Battery module, cooling element and use of such a battery module
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- GS YUASA INT LTD
- Filing Date
- 2017-11-03
- Publication Date
- 2026-07-30
AI Technical Summary
Existing battery modules face safety risks due to thermal runaway, which can lead to fire or explosion, and existing cooling systems reduce energy density and fail to prevent thermal propagation effectively.
A battery module design with thermally conductive cooling elements and a tempering fluid with an evaporation temperature below 80°C, combined with safety valves that open at specific pressures or temperatures to manage thermal runaway and prevent propagation.
The solution enhances safety by preventing thermal runaway and propagation, maintaining energy density, and providing efficient cooling without additional space, using a tempering fluid that evaporates to absorb heat and vent gas automatically.
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Abstract
Description
State of the art
[0001] The invention relates to a battery module according to the preamble of the independent claim. Furthermore, the invention also relates to a cooling element of a battery module. The present invention also relates to the use of a battery module for cooling a battery cell exceeding a safety-critical temperature value.
[0002] It is known from the prior art that battery modules can consist of a plurality of individual battery cells, which can be interconnected in series and / or parallel in an electrically conductive manner. For the operation of battery cells in a preferred temperature range, it is further known that battery modules may include a cooling system which is intended in particular to ensure that the battery cells do not exceed a predetermined temperature. Such cooling systems typically lead to a reduction in the energy density of the battery module.
[0003] However, if the battery cells exceed this specified safety-critical temperature, this can lead to a "thermal runaway" of the battery cell, which poses significant safety risks. Furthermore, this can in turn lead to a "thermal runaway" of neighboring battery cells, a so-called "propagation". This poses a significant security risk.
[0004] Such battery cell runaway can be caused, for example, by internal short circuits within the battery cell, excessive current flows, or excessive charging. Runaway from the battery cell can lead to overheating, which further accelerates exothermic chemical reactions occurring within the battery cell and can ultimately lead to a fire or explosion of the battery cell and the entire battery module.
[0005] A battery module in which the battery cells can be cooled is known from the publication DE 102007024869. Disclosure of the invention
[0006] A battery module with a plurality of battery cells with the characteristics of independent claim offers the advantage that the safety of the battery module can be increased in a simple way. In particular, this can prevent the propagation of a battery cell, which can further increase safety. Furthermore, in one embodiment of a battery module according to the invention, the geometric energy density is not increased compared to battery modules known from the prior art.
[0007] For this purpose, a battery module with a plurality of battery cells is provided. The battery cells are primarily designed as lithium-ion battery cells. Furthermore, the majority of battery cells are electrically connected in series and / or parallel. Furthermore, a cooling element is arranged between two battery cells, which is thermally connected to one of the battery cells. In particular, the cooling element is thermally connected to one of the two battery cells and preferably thermally connected to both battery cells.
[0008] A temperature control fluid is incorporated within the cooling element of the battery module. The temperature control fluid has an evaporation temperature below 80 °C. Preferably, the temperature control fluid has an evaporation temperature between 50 °C and 80 °C. In particular, the temperature control fluid has an evaporation temperature between 60 °C and 70 °C.
[0009] Furthermore, the evaporation temperature can also have a value between 0 °C and 80 °C, and especially above 0°C.
[0010] The measures listed in the dependent claims enable advantageous further developments and improvements of the device specified in the independent claim.
[0011] In this context, "propagation" is understood to mean preventing further heating of a battery cell exceeding a certain safety-critical temperature. This allows it to be returned to a non-critical state and prevents the battery cell from running away. Furthermore, the term "propagation" in this context should also include preventing the heating of a battery cell that is located adjacent to a battery cell that has exceeded a certain safety-critical temperature.
[0012] In particular, a battery module according to the invention offers the advantage that a reliable means of cooling the majority of battery cells is created, which can be easily integrated into the battery module without requiring additional installation space and, in particular, which can also be arranged in addition to existing cooling elements.
[0013] Furthermore, the safety of the battery module can also be increased by means of such a cooling element, whereby it is possible to combine a propagation protection and a cooling system.
[0014] It is possible that the phase transition of the temperature control fluid from solid to gaseous or from liquid to gaseous occurs at a temperature below the safety-critical temperature of the battery cell, thus cooling it, particularly before a safety-critical state is reached. It should also be noted that the respective evaporation temperature is selected depending on the pressure of the temperature control fluid within the cooling element.
