Heat sink for battery device and battery module including heat sink

Abstract

A heat sink (26) for a battery device, the heat sink being configured to prevent heat propagation between battery pack subassemblies, the heat sink (26) comprising: a first contact unit (28) and / or a second contact unit (30) adapted to be in surface contact with a first battery pack subassembly and a second battery pack subassembly, and a support unit (32) sandwiched between the first contact unit (28) and the second contact unit (30). The heat sink (26) extends in a heat sink plane having a heat sink thickness and a heat sink length in a cross-section along the longitudinal axis, and a thermal resistance in the heat sink plane is lower than a thermal resistance in a direction perpendicular to the heat sink plane such that the heat sink ensures a thermal management function and a thermal safety function of the battery device.

Description

Technical Field

[0001] The present disclosure generally relates to methods and assemblies for thermal management of the temperature of battery components and thermal safety features for limiting cell-to-cell heat propagation within a battery. More specifically, but not exclusively, the present invention relates to a battery module having a plurality of electrically interconnected battery cells, wherein individual battery cells are temperature controlled by heat dissipation and insulation. Background Art

[0002] In this application, the "thermal management" function and goal shall refer to keeping the battery and its various subcomponents within desired temperature limits (minimum and maximum) and within a desired variation (ΔT) band from one subcomponent to another. The "thermal safety" function shall refer to limiting the heat propagation between battery subcomponents, especially between cells, with the goal of preventing thermal runaway events (defined below).

[0003] In this document, the terms "battery cell," "battery module," "battery portion," and "battery pack" (and their abbreviations "cell," "module," "portion," and "pack") are used to describe components at different levels of the overall battery assembly. For example, many individual battery cells form the building blocks of a battery module. Multiple battery modules (in combination with auxiliary equipment) in turn form a battery pack.

[0004] For the purposes of this application, a cell is the smallest unit of a battery, comprising a single anode electrical connection and a single cathode electrical connection on an exterior or sealed housing containing one or more pairs of anode and cathode elements. A cell is a single electrochemical unit, and a battery consists of one or more electrically interconnected cells that are connected in series, in parallel, or in series and in parallel, depending on the desired output voltage, current, or capacity.

[0005] The battery device may include one or more battery packs sized to provide power to a vehicle. The battery pack is composed of a battery portion, which may be composed of a plurality of battery modules, each of which is composed of one or more battery cells that deliver current to a load. The battery cells are electrically interconnected.

[0006] A battery pack is composed of multiple sections, which may be composed of multiple battery modules, each of which is composed of one or more battery cells that deliver current to a load. Those skilled in the art will understand that the number of battery cells within a larger battery module, section, group, or related structure is consistent with the power requirements of the device receiving the current from the battery and the thermal operating requirements of the individual cells within the battery. In such batteries, the current of charge and discharge generates heat within the cells and in their interconnection system.

[0007] Electric vehicles (EVs) use lithium-ion batteries composed of cells. The performance of lithium-ion battery cells is very dependent on their temperature. When overheated, the cells may experience reduced electrical performance, damage, and shortened life. Therefore, lithium-ion batteries require a thermal management system to maintain a constant temperature with very low temperature deviation (the temperature distribution on the cell should be uniform, with a maximum deviation of less than 5°C) so that they can work efficiently without damage or malfunction.

[0008] Additionally, lithium-ion batteries may experience a failure known as thermal runaway. The term thermal runaway event refers to an uncontrolled increase in temperature in a battery system. Thermal runaway is a chain reaction within a battery cell that, once initiated, can be very difficult to stop. Thermal runaway occurs when the temperature inside the battery reaches a point that causes a chemical reaction to occur within the battery. This chemical reaction generates more heat, which drives the temperature higher, causing further chemical reactions that generate more heat. During a thermal runaway event, the generation of heat within a battery system or battery cell exceeds the dissipation of heat, thus causing a further increase in temperature. Thermal runaway events can be triggered by a variety of conditions, including a short circuit within a cell, improper use of a cell, physical abuse, manufacturing defects, or exposure of a cell to extreme external temperatures.

[0009] One of the important issues in electric vehicle construction is the thermal management and thermal safety system of the battery (especially lithium-ion batteries have been widely used in electric vehicles).

[0010] Thermal management is essential to the performance and operating life of electric vehicle batteries, and several studies, publications and patent documents address this issue.

[0011] US10686171 discloses a battery module comprising a plurality of battery cells (or batteries) and a plurality of partitions, each of which is inserted between two adjacent cells. The partition includes through holes that form air thermal resistance. The partition is made of thermosetting resin, and the volume of the partition can expand when the temperature of a cell exceeds 200 degrees Celsius.

[0012] Expansion at high temperatures can cause damage to the cells. In addition, heat transfer between cells is reduced, but only to a certain extent.

[0013] It is also known to use cooling fins to conduct heat away from the battery cells. The cooling fins may be made of a material with high thermal conductivity (or low thermal resistance) to transfer the heat to a cooler or heat exchanger.

[0014] For example, US20110189525 discloses a heat exchanger structure used in a battery cell and arranged between opposing surfaces of a first battery stack and a second battery stack. The heat exchanger defines one or more fluid flow channels and is used to dissipate heat.

