Hybrid heat exchange cells module for a system battery
Patent Information
- Application Number
- EP2023727631
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-07
- Filing Date
- 2023-05-09
- Publication Date
- 2025-04-16
Smart Images
Figure 1.1
Abstract
Description
[0001] DESCRIPTION
[0002] TITLE: HYBRID HEAT EXCHANGE CELL MODULE FOR A BATTERY OF A SYSTEM
[0003] The present invention claims priority from French application No. 2205438 filed on 07.06.2022, the content of which (text, drawings and claims) is incorporated herein by reference.
[0004] Technical field of the invention
[0005] The invention relates to batteries which comprise at least one module of electrical energy storage cells which are subject to thermal regulation.
[0006] State of the art
[0007] Some systems, such as certain vehicles (possibly of the automobile type), include at least one battery comprising at least one module of electrical energy storage cells. For example, these electrical energy storage cells may be electrochemical. This is particularly the case for lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd or even lead-acid cells.
[0008] In order to optimize the lifespan of the cells, they need to be subject to almost constant monitoring, in particular their temperature, which must remain within a predefined range. To enable such monitoring, some cell modules include a casing housing the cells and in which thermal regulation (cooling or heating) is carried out by exchanging calories using heat exchange devices.
[0009] Among the heat exchange devices that can be integrated into a cell module housing, mention may in particular be made of those that are passive and two-phase. Such a heat exchange device is arranged, in a cooling phase, so as to drain heat from a hot point to a cold source or via a phase change (and relying in part on the latent heat of vaporization). Generally, the heat drainage uses as a cold source either a convection mechanism (natural or forced) with air, or contact with a cold plate (as described in patent documents LIS-A1 2017 / 0003082 and CN-ll 210607530), which makes integration into a cell module or a battery difficult (in particular due to the existing complexity and / or bulk).Furthermore, passive and two-phase heat exchange devices currently have difficulty ensuring sufficient cooling of the cells when they are subject to significant heating, for example during ultra-fast charging requiring very high charging currents. The invention aims in particular to improve the situation.
[0010] Presentation of the invention
[0011] For this purpose, it offers in particular a cell module suitable for equipping a battery and comprising a housing housing at least two electrical energy storage cells and comprising a passive and two-phase heat exchange device.
[0012] This cell module is characterized by the fact that:
[0013] - that its heat exchange device is in contact with first opposite lateral faces of the cells, except in a lower sub-part and / or an upper sub-part where it is separated from these first lateral faces by a predefined space, and
[0014] - that its casing comprises at least one zone located below or above lower or upper faces of the cells, communicating with the predefined space, and containing a heat transfer and dielectric fluid serving as a cold or hot source for the heat exchange device for the exchange of calories in a cooling or heating phase.
[0015] This provides a hybrid heat exchange cell module that is very efficient in terms of temperature regulation, while being simpler, less bulky and less expensive than the cell modules of the prior art.
[0016] The cell module according to the invention may include other characteristics which may be taken separately or in combination, and in particular:
[0017] - its heat exchange device may be of the so-called heat pipe type, possibly oscillating;
[0018] - its heat exchange device may be in contact with the first lateral faces except at least in its lower sub-part. In this case, its housing may comprise a lower zone located below the lower faces of the cells, and a lower wall comprising an upper face provided with protrusions supporting the cells and intended to raise them relative to the upper face to allow passage of the heat transfer fluid and dielectric under the lower faces of the cells;
[0019] - in the presence of the last option, its cells can be coupled, at the level of their upper faces, to connection elements. In this case, the heat exchange device can be in contact with these connection elements;
[0020] - its heat exchange device may be in contact with the first lateral faces except at least in the upper sub-part. In this case, its housing may comprise an upper zone located above the upper faces of the cells and containing the heat transfer and dielectric fluid;
[0021] - in the presence of the last option, its heat exchange device can extend over at least part of a lower wall of the housing in order to be in contact with at least part of the lower faces of the cells;
[0022] - each cell may comprise two second opposite lateral faces, the second lateral faces of neighboring cells, oriented towards each other, being separated at least in part by an interposed element made of a thermally insulating and electrically non-conductive material, and capable of ensuring a seal against the heat transfer and dielectric fluid between cells to prevent the heat transfer and dielectric fluid from passing between the second lateral faces, as well as possibly managing swelling of the cells;
[0023] - its cells can be of the electrochemical type.