[0015] It is advantageous if the cooling element is arranged in direct mechanical contact with the battery cell. In particular, the cooling element is arranged in direct mechanical contact with a battery cell housing of the battery cell, wherein the electrochemical components of the battery cell are housed in the battery cell housing. This makes it possible to achieve reliable cooling of the battery cell, as a high thermal conductivity can be achieved due to the direct mechanical contact.
[0016] According to one aspect of the invention, the battery module further comprises an additional cooling element, which may in particular be designed as a cooling plate. Preferably, the additional cooling element is directly thermally connected to the cooling element of the battery module. Thus, it is possible to increase the cooling effect of the cooling element by means of a thermally conductive connection with another cooling element. It should be noted that it is of course also possible to arrange the cooling element alone in the battery module, without providing another cooling element.
[0017] Advantageously, the cooling element includes at least one temperature control channel. This temperature control channel is designed, for example, to allow the flow of the temperature control fluid.
[0018] The temperature control channel is designed, for example, to receive the temperature control fluid. This makes it possible to provide different designs which can be adapted to the respective requirements of the cooling element.
[0019] In particular, the majority of battery cells are arranged side by side in a longitudinal direction of the battery module. Preferably, two battery cells are arranged adjacent to each other with their respective largest side surfaces. In particular, the cooling element is arranged between two battery cells and is also thermally conductive and preferably directly connected to one of the largest side surfaces of each of the two battery cells. This allows for reliable heat transfer.
[0020] According to a particularly preferred aspect of the invention, the cooling element further comprises at least one safety valve. The safety valve is designed in such a way that it opens when a certain pressure or temperature is exceeded. This means, for example, that if the evaporation temperature of the temperature control fluid contained within the cooling element is exceeded, gas may escape from the cooling element due to a phase transition from liquid to gaseous or from solid to gaseous. Thus, for example, the internal pressure generated by the evaporation of the temperature control fluid can cause the safety valve to open. This requires a sufficient increase in pressure. It should be noted at this point that the safety valve is preferably designed in such a way that it opens without the need for electronic or mechanical control when a certain pressure or temperature is exceeded. This causes the safety valve to open automatically and without electronic or mechanical control, for example when a certain safety-critical temperature of the battery cell is exceeded, for example due to battery cell runaway, thereby reducing or keeping constant the temperature of the cooling element due to endothermic evaporation of the temperature control fluid, and thus cooling the battery cells. It should also be noted that a phase transition of the temperature control fluid to a gaseous state can lead to a pressure increase within the cooling element. Thus, for example, it is possible to prevent the first run-through of a battery cell in the majority of battery cells, since spatially close cooling of the respective battery cell is possible. Furthermore, the system reliably prevents the spread of thermal runaway to other battery cells. Additionally, the safety valves are arranged in such a way that any escaping gas can expand unhindered.
[0021] Advantageously, at least one safety valve is arranged on a side surface of the cooling element that differs from one of its largest side surfaces. This makes it possible to arrange the cooling element in such a way that its largest side surfaces, which are also directly opposite each other, can be arranged to be thermally conductive and preferably also in direct mechanical contact with the battery cells.
[0022] According to an advantageous aspect of the invention, the at least one safety valve is arranged in such a way that the at least one safety valve is always arranged in relation to a battery cell. For example, at least one safety valve can be located closer to one battery cell than to another battery cell.
[0023] Furthermore, the invention also relates to a cooling element, in particular of a battery module according to the invention as described above. The cooling element is designed to be arranged between two battery cells of a battery module.
[0024] Furthermore, a temperature control fluid is incorporated within the cooling element, which has an evaporation temperature below 80 °C. Preferably, the temperature control fluid has an evaporation temperature between 50 °C and 80 °C. In particular, the temperature control fluid has an evaporation temperature between 60 °C and 70 °C. Furthermore, the temperature control fluid can also have an evaporation temperature with a value between 0° and 80° C, and in particular above 0 °C.
[0025] Of course, it is possible to further develop a cooling element according to the invention with all the further developments described in connection with the battery module according to the invention.
[0026] The present invention also relates to the use of a described battery module according to the invention. The cooling element is designed in such a way that it cools one of the majority of battery cells, which has a temperature value that is above a certain safety-critical value for the battery cell. Thus, it is possible to further increase the safety of the battery module by using the battery module according to the invention, since in particular thermal propagation due to runaway in a battery cell can be prevented or slowed down. List of characters
[0027] Exemplary embodiments of the invention are shown in the drawings and explained in more detail in the following description.