[0015] It is also known to cool electric vehicle batteries by using forced convection of forced air or liquid coolant circulating through cooling channels. For example, documents US2021135307A1, US2014308551A1, CN102117945 and US2008305388A1 disclose a liquid-cooled battery system. US2016204483A1 also discloses cooling fins configured to receive a flow of liquid coolant through a coolant channel, and discloses thermal insulation between units using passive cooling in the battery system without active circulation of a cooling fluid, such as conduction, radiation or convection cooling.

[0016] In US2008 / 0305388, a thin, substantially planar, but not necessarily flat, thermally conductive sheet in contact with each battery cell conducts heat from the cell to a heat exchanger comprising a tube containing a cooling fluid. The sheet is connected to the tube at the end of the sheet, and the tube is outside the perimeter of the battery pack.

[0017] In US2014 / 0308551, various embodiments disclose inter-unit cooling fins that include coolant fluid conducting channels within each fin between adjacent units. The fluid conducting channels are fluidly connected to a manifold outside the perimeter of the unit.

[0018] US2021 / 0135307 also describes various embodiments in which a cooling fluid circulates through fluid channels within substantially planar cooling fins located between adjacent cells.

[0019] In US20160204483, various embodiments also describe cooling fins having fluid channels for actively circulating coolant, and the addition of elements that allow passive (e.g., gravity) flow of coolant in the event of a loss of active (pumping) flow to mitigate the spread of thermal runaway between units.

[0020] CN102117945 uses anisotropic heat conduction and discloses a device comprising a combined heat conducting plate, the combined heat conducting plate comprising a heat conducting layer and a heat insulating layer. The combined heat conducting plate can be arranged between two element units.

[0021] These systems require complex manufacturing and still require the provision of a cooling system that ensures thermal management functionality by removing excess heat from the cells while limiting heat spread between battery cells or modules or between the battery pack and the rest of the vehicle.

[0022] JP2020072005A relates to a plate for suppressing heat transfer for a battery. JP2020072005A discloses a device comprising two flat plates made of heat absorbing or heat insulating material and a corrugated plate extending between the two flat plates. The corrugated plate has the same heat absorbing and / or heat insulating properties as the flat plate 20. Heat will be absorbed to evaporate water or any material.

[0023] The materials of the different layers (flat and corrugated) are very specific. Plates that inhibit heat transfer are particularly expensive and difficult to manufacture.

[0024] The present invention generally relates to a heat sink capable of cooling individual battery cells, battery modules or battery packs and insulating adjacent battery cells, battery modules or battery packs. The present invention also relates to a battery module including such a thermal isolator.

[0025] One aspect of the present invention will involve the selection of certain materials and their arrangement to achieve thermal management and thermal safety functions. Thermal interface materials (TIMs) can be used for thermal management in electronic components because they enhance heat transfer from heat generating components (here, battery cells) to heat sinks (heat sinks, heat exchangers, or coolers). When selecting a TIM for an application, an important aspect is to know the ability of the material to transfer heat, which is usually given by thermal conductivity and / or thermal resistance. Thermal conductivity is a material property and describes the ability of a given material to conduct heat. Materials with high thermal conductivity are better thermal conductors. This property is independent of material size, shape, or orientation in a homogeneous material, and therefore, thermal conductivity is an ideal value. Thermal conductivity is measured in Watts / meter-Kelvin.

[0026] Thermal resistance is simply the mathematical inverse of thermal conductivity. Since both thermal conductivity and thermal resistance are functions of distance (note the "meter" in the denominator of Watts / meter-Kelvin), thinner TIMs transfer heat more efficiently than thicker TIMs. The thermal resistance of a structure is measured between a first point and a second point and depends on the thermal resistance of the individual homogeneous elements and all contact resistances between them. When the thermal resistance of a structure is lower, the structure is a better thermal conductor. Factors such as surface roughness, surface flatness, clamping, the presence of adhesives, non-uniformity, and material thickness all have a large impact on the thermal resistance of a material. Therefore, thermal resistance is a parameter that makes up multiple specific variables of a structure. Thermal resistance is usually expressed in units of m2K / watt. Summary of the invention

[0027] The object of the present invention is to provide a heat sink and a battery module that improves thermal management functions by conducting heat generated in battery cells to, for example, a cooler, and minimizes heat propagation between cells, between modules, and from a battery pack to a vehicle. The heat sink is designed to be arranged between any battery pack subassemblies (e.g., battery modules, battery cells, or battery packs), as disclosed below.

[0028] Therefore, the present invention provides a cooling sheet according to claim 1 and a battery device according to claim 11 .

[0029] More specifically, a heat sink for a battery device configured to prevent heat propagation between cells, modules and / or battery packs to a vehicle comprises: a first contact unit and a second contact unit. The first contact unit (having high thermal conductivity) is in surface contact with a first battery pack subassembly. Such a subassembly is, for example, a single battery cell, or a battery module comprising a plurality of cells, or a battery pack comprising a plurality of battery modules. And the second contact unit may be in surface contact with a second battery pack subassembly. A support unit (or insulator) is arranged adjacent to the first contact unit. The support unit (or insulator) may also be sandwiched between the first contact unit and the second contact unit to create an insulating space between the first contact unit and the second contact unit. The heat sink extends in a plane and defines a height, width and thickness. The thermal resistance in the plane is lower than the thermal resistance in a direction perpendicular to the plane (ie, through the thickness of the heat sink), so that the heat sink provides a thermal management function and a thermal safety function of the battery device. The support unit comprises a structure arranged so that an insulating gap (particularly a fluid gap, preferably an air gap) is maintained between the first contact unit and the second contact unit. The gap forms an insulating layer that prevents heat transfer between the cells.

