Battery for electric or hybrid vehicles, including cross members with ends forming protrusions against a cooling system
The battery design with cross members and protrusions enhances heat dissipation, addressing thermal malfunctions by distributing heat efficiently and reducing the risk of thermal runaway.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- AUTOMOTIVE CELLS CO SE
- Filing Date
- 2024-07-11
- Publication Date
- 2026-06-26
AI Technical Summary
Existing batteries for electric and hybrid vehicles face a high risk of thermal malfunction due to insufficient heat dissipation, leading to a chain reaction of overheating and potential damage or destruction.
The battery design incorporates cross members with ends forming protrusions that extend into a cooling system, enhancing thermal contact and inertia to distribute heat effectively, thereby reducing the risk of thermal runaway.
The design effectively dissipates heat from electrochemical cells, preventing neighboring cells from exceeding critical temperatures and reducing the risk of thermal runaway, even in extreme conditions.
Smart Images
Figure 00000010_0000 
Figure 00000011_0000 
Figure 00000012_0000
Abstract
Description
Title of the invention: Battery for an electric or hybrid vehicle, comprising cross members having ends forming protrusions against a cooling system.
[0001] The present invention relates to an electric battery, in particular for electric or hybrid vehicles. EARLIER ART
[0002] The term "battery" refers to a plurality of electrochemical cells electrically connected to one another. In a particular example of a battery, the plurality of electrochemical cells is arranged in the form of one or more modules, each module comprising several electrochemical cells electrically connected to one another and mechanically assembled by an assembly system, such as assembly plates. An electrochemical cell comprises, in particular, a stack of positive electrodes, negative electrodes, and separators. The positive electrodes connected to one another form a positive terminal of the battery, and the negative electrodes connected to one another form a negative terminal.
[0003] The battery generally includes a casing that helps protect its internal components, particularly the electrochemical cells and electrical connectors. The battery may also include internal structures, such as cross members, to reinforce its rigidity and increase its mechanical resistance, especially against impact on the vehicle.
[0004] Furthermore, during operation, electrochemical cells are likely to produce heat. In order to prevent an excessive rise in temperature inside the battery, which could damage certain internal components or impair their operation, at least some of this heat is dissipated outside the battery by a cooling system.
[0005] For example, it is known to use a cooling plate, generally located below the modules, in thermal contact with at least some of them. The heat released by the electrochemical cells is transferred to the cooling plate, which has fins to dissipate the heat into the atmosphere, or through which a refrigerant fluid flows.
[0006] If the cooling is insufficient, one of the electrochemical cells may undergo thermal runaway. Its temperature increases and The heat generated can cause neighboring cells to overheat. A chain reaction can occur, leading to significant damage or even destruction of the battery.
[0007] One object of the invention is therefore to provide a battery presenting a lower risk of thermal malfunction. Summary of the invention
[0008] To this end, the invention relates to a battery for an electric or hybrid vehicle, comprising:
[0009] - a housing defining a compartment extending in a longitudinal direction and in a transverse direction perpendicular to the longitudinal direction,
[0010] - a plurality of assemblies comprising electrochemical cells capable of function of releasing heat,
[0011] - a plurality of crossbeams extending transversely into the housing, each assemblies extending longitudinally between two of the sleepers, the sleepers comprising two end sleepers such that the assemblies are all situated longitudinally on one side only of each of the two end sleepers, and
[0012] - a cooling system located in the housing or forming a base of the housing, the cooling system being in thermal contact with the assemblies and crossbeams,
[0013] characterized in that each of the two extreme cross members comprises:
[0014] - a main part forming a transverse beam, and
[0015] - two ends opposite each other transversely, each of the two ends having a foot extending against the cooling system and forming a protrusion in the longitudinal direction from the main part on the side opposite the assemblies, each of the two ends being in thermal contact with one of the assemblies.
