Battery assembly

Abstract

The invention relates to a battery assembly comprising at least one battery module (1). According to the invention, the battery module (1) comprises a row in which a plurality of battery cells (2) are arranged, 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 hole (30) communicating with a gas discharge channel (5) for discharging gas generated by thermal runaway, the gas discharge channel is arranged at an upper part (6; 6 ') of the battery module (1). The gas discharge channel (5) is common to the plurality of battery cells (2) and comprises a lower wall (50), an upper wall (52) and two side edges (54), the lower wall is composed of a plate configured to form a heat shield (51), the upper wall is composed of a plate configured to form a heat shield (53), and the two side edges comprise a polymer-based material (56). The battery module (1) comprises a compression system (7) provided with at least one gas outlet (8) in fluid connection with the gas discharge channel (5).

Description

[0001] The present invention relates to a battery assembly configured to manage the exhaust of gases generated by thermal runaway in a battery cell of the battery assembly. More specifically, the present invention relates to a battery assembly comprising at least one battery module, the battery module comprising a plurality of battery cells arranged in a row and provided with a channel for exhausting gases generated by thermal runaway in a battery cell of the battery assembly.

[0002] Thermal runaway in a battery assembly occurs when the temperature of one or more battery cells rises so high that it triggers a chain reaction that accelerates chemical reactions within the battery cell or cells, which contributes to the rapid release of thermal energy. Thermal runaway can be caused by insufficient cooling of the battery cells during operation of the battery assembly. Thermal runaway 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 generated gases may cause fires or explosions. Therefore, thermal runaway on one or more high-capacity battery cells, especially battery cells using NMC (nickel, manganese, cobalt) technology, may result in the release of gases with temperatures above 900°C within the battery assembly.

[0003] In the prior art, in particular according to document US2019 / 0173068A1, but also according to documents EP2637235A1, US2015 / 214525A1 and EP2538470A1, a battery assembly is known, which comprises a battery module, which comprises a plurality of battery cells arranged in a row, and the battery module is provided with a gas discharge channel. In the disclosed module, the discharge channel is fluidly connected to the plurality of battery cells by means of a slot extending along the discharge channel, which slot is common to the plurality of battery cells. This arrangement makes it possible to ensure the discharge of gases generated by thermal runaway in one battery cell. However, this device for discharging gases generated by thermal runaway in one battery cell cannot significantly reduce the risk of thermal runaway in other battery cells.

[0004] The invention has for its object in particular to provide a battery assembly which makes it possible to minimize the propagation of thermal runaway from one battery cell to other battery cells.

[0005] To this end, the subject of the 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 plate, each separate battery cell chamber comprising a vent hole communicating with a gas discharge channel for discharging gases generated by thermal runaway, the gas discharge channel being arranged in the upper part of the battery module, the gas discharge channel being common to the plurality of battery cells and comprising a lower wall, an upper wall and two side edges, the lower wall being constituted by a plate configured to form a heat shield, the upper wall being constituted by a plate configured to form a heat shield, the two side edges comprising a polymer-based material, the battery module comprising a compression system provided with at least one gas outlet fluidically connected to the gas discharge channel.

[0006] Therefore, a battery module, in which each battery cell is located in a separate battery cell chamber, each separate battery cell chamber including a vent hole connected to a gas discharge channel arranged in the upper part of the battery module for discharging gas generated by thermal runaway, can reduce the risk of thermal runaway of one battery cell among a plurality of battery cells propagating to other battery cells. The presence of the vent hole in each battery cell chamber can reduce the risk of contact between the gas generated by thermal runaway of one battery cell and other battery cells. In addition, the battery module is provided with a gas discharge channel arranged in its upper part, the gas discharge channel being common to a plurality of battery cells and comprising a lower wall composed of a plate configured to form a heat shield, an upper wall composed of a plate configured to form a heat shield, and two side edges comprising a polymer-based material. Therefore, the gas discharge channel having such a structure makes it possible to have such a discharge channel: the discharge channel is configured to reduce the spread of heat generated in the battery assembly, while having the flexibility of the channel, which can withstand the significant temperature and pressure stresses associated with the discharge of gas generated by thermal runaway. Preferably, the upper wall composed of a plate configured to form a heat shield is a stainless steel plate or a ceramic plate. The presence of a compression system provided with at least one gas outlet fluidically connected to the gas discharge channel allows to improve the durability and safety of the battery assembly due to possible expansion of the battery cell during its service life. The compression applied to the battery cell by the compression system is related not only to the technology of the battery cell, but also to the format of the battery cell. Preferably, the lower wall of the discharge channel consists of a metal or ceramic plate, preferably of a metal plate covered with a ceramic coating on its portion exposed to the gases generated by thermal runaway. Preferably, the upper wall of the discharge channel consists of a metal plate covered with a ceramic coating on its portion exposed to the gases generated by thermal runaway. The concepts of "upper" and "lower" in relation to the gas discharge channel are taken as reference to the ground when the battery assembly is in the working position. The expression "polymer-based material" means that the material contains at least 50% by weight of said polymer.