[0030] The gaps are defined or predetermined, and their design can be adapted to the shape, size or performance requirements of the battery subassembly.

[0031] This sandwich structure provides low thermal resistance in the plane of the heat sink, but good thermal resistance in the direction perpendicular to the plane of the heat sink (through the thickness of the heat sink). The sandwich structure allows cooling of individual cells while insulating one cell from adjacent cells. Thus, less than 20%

[0032] (and even more specifically less than 10%, and even more specifically less than 5%) of the heat is transferred from one battery pack subassembly to another. This arrangement also promotes uniform temperature within the cell.

[0033] In another embodiment, the structure comprises a support plate sandwiched between the first spacer and the second spacer, so that the insulating gap, in particular the fluid gap, is provided on both sides of the plate. For example, the plate extends parallel to the first contact unit and / or the second contact unit. The fluid gaps on both sides of the support plate increase the thermal resistance.

[0034] In another embodiment, the insulating gap(s) are fluid gap(s) or more specifically air gap(s).Such air gap(s) are easy to implement and are satisfactory.

[0035] In yet another embodiment, the first contact unit and / or the second contact unit (conductor) and the structure are made of two different materials. More specifically, the first contact unit and / or the second contact unit are made of a material with high thermal conductivity, and the structure or the support unit is made of a material with low thermal conductivity. For example, a high thermal conductivity material is a material with a thermal conductivity in the range of 100 W·m-1·K-1 to 3000 W·m-1·K-1. Graphite or copper are materials with high thermal conductivity. And a low thermal conductivity material is a material with a thermal conductivity lower than 400 W·m-1·K-1. Some metals, plastics or glasses have low thermal conductivity.

[0036] In another embodiment, the first contact unit and / or the second contact unit may be made of copper and / or aluminum with or without graphite. Specifically, the first contact unit and / or the second contact unit are made of copper, or made of copper bonded to graphite, or made of aluminum bonded to graphite. The first contact unit and / or the second contact unit may also be made of a steel alloy bonded to graphite.

[0037] In one embodiment, the structure is made of paper. Paper insulation is inexpensive and strong enough for this purpose.

[0038] In one embodiment, a structure made of paper can be coupled to a contact unit made of graphite. In fact, graphite provides good flexibility.

[0039] In one embodiment, the structure is made of a mica-based material.

[0040] In one embodiment, the fluid gap has a thickness in cross section of about 0.05 mm to 1 mm.

[0041] In one embodiment, the support structure has a grid pattern.The grid pattern allows for a regular thickness of the fluid gap.

[0042] In one embodiment, the structure is at least partially corrugated.

[0043] In one embodiment, a structure includes at least one intermediate plate having a first surface, a second surface opposite the first surface, a plurality of first spacers extending from the first surface, and a plurality of second spacers extending from the second surface.

[0044] In one embodiment, the total thickness of the heat sink in a direction perpendicular to the plane of the heat sink is less than 10 mm, and in particular between 0.5 mm and 2 mm.

[0045] The present invention also relates to a battery module, comprising a plurality of electrically interconnected battery cells and a plurality of heat sinks as described above, wherein each heat sink is arranged to be thermally connected to at least two of the plurality of battery cells or battery pack subassemblies, and wherein a first contact unit and a second contact unit are connected to a cooler.

[0046] In one embodiment, the heat sink and the plurality of battery cells comprise a substantially planar configuration such that an adjacent facing relationship is formed between a heat sink and at least two of the plurality of battery cells.

[0047] In one embodiment, the first heat sink includes a first contact unit contacting the first battery cell, the second heat sink includes a second first contact unit contacting the second battery cell, and the expansion compensator is disposed between the two heat sinks.

[0048] In one embodiment, the first contact unit is in surface contact with the first battery cell, and the second contact unit is in surface contact with the second battery cell.

[0049] The present invention also relates to a support unit for a heat sink, the support unit comprising a structure arranged to establish an insulating gap, wherein the structure comprises at least one intermediate plate having a first surface, a second surface opposite to the first surface, a plurality of first spacers extending from the first surface, and a plurality of second spacers extending from the second surface.

[0050] The invention and its advantages will be better understood by reading the following description, given by way of example only, and with reference to the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A battery module according to the prior art is shown;

[0052] FIG. 2A to FIG. 2I shows cross-sectional views of nine different embodiments of a heat sink according to the present invention;

[0053] Figure 3A and Figure 3B Two further embodiments (embodiments 12 and 13) of the heat sink according to the present invention are schematically shown in exploded views, wherein Figure 3A A first battery cell and a second battery cell and a cooler are also shown in dotted lines to constitute a battery module;

[0054] FIG. 4A to FIG. 4C A battery cell or battery module with a heat sink according to the present invention is schematically shown, wherein Figure 4A A prismatic battery module or battery cell having a parallelepiped shape is schematically shown, wherein Figure 4BThe schematic diagram shows a prismatic battery module or battery cell having an elliptical cross section, and wherein Figure 4C A cylindrical battery module or cell is shown;

[0055] FIG. 5A to FIG. 5C A battery cell or battery module with a heat sink according to another embodiment of the present invention is shown, wherein Figure 5A A prismatic battery module or battery cell having a parallelepiped shape is schematically shown, wherein Figure 5B The schematic diagram shows a prismatic battery module or battery cell having an elliptical cross section, and wherein Figure 5C A cylindrical battery module or cell is shown;

