Battery assembly

Abstract

The present invention relates to a battery assembly comprising at least one battery module (1). According to the invention, said battery module (1) comprises a plurality of rows of battery cells (2), each battery cell (2) being placed in a separate battery cell (2) chamber (3) and separated from one another by a partition (4), each separate battery cell chamber (3) comprising a vent hole (30) communicating with a gas discharge channel (5) for discharging gases generated by thermal runaway, said gas discharge channel being arranged in an upper portion (6; 6') of said battery module (1), said gas discharge channel (5) being common to said plurality of battery cells (2) and comprising a lower wall (50) consisting of a plate configured to form a thermal shield (51), an upper wall (52) consisting of a plate configured to form a thermal shield (53) and two side edges (54) comprising a polymeric-based material (56), said battery module (1) comprising a compression system (7) provided with at least one gas outlet (8) in fluid connection with said gas discharge channel (5).

Description

[0001] This invention relates to a battery assembly configured to manage the discharge of gases generated by thermal runaway within the battery cells of the battery assembly. More specifically, this invention relates to a battery assembly comprising at least one battery module, said battery module including a plurality of battery cells arranged in a row and provided with channels for discharging gases generated by thermal runaway within the battery cells of the battery assembly.

[0002] Thermal runaway occurs in a battery assembly when the temperature of one or more battery cells rises to the point that it triggers a chain reaction. This chain reaction accelerates chemical reactions within the battery cell or multiple battery cells, facilitating the rapid release of heat. Thermal runaway can be caused by insufficient cooling of the battery cells during assembly operation. It can also be triggered by other events such as short circuits, mechanical shocks, exposure to extreme temperatures, or manufacturing defects. During thermal runaway, hot gases and other flammable materials may escape from one or more battery cells. If not properly managed, the resulting gases can lead to fire or explosion. Therefore, thermal runaway in one or more high-capacity battery cells (especially those using NMC (nickel-manganese-cobalt) technology) can result in the release of gases at temperatures exceeding 900°C within the battery assembly.

[0003] In the prior art, particularly according to US2019 / 0173068A1, but also according to EP2637235A1, US2015 / 214525A1 and EP2538470A1, a battery assembly is known that includes a battery module comprising a row of multiple battery cells, the battery module being provided with a gas venting channel. In the disclosed module, the venting channel is fluidly connected to the multiple battery cells by means of a slot extending along the venting channel, the slot being shared by the multiple battery cells. This arrangement ensures the venting of gases generated by thermal runaway within one battery cell. However, such a device for venting gases generated by thermal runaway within one battery cell does not significantly reduce the risk of thermal runaway in other battery cells.

[0004] The present invention is particularly intended to provide a battery assembly that enables the minimization of the propagation of thermal runaway from one battery cell to other battery cells.

[0005] Therefore, the subject of this invention is a battery assembly comprising at least one battery module. According to the invention, the battery module comprises a plurality of battery cells arranged in a row, each battery cell being placed in a separate battery cell chamber and separated from each other by a partition. Each separate battery cell chamber includes a vent communicating with a gas exhaust channel for discharging gases generated by thermal runaway. This gas exhaust channel is arranged in the upper part of the battery module, is shared by the plurality of battery cells, and includes a lower wall, an upper wall, and two side edges. The lower wall is formed by a plate configured to form a heat shield, the upper wall is formed by a plate configured to form a heat shield, and the two side edges comprise a polymer-based material. The battery module includes a compression system having at least one gas outlet in fluid communication with the gas exhaust channel.

[0006] Therefore, the battery module—where each battery cell is located in a separate battery cell chamber, and each separate battery cell chamber includes a vent communicating with a gas exhaust channel arranged in the upper part of the battery module for venting gases generated by thermal runaway—can reduce the risk of thermal runaway from one battery cell propagating to other battery cells. The presence of vents in each battery cell chamber reduces the risk of contact between gases generated by thermal runaway from one battery cell and other battery cells. Furthermore, the battery module is provided with a gas exhaust channel arranged in its upper part, which is shared by multiple battery cells and includes a lower wall formed by a plate configured to form a heat shield, an upper wall formed by a plate configured to form a heat shield, and two side edges comprising a polymer-based material. Thus, a gas exhaust channel with this structure allows for an exhaust channel configured to reduce the propagation of heat generated within the battery assembly while possessing the flexibility to withstand the significant temperature and pressure stresses associated with the emission of gases generated by thermal runaway. Preferably, the upper wall formed by the plate configured to form a heat shield is a stainless steel plate or a ceramic plate. The presence of a compression system having at least one gas outlet fluidly connected to the gas emission channel allows for improved battery assembly durability and safety due to potential expansion of the battery cells during their service life. The compression applied to the battery cells via the compression system relates not only to the battery cell technology but also to the battery cell configuration. Preferably, the lower wall of the emission channel is constructed of a metal or ceramic plate, preferably a metal plate with a ceramic coating on the portion exposed to gases generated by thermal runaway. Preferably, the upper wall of the emission channel is constructed of a metal plate with a ceramic coating on the portion exposed to gases generated by thermal runaway. The concepts of "upper" and "lower" in relation to the gas emission channel are relative to the ground when the battery assembly is in the operating position. The expression "polymer-based material" means that the material contains at least 50% by weight of the polymer.