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

[0008] Therefore, due to the high tolerance of the cells constituting the polymer foam, the presence of the polymer foam can achieve a given degree of sealing and limit the amount of gas that may escape from the exhaust channel arranged in the upper part of the battery module. The concept of the "upper part" of the battery module mentioned here is determined with reference to the ground when the battery assembly is in the working position.

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

[0010] Therefore, the presence of the metal film or the ceramic film at least on the portion of the side edge exposed to the gas generated by thermal runaway makes it possible to avoid the polymer-based material from being degraded due to the heat dissipation effect or the heat shielding effect.

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

[0012] Thus, the flange of the upper wall constituted by the plate configured to form the heat shield constitutes at least one of the two side edges of the gas discharge channel for the gases generated by thermal runaway, preferably constitutes the two side edges of the gas discharge channel for the gases generated by thermal runaway, making it possible to reduce the risk of degradation of the polymer-based material. Advantageously, the plate configured to form the heat shield also integrates a specific shape that makes it possible to protect the polymer-based material, which is constituted by the flange of the upper wall constituted by the plate configured to form the heat shield, preferably in the form of a groove or an angled piece.

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

[0014] Therefore, the exhaust channel located in the middle of the upper part of the battery module allows for optimized exhaust of gases generated by thermal runaway in the battery module. The expression "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 parts along the arrangement direction of the plurality of battery cells.

[0015] According to a preferred embodiment, in the battery assembly according to the present invention, a compression system provided with at least one gas outlet fluidly connected to the gas exhaust channel includes at least two compression plates, and the at least two compression plates are located on both sides of the battery module in the arrangement direction of the plurality of battery cells, and at least one of the two plates, preferably the two plates, includes a gas outlet, and the gas outlet is in the form of a pipe perpendicular to the arrangement direction of the plurality of battery cells, and the pipe points to 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 the plurality of battery cells allows controlled discharge of gas generated by thermal runaway from the bottom of the battery module.

[0017] According to a preferred embodiment of the aforementioned embodiment, in the battery assembly, at least one of the two compression plates comprises a compression panel and a heat protection panel, the heat protection panel comprises a gas outlet in the form of a pipe perpendicular to the arrangement direction of the plurality of battery cells, the heat protection panel is based on a material selected from a ceramic material and a metal material, preferably, the heat panel is made of steel. Preferably, the compression panel is based on polyphthalamide (PPA).

[0018] Therefore, using a heat protection panel based on a material selected from ceramic materials and metallic materials can minimize the spread of heat energy of gases generated by thermal runaway within the battery assembly. The expression "heat protection panel based on one material" means that the heat protection panel consists 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 including a gas discharge line in a middle portion and a gas discharge area on an outer edge of the support frame, the gas discharge line in the middle portion 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] Thus, a battery assembly comprising a support frame for at least one battery module, wherein the support frame comprises gas discharge lines in a middle portion and gas discharge areas on its outer edges, is able to ensure optimal discharge of gases generated by thermal runaway while optimizing their cooling when the support frame is close to cooling plates.

[0021] According to a preferred embodiment, the battery assembly according to the invention is such that the gas discharge line in the middle part and the gas discharge area on the outer edge of the support frame are provided with an outlet including a safety valve. Preferably, the safety valve is a diaphragm valve, the diaphragm being preferably a diaphragm based on polytetrafluoroethylene (PTFE).

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

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

[0024] Therefore, the gas generated by the thermal runaway is exhausted more efficiently. In addition, the deflector protects the vent hole by preventing the gas generated by the thermal runaway moving in the exhaust passage from approaching the vent hole.

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

[0026] According to other optional features of the battery assembly according to the present invention, taken alone or in combination:

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

[0028] - The battery module comprises a metal locking plate, preferably made of aluminum, which is screwed to the compression system and the cooling plate. Such a locking plate can increase the heat exchange area between the battery cells and the cooling plate.

[0029] -The upper part of the battery module is integrated with:

[0030] - Devices for positioning and securing electrical conduits or "bus bars";

[0031] - Device for positioning and fixing flexible printed circuits.