[0016] According to particular embodiments, the battery comprises one or more of the following features, taken alone or in all technically possible combinations:
[0017] - the foot has an extension in the transverse direction of between 50 mm and 200 mm, preferably between 80 mm and 150 mm;
[0018] - the protuberance has an average thickness in an upward direction perpendicular to the longitudinal and transverse directions, the average thickness being between 4 mm and 8 mm;
[0019] - the electrochemical cells of each of the assemblies are successive in the transverse direction, the foot extending opposite at least two of the electrochemical cells of one of the assemblies in the longitudinal direction, preferably only two electrochemical cells, the two electrochemical cells being successive and one of the two electrochemical cells being extreme transversely in one of the sets;
[0020] - the foot has a convergent shape in the longitudinal direction of the side opposed to sets;
[0021] - each of the two ends comprises an overthickness on the main part in the longitudinal direction, the excess thickness extends from the base in an elevation direction perpendicular to the longitudinal and transverse directions;
[0022] - the excess thickness gradually thins in the direction of elevation;
[0023] - the main part of each of the two end crossbars has an "L" shape cut perpendicular to the transverse direction, at least one of the assemblies being sandwiched between the base of the "L" and the cooling system;
[0024] - wherein the cooling system comprises a plate having a face made of thermal contact with the base of each of the two ends of the two extreme crossbeams; and
[0025] - the cooling system includes a layer of glue or thermal paste defining said face. Brief description of the drawings
[0026] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings, in which:
[0027] [Fig-1] [Fig.1] is a schematic, top view of a battery according to the invention,
[0028] [Fig.2] [Fig.2] is a schematic, perspective view of the battery shown on [Fig. 1], without the casing, some crossbeams are raised to show their shapes,
[0029] [Fig.3] [Fig.3] is a view analogous to that of [Fig.2], centered on one of the two ends of one of the two extreme crossbeams shown in figures 1 and 2,
[0030] [Fig.4] [Fig.4] is a schematic view of the end shown in [Fig.3] and of the casing shown in [Fig. 1], in section perpendicular to the transverse direction, and
[0031] [Fig. 5] [Fig. 5] is a graph showing the maximum temperature reached by a electrochemical cell near an electrochemical cell located in a corner of the housing, the latter undergoing thermal runaway, the maximum temperature being represented as a function of the extension of the foot formed by the end shown in figures 3 and 4. DETAILED DESCRIPTION Battery
[0032] With reference to figures 1 and 2, a battery 10 according to the invention is described, for an electric or hybrid vehicle (not shown).
[0033] The battery 10 includes a housing 12 defining a housing 14 extending in a longitudinal direction X and in a transverse direction Y perpendicular to the longitudinal direction X, and which are for example the longitudinal and transverse directions of the vehicle.
[0034] We also define an elevation direction Z perpendicular to the longitudinal direction X and to the transverse direction Y, and which is for example vertical when the vehicle is on a horizontal surface (not shown).
[0035] The battery 10 comprises a plurality of assemblies 16 comprising several electrochemical cells 18 capable, in operation, of releasing heat, and a plurality of cross members 20 extending transversely in the housing 14, each of the assemblies 16 extending longitudinally between two of the cross members.
[0036] The battery 10 includes a cooling system 22 located in the housing 14 or forming a bottom of the housing, the cooling system being in thermal contact with the assemblies 16 and the cross members 20.
[0037] The battery 10 advantageously includes electrical connectors (not shown) adapted to connect the electrochemical cells 18 to each other and the assemblies 16 to each other.
[0038] The housing 12 is for example parallelepiped in shape, and rectangular or square in view according to the elevation direction Z.
[0039] In the example, in each of the sets 16, the electrochemical cells 18 are successive in the transverse direction Y.
[0040] In an alternative not shown, the electrochemical cells 18 are successive in the longitudinal direction X.
[0041] The housing 12, the cross members 20 and the assemblies 16 advantageously define between them an interstitial space 24 forming a perimeter of the assemblies and the cross members around the elevation direction Z. Crossbeams
[0042] The crossbeams 20 comprise two end crossbeams 20A, 20B such that the assemblies 16 are all located longitudinally on one side only of each of the two end crossbeams.
[0043] Each of the two extreme cross members 20A, 20B comprises a main part 26 forming a transverse beam, and two ends 28, 30 opposed to each other transversely.
[0044] In the example, the two extreme cross members 20A, 20B are symmetrical to each other with respect to a plane PI ([Fig. 1]) perpendicular to the longitudinal direction X, and advantageously with respect to a plane P2 perpendicular to the transverse direction Y. The two extreme cross members 20A, 20B are, in the example, structurally analogous to each other.
