Battery Assembly

Abstract

The present invention relates to a battery assembly including at least one battery module 1. The battery module 1 includes a row of battery cells 2, each of which is installed in an individual battery cell chamber 3 and isolated from the others by a partition plate 4. Each individual battery cell chamber 3 includes a vent 30 located in an upper portion 6, 6' of the battery module 1 and leading to a gas discharge path 5 for gas generated by thermal runaway. The gas discharge path 5 is common to the battery cells 2 and includes a lower partition 50 made of a plate 51 configured to form a heat shield, an upper partition 52 made of a plate 53 configured to form a heat shield, and two side edges 54 made of a polymer-based material 56. The battery module 1 includes a compression system 7 with at least one gas outlet 8 fluidly connected to the gas discharge path 5.

Description

[Technical Field]

[0001] The present invention relates to a battery assembly configured to manage the escape of gas generated by thermal runaway within battery cells of the battery assembly. More specifically, the present invention relates to a battery assembly including at least one battery module, the battery module including a string of multiple battery cells, and including an escape path for gas generated by thermal runaway within battery cells of the battery assembly. [Background technology]

[0002] Thermal runaway in a battery assembly occurs when the temperature of one or more battery cells rises, initiating a chain reaction that accelerates chemical reactions within the battery cells and causes the rapid release of thermal energy. During the operation of a battery assembly, thermal runaway can occur if one or more battery cells are not properly cooled. Thermal runaway can also occur due to other events, such as a short circuit, physical impact, exposure to extreme temperatures, or manufacturing defects. During a thermal runaway, hot gases and other flammable materials can be emitted from one or more battery cells. If not properly managed, the gases produced can cause a fire or explosion. Thus, thermal runaway in one or more battery cells with high capacity, more specifically those using NMC (nickel, manganese, cobalt) technology, can result in the release of gases exceeding 900°C within the battery assembly.

[0003] In the prior art, battery assemblies including battery modules each including a row of multiple battery cells are already known, as disclosed in, inter alia, U.S. Patent Application Publication No. 2019 / 0173068, European Patent No. 2637235, U.S. Patent Application No. 2015 / 214525, and European Patent No. 2538470, and the like. The battery modules are provided with a gas exhaust path. In the disclosed modules, the exhaust path is fluidly connected to the multiple battery cells by a slit extending along the exhaust path, which slit is common to the multiple battery cells. This type of arrangement allows the exhaust of gas generated by thermal runaway in any of the battery cells. However, this type of exhaust device for gas generated by thermal runaway in any of the battery cells does not significantly reduce the risk of thermal runaway in the other battery cells. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2019 / 0173068 [Patent Document 2] European Patent No. 2637235 [Patent Document 3] U.S. Patent Application No. 2015 / 214525 [Patent Document 4] European Patent No. 2538470 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims, inter alia, to provide a battery assembly that can minimize the propagation of thermal runaway from any one battery cell to another. [Means for solving the problem]

[0006] To this end, the present invention is directed to a battery assembly including at least one battery module, wherein the battery module includes a row of battery cells, each battery cell being installed in an individual battery cell chamber and isolated from each other by a partition plate, each individual battery cell chamber including a vent located in an upper portion of the battery module and leading to a discharge path for gas generated by thermal runaway, the discharge path being common to the battery cells and including a lower partition made of a plate configured to form a heat shield, an upper partition made of a plate configured to form a heat shield, and two side edges including a polymer-based material, and the battery module includes a compression system with at least one gas outlet fluidly connected to the gas discharge path.