[0056] Figure 6 Shows Figure 2C A cross-sectional view of a variation of an alternative embodiment of the present invention;

[0057] Figure 7 An embodiment of a support structure of a heat sink according to the present invention is shown;

[0058] Figure 8 Another embodiment of the support structure of the heat sink according to the present invention is shown in a cross-sectional view;

[0059] Fig. 9 The integration of an expansion compensator within a heat sink or between two heat sinks is shown. DETAILED DESCRIPTION

[0060] The embodiments of the present disclosure will be best understood by reference to the accompanying drawings, in which the same reference numerals represent the same or similar elements. It is readily understood that the components of the disclosed embodiments may be arranged and designed in a variety of different configurations, as generally described and illustrated in the drawings herein. Therefore, the following detailed description of the embodiments of the systems and methods of the present disclosure is not intended to limit the scope of the present disclosure as claimed, but is merely representative of possible embodiments of the present disclosure. In addition, unless otherwise indicated, the steps of the method do not necessarily need to be performed in any particular order or even sequentially, nor do they need to be performed only once.

[0061] In some cases, well-known features, structures or operations are not shown or described in detail. In addition, in one or more embodiments, the described features, structures or operations can be combined in any suitable manner. It will also be readily understood that, as generally described and shown in the drawings herein, the components of the embodiments can be arranged and designed in a variety of different configurations.

[0062] Figure 1An end view of a battery module 10 according to the prior art is shown. The battery module 10 includes a plurality of battery cells 12. A cooling fin 14 is located between adjacent pairs of battery cells 12. The cross-section of each cooling fin 14 is L-shaped, with a first longer surface in contact with a first battery cell, and a second surface (base) smaller than the first surface and in contact with a cooler 16. The cooler 16 may be passive (e.g., a radiating radiator) or active (e.g., a heat exchanger for gas or liquid flowing therein). For example, two L-shaped cooling fins 14 are provided between two adjacent battery cells 12. The cooler 16 may be significantly flat and may include several layers 18, 20, 22, 24. The first layer 18 is, for example, a thermal pad, the second layer 20 may be a first cooling plate, the third layer 22 may be a fluid channel for conveying a coolant, and the last layer 24 may be a second cooling plate. Each battery heat sink 14 is, for example, made of aluminum or other materials having good thermal conductivity and transferring heat from the battery cell it contacts to the cooler 16.

[0063] As mentioned earlier, Figure 1 The cooling fins 14 perform a thermal management function by conducting excess heat away from the cells 12, but do not perform a thermal safety function (as defined above). Heat transfer between battery cells is possible, and such heat transfer between cells may lead to a "runaway event" in an adjacent cell. The term thermal runaway event refers to an uncontrolled increase in temperature in a battery system. During a thermal runaway event, the generation of heat within the battery system or battery cells exceeds the dissipation of heat, thereby causing a further increase in temperature. Thermal runaway events can be triggered by various conditions, including a short circuit within the cell, improper use of the cell, physical abuse, manufacturing defects, or exposure of the cell to extreme external temperatures. In order to avoid such runaway events, a safe thermal function is necessary.

[0064] FIG. 2A to FIG. 2I , Figure 3A , Figure 3B , Figure 4 and Figure 6 Several embodiments of heat sinks 26 according to the present invention are shown, which provide thermal management functions and thermal safety functions. Such heat sinks 26 are suitable for replacing Figure 1 The cooling fins 14 are shown in FIG.

[0065] like FIG. 2A to FIG. 2I , Figure 3A , Figure 3B , Figure 4 and Figure 6As shown, the improved heat sink 26 generally includes a first contact unit 28, a second contact unit 30, and a support unit 32 sandwiched between the first contact unit 28 and the second contact unit 30. The heat sink 26 has a substantially planar geometry, and its thickness is much smaller than its height or length (width). For example, the ratio between the height and the thickness is between 25 and 1000. In this case, planar does not necessarily mean flat. The safety heat sink can be shaped to conform to the outer shape of the battery subassembly, which can be flat, cylindrical, or prismatic.

[0066] For example, Figure 3A As shown, the first contact unit 28 includes a substantially flat configuration, with a thickness t much smaller than a height H or a length L. More specifically, the first contact unit 28 includes a first portion 34 adapted to contact a first battery cell 36 and a second portion 38 adapted to contact a cooler 40 (see Figure 3A The first contact unit 28 may be substantially L-shaped. The first portion 34 is substantially planar, having a first surface 42 adapted to face outward and contact the first battery cell 36 and a second surface 44 opposite to the first surface and facing inward. The first portion 34 has, for example, a height of about 100 mm to 300 mm and a thickness of about 0.05 mm to 1 mm. The second portion 38 has a smaller length and a smaller surface than the first portion 34.

[0067] The second contact unit 30 is obviously identical to the first contact unit 28 (and is arranged in a mirror-image geometry). The second contact unit 30 includes a first portion 34 adapted to contact the second battery cell 37 and a second portion 38 adapted to contact the cooler 40. The second portion 38 extends, for example, perpendicular to the first portion 34. The second contact unit 30 can be obviously L-shaped. The second portion 38 has a smaller length and a smaller surface than the first portion. The first portion 34 is substantially planar, having a first surface 42 adapted to face outward and contact the second battery cell 37 and a second surface 44 opposite to the first surface 42 and facing inward. The first portion 34 has, for example, a height of approximately 100 mm to 300 mm and a thickness of approximately 0.05 mm to 1 mm.