[0007] According to a preferred embodiment, in the battery assembly according to the invention, the polymer-based material includes polymer foam.

[0008] Therefore, due to the high tolerance of the pores constituting the polymer foam, its presence achieves a given degree of sealing and limits the amount of gas that may escape from the venting channels located on the upper part of the battery module. The concept of "upper part" of the battery module here is defined with reference to the ground when the battery assembly is in its operating position.

[0009] According to a preferred embodiment, in the battery assembly according to the invention, the polymer-based material constituting the two side edges is covered with a metal or ceramic film at least on the portion exposed to the gas generated by thermal runaway.

[0010] Therefore, the presence of a metal or ceramic film at least on the side edge exposed to the gas generated by thermal runaway prevents the polymer-based material from deteriorating due to heat dissipation or thermal shielding effects.

[0011] According to a preferred embodiment, in the battery assembly according to the invention, at least one of the two side edges of the gas discharge channel for discharging gases generated by thermal runaway is partially formed by a flange of an upper wall, said upper wall being constructed of a plate configured to form a heat shield. Preferably, the two side edges of the gas discharge channel for discharging gases generated by thermal runaway are partially formed by a flange of an upper wall, said upper wall being constructed of a plate configured to form a heat shield. More preferably, one or more side edges made of a polymer-based material are inserted into grooves or corner pieces present in the upper wall, said upper wall being constructed of a plate configured to form a heat shield.

[0012] Therefore, the flange of the upper wall formed by the plate configured to form a heat shield constitutes at least one of the two side edges of a gas exhaust channel for discharging gases generated by thermal runaway, preferably constituting both side edges of a gas exhaust channel for discharging gases generated by thermal runaway, which can reduce the risk of degradation of polymer-based materials. Advantageously, the plate configured to form a heat shield also integrates a specific shape that allows protection of polymer-based materials, which is formed by the flange of the upper wall formed by the plate configured to form a heat shield, preferably in the form of a groove or angular piece.

[0013] According to a preferred embodiment, in the battery assembly according to the invention, the gas emission channel is located in the middle of the upper part of the battery module.

[0014] Therefore, the exhaust channel located in the middle of the upper part of the battery module allows for optimized emission of gases generated by thermal runaway within the battery module. The statement "in the middle of the upper part of the battery module" means that the gas exhaust channel is located on a straight line that cuts the upper part of the battery module into two approximately equal sections along the arrangement of the multiple battery cells.

[0015] According to a preferred embodiment, in the battery assembly according to the invention, a compression system having at least one gas outlet fluidly connected to a gas emission channel includes at least two compression plates located on both sides of the battery module in the arrangement direction of the plurality of battery cells. At least one of the two plates, preferably the two plates, includes a gas outlet in the form of a pipe perpendicular to the arrangement direction of the plurality of battery cells, the pipe pointing towards the bottom of the battery module.

[0016] Therefore, a compression system including a gas outlet in the form of a pipe perpendicular to the arrangement direction of multiple battery cells allows for control of the discharge of gas generated by thermal runaway from the bottom of the battery module.

[0017] According to a preferred embodiment of the foregoing embodiments, in the battery assembly, at least one of the two compression plates includes a compression panel and a thermal protection panel. The thermal protection panel includes a gas outlet in the form of a pipe perpendicular to the arrangement direction of the plurality of battery cells. The thermal protection panel is based on a material selected from ceramic and metallic materials. Preferably, the thermal protection panel is made of steel. Preferably, the compression panel is based on polyphthalamide (PPA).

[0018] Therefore, using a thermal protection panel based on a material selected from ceramic and metallic materials can minimize the propagation of thermal energy from gases generated by thermal runaway within the battery assembly. The statement "thermal protection panel based on a material" means that the thermal protection panel is composed of at least 50% by weight of said material.