[0007] In this way, a battery module in which each battery cell is located in an individual battery cell chamber, including a vent hole located at the top of the battery module and connected to a discharge path for gas generated by thermal runaway, can reduce the risk of thermal runaway propagation from one battery cell to another among the multiple battery cells. The presence of a vent hole in each battery cell chamber reduces the risk of contact between gas generated by thermal runaway in one battery cell and the other battery cells. The battery module further includes a gas discharge path located at the top of the battery module. The discharge path is common to the multiple battery cells and includes a lower partition made of a plate configured to form a heat shield, an upper partition made of a plate configured to form a heat shield, and two side edges made of a polymer-based material. This type of structure allows the discharge path to be configured to suppress the propagation of heat generated within the battery assembly while ensuring the flexibility of the path to withstand high temperatures and pressures resulting from the discharge of gas generated by thermal runaway. Preferably, the upper partition made of a plate configured to form a heat shield is made of stainless steel or ceramic. The presence of a compression system with at least one gas outlet fluidly connected to the gas exhaust path allows the battery cells to expand during their service life, thereby improving the durability and safety of the battery assembly. The compression exerted on the battery cells by the compression system is related not only to the battery cell technology but also to the battery cell type. Preferably, the lower partition of the exhaust path is made of a metal plate or a ceramic plate, and preferably is made of a metal plate with a ceramic coating on the part exposed to the gas generated by thermal runaway. Preferably, the upper partition of the exhaust path is made of a metal plate with a ceramic coating on the part exposed to the gas generated by thermal runaway. The terms "upper" and "lower" with respect to the gas exhaust path are understood relative to the ground, with respect to the battery assembly in its operating position. The expression "polymer-based material" means that the material contains at least 50% by weight of said polymer.

[0008] According to one preferred embodiment, in the battery assembly according to the invention, the polymer-based material comprises a polymer foam.

[0009] In this way, the presence of the polymer foam allows a certain level of sealing to be created by the tolerance of the height of the small holes that make up the foam, thereby limiting the amount of gas that can be discharged through the gas discharge path located at the top of the battery module, the concept of "top" being understood relative to the ground with respect to the battery assembly in its operating position.

[0010] According to one preferred embodiment, in the battery assembly according to the present invention, the polymeric material that constitutes the two side edges is coated with a metal or ceramic film at least in the areas that are exposed to gases generated by thermal runaway.

[0011] In this way, the presence of a metal film or ceramic film at least on the side edge portion exposed to gas generated by thermal runaway can prevent deterioration of the polymer-based material due to its heat dissipation or heat barrier effect.

[0012] According to a preferred embodiment, in the battery assembly of the present invention, at least one of the two side edges of the exhaust path for gas generated by thermal runaway is partially formed by a fold of the upper partition made of a plate configured to form a heat shield. Preferably, a portion of the two side edges of the exhaust path for gas generated by thermal runaway is partially formed by a fold of the upper partition made 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 a groove or angle present in the upper partition made of a plate configured to form a heat shield.

[0013] In this way, the risk of degradation of the polymer-based material can be reduced by folding back the upper partition made of a plate configured to form a heat shield, which constitutes at least one of the two side edges of the exhaust path for gas generated by thermal runaway, preferably two side edges of the exhaust path for gas generated by thermal runaway. Advantageously, the plate configured to form the heat shield also has a special shape that can protect the polymer-based material, and this special shape is constituted by folding back the upper partition made of a plate configured to form a heat shield, preferably the folding back has the shape of a groove or an angle.

[0014] According to a preferred embodiment, in the battery assembly according to the present invention, the gas exhaust path is located at the center of the top of the battery module.

[0015] In this way, the exhaust path is located at the center of the upper part of the battery module, thereby optimizing the exhaust of gas generated by thermal runaway within the battery module. The expression "the center of the upper part of the battery module" means that the gas exhaust path is located on a line that approximately bisects the upper part of the battery module in the direction of the rows of the multiple battery cells.

[0016] According to a preferred embodiment, in the battery assembly according to the invention, the compression system with at least one gas outlet fluidly connected to the gas discharge path comprises at least two compression plates located on either side of the battery module in the direction of the rows of the battery cells, at least one of the two plates, preferably both plates, comprises a conduit-shaped gas outlet perpendicular to the direction of the rows of the battery cells, said conduit being directed downwards on the battery module.

[0017] In this way, a compression system including a conduit-shaped gas outlet perpendicular to the direction of the rows of the battery cells allows controlled outlet of gas generated by thermal runaway from below the battery module.

[0018] According to a preferred embodiment of the above-mentioned embodiment, in the battery assembly, at least one of the two compression plates includes a compression panel including a conduit-shaped gas outlet perpendicular to the direction of the rows of the battery cells, and a heat shield panel, the heat shield panel is based on a material selected from ceramic materials and metal materials, and preferably the heat shield panel is made of steel. Preferably, the compression panel is based on polyphthalamide (PPA).