[0068] The first contact unit 28 and the second contact unit 30 are both implemented by materials with high thermal conductivity. For example, the first contact unit 28 or the second contact unit 30 may be made of graphite, or copper, or an aluminum alloy, or a steel alloy, or some combination of these materials. More specifically, the contact units 28, 30 are made of copper or graphite. They allow heat to be transferred from the first portion 34 to the cooler 40, thereby removing heat from the inside of the battery module. Therefore, the thermal conductivity within the plane of the heat sink formed by the first portion 34 is relatively high. The contact unit transfers heat but does not absorb heat.

[0069] A support unit 32 is provided between the first contact unit 28 and the second contact unit 30. The support unit 32 extends between the second surface of the first contact unit 28 and the second surface of the second contact unit 30. The support unit 32 includes at least one material different from the first contact unit 28 or the second contact unit 30. The support unit 32 may be made of one or more materials having low thermal conductivity. In any case, the support unit 32, as a whole, has a high thermal resistance as a structure. For example, the support unit 32 may include a structure 50 made of metal, plastic, glass, paper, aluminum, mica or steel alloy. More specifically, the support structure is made of mica or paper material. Mica and paper are lightweight materials and allow low thermal conductivity. More specifically, a thermal conductivity of about 0.001 W / mK can be obtained using these materials. The shape or arrangement of the structure 50 makes the support unit 32 have a higher thermal resistance than the contact units 28, 30. The support unit 32 may include, for example, a structure arranged to provide a fluid gap 52 (e.g., an air gap) between the first contact unit 28 and the second contact unit 30. Generally, the support unit 32 may be composed of a structure 50 and (one or more) air gaps 52 .

[0070] The first contact unit 28 and the second contact unit 30 generally extend over most of the facing surfaces of the battery cells 36, 37 and are in contact with them, and are designed to contact the cooler 40. Generally, the support unit 32 is not designed to contact the cooler 40, but is designed to fully extend between the first contact unit 28 and the second contact unit 30, spatially separate the first contact unit 28 and the second contact unit 30, and thermally insulate the two. The support unit 32 forms a thermal barrier.

[0071] The heat sink 26 including the support unit 32 and the first contact unit 28 and the second contact unit 30 extends in a heat sink plane and has a heat sink length Lfin, a heat sink height Hfin and a heat sink thickness t fin . Heat sink height Hfin and heat sink thickness t fin The ratio between is between 25 and 1000. The structure of the heat sink 26 is clearly planar and can be flat or shaped to conform to the outer shape of the battery cells 36, 37. Due to the isolating fluid gap created by the support unit and / or the different thermal conductivities of the different materials used on the contact units 28, 30 relative to the support unit 32, the thermal resistance in the plane of the heat sink is lower than the thermal resistance in the direction perpendicular to the plane of the heat sink (across the thickness). The heat sink 26 constructed in this way provides a thermal management function of removing heat to the cooler 16, 40 and a thermal safety function of isolating heat propagation between adjacent cells 26, 37 in the battery module or adjacent battery pack subassembly.

[0072] Figure 3AThe battery cells 36, 37 are shown as having a prismatic form. However, as mentioned above, the shape of the battery cells can be different. For example, the battery cells can have a cylindrical shape as shown in FIG. 4. The dashed lines in FIG. 4 schematically represent heat sinks having a shape consistent with the appearance of cylindrical battery cells. In other embodiments (not shown), the battery cells can also be pouch cells.

[0073] The support unit 32 may have different designs or arrangements, for example FIG. 2A to FIG. 2I , Figure 3A , Figure 3B As shown in Figure 4.

[0074] exist Figure 2A In the embodiment, the support unit 32 includes a structure 50 and an air gap 52. The structure 50 includes a first plate 501 connected to the second inner surface 44 of the first contact unit 28 and a second plate 502 connected to the second inner surface 44 of the second contact unit 30. For example, the plates 501, 502 extend over most of the second surface 44 of the contact unit 28 and are in surface contact with the second surface 44. The plates 501, 502 can be bonded to the second surface 44 of the contact units 28, 30. A spacing structure 503 is provided between the first plate 501 and the second plate 502. The spacing structure 503 is wavy (corrugated) in cross section and forms a plurality of fluid gaps or air gaps 52 between the first plate 501 and the second plate 502. The wavy spacing structure 503 and the first plate 501 and the second plate 502 can be made of the same material. The material has low thermal conductivity, for example, it can be a structured metal, plastic, glass, paper, aluminum or steel alloy. Alternative spacing structures may include fixing points, glue, parallelepipeds, rods (linear fixings), and grids, as further described below. The spacing structure may also be formed from sintered points or foamed points. The spacing structure 503 may include different elements and may be formed from different parts that may or may not be connected. More specifically, the spacing structure 503 may include a first substructure located on one side of the first plate and a second substructure located on the other side of the first plate.

[0075] exist Figure 2B In the embodiment, the structure 50 of the support unit 32 is Figure 2A The structure of the support unit 32 is similar to that of the support unit 32, except that the first plate 501 and the second plate 502 are not in surface contact with the second surface 44. The first plate 501 and the second plate 502 are fixed to the second surface 44 and spaced apart from it by fixing points 504, which can be, for example, sintering points or glue points. These fixing points 504 can be arranged to provide additional fluid gaps or air gaps between the contact units 28, 30 and the plates 501, 502. Alternatively, linear fixings can be provided instead of fixing points 54. For example, a grid (see Figure 3A and Figure 3B ) can be arranged between the plate and the contact unit.

