control fluid conduction device.

[0021] The second temperature-control fluid guide device is designed in this case for a second temperature-control fluid to flow through.

[0022] Furthermore, the second temperature-control fluid guiding device has a second conveyor unit which is designed to absorb kinetic energy from a second temperature-control fluid, in particular flowing through the second temperature-control fluid guiding device.

[0023] In this case, the second temperature-control fluid-conducting device has at least one port which is designed for a fluid-conducting connection to a further temperature-control fluid-conducting device.

[0024] Furthermore, the battery system comprises a heat exchanger unit which is designed to be thermally connected to the first temperature-control fluid guiding device and to the second temperature-control fluid guiding device and is also designed to transfer heat between the first temperature-control fluid guiding device and the second temperature-control fluid guiding device.

[0025] In this case, the first conveyor element and the second conveyor element are connected to one another in a coupled manner in such a way that the second conveyor element can transfer mechanical work to the first conveyor element.

[0026] Advantageous developments and improvements of the device specified in the independent claim are possible by means of the measures listed in the dependent claims.

[0027] In this case, it is advantageous if the first temperature-control fluid is accommodated in the first temperature-control fluid guide device.

[0028] In this case, the first temperature control fluid can be designed as a water-glycol mixture or as a dielectric temperature control fluid.

[0029] A dielectric fluid is a fluid which is not electrically conductive in this respect.

[0030] In particular, the first temperature control fluid is different from the second temperature control fluid.

[0031] In other words, the first temperature-control fluid-conducting device can also be referred to here as the internal temperature-control circuit of the battery module, for example.

[0032] Thus, the first temperature control fluid, which is designed, for example, as a water-glycol mixture or as a dielectric temperature control fluid, can also be referred to as internal temperature control fluid of the battery module.

[0033] It is thus possible for the battery system according to the invention to be connected to a further temperature-control fluid conducting device without the temperature-control fluid utilized by the further temperature-control fluid conducting device being used for indirect, direct temperature control of the battery modules.

[0034] For example, with the battery system according to the invention it is thus possible to select the first temperature control fluid and thus the design of the battery module for direct temperature control independently of vehicle manufacturer specifications or requirements of another temperature control fluid supply system.

[0035] The battery module can therefore be designed to be as independent as possible from the corresponding climate control system components present in the vehicle, such as pumps and hoses.

[0036] The battery system according to the invention is therefore a compact unit which can be connected by means of at least one port, for example to another temperature-control fluid-conducting device of the vehicle and can thus be integrated into the vehicle in a simple manner.

[0037] The battery module expediently comprises a temperature control plate which is thermally connected to a plurality of battery cells.

[0038] In this case, the temperature control plate is designed such that a first temperature control fluid can flow through it.

[0039] It is thereby possible to provide reliable temperature control for a plurality of battery cells by means of a temperature control plate through which a first temperature control fluid can flow.

[0040] For this purpose, the temperature control plate can, for example, comprise a plurality of flow channels.

[0041] It is particularly expedient if the battery module comprises an interior.

[0042] In this case, a plurality of battery cells are accommodated in the interior.

[0043] Furthermore, the interior is designed such that a first temperature control fluid can flow through it.

[0044] In this case, it is preferred that a plurality of battery cells are arranged in such a way that a first temperature control fluid can flow directly around them.

[0045] For this purpose, the interior space can be sealed in a fluid-tight manner with respect to the surrounding environment, for example, apart from a first port designed for the inflow of the temperature control fluid into the interior space and a second port designed for the outflow of the temperature control fluid from the interior space.

[0046] As a result, it is possible, in a particularly simple manner, to further improve the heat conduction which is limited due to the thermal resistance between the plurality of battery cells and the temperature control plate when constructing a battery module with a temperature control plate.

[0047] Furthermore, by circulating the first temperature control fluid indirectly around the plurality of battery cells, the proportion of the surface of the plurality of battery cells that indirectly contributes to temperature control can be further increased compared to a solution using a temperature control plate, since in the case of a solution using a temperature control plate, in particular only the bottom of the plurality of battery cells can contribute to temperature control.