[0019] Thus, the use of a heat shield 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 expression "heat shield panel based on a material" means that the heat shield panel consists of at least 50% by weight of said material.

[0020] 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 central portion of the support frame and a gas discharge zone along an outer edge, the gas discharge line in the central portion of the support frame and the gas discharge zone along an outer edge are fluidly connected with a gas outlet of a compression system, preferably, the gas outlet of the compression system has a conduit shape in a compression plate of the battery module, and the conduit is perpendicular to the direction of the rows of the plurality of battery cells.

[0021] In this manner, the battery assembly includes a support frame for at least one battery module, the support frame including a central gas exhaust line and gas exhaust zones along the outer edge, thereby optimizing the cooling of gases when the support frame is in proximity to a cooling plate while allowing optimal exhaust of gases generated by thermal runaway.

[0022] According to one preferred embodiment, in the battery assembly according to the invention, the gas exhaust line in the center of the support frame and the gas exhaust zone at the outer periphery are provided with outlets containing safety valves, which are preferably diaphragm valves, preferably polytetrafluoroethylene (PTFE) based diaphragms.

[0023] In this way, the presence of the safety valve makes it possible to control the discharge of gases generated by thermal runaway.

[0024] According to one preferred embodiment, the exhaust path arranged at the top of the battery module has a plurality of deflectors configured to guide gases generated by thermal runaway.

[0025] In this way, the gases generated by thermal runaway are more effectively exhausted. Furthermore, the deflector can protect the vent by keeping out the gases generated by thermal runaway that have migrated into the exhaust path.

[0026] According to a preferred embodiment, the battery assembly includes a cooling plate common to the assembly of one battery module or even common to the assembly of several battery modules, said cooling plate being thermally connected to the support frame, preferably bonded to the support frame, more preferably constituting the support frame.

[0027] Other optional features of the battery assembly according to the present invention, taken alone or in combination, include: - The battery cells of a battery module are connected in series or in parallel. The battery module includes a metal locking plate, preferably made of aluminum, screwed to the compression system and the cooling plate, which increases the heat exchange area between the battery cells and the cooling plate. - the upper part of the battery module comprises: -Means for positioning and fixing electrical wiring (in English "Busbar"). -A means of positioning and fixing flexible printed circuits.

[0028] The present invention is also directed to a motor vehicle including a battery assembly according to the present invention.

[0029] The invention will be better understood from a reading of the following description, given by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0030] [Figure 1] 1 is an exploded view of a battery module of a battery assembly according to the present invention. [Figure 2] 2 is a bottom view of an upper portion of a battery module of the battery assembly shown in FIG. 1. FIG. [Figure 3] 2 is a cross-sectional view of an upper portion of a battery module of the battery assembly shown in FIG. 1. [Figure 4] 2 is a side view of a portion of a compression system of a battery module of the battery assembly shown in FIG. 1. [Figure 5] FIG. 2 is an exploded view of a portion of a compression system of a battery module of the battery assembly shown in FIG. 1. [Figure 6] 2 is a longitudinal cross-sectional view of a battery module of the battery assembly shown in FIG. 1. [Figure 7] 2 is a partial cross-sectional view of the upper surface of the support frame of the battery module of the battery assembly shown in FIG. 1. [Figure 8] 2 is a top view of a support frame of a battery module of the battery assembly shown in FIG. 1. [Figure 9] 2 is a bottom view of the top of the battery module of the battery assembly shown in FIG. 1 according to an alternative embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] A battery assembly according to one embodiment of the present invention is shown in Figures 1 to 9, in which like elements are designated by like reference numerals.

[0032] FIG. 1 shows a battery module 1 of a battery assembly according to the present invention. The battery module 1 includes a row of battery cells 2, each of which is installed in an individual battery cell chamber and isolated from the others by a partition plate. Each individual battery cell chamber includes a vent 30 leading to a gas discharge path 5 located in an upper portion 6 of the battery module 1. The discharge path 5 is common to the battery cells 2 and is located at a center 60 of the upper portion 6 of the battery module 1. The battery module 1 further includes a compression system 7 having at least one gas outlet fluidly connected to the gas discharge path 5. The battery module 1 also includes two metal locking plates 10, preferably made of aluminum, screwed to the compression system 7 and a cooling plate. The locking plates 10 increase the heat exchange area between the battery cells 2 and the cooling plate.