[0076] like Figure 2C As shown, the structure 50 can also be made of a plate 501, which extends between the second surface 44 of the first contact unit 28 and the second contact unit 30 and is fixed to the second surface 44 by fixing points 504. These fixing points 504 can be, for example, sintering points or glue points. These fixing points 504 are arranged to set a fluid gap or air gap 52 between the contact units 28, 30 and the plate 501. Alternatively, linear fixings can be provided instead of fixing points. For example, a grid is provided between the plate and the contact units.

[0077] exist Figure 2D In the embodiment, the structure 50 is a hollow parallelepiped having first and second longitudinal plates 501, 502 in contact with the second surfaces 44 of the first and second contact units 28, 30, and side surfaces 506 connecting the first and second longitudinal surfaces 501, 502. The hollow space forms a fluid gap 52.

[0078] exist Figure 2E In the example, structure 50 is clearly similar to Figure 2D The parallelepiped of FIG. 4 is a parallelepiped, except that the first longitudinal plate 501 and the second longitudinal plate 502 are not in surface contact with the second surface 44, but are fixed to the second surface via fixing points 504, which can be, for example, sintering points or glue points. These fixing points 504 can be arranged to provide additional fluid gaps or air gaps between the contact unit and the parallelepiped. Alternatively, linear fixings can be provided instead of fixing points. For example, a grid can be provided between the plate and the contact unit.

[0079] Figure 2F The structure 50 has a ladder shape, and includes a first plate 501 in surface contact with the first contact unit 28, and a second plate 502 in surface contact with the second contact unit 30. The first plate 501 and the second plate 502 are connected together at certain intervals by a plurality of rods 508 perpendicular to the first plate 501 and the second plate 502. A fluid gap 52 is provided between two adjacent rods and the first plate and the second plate.

[0080] exist Figure 2G In the example, structure 50 is clearly similar to Figure 2F The structure 50 of FIG. 5 is different in that the first plate 501 and the second plate 502 are not in surface contact with the second surface 44. The first plate 501 and the second plate 502 are fixed to the second surface 44 and spaced apart from it by fixing points 504, which can be, for example, sintering points or glue points. These fixing points 504 can be arranged to provide additional fluid gaps or air gaps 52 between the contact units 28, 30 and the plates 501, 502. Alternatively, a fixing member using a rod 508, a linear element or a grid can be provided instead of a fixing point.

[0081] exist Figure 2H and Fig.2I In the embodiment, the structure 50 includes a plurality of plates 501, 502, 511, 512 extending parallel to each other and connected to each other by rods 508. The rods 508 may extend perpendicularly to the plates 501, 502. For example, four plates are provided. The outermost plates 501, 502 are connected to the contact units 28, 30. Figure 2H In the embodiment, the outermost plates 501, 502 are in surface contact with the contact units 28, 30. Fig.2I In the embodiment, a linear or point fixing member 504 is provided.

[0082] exist Figure 6 In the embodiment, the support unit 32 comprises a structure made of three plates and a spacing structure 503, so that a plurality of spacers are arranged on each side of each plate. The spacers can be stacked or staggered one below the other, such as Figure 6 shown.

[0083] like Figure 7 As can be seen in FIG. 5 , the spacing structure 503 may consist of a plurality of strips extending longitudinally over the width of the first plate 501. More specifically, the spacers may be strips uniformly arranged on the first plate 501. Each strip may have a width between 1 mm and 5 mm (and more specifically between 1 mm and 1.5 mm). In order to ensure the rigidity of the support unit and the presence of the air gap 52 created by the spacers, the strips may be arranged at a distance d of at least 5 mm from each other.

[0084] Figure 8 An embodiment of a support structure 32 having a first plate 501 is shown. The first plate has a first surface and a second surface opposite the first surface. A plurality of first spacers are arranged on the first surface, and a plurality of second spacers are arranged on the second surface. The support structure 32 may have a width between 50 mm and 300 mm and a length L between 50 mm and 1000 mm.

[0085] Figure 3A Another embodiment of the heat sink 26 is shown in an exploded view. The first battery cell 36 and the second battery cell 37 are indicated by dashed lines. The cooler 40 is also indicated by dashed lines. Between the first battery cell 36 and the second battery cell 36, a heat sink 26 having a first contact unit 28 and a second contact unit 30 is arranged. Each contact unit 28, 30 has an L-shape, which has a first portion 34 extending along the surface of the battery cells 36, 37 and a second portion 38 smaller than the first portion 34, the second portion facing the cooler 40 and directly or indirectly contacting the cooler. The first contact unit 28 and the second contact unit 30 are both made of the same material with high thermal conductivity. The material can be copper or an aluminum alloy.

[0086] exist Figure 3B In the embodiment shown, it is similar in other respects to Figure 3A In an embodiment, the first contact unit 28 and the second contact unit 30 are each made of two different materials. For example, a graphite plate 60 is bonded to a plate 62 of copper, an aluminum alloy or a steel alloy. This layered structure allows for better flexibility. In fact, graphite is more elastic or more flexible than copper or aluminum, and the entire system is easier to manufacture, handle or use. The contact height H corresponds to the heat sink height Hfin. The first portion 34 of the contact unit 28, 30 has a contact thickness t (see Figure 2) which may be approximately 0.05 mm to 1 mm. Figure 3A ). The first portion 34 of the contact unit 28, 30 has a contact length L which may be approximately 100 mm to 1000 mm.