[0048] As a result, direct or indirect temperature control can be implemented by circulating the plurality of battery cells in an indirect manner with the first temperature control fluid, wherein the heat transfer between the plurality of battery cells and the first temperature control fluid is further increased and in particular maximized, since, for example, the entire surface of the plurality of battery cells can be used for temperature control.

[0049] In particular, it is thereby possible to further improve the temperature control of a plurality of battery cells and thus to avoid high cell temperatures, in particular, for example during rapid charging operations.

[0050] According to a preferred aspect of the present invention, the second conveying unit is configured as a turbine, an impeller or a paddle wheel.

[0051] This makes it possible for the second delivery unit to absorb kinetic energy from the second temperature-control fluid flowing through the second temperature-control fluid guide device in a simple and also reliable manner.

[0052] At this point it should be noted that the second conveyor unit preferably does not comprise an actively driven drive unit, such as a motor.

[0053] The absorbed kinetic energy is converted in particular into rotational energy or rotational work.

[0054] According to another preferred aspect of the present invention, the first conveying element and the second conveying element are connected to each other in a mechanically coupled manner.

[0055] In this case, the mechanically coupled connection can be designed, for example, by means of a mechanical shaft, whereby in particular a simple transmission of rotational work is also possible.

[0056] According to another preferred aspect of the present invention, the first conveying element and the second conveying element are connected to each other by magnetic coupling.

[0057] As a result, it is advantageously possible, for example, to dispense with additional shaft seals.

[0058] At this point it should be noted that the second delivery unit absorbs kinetic energy from the second temperature-control fluid, which flows through the second temperature-control fluid guide device, for example, and converts the absorbed kinetic energy into rotational energy or rotational work.

[0059] Since the first conveyor unit and the second conveyor unit are connected to one another, in particular mechanically and / or magnetically coupled, rotational energy or rotational work can be transferred from the second conveyor unit to the first conveyor unit.

[0060] As a result, the first delivery unit can deliver the first temperature-control fluid contained in the first temperature-control fluid guiding device, so that the first temperature-control fluid can flow through the first temperature-control fluid guiding device.

[0061] In other words, this means, in particular, that a flow of the second temperature-control fluid through the second temperature-control fluid-conducting device results in a flow of the first temperature-control fluid through the first temperature-control fluid-conducting device.

[0062] Thus, for example, the flow energy of the second temperature-control fluid in the second temperature-control fluid guide device is formed due to the coupling of the first conveying element to the second conveying element so that the first temperature-control fluid is forced to flow through the first temperature-control fluid guide device.

[0063] The first temperature-control fluid can thus be circulated without requiring an additional actively driven conveying element, such as a pump, in the first temperature-control fluid guide device.

[0064] In this case, the first conveying element can be designed, for example, as an impeller or a paddle wheel.

[0065] As a result, the first temperature-control fluid can be conveyed in a simple manner via the first temperature-control fluid guide device.

[0066] It is particularly expedient if the first temperature-control fluid guiding device and the second temperature-control fluid guiding device are separated in a completely fluid-conducting manner.

[0067] It is thereby possible to form two flow regions which are designed to be completely separate from one another, without mixing of the first temperature control fluid with the second temperature control fluid being possible.

[0068] Thus, the temperature control of the battery module with the first temperature control fluid can be designed independently of the second temperature control fluid.

[0069] In particular, the second temperature-control fluid guide device can be connected in a fluid-conducting manner to a temperature-control system of the vehicle, which can include, for example, hoses, a pump or a compressor.

[0070] In particular, it is thereby possible, by means of the sealed separation of the first temperature control fluid and the second temperature control fluid from one another, to guide a temperature control fluid that complies with standards and is specified by the vehicle manufacturer, for example, in the first temperature control fluid guide device.

[0071] For the sake of completeness, it should also be stated at this point that for the heat transfer between the first temperature-control fluid guide device and the second temperature-control fluid guide device and therefore also between the first temperature-control fluid and the second temperature-control fluid, any heat exchanger unit can be used which separates the first temperature-control fluid guide device and the second temperature-control fluid guide device from each other in a fluid-conducting manner.

[0072] For example, such a heat exchanger can be designed as a plate structure or as a double-tube structure with spiral or linear transfer tubes. In particular, such a heat exchanger unit should be adapted to the available installation space.