[0033] 2 is a bottom view of the battery module shown in FIG. 1 , disclosing the upper part 6. The upper part 6 of the battery module 1 includes an upper partition 52 of the gas exhaust path, the partition including a plate configured to form a heat shield, constituting the upper partition 52 of the gas exhaust path. It can be seen that the folds of the upper partition, which is made of a plate configured to form a heat shield, form at least a portion of two side edges 54 of the exhaust path for gas generated by thermal runaway, and these folds have the shape of a groove or angle. The upper part 6 further includes a positioning and fixing means for electrical wiring ("busbar") 55 and a positioning and fixing means for a flexible printed circuit (not shown).

[0034] 3 shows a cross-section of the upper portion 6 of the battery module 1 shown in FIG. 1. The upper portion 6 of the battery module 1 includes a discharge path 5 for gas generated by thermal runaway, the path being formed by a lower partition 50 made of a plate 51 configured to form a heat shield, an upper partition 52 made of a plate 53 configured to form a heat shield, and two side edges 54. The two side edges 54 of the gas discharge path 5 are formed, on the one hand, by a fold of the upper partition 52 made of the plate 53 configured to form a heat shield, and, on the other hand, by a polymer-based material 56. It can be seen that, at the side edges 54, the polymer-based material 56 is inserted into a groove or angle present in the upper partition 52 made of the plate 53 configured to form a heat shield.

[0035] 4 and 5 show one of two plates 70 of the compression system. Plate 70 includes a compression panel 700, preferably made of polyphthalamide (PPA), and a heat shield panel 701, preferably made of steel, with a gas outlet 71. Figure 5 shows a view of the heat shield panel 701 including the gas outlet 71.

[0036] 6 shows a longitudinal cross section along plane A of battery module 1 of the battery assembly shown in FIG. 1. Battery module 1 includes a row of battery cells (not shown), each battery cell being installed in an individual chamber 3 for battery cell 2 and isolated from each other by a partition plate 4, and each individual chamber 3 for battery cell 2 includes a vent 30 leading to a gas exhaust path 5 located in an upper portion 6 of battery module 1, said exhaust path 5 being common to the plurality of battery cells. Battery module 1 includes a compression system 7 having at least one gas outlet 8 fluidly connected to gas exhaust path 5. Arrows indicate the direction of exhaust of gas generated in battery module 1 due to thermal runaway.

[0037] Figure 7 shows a partial cross section of the top surface of the support frame 9 of the battery module 1 of the battery assembly shown in Figure 1. The support frame 9 supports individual chambers 3 for the battery cells, which are isolated from each other by dividers 4. A metal locking plate 10 is thermally connected to the support frame 9. The figure also shows the gas outlet 8 of the compression system. The arrows indicate the direction of gas flow generated by thermal runaway.

[0038] 8 is a top view of the support frame 9 of the battery module 1 of the battery assembly shown in FIG. 1. The support frame 9 includes a gas exhaust line 90 in the center of the support frame 9, a gas exhaust zone 91 on the outer edge of the support frame 9, and outlets 92 at the gas exhaust line 90 in the center of the support frame 9 and the gas exhaust zone 91 on the outer edge. Each outlet 92 is equipped with a safety valve 93. The support frame 9 includes a cooling plate 94. Arrows indicate the direction in which gas generated by thermal runaway in the battery module is exhausted.

[0039] FIG. 9 shows a bottom view of the upper portion 6' of a battery module 1 according to a modified embodiment of the present invention. The upper portion 6' of this battery module 1 differs from the battery modules previously described in that the exhaust channel 5 arranged on the upper portion 6' of the battery module 1 includes multiple deflectors 57 configured to guide gas generated by thermal runaway for more effective exhaust. Each deflector 57 has a generally "V"-shaped linear rib shape. When gas enters one of the deflectors and reaches the apex of the "V" of the deflector, the gas is deflected to both sides of the deflector, preventing gas from entering the "V." In other words, the deflectors form an arrow pattern in the exhaust channel 5 that points opposite the gas exhaust direction. The deflectors 57 can be arranged in the exhaust channel 5 so as to be located above some or even all of the vents 30, so that the vents lead into the exhaust channel 5 inside the "V" of one of the deflectors 57. In this way, gas that may result from thermal runaway of other battery cells 2 will not enter the vent 30, thereby preventing the gas from damaging the vent 30. [Explanation of symbols]