[0032] The invention also relates to a motor vehicle comprising a battery assembly according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0035] [ Figure 2 ]yes Figure 1 Bottom view of the upper portion of the battery module of the battery pack shown.

[0036] [ Figure 3 ]yes Figure 1 Cross-section of the upper portion of a battery module of the battery assembly shown.

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

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

[0039] [ Figure 6 ]yes Figure 1 Longitudinal section through a battery module of the battery assembly shown.

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

[0041] [ Figure 8 ]yes Figure 1 A top view of a battery module support frame of the battery assembly is shown.

[0042] [ Fig. 9 ] is a variant embodiment according to the present invention Figure 1 A bottom view of the upper portion of a battery module of a battery assembly is shown. DETAILED DESCRIPTION

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

[0044] Figure 1 A battery module 1 of a battery assembly according to the present invention is represented. The battery module 1 comprises 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 a partition plate, each separate battery cell chamber comprising a vent 30 communicating with a gas discharge channel 5 arranged in the upper part 6 of the battery module 1, the discharge channel 5 being common to the plurality of battery cells 2 and being located at the middle 60 of the upper part 6 of the battery module 1. The battery module 1 also comprises a compression system 7 provided with at least one gas outlet fluidically connected to the gas discharge channel 5. The battery module 1 comprises two metal locking plates 10, preferably made of aluminum, which are screwed to the compression system 7 and the cooling plate. The locking plates 10 make it possible to increase the heat exchange area between the battery cells 2 and the cooling plate.

[0045] Figure 2 The bottom view shows the 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 of the gas discharge channel, which wall includes a plate that is configured to form a heat shield and constitutes the upper wall 52 of the gas discharge 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 part of the two side edges 54 of the channel for discharging gases generated by thermal runaway, and these flanges are in the form of grooves (gorge) or angles (cornière). The upper part 6 also includes means for positioning and fixing electrical conduits or "bus bars" 55 and means for positioning and fixing flexible printed circuits (not shown).

[0046] Figure 3 Shows Figure 1 . The upper part 6 of the battery module 1 comprises a gas discharge channel 5 for discharging gases generated by thermal runaway, the channel being formed by a lower wall 50, an upper wall 52 and two side edges 54, the lower wall 50 being formed by a plate configured to form a heat shield 51, and the upper wall 52 being formed by a plate configured to form a heat shield 53. The side edges 54 of the gas discharge channel 5 are formed on the one hand by the flanges of the upper wall 52, which are formed by a plate configured to form a 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 pieces present in the upper wall 52, which is formed by a plate configured to form a heat shield 53.

[0047] Figure 4 and Figure 5 One of two panels 70 of a compression system is shown. The panel 70 comprises a compression panel 700, preferably made of polyphthalamide (PPA), and a heat protection panel 701, preferably made of steel, provided with a gas outlet 71 . Figure 5 A view of a heat protection panel 701 comprising gas outlets 71 is shown.

[0048] Figure 6 Shown along Figure 1 . A longitudinal section of a plane A of a battery module 1 of a battery assembly shown in . The battery module 1 comprises a plurality of battery cells (not shown) arranged in a row, each battery cell being placed in a separate battery cell 2 chamber 3 and separated from each other by a partition plate 4, each separate battery cell 2 chamber 3 comprising a vent 30 connected to a gas exhaust channel 5 arranged in an upper part 6 of the battery module 1, the exhaust channel 5 being common to the plurality of battery cells. The battery module 1 comprises a compression system 7 equipped with at least one gas outlet 8 fluidically connected to the gas exhaust channel 5. Arrows indicate the exhaust direction of the gas generated by thermal runaway within the battery module 1.

[0049] Figure 7 Shows Figure 1 1 is a partial cross-section of the top of a support frame 9 of a battery module 1 of a battery assembly shown in FIG. The support frame 9 supports the 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. A gas outlet 8 of the compression system is also shown. The arrows indicate the flow direction of the gas generated by thermal runaway.

[0050] Figure 8 Shows Figure 1 9 is a top view of a support frame 9 of a battery module 1 of a battery assembly shown in FIG. The support frame 9 includes a gas discharge line in a middle portion 90 of the support frame 9, a gas discharge area on an outer edge 91 of the support frame 9, an outlet 92 of 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 provided with a safety valve 93. The support frame 9 includes a cold plate 94. Arrows indicate the discharge direction of the gas generated by thermal runaway in the battery module.