[0024] The invention also proposes a battery comprising at least one cell module of the type presented above.
[0025] The invention also provides a system, possibly a vehicle, comprising a battery of the type presented above. Brief description of the figures
[0026] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which: [Fig. 1] illustrates schematically and functionally, in a side view, a first exemplary embodiment of a cell module according to the invention, [Fig. 2] illustrates schematically and functionally, in a sectional view in the plane II-II of Figure 1, the cell module of Figure 1,
[0027] [Fig. 3] schematically and functionally illustrates, in a sectional view in the plane III-III of Figures 1, 4, 6 and 8, the cell module of Figures 1, 4, 6 and 8,
[0028] [Fig. 4] schematically and functionally illustrates, in a side view, a second exemplary embodiment of a cell module according to the invention,
[0029] [Fig. 5] schematically and functionally illustrates, in a sectional view in the plane VV of Figure 4, the cell module of Figure 4,
[0030] [Fig. 6] schematically and functionally illustrates, in a side view, a third exemplary embodiment of a cell module according to the invention, [Fig. 7] schematically and functionally illustrates, in a sectional view in plane VII-VII of Figure 6, the cell module of Figure 6,
[0031] [Fig. 8] schematically and functionally illustrates, in a side view, a fourth exemplary embodiment of a cell module according to the invention, and
[0032] [Fig. 9] schematically and functionally illustrates, in a sectional view in plane IX-IX of Figure 8, the cell module of Figure 8.
[0033] Detailed description of the invention
[0034] The invention aims in particular to propose a hybrid heat exchange MC cell module intended to equip a rechargeable battery of a system.
[0035] In the following, it is considered by way of non-limiting example that the rechargeable battery is intended to equip a system constituting a vehicle of the automobile type, such as for example a car. But the invention is not limited to this type of system. It in fact concerns any system comprising at least one battery with module(s) of electrical energy storage cells, and in particular vehicles (land, sea (or river), and air), appliances (possibly household appliances), installations (possibly industrial type), and buildings.
[0036] Furthermore, it is considered in the following, by way of non-limiting example, that the vehicle comprises a powertrain (or GMP) of the all-electric type, that is to say comprising an electric motor coupled to the rechargeable battery (which is then called the main (or traction) battery). But the GMP could be of the hybrid type, that is to say comprising a thermal engine and an electric motor coupled to the rechargeable battery.
[0037] Finally, it is considered in the following, by way of non-limiting example, that each CS cell of an MC cell module is of the electrochemical type. But the invention is not limited to this type of electrical energy storage cell. It in fact relates to any type of electrical energy storage cell which must be subject to thermal regulation.
[0038] For example, the CS electrochemical cells of the battery are of the lithium-ion (or Li-ion) type. But these CS electrochemical cells could also be of the Ni-Mh or Ni-Cd or even lead type, for example.
[0039] Figures 1, 4, 6 and 8 schematically illustrate four examples of MC cell modules according to the invention intended to equip a rechargeable battery of a system (here a motor vehicle).
[0040] As illustrated, a cell module MC, according to the invention, comprises a housing BM, at least two electrical energy storage cells CS, a passive and two-phase heat exchange device DE, and a heat transfer and dielectric fluid (and therefore not conducting electricity).
[0041] The BM housing houses the CS cells, the DE heat exchange device and the heat transfer and dielectric fluid.
[0042] Furthermore, this BM housing may comprise lower and upper sub-parts coupled together, for example by screwing, or a main part and a cover.
[0043] Note that in the four examples illustrated the MC cell module comprises three CS cells (see Figures 2, 3, 5, 7 and 9). But the number of CS cells in an MC cell module can take any value greater than or equal to two. Furthermore, the number of MC cell modules in a rechargeable battery can take any value greater than or equal to one.