[0040] 1 Battery Module 2 battery cells 3 Separate chambers for battery cells 4 Dividers 5 Gas Exhaust Route 6, 6' Top of battery module 7 Compression System 8 Gas outlet of the compression system 9 Support Frame 10 Metal Lock Plate 30 Individual chamber vents for battery cells 50 Lower partition of gas exhaust path 51 Plate configured to form a heat shield that serves as a lower partition of the gas exhaust path 52 Upper partition of gas exhaust path 53 Plate configured to form a heat shield that serves as an upper partition for the gas exhaust path 54 Two side edges of the gas discharge path 55 Positioning and fixing means for electrical wiring ("Busbar") 56 Polymer-based materials 57 Deflector 60 Top center of module 70 Compression System Compression Plate 71 Compression plate gas outlet 90 Gas exhaust line at the center of the support frame 91 Gas discharge zone at the outer edge of the support frame 92 Gas discharge line in the center of the support frame and outlet of the gas discharge zone at the outer edge 93 Safety valve 94 Cooling Plate 700 Compression Panel 701 Heat-shielding panel

Claims

1. a battery module (1) including a row of a plurality of battery cells (2), each of the battery cells (2) being installed in an individual chamber (3) for the battery cell (2) and isolated from each other by a partition plate (4); each individual chamber (3) for the battery cell including a vent (30) arranged in an upper portion (6, 6') of the battery module (1) and leading to a gas discharge path (5) for gas generated by thermal runaway, the gas discharge path (5) being common to the plurality of battery cells (2), the gas discharge path (5) including a lower partition (50) made of a plate (51) configured to form a heat shield, an upper partition (52) made of a plate (53) configured to form a heat shield, and two side edges (54) including a polymer-based material (56); and the battery module (1) including a compression system (7) having at least one gas outlet (8) fluidly connected to the gas discharge path (5).

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

3. 3. The battery assembly of claim 1, wherein at least one of the two side edges (54) of the gas exhaust path (5) for gas generated by thermal runaway is partially formed by a fold of the upper partition (52) made of the plate (53) configured to form a heat shield.

4. 4. The battery assembly according to claim 1, wherein the gas exhaust path (5) is located in the center (60) of the upper portion (6, 6') of the battery module (1).

5. 5. The battery assembly according to claim 1, wherein the compression system (7) having at least one gas outlet (8) fluidly connected to the gas discharge path includes at least two compression plates (70) located on both sides of the battery module (1) in the direction of the rows of the battery cells (2), and at least one of the two compression plates (70) includes a conduit-shaped gas outlet (71) perpendicular to the direction of the rows of the battery cells (2), the conduit being directed downwardly of the battery module (1).

6. 6. The battery assembly according to claim 5, wherein the at least one of the two compression plates includes a compression panel (700) and a heat shield panel (701) including the gas outlet (71) in the shape of a conduit perpendicular to the direction of the rows of the plurality of battery cells (2), and the heat shield panel (701) is based on a material selected from ceramic materials and metallic materials.

7. 7. The battery assembly according to claim 1, comprising a support frame (9) for at least one battery module (1), the support frame (9) comprising a gas discharge line (90) in a central portion of the support frame (9) and a gas discharge zone (91) in an outer peripheral portion thereof, the gas discharge line (90) in the central portion of the support frame (9) and the gas discharge zone (91) in an outer peripheral portion thereof being fluidly connected to the gas outlet (8) of the compression system (7).

8. 8. The battery assembly according to claim 7, wherein the gas discharge line (90) in the central part of the support frame (9) and the gas discharge zone (91) in the outer edge part are provided with an outlet (92) including a safety valve (93).

9. 9. The battery assembly of claim 8, wherein the safety valve (93) is a diaphragm valve.

10. 10. The battery assembly according to claim 1, wherein the gas exhaust path (5) arranged on 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 claims 1 to 10.

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