[0028] It shows Fig. 1 in a perspective view a first embodiment of a battery module according to the invention, Fig. 2 in a perspective view a second embodiment of a battery module according to the invention, Fig. 3 in a sectional view from the side a first embodiment of a cooling element according to the invention, Fig. 4 in a sectional view from the side a second embodiment of a cooling element according to the invention, Fig. 5 in a perspective view a third embodiment of a cooling element according to the invention, Fig. 6 in a perspective view a fourth embodiment of a cooling element according to the invention, Fig. 7. A first possibility for cooling a safety-critical battery cell and Fig. 8 a second possibility of cooling a safety-critical battery cell.
[0029] The Fig. Figure 1 schematically shows a first embodiment of a battery module according to the invention in a perspective view. 1 .
[0030] The battery module 1 has a majority of battery cells 2 on, which are designed in particular as lithium-ion battery cells. The majority of battery cells 2 This is done using cell connectors 3 electrically conductively interconnected, whereby the one in the Fig. 1. The illustrated embodiment shows an electrically serial connection of the individual battery cells. 2 shows each other. In particular, the battery cells exhibit 2 each one battery cell housing 21on, in which the electrochemical components of the battery cells 2 are arranged. Furthermore, the battery cells exhibit 2 voltage taps each 22 on, which are electrically conductive with the cell connectors 3 are connected.
[0031] Furthermore, the battery module 1 Cooling elements 4 on, which each between two battery cells 2 are arranged. The cooling elements 4 are thermally conductive with a battery cell 2 tied together.
[0032] Furthermore, as will be described later, within the cooling element 4 a temperature control fluid was included.
[0033] The cooling elements 4 are, as from the Fig. 1 can be seen, each in direct mechanical contact with a respective battery cell 2 arranged. In particular, the cooling elements 4according to the Fig. 1 shown embodiment of the battery module 1 each in direct mechanical contact with the battery cell housing 21 the respective battery cell 2 arranged.
[0034] Furthermore, the Fig. 1, that the battery module 1 furthermore another cooling element 5 may include. The additional cooling element can then be used 5 according to the Fig. 1 shown embodiment of the battery module 1 for example as a cooling plate 6 be trained.
[0035] The additional cooling element is included. 5 and especially the cooling plate 6 directly heat-conducting with the cooling element 4 tied together. For example, this can be direct heat-conducting contact between the other cooling element. 5 and especially the cooling plate 6as well as the cooling element 4 may be formed due to direct mechanical contact or through jointly formed temperature control channels.
[0036] The majority of battery cells 2 is in a longitudinal direction 7 of the battery module 1 arranged side by side. Furthermore, there are two battery cells each. 2 with their largest side surfaces 8 each one arranged next to the other. It can also be seen that the cooling elements 4 each also directly adjacent and preferably also in mechanical contact with the largest side surfaces 8 the battery cells 2 are arranged.
[0037] It should be noted at this point that the cooling elements 4 Safety valves 9These may include devices that open when a certain pressure or temperature is exceeded, allowing air to escape inside the cooling element. 4 Gas can escape, whereby the safety valves 9 will be described later.
[0038] The safety valves 9 are involved, as can be seen from the Fig. 1 can be seen on a side surface 10 of the cooling element 4 arranged. The side surface is 10 differing from one of the largest side surfaces of the cooling element. The largest side surface of the cooling element 4 is directly adjacent to and, in particular, mechanically in contact with the largest side surface 8 the respective battery cell 2 arranged.
[0039] The Fig. Figure 2 shows a second embodiment of a battery module according to the invention. 1 .
[0040] The difference lies in the Fig. 2 second embodiment of the battery module shown 1 from the in the Fig. 1 first embodiment of the battery module shown 1 firstly, because in the Fig. In the first embodiment shown in 1, a further cooling element 5 is ordered, whereupon in the Fig. The second embodiment shown in 2 is omitted. Furthermore, the design differs from the Fig. 2 second embodiment of the battery module shown 1 from the in the Fig. 1 first embodiment of the battery module shown 1 because in the Fig. 2 second embodiment shown between two battery cells 2 always a cooling element 4 is arranged, whereas in the Fig. 1 first embodiment shown in the longitudinal direction 7 alternating between two battery cells2 a cooling element 4 is arranged and between two battery cells 2 no cooling element 4 is arranged.
[0041] Of course, it is also possible to combine the two designs.