[0045] The main part 26 of each of the two extreme cross members 20A, 20B advantageously has an "L" shape in cross-section perpendicular to the transverse direction Y ([Fig.4]), at least one of the assemblies 16 being sandwiched between the base of the "L" and the cooling system.
[0046] In the example, the crossbeams 20 which are not in extreme position advantageously have a "T" shape in section perpendicular to the transverse direction Y.
[0047] As can be seen in [Fig. 3], each of the two ends 28, 30 has a foot 32 extending against the cooling system 22 and forming a protrusion in the longitudinal direction X from the main part 26 on the side opposite the assemblies 16. Each of the two ends 28, 30 includes, for example, an overthickness 34 on the main part 26 in the longitudinal direction X, the overthickness 34 extending from the foot 32 in the elevation direction Z. Each of the two ends 28, 30 is in thermal contact with at least one of the assemblies 16.
[0048] The foot 32 is advantageously made of the same material as the crossbars 20, preferably aluminum.
[0049] The foot 32 advantageously has an extension L in the transverse direction Y of between 50 and 200 mm, preferably between 80 and 150 mm.
[0050] The foot 32 extends opposite at least two electrochemical cells 18A, 18B ([Fig.3]) of one of the assemblies 16 in the longitudinal direction X, preferably only two electrochemical cells, the two electrochemical cells 18A, 18B being successive and one of the two electrochemical cells 18A, 18B being extreme transversely in one of the assemblies 16.
[0051] The protrusion advantageously has an average thickness E in the elevation direction Z of between 4 and 8 mm, for example about 6 mm. The foot 32 has, for example, a convergent shape in the longitudinal direction X on the side opposite the assemblies 16.
[0052] Advantageously, the extra thickness 34 gradually thins in the Z-direction, in this example until it merges into the main part 26. Cooling system
[0053] The cooling system 22 advantageously comprises a plate 36 defining a circuit (not shown) for a cooling fluid (not (represented), the plate 36 having a face 38 in thermal contact with the foot 32 of each of the two ends 28, 30 of the two extreme cross members 20A, 20B. The cooling system 22 is advantageously in thermal contact with the main part 26 of each of the cross members 20 in the transverse direction Y, as well as with the electrochemical cells 18, 18A, 18B.
[0054] The cooling system 22 includes, for example, a layer 40 of adhesive or thermal paste defining the face 38 and adapted to facilitate thermal conduction. Such adhesives or pastes are known per se. An example of a thermal adhesive is silicone adhesive (BERGQUIST LIQUI BOND TLB SA2005RT), and an example of a thermal paste is silane-terminated polymer (STP) by SikaBiresin® TC-455. Operation
[0055] During operation, the battery assemblies 16 of the battery 10 generate heat. Some of the heat generated by an electrochemical cell 18A located in a corner of the housing 14 is transferred to one of the two ends 28, 30 of one of the two outermost cross members 20A, 20B. The foot 32 and the optional additional thickness 34 constitute a volume of material that increases the thermal inertia of the two ends 28, 30. This allows at least some of the heat generated by the electrochemical cell 18A to be absorbed and transferred to the cooling system 22.
[0056] The foot 32, thanks to its contact surface 42 with the cooling system 22, efficiently dissipates heat towards the cooling system 22, without obstructing the interstitial space 24. Tests
[0057] Figure 5 illustrates simulation results with a 6 mm thick foot 32 in the Z-axis elevation direction. A cooling fluid at 45°C flows through the plate 36 of the cooling system 22. The cooling fluid flow rate is, for example, 15 liters / min. The thermal conductivity of the layer 40 is 0.6 W / mK.
[0058] A thermal runaway is simulated in the extreme cell 18A and the maximum temperature reached in the neighboring cell 18B in the same assembly 16 is calculated as a function of the extension L of the foot 32 in the transverse direction Y.
[0059] It is observed that in the absence of foot 32 (extension L of 0 mm), the neighboring cell 18B reaches a temperature of 145°C, quite close to the critical temperature.
[0060] When the extension L is 100 mm, the temperature reached is approximately 141.5°C, and 140°C for an extension L of 200 mm.
[0061] For higher extensions, the temperature reached no longer decreases. Benefits
[0062] Thanks to the characteristics described above, battery 10 presents a lower risk of thermal malfunction.