[0073] In summary, it should also be noted at this point that, for example, to cool a battery module, a first temperature control fluid flows through the first temperature control fluid guide device and, due to the heat-conducting connection between the first temperature control fluid guide device and the battery module, absorbs heat from a plurality of battery cells, thereby making it possible to cool the battery cells.

[0074] Due to the heat-conducting connection between the heat exchanger unit and the first and second temperature-control fluid guide devices, the first temperature-control fluid can transfer absorbed heat to the second temperature-control fluid by means of the heat exchanger unit, thereby in turn cooling the first temperature-control fluid.

[0075] In this case, the first temperature-control fluid conducting device is designed as a closed circuit.

[0076] Of course, a plurality of battery cells can also be heated by means of the battery system.

[0077] For this purpose, the first temperature control fluid flows through the first temperature control fluid guide device and, due to the heat-conducting connection between the first temperature control fluid guide device and the battery module, can output heat to the plurality of battery cells, whereby the plurality of battery cells can be heated. Here, due to the heat-conducting connection between the heat exchanger unit and the first temperature control fluid guide device and the second temperature control fluid guide device, the first temperature control fluid can absorb heat from the second temperature control fluid by means of the heat exchanger unit, whereby the first temperature control fluid can be heated again.

[0078] In this case, the first temperature-control fluid conducting device is designed as a closed circuit.

[0079] Overall, here both when cooling a plurality of battery cells by means of the first temperature control fluid and when heating a plurality of battery cells by means of the first temperature control fluid, a flow of the first temperature control fluid is caused solely by the flow energy of the second temperature control fluid.

[0080] Furthermore, the invention relates to a vehicle which comprises the battery system according to the invention and which has just been described.

[0081] In this case, at least one port of the second temperature-control fluid-conducting device is connected in a fluid-conducting manner to another temperature-control fluid-conducting device of the vehicle.

[0082] Furthermore, the further temperature-control fluid guiding device comprises a further conveying element.

[0083] Here, the further delivery unit is designed to deliver the second temperature-control fluid via the further temperature-control fluid guide device and the second temperature-control fluid guide device. In particular, the further delivery element is designed as an actively driven delivery element, such as a pump.

[0084] In this case, due to the coupled connection of the first and second conveyor elements, the further conveyor element can bring about a flow of the first temperature control fluid through the first temperature control fluid guide device, thus ensuring reliable temperature control of the battery module.

[0085] Of course, it is possible at this point that the battery system of the vehicle can be developed using all of the advantageous developments described in conjunction with the battery system according to the invention.

[0086] The invention also relates to a method for operating a battery system according to the invention.

[0087] In this case, in a first method step, a battery system according to the invention is provided.

[0088] In a second method step, the first temperature-control fluid is accommodated in the second temperature-control fluid guide device.

[0089] In a third method step, a second temperature-control fluid flows through the second temperature-control fluid guide device.

[0090] In this case, mechanical work is transferred from the second conveyor element to the first conveyor element.

[0091] Here, due to the coupled connection of the first and second conveying elements, a flow of the second temperature control fluid through the second temperature control fluid guide device can cause a flow of the first temperature control fluid through the first temperature control fluid guide device, thus reliably controlling the temperature of the battery module.

[0092] The method is carried out in this case in such a way that a plurality of battery cells, which are preferably designed as lithium-ion battery cells or lithium-polymer battery cells, have a temperature below 35° C. For example, at temperatures above 35° C., the flow rate of the second temperature control fluid can be increased, so that increased heat dissipation is also possible with the aid of the first temperature control fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] An exemplary embodiment of the invention is shown in the single drawing and is explained in more detail in the following description.

[0094] Figure 1 An embodiment of a battery system according to the invention is schematically shown. DETAILED DESCRIPTION

[0095] Should Figure 1 An embodiment of a battery system 1 according to the invention is shown schematically.

[0096] The battery system 1 can in particular be Figure 1 The battery system 1 of the vehicle cannot be seen.

[0097] The battery system 1 comprises a battery module 2 which comprises a plurality of battery cells 3 .