[0042] Both in the Fig. 1 as well as the Fig. 2 are defined by the reference numeral 11 The arrows indicate exemplary cooling flows, which are intended to illustrate that the cooling elements 4 reliable and uniform cooling of the majority of battery cells 2 is trained.
[0043] It should also be noted at this point that the arrows are marked with the reference symbol. 11 contrary to the direction of the heat flows, which are present in the majority of battery cells 2 on the cooling elements 4 They are to be transferred, shown, and serve solely to illustrate the uniform and efficient cooling.
[0044] The Fig. Figure 3 shows a sectional view from the side of a first embodiment of a cooling element according to the invention. 4 , which in particular includes a cooling element 4 a battery module according to the invention 1 according to the Fig. 1 or Fig. 2 is.
[0045] In particular, the focus is on one of the largest side surfaces. 12 of the cooling element 4 shown which are immediately adjacent and preferably also mechanically contacting the largest side surface 8 the respective battery cell 2 is ordered.
[0046] The side surfaces are also shown for clarification. 10 marked which of the largest side faces 12 are different.
[0047] In the Fig. 3 first embodiment of the cooling element shown 4 The cooling element 4a temperature control channel 13 on, which is supplied by a temperature control fluid 14 is flowed through. Of course, the invention is not limited to the illustrated design of the temperature control channel. 13 It is not limited, but other design options are also conceivable.
[0048] Furthermore, the flow channel 13 also with one in the Fig. 1 shown cooling plate 6 be fluid-conducting.
[0049] Furthermore, from the Fig. 3. To recognize that the safety valves 9 are arranged in such a way that they are connected to the temperature control channel 13 are connected in such a way that within the temperature control body 13 forming gas via the safety valves 9 from the temperature control channel 13 can escape.
[0050] The Fig. Figure 4 shows a sectional view from the side of a second embodiment of a cooling element according to the invention. 4 , which in particular includes a cooling element 4 a battery module according to the invention 1 according to the Fig. 1 or Fig. 2 is.
[0051] In particular, the difference lies in the Fig. 4 second embodiment of the cooling element shown 4 from the in Fig. 3 first embodiment of the cooling element shown 4 because the cooling element 4 according to Fig. 4 in contrast to the one in the Fig. 3 first embodiment of the cooling element shown 4 an interior 15 forms, in which the temperature control fluid 14 has been recorded. The interior 15 can also be used as a reservoir 16 It is designated as such and is designed in particular in such a way that the temperature control fluid is evenly distributed.14 over the entire cooling element 4 is possible.
[0052] It goes without saying that the invention does not apply to the depicted design of the interior space. 15 is limited, but other design options are also conceivable.
[0053] Furthermore, from the Fig. 4. To recognize that the safety valves 9 are arranged in such a way that they align with the interior 15 are connected in such a way that within the interior 15 forming gas via the safety valves 9 from the temperature control channel 13 can escape.
[0054] The in the Fig. 3 and Fig. 4 temperature control fluids to be identified 14 It has an evaporation temperature below 80 °C. Preferably, the temperature control fluid 14 an evaporation temperature with a value between 50 degrees and 80 °C. In particular, the temperature control fluid exhibits 14 an evaporation temperature with a value between 60 °C and 70 °C. If a battery cell exceeds 2 , which are thermally conductive with the cooling element 4 is connected, a safety-critical temperature for the respective battery cell 2 , so the battery cell 2 on the cooling element 4 The transferred heat causes the evaporation temperature of the temperature control fluid to rise. 14 is exceeded. This causes the temperature control fluid to evaporate. 14 and thus at least partially transitions into the gaseous state, with the respective enthalpy of vaporization being that of the battery cell 2 can absorb emitted heat and thus the battery cell 2 can cool. The gaseous component of the temperature control fluid 14 can be done using the safety valves 9 escape.
[0055] The Fig. Figure 5 shows a perspective view of a third embodiment of a cooling element according to the invention. 4 .
[0056] The safety valves shown are... 9 evenly across the smallest side surfaces 10 distributed, whereby this is understood in particular to mean that the safety valves 9 in the longitudinal direction 7 at an equal distance from the adjacent battery cells 2 are arranged.
[0057] The Fig. Figure 6 shows a perspective view of a fourth embodiment of a cooling element according to the invention. 4 .
[0058] The safety valves shown are... 9 on the front side surface 101 evenly across the front side surface 101 distributed, and especially analogous to Fig. 5, arranged.