[0019] According to a preferred embodiment, the battery assembly includes a support frame for at least one battery module. The support frame includes a gas discharge line in a middle section and a gas discharge area on the outer edge of the support frame. The gas discharge line in the middle section and the gas discharge area on the outer edge of the support frame are fluidly connected to a gas outlet of a compression system. Preferably, the gas outlet of the compression system is in the form of a pipe within a compression plate of the battery module, the pipe being perpendicular to the arrangement direction of the plurality of battery cells.

[0020] Therefore, a battery assembly including a support frame for at least one battery module—wherein the support frame includes a gas venting line in the middle section and a gas venting area on its outer edge—is able to ensure optimal venting of gases generated by thermal runaway, while optimizing their cooling when the support frame is close to a cooling plate.

[0021] According to a preferred embodiment, the battery assembly according to the invention is provided with gas emission lines in the middle section and gas emission areas on the outer edge of the support frame, each including an outlet with a safety valve. Preferably, the safety valve is a diaphragm valve, the diaphragm being preferably based on polytetrafluoroethylene (PTFE).

[0022] Therefore, the presence of a safety valve enables the controlled release of gases generated by thermal runaway.

[0023] According to a preferred embodiment, the gas emission channel arranged in the upper part of the battery module has a plurality of deflectors configured to guide the gas generated by thermal runaway.

[0024] Therefore, the gases generated by thermal runaway are discharged more effectively. Furthermore, the deflector protects the vent by preventing thermal runaway gases moving through the exhaust channel from approaching the vent.

[0025] According to a preferred embodiment, the battery assembly includes a cooling plate shared by the entire battery module, or even by all battery modules. The cooling plate is thermally connected to a support frame, preferably adjacent to the support frame, and more preferably the cooling plate constitutes the support frame.

[0026] Other optional features of the battery assembly according to the invention, used individually or in combination:

[0027] - The battery cells of the battery module are connected in series or in parallel.

[0028] The battery module includes a metal locking plate, preferably made of aluminum, which is threaded onto the compression system and the cooling plate. This locking plate increases the heat exchange area between the battery cells and the cooling plate.

[0029] -The upper part of the battery module integrates:

[0030] - A device used for positioning and securing electrical conduits or "busbars";

[0031] - A device for positioning and securing flexible printed circuits.

[0032] The present invention also relates to a motor vehicle comprising a battery assembly according to the present invention. Attached Figure Description

[0033] The invention will be better understood by reading the following description, given only as an example and with reference to the accompanying drawings, in which:

[0034] [ Figure 1 [ ] is an exploded view of the battery module of the battery assembly according to the present invention.

[0035] [ Figure 2 ]yes Figure 1 A bottom view of the upper part of the battery module of the battery pack shown.

[0036] [ Figure 3 ]yes Figure 1 The cross-section of the upper part of the battery module of the battery assembly shown.

[0037] [ Figure 4 ]yes Figure 1 A side view of a portion of the compression system of the battery module of the battery assembly shown.

[0038] [ Figure 5 ]yes Figure 1An exploded view of a portion of the compression system of the battery module in the battery assembly shown.

[0039] [ Figure 6 ]yes Figure 1 The longitudinal section of the battery module of the battery assembly shown.

[0040] [ Figure 7 ]yes Figure 1 A partial cross-sectional view of the top of the battery module support frame of the battery assembly shown.

[0041] [ Figure 8 ]yes Figure 1 Top view of the battery module support frame of the battery assembly shown.

[0042] [ Figure 9 [This is a variant embodiment of the present invention] Figure 1 The top view of the battery module of the battery assembly shown. Detailed Implementation

[0043] Figures 1 to 9 A battery assembly according to an embodiment of the present invention is shown. Figures 1 to 9 In the figures, similar elements are represented by the same reference numerals.

[0044] Figure 1 A battery module 1, representing a battery assembly according to the present invention, is shown. The battery module 1 includes a plurality of battery cells 2 arranged in a row, each battery cell 2 being placed in a separate battery cell chamber 2 and separated from each other by partitions. Each separate battery cell chamber includes a vent 30 communicating with a gas exhaust channel 5 disposed in the upper portion 6 of the battery module 1. The exhaust channel 5 is shared by the plurality of battery cells 2 and is located at the middle 60 of the upper portion 6 of the battery module 1. The battery module 1 also includes a compression system 7, which has at least one gas outlet in fluid communication with the gas exhaust channel 5. The battery module 1 includes two metal locking plates 10, preferably made of aluminum, which are threadedly connected to the compression system 7 and a cooling plate. The locking plates 10 allow for an increase in the heat exchange area between the battery cells 2 and the cooling plate.