[0098] In this case, the plurality of battery cells 3 can be designed, for example, as lithium-ion battery cells or as lithium-polymer battery cells.

[0099] The battery system 1 has a first temperature-control fluid conducting device 4 .

[0100] The first temperature-control fluid guide device 4 is designed in this case such that a first temperature-control fluid 5 can flow through it.

[0101] In particular, a first temperature-control fluid 5 is accommodated in the first temperature-control fluid guide device 4 .

[0102] In this case, the first temperature control fluid 5 can be designed as a water-glycol mixture or as a dielectric temperature control fluid.

[0103] In this case, the first temperature-control fluid guiding device 4 further comprises a first conveyor unit 6 which is designed to convey the first temperature-control fluid 5 through the first temperature-control fluid guiding device 4 .

[0104] In this case, the first conveying unit 4 can be designed, for example, as an impeller or a paddle wheel.

[0105] In this case, the first temperature-control fluid guide device 4 is also connected in a thermally conductive manner to the battery module 2 .

[0106] also, Figure 1 It is shown that the battery module 2 can comprise a temperature control plate 14 which is thermally connected to a plurality of battery cells 3. It is also shown that a first temperature control fluid 5 can flow through the temperature control plate 14.

[0107] also, Figure 1 It is also shown that the battery module 2 can include an inner cavity 15 , wherein a plurality of battery cells 3 are accommodated in the inner cavity 15 .

[0108] In this case, the interior 15 is designed such that the first temperature control fluid 5 can flow through it.

[0109] In particular, the battery module 2 further comprises a first port 151 designed to allow the first temperature control fluid 5 to enter the interior 15 and a second port 152 designed to discharge the first temperature control fluid 5 from the interior 15. In this case, a plurality of battery cells 3 can preferably be arranged so that the first temperature control fluid 5 can flow around them in a non-indirect manner.

[0110] Furthermore, the battery system 1 has a second temperature-control fluid conducting device 7 . The second temperature-control fluid conducting device 7 is designed in this case such that a second temperature-control fluid 8 can flow through it.

[0111] The second temperature-control fluid guide device 7 here also has a second delivery unit 9 which is designed to absorb kinetic energy from the second temperature-control fluid 8 .

[0112] In this case, the second delivery element 9 can be designed, for example, as a turbine, an impeller or a paddle wheel.

[0113] Furthermore, the second temperature-control fluid guide device 7 comprises a port 10 which is designed for a fluid-conducting connection to a further temperature-control fluid guide device 11 .

[0114] according to Figure 1 In the exemplary embodiment of a battery system 1 shown in FIG, the port 10 is connected in a fluid-conducting manner to a further temperature-control fluid guide device 11 of the vehicle (not visible).

[0115] Furthermore, the battery system 1 comprises a heat exchanger unit 12 . The heat exchanger unit 12 is designed to transfer heat from the first temperature-control fluid-conducting device 4 to the second temperature-control fluid-conducting device 7 .

[0116] Temperature control of the battery module 2 by means of the second temperature control fluid 8 is therefore possible.

[0117] Furthermore, the first conveyor element 6 and the second conveyor element 9 are connected to each other in a coupled manner by means of a coupling element 13. In this case, mechanical work can be transferred from the second conveyor element 9 to the first conveyor element 6 by means of the coupling element 13. In this case, the coupling element 13 can be designed in such a way that the first conveyor element 6 and the second conveyor element 9 are connected to each other mechanically coupled or in such a way that the first conveyor element 6 and the second conveyor element 9 are connected to each other magnetically coupled.

[0118] At this point it should once again be noted that the first temperature-control fluid guiding device 4 and the second temperature-control fluid guiding device 7 are separated in a fluid-conducting manner.

[0119] The battery system 1 can be connected to a temperature control system of the vehicle (not visible).

[0120] The battery system 1 also has a port 10 which is connected to the Figure 1 It is connected in a fluid-conducting manner to a further temperature-control fluid guide device 11 of the vehicle.

[0121] In this case, the further temperature-control fluid guiding device 11 has a further conveying element 16 which can be designed as a pump, for example.