[0087] exist Figure 3A and Figure 3B , the support unit 32 extends between the two contact units 28, 30 and comprises a structure 50 comprising a plate 501 sandwiched between a first grid 64 and a second grid 66. Depending on the plate material, the plate 501 can be in contact with the cooler 40 (if the plate material has, for example, a high thermal conductivity) or at a distance from the cooler (for example, for a plate material with a lower thermal conductivity). The grids 64, 66 are made of paper, for example. The holes 70 in the grids form a fluid gap (air gap) 52 between the contact unit and the plate 501.

[0088] The plate 501 has a thickness t of about 0.02 mm to 1 mm. p The plate 501 is made of, for example, an aluminum alloy or a steel alloy or paper. As described above, the plate 501 may or may not contact the cooler 40, depending on the thermal conductivity of the plate material. The dimensions (length Lp and height Hp) of the plate 501 are obviously the same as the dimensions of the first portion 34 of the contact unit 28, 30.

[0089] Each grid has a thickness t of about 0.02 mm to 1.0 mm. grid , which allows the air gaps 52 to have approximately the same thickness. The grids 64 , 66 may be bonded to the plate 501 or the contact units 28 , 30 .

[0090] The heat sink 26 formed by the contact units 28, 30, the grids 64, 66 and the plate 501 thus has a total heat sink thickness t in the cross section in the range of 0.5 mm to 10 mm, more specifically in the range of 0.5 mm to 4 mm. fin For example, the heat sink between battery modules will have a greater thickness than the heat sink between cells. Thus, the first range may apply to the heat sink between battery modules, wherein the second range may apply to the heat sink between battery cells. Specifically, the heat sink between cells may be provided with a thickness between 0.5 mm and 2 mm.

[0091] A battery subassembly, such as a battery module, may also be surrounded by one or more cooling fins as described below, wherein the first contact unit is in surface contact with, for example, one battery module, and wherein the second contact unit is in surface contact with another battery module.

[0092] For illustration purposes, FIG. 4A to FIG. 4C A battery cell or battery module having a heat sink 26 is schematically shown. In these figures, the center of the arrangement (the portion extending within the first contact unit 28) may be a battery cell 36 or a battery module M including a plurality of battery cells. The heat sink 26 includes a first contact unit 28, a second contact unit 30, and a structure 50 arranged to form a fluid gap 52. The structure 50 includes a first plate 501, a second plate 502, and a spacing structure 503. In the figures, a specific structure of the heat sink 26 is shown by way of example. For example, any heat sink arrangement disclosed above may be used.

[0093] As shown in the figures, one cooling fin 26 may surround the cell (particularly for a cylindrical cell or for a prismatic cell with an elliptical cross section), or several cooling fins 26 may be arranged adjacent to each other to surround, for example, a battery module.

[0094] Figure 4A A prismatic battery module M or battery cell 36 having a parallelepiped shape is schematically shown. Figure 4A is a side view. The heat sink 26 surrounds the parallelepiped shape (except for the base). Figure 4B In FIG. 4 , the prismatic battery module M or battery cell 36 has an elliptical cross-section. Figure 4C 2 shows a cylindrical battery module M or a battery cell C. A heat sink 26 surrounds the entire periphery of the module M or the cell.

[0095] FIG. 5A to FIG. 5C A battery cell 36 or a battery module M having a heat sink 26 is also schematically shown. In these figures, the heat sink 26 does not include a second contact unit. In these embodiments, the heat sink only includes a first contact unit 28 and a support unit 32. The support unit 32 includes a structure 50 that forms an air gap 52. The structure 50 shown includes a first plate 501 surrounding the first contact unit 28 and in surface contact with the first contact unit 28, a spacing structure 503, and a second plate 502 surrounding the spacing structure 503. Figure 5A is a schematic side view, and the module M or cell 36 (prismatic battery module M or battery cell 36 having a parallelepiped shape) is therefore surrounded only on three sides (the fourth side is the base). Figure 5B and Figure 5C is a schematic cross-sectional view showing a heat sink surrounding the battery module M or the battery cell 36 .

[0096] As mentioned above, the heat sink 26 may include only one contact unit 28, which constitutes the first contact unit and the support structure. Between the two heat sinks of this design, an expansion compensator 72 may be provided, such as Fig. 9 As shown. The expansion compensator 72 can be a plastic expansion compensator or a metal expansion compensator. The expansion compensator 72 forms a compensation system for the expansion of the electrochemical cells constituting the battery. During the charging of a battery cell, such as a lithium-ion type battery cell, the housing of the battery cell expands. In the case of a cell in prismatic form (also called a prismatic cell), the expansion mainly occurs on the two largest lateral planes of the prismatic housing that face each other. This expansion is amplified when the charge state of the battery cell moves closer to the fully charged state. When the cells are connected to each other one after the other in the housing and the thickness of each cell increases, the total length of the battery increases significantly, which is caused by the sum of the increases in the thickness of the individual cells. Since the housing is usually made of a rigid material and the gap between the cell and the wall of the housing is limited, the expansion of the cell puts the wall of the housing under pressure, which may lead to its irreversible deformation, or to premature aging of the cell, or even to damage to the battery. Therefore, an expansion compensator 72 is used, which prevents the housing from deforming under the effect of the expansion of the cell during the charging of the cell.