[0045] Figure 2 Shown from below Figure 1The upper part 6 of the battery module 1 is shown. The upper part 6 of the battery module 1 includes an upper wall 52 for a gas venting channel, the wall comprising a plate configured to form a heat shield and constituting the upper wall 52 of the gas venting channel. It can be seen that the flanges of the upper wall formed by the plate configured to form a heat shield form at least a portion of the two side edges 54 of the channel for venting gases generated by thermal runaway; these flanges are in the form of gorges or corner pieces. The upper part 6 also includes means for positioning and securing electrical conduits or "busbars" 55 and means for positioning and securing flexible printed circuits (not shown).

[0046] Figure 3 It shows Figure 1 The diagram shows a cross-section of the upper portion 6 of the battery module 1. The upper portion 6 of the battery module 1 includes a gas venting channel 5 for discharging gases generated by thermal runaway. This channel is formed by a lower wall 50, an upper wall 52, and two side edges 54. The lower wall 50 is constructed of a plate forming a heat shield 51, and the upper wall 52 is constructed of a plate forming a heat shield 53. The side edges 54 of the gas venting channel 5 are formed, on one hand, by a flange of the upper wall 52 (which is constructed of the plate forming the heat shield 53), and on the other hand, by a polymer-based material 56. It can be seen that the side edges 54 allow the polymer-based material 56 to be inserted into grooves or angled members present in the upper wall 52, which is constructed of the plate forming the heat shield 53.

[0047] Figure 4 and Figure 5 One of two plates 70 of a compression system is shown. The plate 70 includes a compression panel 700 and a heat protection panel 701. The compression panel 700 is preferably made of polyphthalamide (PPA), and the heat protection panel 701 is preferably made of steel. The heat protection panel 701 is provided with a gas outlet 71. Figure 5 A view of a thermal protection panel 701 including a gas outlet 71 is shown.

[0048] Figure 6 It shows along Figure 1 The diagram shows a longitudinal section of plane A of battery module 1 of the battery assembly. Battery module 1 comprises a column of multiple battery cells (not shown), each battery cell housed in a separate battery cell 2 chamber 3 and separated from each other by a partition 4. Each separate battery cell 2 chamber 3 includes a vent 30 communicating with a gas exhaust channel 5 disposed in the upper part 6 of battery module 1, the exhaust channel 5 being shared by the multiple battery cells. Battery module 1 includes a compression system 7 equipped with at least one gas outlet 8 fluidly connected to the gas exhaust channel 5. Arrows indicate the direction of gas discharge generated by thermal runaway within battery module 1.

[0049] Figure 7 It shows Figure 1 A partial cross-section of the top of the support frame 9 of the battery module 1 of the battery assembly is shown. The support frame 9 supports individual battery cell chambers 3 separated from each other by partition plates 4. A metal locking plate 10 is thermally connected to the support frame 9. The gas outlet 8 of the compression system is also shown. Arrows indicate the flow direction of gas generated by thermal runaway.

[0050] Figure 8 It shows Figure 1 The image shows a top view of the support frame 9 of the battery module 1 of the battery assembly. The support frame 9 includes a gas discharge line in the middle portion 90 of the support frame 9, a gas discharge area on the outer edge 91 of the support frame 9, and outlets 92 for the gas discharge line in the middle portion 90 and the gas discharge area on the outer edge 91 of the support frame 9. Each outlet 92 is equipped with a safety valve 93. The support frame 9 includes a cold plate 94. Arrows indicate the direction of gas discharge generated by thermal runaway within the battery module.

[0051] Figure 9 This is a bottom view of the upper portion 6' of the battery module 1 according to a variant embodiment of the present invention. The upper portion 6' of the battery module 1 differs from the one described above in that the exhaust channel 5 arranged in the upper portion 6' of the battery module 1 has a plurality of deflectors 57 configured to guide gases generated by thermal runaway for more efficient exhaust. Each deflector 57 is in the form of a generally "V"-shaped straight rib, such that gas encountering one of the deflectors reaches the top of the "V" of that deflector and bypasses it on both sides, thus protecting the interior of the "V" from the gas. In other words, the deflectors form an arrow pattern, the direction of which is opposite to the gas exhaust direction in the exhaust channel 5. The deflectors 57 can be arranged in the exhaust channel 5 above some or even all of the vent holes 30, such that the vent holes 30 open into the exhaust channel 5 from the interior of the "V" of one of the deflectors 57. In this way, the vent 30 is protected from gases that may come from the thermal runaway of another battery cell 2, which prevents these gases from damaging the vent 30.