[0044] As illustrated at least partially in the various figures, each CS cell comprises at least two first lateral faces FL1 opposite each other and here vertical, two second lateral faces FL2 opposite each other, here vertical, and each joining the two first lateral faces FL1, an upper face FSC here horizontal, and a lower face FIC here horizontal. In addition, the CS cells are coupled to connection elements EC. It will be noted that in the four examples illustrated non-limitingly in Figures 1 to 9, the coupling of the CS cells to the connection elements EC is done at their upper faces FSC. But in an alternative embodiment (not shown) the coupling of the CS cells to the connection elements EC could be done at their lower faces FIC.
[0045] The heat exchange device DE is in contact with the first lateral faces FL1 of the cells CS, except in a lower sub-part (figures 1 and 4) and / or an upper sub-part (figures 6 and 8) where it is separated from these first lateral faces FL1 by a predefined space (or recess) EP. It will be understood that the heat exchange device DE can be in contact with the first lateral faces FL1:
[0046] - except in their lower sub-part (figures 1 and 4), or
[0047] - except in their upper sub-part (figures 6 and 8), or even
[0048] - except in their lower and upper sub-parts (not shown).
[0049] Each predefined space (or recess) EP is defined by a local reduction in the thickness of the heat exchange device DE (here following the direction which is perpendicular to the first lateral faces FL1).
[0050] It will be noted that in the embodiments illustrated non-limitingly in Figures 1 to 9, the cells CS have a rectangular section, and their first lateral faces FL1 have a smaller surface area than that of the second lateral faces FL2. But in an alternative embodiment (not illustrated) the first lateral faces FL1 could have a larger surface area than that of the second lateral faces FL2.
[0051] The BM housing comprises at least one zone ZI or ZS located below the lower faces FIC of the CS cells (figures 1 and 4) or above the upper faces FSC of the CS cells (figures 6 and 8), communicating with the predefined space EP, and containing the heat transfer and dielectric fluid. The latter then serves as a cold or hot source for the heat exchange device DE for the exchange of calories in a cooling or heating phase. It therefore serves as a cold source in a cooling phase and as a hot source in a heating phase.
[0052] This provides a hybrid heat exchange MC cell module that is particularly effective in temperature regulation, even when the CS cells are subject to significant heating, for example during ultra-fast charging requiring very high charging currents. In addition, the heat transfer and dielectric fluid serving as a cold (or hot) source replaces the convection mechanism or the cold plate, thus allowing a significant simplification and a reduction in the size and cost of the MC cell module, which facilitates its integration into a battery and makes the latter less expensive and more compact. For example, the heat transfer and dielectric fluid can be a liquid. Thus, it can for example be an oil, preferably non-fluorinated in order to remain single-phase, and also preferably biodegradable.
[0053] Also for example, the heat exchange device DE can be of the so-called heat pipe type, preferably flat. As an illustrative example, it could be of the so-called oscillating heat pipe type (or "pulsating heat pipe" (or PHP)). It is recalled that an oscillating heat pipe is in the form of a capillary-sized coil and partially filled with a saturated fluid which is divided into vapor pockets and liquid plugs. The pressure difference between two vapor pockets provides the driving force for the movement of the fluid.
[0054] When the heat exchange device DE is a heat pipe device, it may, for example, be made using a first plate machined to form a closed circuit in which the two-phase fluid will circulate and a second plate brazed onto the first plate to make the assembly watertight. Then, the heat exchange device DE is added to the housing BM, and for example welded to at least one internal face of the latter (BM), before the introduction of the cells CS. Alternatively, one of the two plates of the heat exchange device DE may be a wall (or walls) of the housing BM, the other plate then being brazed onto the internal face of this (these) wall(s) of the housing BM.In this variant, the internal face of the wall(s) of the BM housing can be machined to form the closed circuit for the two-phase fluid, or a plate forming the closed circuit for the two-phase fluid can be machined and this machined plate can be brazed onto the internal face of at least one wall of the BM housing.