[0097] The expansion compensator may be made entirely of plastic material and include a planar body and a plurality of ribs protruding from the planar body toward the first battery cell and / or the second battery cell. In another embodiment, the expansion compensator 72 may be at least partially made of metal and have a spring carrier.

[0098] The entire arrangement of the heat sink allows for high thermal resistance (low thermal conductivity) in the horizontal direction (between two adjacent cells 36, 37 or two adjacent battery subassemblies) and low thermal resistance (high thermal conductivity) along the length and width of the contact cells 28, 30 for conducting heat to the cooler 40. The cooling system including multiple heat sinks 26 is therefore completely passive, light and non-bulky.

[0099] Although specific examples have been illustrated and described herein, various alternative and / or equivalent embodiments may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any modifications or variations of the specific examples discussed herein.

[0100] Reference numerals

[0101] Battery module 10

[0102] Battery cell 12

[0103] Cooling fin 14

[0104] Cooler 16

[0105] First floor 18

[0106] Second floor 20

[0107] Third floor 22

[0108] The last layer 24

[0109] Thermal Isolator 26

[0110] The first contact unit 28

[0111] The second contact unit 30

[0112] Support unit 32

[0113] Part 134

[0114] First battery unit 36

[0115] Part 238

[0116] Cooler 40

[0117] First surface 42

[0118] Second surface 44

[0119] Structure 50

[0120] Plates 501, 502, 511, 512

[0121] Fixed point 504

[0122] Side 506

[0123] Rod 508

[0124] Bump 510

[0125] Fluid gap 52

[0126] Hole 70

[0127] Expansion compensator 72

[0128] High contact unit H

[0129] Length contact unit L

[0130] Height plate Hp

[0131] Length plate Lp

[0132] Heat sink length Lfin

[0133] Heat sink height Hfin

[0134] Contact element thickness t

[0135] Plate thickness t p

[0136] Grid thickness t grid

[0137] Sheet / total thickness t fin

Claims

1. A heat sink (26) for a battery device, the heat sink being configured to prevent heat propagation between battery pack subassemblies, the heat sink (26) comprising: A first contact unit (28) adapted to be in surface contact with the first battery pack subassembly (12); a supporting unit (32) adjacent to the first contact unit (28); wherein the heat sink (26) extends in a heat sink plane, has a heat sink thickness (tfin) and a heat sink length (Hfin) in a cross section along the longitudinal axis, wherein the heat sink thickness is smaller than the heat sink length, and wherein the thermal resistance in the heat sink plane (X, Y) is lower than the thermal resistance in a direction perpendicular to the heat sink plane, so that the heat sink ensures a thermal management function and a thermal safety function of the battery device, and wherein the contact unit is made of a first material, the support unit is made of a second material, the first material is different from the second material, and The support unit (32) comprises a structure (50) arranged to establish an insulating gap (52) between the first contact unit (28) and the second contact unit (30).

2. The heat sink (26) according to claim 1, further comprising a second contact unit (30) adapted to surface-contact the second battery pack subassembly (12), and wherein: The supporting unit (32) is sandwiched between the first contact unit (28) and the second contact unit (30).

3. The heat sink (26) according to claim 1 or 2, wherein: The structure (50) comprises a plate (501) sandwiched between spacer structures (503) such that an insulating gap (52) is provided on both sides of the plate (501).

4. The heat sink (26) according to any one of claims 1 to 3, wherein: The insulating gap (52) is a fluid gap, and preferably an air gap.

5. The heat sink (26) according to any one of claims 1 to 4, wherein: The first contact unit (28) and the second contact unit (30) on the one hand and the structure (50) on the other hand are made of two different materials.

6. The heat sink (26) according to any one of claims 1 to 5, wherein: The first contact unit and / or the second contact unit include copper and / or aluminum and / or graphite.

7. The heat sink (26) according to any one of claims 1 to 6, wherein: The structure (50) is made of paper material or mica-based material.

8. The heat sink (26) according to any one of claims 1 to 7, wherein: The fluid gap has a thickness in cross section of about 0.05 mm to 1 mm.

9. The heat sink (26) according to any one of claims 1 to 9, wherein: The structure (50) has a grid pattern.

10. The heat sink (26) according to any one of claims 1 to 9, wherein: The structure (50) includes at least one intermediate plate having a first surface, a second surface opposite the first surface, a plurality of first spacers extending from the first surface, and a plurality of second spacers extending from the second surface.

11. The heat sink (26) according to any one of claims 1 to 10, wherein: The total thickness of the heat sink in a direction perpendicular to the heat sink plane is less than 10 mm, and in particular between 0.5 mm and 4 mm.

12. A battery module comprising a plurality of electrically interconnected battery cells and a plurality of heat sinks according to claim 1, wherein: Each heat sink is arranged in thermal communication with at least one of the plurality of battery cells, and wherein the first contact unit is connected to a cooler.

13. The battery module according to claim 12, wherein: The first heat sink includes a first contact unit contacting the first battery cell, the second heat sink includes a second first contact unit contacting the second battery cell, and the expansion compensator is disposed between the two heat sinks.

14. A support unit (32) for a heat sink (26) according to any one of claims 1 to 11, comprising a structure (50) arranged to establish an insulating gap (52), wherein: The structure (50) includes at least one intermediate plate having a first surface, a second surface opposite the first surface, a plurality of first spacers extending from the first surface, and a plurality of second spacers extending from the second surface.

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