[0052] List of reference numerals

[0053] 1: Battery Module

[0054] 2: Battery Unit

[0055] 3: Separate battery cell chamber

[0056] 4: Divider

[0057] 5: Gas emission channel

[0058] 6; 6': Upper part of the battery module

[0059] 7: Compression System

[0060] 8: Gas outlet of the compression system

[0061] 9: Supporting Frame

[0062] 10: Metal locking plate

[0063] 30: Vent for individual battery cell chambers

[0064] 50: Lower wall of the gas emission channel

[0065] 51: A plate constructed to form a heat insulation cover for the lower wall of a gas exhaust channel.

[0066] 52: Upper wall of the gas emission channel

[0067] 53: A plate constructed to form a heat insulation cover for the upper wall of the gas emission channel.

[0068] 54: The two side edges of the gas emission channel

[0069] 55: Devices used for positioning and securing electrical conduits or "busbars".

[0070] 56: Polymer-based materials

[0071] 57: Deflector

[0072] 60: The middle of the upper part of the module

[0073] 70: Compression plate of the compression system

[0074] 71: Gas outlet of the compression plate

[0075] 90: Gas exhaust pipeline in the middle section of the supporting frame

[0076] 91: Gas emission area on the outer edge of the support frame

[0077] 92: The outlet of the gas emission pipeline in the middle section and the outlet of the gas emission area on the outer edge of the supporting frame.

[0078] 93: Safety valve

[0079] 94: Cold Plate

[0080] 700: Compression Panel

[0081] 701: Thermal protection panel.

Claims

1. A battery assembly comprising at least one battery module (1), the battery module (1) comprising a plurality of battery cells (2) arranged in a row, each battery cell (2) being placed in a separate battery cell (2) chamber (3) and separated from each other by a partition plate (4), each separate battery cell chamber (3) comprising a vent (30) communicating with a gas discharge channel (5) for discharging gas generated by thermal runaway, the gas discharge channel (5) being arranged in the upper part (6; 6') of the battery module (1), the gas... The emission channel (5) is shared by the plurality of battery cells (2) and includes a lower wall (50), an upper wall (52), and two side edges (54). The lower wall (50) is constructed of a plate forming a heat shield (51), the upper wall (52) is constructed of a plate forming a heat shield (53), and the two side edges (54) are made of a polymer-based material (56). The battery module (1) includes a compression system (7) having at least one gas outlet (8) in fluid connection with the gas emission channel (5). in, The battery assembly includes a support frame (9) for at least one battery module (1), the support frame (9) including a gas discharge line in a middle portion (90) and a gas discharge area on the outer edge (91) of the support frame (9), the gas discharge line in the middle portion (90) and the gas discharge area on the outer edge (91) of the support frame (9) being fluidly connected to the gas outlet (8) of the compression system (7).

2. The battery assembly according to claim 1, wherein, The polymer-based material (56) constituting the two side edges (54) is covered with a metal or ceramic film at least on the portion of it exposed to the gas generated by thermal runaway.

3. The battery assembly according to claim 1, wherein, At least one of the two side edges (54) of the gas discharge channel (5) for discharging gas generated by thermal runaway is partially formed by the flange of the upper wall (52), which is formed by the plate configured to form a heat shield (53).

4. The battery assembly according to any one of claims 1-3, wherein, The gas emission channel (5) is located at the middle (60) of the upper part (6; 6') of the battery module (1).

5. The battery assembly according to any one of claims 1-3, wherein, The compression system (7), which is provided with at least one gas outlet (8) fluidly connected to the gas discharge channel, includes at least two compression plates (70) located on both sides of the battery module (1) in the arrangement direction of the plurality of battery cells (2). At least one of the two compression plates (70) includes a gas outlet (71) in the form of a pipe perpendicular to the arrangement direction of the plurality of battery cells (2) and the pipe points to the bottom of the battery module (1).

6. The battery assembly according to claim 5, wherein, At least one of the two compression plates (70) includes a compression panel (700) and a heat protection panel (701), the heat protection panel (701) including the gas outlet (71) in the form of a pipe perpendicular to the arrangement direction of the plurality of battery cells (2), the heat protection panel (701) being based on a material selected from ceramic and metallic materials.

7. The battery assembly according to any one of claims 1-3, wherein, The gas discharge pipeline in the intermediate section (90) and the gas discharge area on the outer edge (91) of the support frame (9) are provided with an outlet (92) including a safety valve (93).

8. The battery assembly according to claim 7, wherein, The safety valve (93) is a diaphragm valve.

9. The battery assembly according to any one of claims 1-3, wherein, The gas emission channel (5) arranged in the upper part (6') of the battery module (1) has a plurality of deflectors (57) configured to guide the gas generated by thermal runaway.

10. A motor vehicle comprising a battery assembly according to any one of the preceding claims.

Images