[0055] Other types of heat pipes can be used, including thermosyphon or capillary pump heat pipes.
[0056] The use of heat pipes is advantageous because it allows the DE heat exchange device to have a low thickness, typically less than 2.5 mm.
[0057] It should be noted that the heat exchange device DE of an MC cell module can possibly be subdivided into two independent sub-parts and associated respectively with the first two side faces FL1. But one could consider having a heat exchange device DE in a single part.
[0058] At least four exemplary embodiments can be envisaged for a cell module MC. They are described below with reference to Figures 1 to 9. In a first exemplary embodiment, illustrated in Figures 1 to 3, the heat exchange device DE is in contact with the first lateral faces FL1 except at least in the lower sub-part. In this case, the housing BM comprises a lower zone ZI located below the lower faces FIC of the cells CS and a lower wall PI which comprises an upper face FSP provided with protrusions (or spacers) PS supporting the cells CS. These protrusions (or spacers) PS are intended to raise the cells CS relative to the upper face FS of the lower wall PI in order to allow the passage of the heat transfer fluid and dielectric under the lower faces FIC of the cells CS (and therefore in the lower zone ZI), and possibly at least partly between the second lateral faces FL2 of the cells CS.It will be understood that the heat transfer and dielectric fluid then serves not only as a cold (or hot) source for the heat exchange device DE where the predefined space EP is defined, but also to cool (heat) directly (by contact) the lower faces FIC and the lower sub-parts of the first lateral faces FL1 as well as possibly the lower sub-parts of the second lateral faces FL2.
[0059] In a second exemplary embodiment, illustrated in Figures 3 to 5 and a variant of the first exemplary embodiment, the heat exchange device DE is not only in contact with the first lateral faces FL1 except at least in the lower sub-part, but also in contact with the connection elements EC. Thus, it is possible to act not only on the temperature of the cells CS, but also on the temperature of the connection elements EC, which is particularly advantageous.
[0060] In a third embodiment, illustrated in Figures 3, 6 and 7, the heat exchange device DE is in contact with the first lateral faces FL1 except at least in the upper sub-part. In this case, the housing BM comprises an upper zone ZS located above the upper faces FSC of the cells CS and containing the heat transfer fluid and dielectric, and in which the connection elements EC are possibly installed. It will be noted that the heat transfer fluid and dielectric is present above the upper faces FSC of the cells CS, and possibly also at least partly between the second lateral faces FL2 of the cells CS.It will be understood that the heat transfer and dielectric fluid then serves not only as a cold (or hot) source for the heat exchange device DE where the predefined space EP is defined, but also to cool (heat) directly (by contact) the upper faces FSC and the upper sub-parts of the first lateral faces FL1 as well as possibly the upper sub-parts of the second lateral faces FL2 and any connection elements EC.
[0061] In a fourth embodiment, illustrated in Figures 3, 8 and 9 and a variant of the third embodiment, the heat exchange device DE is not only in contact with the first lateral faces FL1 except at least in the upper sub-part, but also extends over at least part of the lower wall PI of the housing BM in order to be in contact with at least part of the lower faces FIC of the cells CS. Thus, it is possible to act not only on the temperature of the cells CS (via almost all their faces), but also on the temperature of the connection elements EC when they are installed in the upper zone ZS, which is particularly advantageous.
[0062] It will be noted, as illustrated non-limitingly in Figures 2, 3, 5, 7 and 9, that the second lateral faces FL2 of neighboring cells CS, oriented towards each other, can be separated at least in part by an interposed element El made of a thermally insulating and electrically non-conductive material. Each interposed element El is then capable of ensuring a seal against the heat transfer fluid and dielectric between neighboring cells (between at least part of their second lateral faces FL2) to prevent the passage of the heat transfer fluid and dielectric between these second lateral faces FL2 (except where there is no interposed element El).