[0063] Indeed, if an electrochemical cell 18 located in the middle of the others undergoes thermal runaway, the heat released is distributed among the neighboring electrochemical cells 18. Thus, the temperature of these neighboring cells does not rise above a critical temperature, for example 150°C, which would cause them to thermal runaway.
[0064] If an electrochemical cell 18 in an extreme position, such as electrochemical cell 18A, undergoes thermal runaway, the heat released is distributed towards the neighboring electrochemical cells, which are fewer in number than for a non-extreme electrochemical cell, and towards one of the two ends 28, 30 of one of the two extreme cross members 20A, 20B. Now, the ends 28, 30 have improved thermal inertia, thanks to the foot 32. Thus, the risk of thermal runaway is reduced, even for an extreme electrochemical cell 18, which is not surrounded by other electrochemical cells.
Claims
Demands
1. A battery (10) for an electric or hybrid vehicle, comprising: - a casing (12) defining a housing (14) extending in a longitudinal direction (X) and in a transverse direction (Y) perpendicular to the longitudinal direction (X), - a plurality of assemblies (16) comprising electrochemical cells (18, 18A, 18B) capable of generating heat during operation, - a plurality of cross members (20, 20A, 20B) extending transversely in the housing (14), each of the assemblies (16) extending longitudinally between two of the cross members (20, 20A, 20B), the cross members comprising two end cross members (20A, 20B) such that the assemblies (16) are all located longitudinally on one side of each of the two end cross members (20A, 20B), and - a cooling system (22) located in the housing (14) or forming a housing fund (14),the cooling system (22) being in thermal contact with the assemblies (16) and the crossbeams (20, 20A, 20B), characterized in that each of the two extreme crossbeams (20A, 20B) comprises: - a main part (26) forming a transverse beam, and - two ends (28, 30) opposed to each other transversely, each of the two ends (28, 30) having a foot (32) extending against the cooling system (22) and forming a protrusion in the longitudinal direction (X) from the main part (26) on the side opposite the assemblies (16), each of the two ends (28, 30) being in thermal contact with one of the assemblies (16).
2. Battery (10) according to claim 1, wherein the foot (32) has an extension (L) in the transverse direction (Y) of between 50 mm and 200 mm, preferably between 80 mm and 150 mm.
3. Battery (10) according to claim 1 or 2, wherein the protrusion has an average thickness (E) in an elevation direction (Z) perpendicular to the longitudinal direction (X) and to the transverse direction (Y), the average thickness (E) being between 4 mm and 8 mm.
4. Battery (10) according to any one of claims 1 to 3, wherein the electrochemical cells (18, 18A, 18B) of each of the assemblies (16) are successive in the transverse direction (Y), the foot (32) extending opposite at least two of the electrochemical cells (18, 18A, 18B) of one of the assemblies (16) in the longitudinal direction (X), preferably only two electrochemical cells, the two electrochemical cells (18A, 18B) being successive and one (18A) of the two electrochemical cells (18A, 18B) being extreme transversely in one of the assemblies (16).
5. Battery (10) according to any one of claims 1 to 4, wherein the foot (32) has a convergent shape in the longitudinal direction (X) on the side opposite the assemblies (16).
6. Battery (10) according to any one of claims 1 to 5, wherein each of the two ends (28, 30) comprises an overthickness (34) on the main part (26) in the longitudinal direction (X), the overthickness (34) extending from the foot (32) in an elevation direction (Z) perpendicular to the longitudinal direction (X) and to the transverse direction (Y).
7. Battery (10) according to claim 6, wherein the overthickness (34) gradually thins in the elevation direction (Z).
8. Battery (10) according to any one of claims 1 to 7, wherein the main part (26) of each of the two end cross members (20A, 20B) has an "L" shape in cross section perpendicular to the transverse direction (Y), at least one of the assemblies (16) being sandwiched between the base of the "L" and the cooling system (22).
9. Battery (10) according to any one of claims 1 to 8, wherein the cooling system (22) comprises a plate (36) having a face (38) in thermal contact with the foot (32) of each of the two ends (28, 30) of the two extreme cross members (20A, 20B).
10. Battery (10) according to claim 9, wherein the cooling system (22) comprises a layer (40) of glue or thermal paste defining said face (38).