[0122] The further conveying element 16 is designed here to convey the second temperature-control fluid 8 via the second temperature-control fluid guiding device 7 and the further temperature-control fluid guiding device 11 .

[0123] Thus, due to the mechanical or magnetic coupling of the first conveyor element 6 with the second conveyor element 9 by means of the coupling element 13 , in particular the further conveyor element 16 can cause the first temperature control fluid 5 to flow through the first temperature control fluid guide device 4 , so that the battery system 1 itself does not require actively driven conveyor elements.

Claims

1. A battery system comprising a battery module (2) comprising a plurality of battery cells (3), wherein the battery cell (3) is designed as a lithium-ion battery cell or as a lithium-polymer battery cell, The battery system (1) comprises a first temperature-control fluid guide device (4), which is designed to allow a first temperature-control fluid (5) to flow through it, and further comprises a first conveying element (6) which is designed to convey the first temperature-control fluid (5) through the first temperature-control fluid guide device (4); and The first temperature regulating fluid guide device (4) is thermally connected to the battery module (2). The battery system (1) comprises a second temperature-control fluid guide device (7) which is designed so that a second temperature-control fluid (8) can flow through it and further comprises a second delivery element (9) which is designed to absorb kinetic energy from the second temperature-control fluid (8). The second temperature-control fluid guide device (7) has at least one port (10) which is designed for fluid-conducting connection to a third temperature-control fluid guide device (11), The battery system (1) further comprises a heat exchanger unit (12) which is designed to conduct heat to the first temperature-control fluid guide device (4) and the second temperature-control fluid guide device (7), wherein the heat exchanger unit is designed to transfer heat between the first temperature-control fluid guide device (4) and the second temperature-control fluid guide device (7). It is characterized in that The first conveying element (6) and the second conveying element (9) are coupled to one another in such a way that mechanical work can be transmitted from the second conveying element (9) to the first conveying element (6).

2. The battery system according to claim 1, It is characterized in that A first temperature-control fluid (5) is accommodated in the first temperature-control fluid guide device (4), wherein the first temperature-control fluid (5) is designed as a water-glycol mixture or a dielectric temperature-control fluid.

3. The battery system according to any one of claims 1 to 2, It is characterized in that The battery module (2) comprises a temperature regulating plate (14) thermally connected to the plurality of battery cells (3). The temperature control plate (14) is designed so that the first temperature control fluid (5) can flow through it.

4. The battery system according to claim 1 or 2, It is characterized in that The battery module (2) comprises an inner cavity (15) in which the plurality of battery cells (3) are accommodated. The inner space (15) is designed such that the first temperature control fluid (5) can flow through it.

5. The battery system according to claim 4, The plurality of battery cells (3) are arranged so that the first temperature-control fluid (5) can flow around them in a non-indirect manner.

6. The battery system according to claim 1 or 2, It is characterized in that The second conveying element (9) is designed as a turbine, an impeller or a paddle wheel.

7. The battery system according to claim 6, It is characterized in that The first conveying element (6) and the second conveying element (9) are connected to each other mechanically and / or magnetically.

8. The battery system according to claim 1 or 2, It is characterized in that The first temperature-control fluid guide device (4) and the second temperature-control fluid guide device (7) are separated in a fluid-conducting manner. 9 . The battery system according to claim 1 , wherein the battery system is a battery system of a vehicle.

10. A vehicle comprising a battery system (1) according to any one of claims 1 to 9, wherein at least one port (10) of the second temperature-control fluid guide device (7) is fluidically connected to a third temperature-control fluid guide device (11) of the vehicle, It is characterized in that The third temperature-control fluid guide device (11) has a third conveying element (16) which is designed to convey the second temperature-control fluid (8) through the third temperature-control fluid guide device (11) and the second temperature-control fluid guide device (7).

11. A method for operating a battery system (1) according to one of claims 1 to 9, It is characterized in that In one method step, a battery system (1) according to one of claims 1 to 9 is provided, and in a second method step, a first temperature-control fluid (5) is accommodated in the first temperature-control fluid guide device (4), and in a third method step, a second temperature-control fluid (8) flows through the second temperature-control fluid guide device (7), In this process, mechanical work is transferred from the second conveyor element (9) to the first conveyor element (6).

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