[0063] In the four embodiments illustrated non-limitingly in the figures, each intercalary element El extends over a portion of the second lateral faces FL2 of the neighboring CS cells, so as to allow an extension of the lower zone ZI upwards (figures 1 to 5) or of the upper zone ZS downwards (figures 6 to 9). This makes it possible to further improve the thermal regulation. But in an alternative embodiment (not illustrated) each intercalary element El could extend over the entirety of the second lateral faces FL2 of the neighboring CS cells.
[0064] Generally speaking, the surface area occupied by each intermediate element El is chosen according to the desired performance, in particular in terms of thermal insulation and possibly absorption of swelling. Indeed, the intermediate elements El are intended to prevent the passage of heat transfer fluid and dielectric between at least part of the second lateral faces FL2 (to limit pressure losses) and to limit thermal conduction and / or thermal radiation during thermal runaway of a CS cell, as well as possibly (and preferably) to manage the swelling of the CS cells (which then requires that they have flexible mechanical properties with low hardness so as not to compress the CS cells too much and degrade their internal electrochemical layers).It should also be noted that the contact between the heat exchange device DE and each cell CS (and possibly the connection elements EC) can be made via a thermal interface pad (made from a TIM type material (“Thermal Interface Material”)), possibly in the form of a thermal paste which makes it possible to avoid air pockets at the contact surfaces and to insulate the connection elements EC from all electrically conductive parts.
Claims
DEMANDS 1. Cell module (CM) suitable for equipping a battery and comprising a housing (BM) containing at least two electrical energy storage cells (CS) and comprising a passive, two-phase heat exchange device (DE), characterized in that said heat exchange device (DE) is in contact with first opposite lateral faces (FL1) of said cells (CS), except in a lower sub-part and / or an upper sub-part where it is separated from these first lateral faces (FL1) by a predefined space (EP), and in that said housing (BM) comprises at least one zone (ZI, ZS) located below or above lower (FIC) or upper (FSC) faces of said cells (CS), communicating with said predefined space (EP), and containing a heat transfer fluid and dielectric serving as a cold or hot source for said heat exchange device (DE) for the exchange of heat in a cooling or heating phase.
2. Cell module according to claim 1, characterized in that said heat exchange device (DE) is of the so-called heat pipe type.
3. Cell module according to claim 2, characterized in that said heat pipes are oscillating.
4. Cell module according to any one of claims 1 to 3, characterized in that said heat exchange device (DE) is in contact with said first lateral faces (FL1) except at least in said lower sub-part, and in that said housing (BM) comprises a lower zone (ZI) located below said lower faces (FIC) of the cells (CS), and a lower wall (PI) comprising an upper face (FSP) provided with protrusions (PS) supporting said cells (CS) and intended to raise them relative to said upper face (FSP) to allow passage of said heat transfer and dielectric fluid under said lower faces (FIC) of said cells (CS).
5. Cell module according to claim 4, characterized in that said cells (CS) are coupled, at the level of their upper faces (FSC), to connection elements (EC), and in that said heat exchange device (DE) is in contact with said connection elements (EC).
6. Cell module according to any one of claims 1 to 3, characterized in that said heat exchange device (DE) is in contact with said first lateral faces (FL1) except at least in said upper sub-part, and in that said housing (BM) comprises an upper zone (ZS) located above said upper faces (FSC) of the cells (CS) and containing said heat transfer and dielectric fluid.
7. Cell module according to claim 6, characterized in that said heat exchange device (DE) extends over at least a part of a lower wall (PI) of said housing (BM) in order to be in contact with at least a part of said lower faces (FIC) of the cells (CS).
8. Cell module according to any one of claims 1 to 7, characterized in that each cell (CS) comprises two opposing second lateral faces (FL2), the second lateral faces (FL2) of neighboring cells (CS), oriented towards each other, being separated at least in part by an intercalated element (El) made of a thermally insulating and electrically non-conductive material, and suitable for ensuring a seal of said heat transfer fluid and dielectric between cells (CS) to prevent a passage of said heat transfer fluid and dielectric between said second lateral faces (FL2).
9. Battery, characterized in that it comprises at least one cell module (CM) according to one of the preceding claims.
10. System, characterized in that it comprises at least one battery according to claim 9.