[0051] Fig. 9 6 ' is a bottom view of the upper part 6 'of the battery module 1 according to a variant embodiment of the present invention. The upper part 6 'of the battery module 1 is different from the above in that the exhaust channel 5 arranged in the upper part 6 'of the battery module 1 has a plurality of deflectors 57, which are configured to guide the gases generated by thermal runaway so as to discharge them more efficiently. Each deflector 57 is in the form of a straight rib in a roughly "V" shape, so that the gas encountering one of the deflectors reaches the top of the "V" of the deflector and bypasses the deflector on both sides thereof, so that the inside of the "V" is protected from the gas. In other words, the deflector forms an arrow pattern, the direction of which is opposite to the gas discharge direction in the exhaust channel 5. The deflector 57 can be arranged in the exhaust channel 5 to be located above some vents 30, or even above all vents 30, so that the vent 30 is inside the "V" of one of the deflectors 57 to pass into the exhaust channel 5. In this way, the vent 30 is protected from gases that may come from thermal runaway of another battery cell 2 , which can prevent these gases from damaging the vent 30 .

[0052] List of Reference Numerals

[0053] 1: Battery module

[0054] 2: Battery Cell

[0055] 3: Separate battery cell chamber

[0056] 4: Separator

[0057] 5: Gas discharge channel

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

[0059] 7: Compression system

[0060] 8: Gas outlet of compression system

[0061] 9: Support frame

[0062] 10: Metal locking plate

[0063] 30: Vent holes for individual battery cell chambers

[0064] 50: Lower wall of gas discharge channel

[0065] 51: Plate of the heat shield configured to form the lower wall of the gas discharge passage

[0066] 52: Upper wall of gas discharge channel

[0067] 53: A plate configured to form a heat shield of the upper wall of the gas discharge passage

[0068] 54: Two side edges of the gas discharge channel

[0069] 55: Device for locating and securing electrical conduits or "bus bars"

[0070] 56: Polymer-based materials

[0071] 57: Deflector

[0072] 60: Middle of the upper part of the module

[0073] 70: Compression plate of compression system

[0074] 71: Gas outlet of compression plate

[0075] 90: Gas discharge line in the middle part of the support frame

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

[0077] 92: The outlet of the gas discharge line in the middle part and the outlet of the gas discharge area on the outer edge of the support 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), the vent (30) being connected to a gas exhaust channel (5) for exhausting gas generated by thermal runaway, the gas exhaust channel (5) being arranged in an upper portion (6; 6') of the battery module (1), ... The exhaust channel (5) is common to the plurality of battery cells (2) and comprises a lower wall (50), an upper wall (52) and two side edges (54), the lower wall (50) being formed by a plate configured to form a heat shield (51), the upper wall (52) being formed by a plate configured to form a heat shield (53), the two side edges (54) comprising a polymer-based material (56), the battery module (1) comprising a compression system (7), the compression system (7) being provided with at least one gas outlet (8) fluidically connected to the gas exhaust channel (5).

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 film or a ceramic film at least on its portion exposed to the gas generated by thermal runaway.

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

4. A battery assembly according to any one of the preceding claims, wherein: The gas exhaust passage (5) is located in the middle (60) of the upper portion (6; 6') of the battery module (1).

5. A battery assembly according to any one of the preceding claims, wherein: The compression system (7) provided with at least one gas outlet (8) fluidly connected to the gas discharge channel comprises at least two compression plates (70), the at least two compression plates (70) being 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 plates (70) comprising a gas outlet (71), the gas outlet (71) being in the form of a pipe perpendicular to the arrangement direction of the plurality of battery cells (2), the pipe pointing to the bottom of the battery module (1).

6. A battery assembly according to the preceding claim, wherein: At least one of the two compression plates (70) comprises a compression panel (700) and a heat protection panel (701), the heat protection panel (701) comprising 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 a ceramic material and a metal material.

7. A battery assembly according to any one of the preceding claims, wherein: The battery assembly comprises a support frame (9) for at least one battery module (1), the support frame (9) comprising a gas discharge line in a middle portion (90) and a gas discharge area on an 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 a gas outlet (8) of the compression system (7).

8. Battery assembly according to the preceding claim, wherein: The gas discharge line in the middle part (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).

9. Battery assembly according to the preceding claim, wherein: The safety valve (93) is a diaphragm valve.

10. A battery assembly according to any one of the preceding claims, wherein: The gas discharge passage (5) arranged in the upper portion (6') of the battery module (1) has a plurality of deflectors (57) configured to guide gas generated by thermal runaway.

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

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