[0059] The safety valves shown are... 9on the upper side surface 102 arranged in such a way that the safety valves 9 always one battery cell 2 can be assigned. In particular, those with the reference number 91 designated safety valves 9 one to the right of the cooling element 4 arranged battery cell 2 assigned and those with the reference mark 92 designated safety valves 9 one to the left of the cooling element 4 arranged battery cell 2 assigned.
[0060] This is in the Fig. 5 and Fig. 6. To recognize once again that the safety valves 9 each on one of the smallest side surfaces 10 are arranged which are bordered by a largest side surface 12 of the cooling element 4 They are different.
[0061] The Fig. Figure 7 shows a first possibility for cooling a safety-critical battery cell. 200 , which, for example, has a temperature above a safety-critical value, as shown in the left-hand illustration of the Fig. 7 is supposed to be indicated.
[0062] In the right-hand representation of the Fig. 7 shows that the temperature control fluid 14 evaporates and thus the battery cell 200 can be cooled. The safety valves then open. 9 on the side surfaces 10 .
[0063] It should be noted at this point that the cooling element 4 in particular according to Fig. 5 is trained.
[0064] The Fig. Figure 8 shows a second possibility for cooling a safety-critical battery cell. 200 , which, for example, has a temperature above a safety-critical value, as shown in the left-hand illustration of the Fig. 8 is supposed to be indicated.
[0065] In the right-hand representation of the Fig. 8 shows that temperature control fluid 14 escapes, and thus the battery cell 200 can be cooled. The safety valves then open. 91 on the upper side surface 102 and the safety valves 9 on the front side surface 10 .
[0066] It should be noted at this point that the cooling element 4 in particular according to Fig. 6 is trained.
[0067] Furthermore, it is of course also possible to use the safety valves. 9 outflowing, liquid temperature control fluid 14 contribute to cooling.
[0068] It should be noted at this point that all the exemplary embodiments shown serve only to describe the invention and can in particular be combined with one another. QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] DE 102007024869
[0005]
Claims
[1] Battery module with a plurality of battery cells (2), especially lithium-ion battery cells, whereby the majority of battery cells (2) are electrically connected in series and / or in parallel, and a cooling element (4) is arranged between two battery cells (2), which is thermally connected to one battery cell (2), characterized by , that a temperature control fluid (14) is included within the cooling element (4), which has an evaporation temperature of a value below 80°C, preferably a value between 50°C and 80°C, and in particular a value between 60°C and 70°C. [2] Battery module according to the preceding claim 1, characterized by, that the cooling element (4) is arranged in direct mechanical contact with the battery cell (2), in particular in direct mechanical contact with a battery cell housing (21) of the battery cell (2). [3] Battery module according to any one of the preceding claims 1 to 2, characterized by , that the battery module (1) also includes another cooling element (5), in particular a cooling plate (6), which in particular is directly connected to the cooling element (4) in a thermally conductive manner. [4] Battery module according to any one of the preceding claims 1 to 3, characterized by , that the cooling element (4) comprises at least one temperature control channel (13) which is designed to allow flow of the temperature control fluid (14) or which is designed to receive the temperature control fluid (14). [5] Battery module according to any one of the preceding claims 1 to 4, characterized by , that the majority of battery cells (2) are arranged side by side in a longitudinal direction (7) of the battery module (1), and furthermore Each pair of battery cells (2) are arranged adjacent to each other with their respective largest side surfaces (8). [6] Battery module according to any one of the preceding claims 1 to 5, characterized by , that the cooling element (4) further comprises at least one safety valve (9) which, when It opens when a certain pressure or temperature is exceeded. [7] Battery module according to the preceding claim 6, characterized by , that at least the safety valve (9) is arranged on a side surface (10) of the cooling element (4) that differs from a largest side surface (12) of the cooling element (4). [8] Battery module according to the preceding claim 7, characterized by, that the at least one safety valve (9) is arranged such that the at least one safety valve (9, 91, 92) is always assigned to a battery cell (2). [9] Cooling element of a battery module (1) in particular of a battery module (1) according to claims 1 to 8, wherein the cooling element (4) is formed into an arrangement between two battery cells (2) of a battery module (1), characterized by , that a temperature control fluid (14) is included within the cooling element (4), which has an evaporation temperature of a value below 80°C, preferably a value between 50°C and 80°C, and in particular a value between 60°C and 70°C. [10] Use of a battery module (1) according to any one of claims 1 to 8, wherein the cooling element (4) is designed in such a way that a battery cell (2) of the plurality of battery cells (2) which has a temperature value which is above a certain safety-critical temperature value for the battery cell (2) is cooled.