Battery module for extraterrestrial vehicle

Abstract

To provide a battery module for extraterrestrial vehicles that meets all the requirements of a space industry while being of simple design.SOLUTION: Provided is a battery module 2a for an extraterrestrial vehicle, comprising a plurality of battery cells 14 mechanically assembled together and electrically connected together. Each battery cell comprises a central body, a plurality of batteries disposed in pairs on both sides of the central body, two busbars, two covers 32 mounted on the busbars, and two casings fitted to opposite lateral faces of the batteries; comprises a central mechanical support plate 38a mounted against the covers of the battery cells on the side of a lateral assembly face of the battery module; comprises heating systems 56 on the side opposite the covers; and comprises an external thermal protection plate 6a mounted on the covers on the side opposite the lateral assembly face of the battery module, delimiting with them at least one internal ejecta containment volume which opens to the outside via particle filters 54.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to the general field of electric batteries for space applications, particularly on board extraterrestrial vehicles.

[0002] For future extraterrestrial missions, such as to the Moon or Mars, it will be necessary to design space equipment that must operate under extremely harsh environmental conditions (no air, no pressure, a very large temperature range from -170°C to +150°C, solar and cosmic radiation, etc.) Such equipment includes, in particular, vehicles, but also electrical stations, habitats, power tools, etc.

[0003] It is well known that lithium-ion batteries are used to power such space equipment, and these batteries typically consist of multiple batteries mechanically assembled and electrically connected.

[0004] For space applications, such batteries must have maximum energy density in minimum space, and the temperature of the battery must be uniform, despite the operating temperature range of -20°C to +60°C for lithium-ion batteries.

[0005] For obvious safety reasons, it is also very important to prevent the propagation of thermal runaway between different batteries. Furthermore, in the event of extreme thermal runaway in a battery, the internal glowing part (also known as the ejector) of the damaged cell must be ejected out of the battery without damaging other batteries that must continue to function to ensure the safety of the astronauts.

[0006] These specialized requirements make these space batteries very costly to design, with very long lead times, low production volumes, and proprietary, non-standard packaging for each manufacturer. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the main object of the present invention is to overcome these drawbacks by providing a battery with a simple design while meeting all the requirements of the space industry. [Means for solving the problem]

[0008] According to the invention, this object is achieved by a battery module for an extraterrestrial vehicle, comprising: Battery modules for extraterrestrial vehicles A plurality of mechanically assembled and electrically connected battery cells, each battery cell comprising: a central body forming the support; a plurality of batteries arranged in pairs on either side of the central body; Two bus bars attached to each pole of the battery to electrically connect the batteries, Two covers attached to the busbars, and a plurality of battery cells, each having two side casings attached to opposite sides of the battery and secured to the central body; a central mechanical support plate attached to the cover of the battery cells on a side of the lateral assembly surface of the battery module, the central mechanical support plate having a heating system on the opposite side of the cover; and an external thermal protection plate (6) attached to the cover of the battery cell opposite the lateral assembly face of the battery module and defining, together with the cover, at least one internal emission containment volume that opens to the outside via a particle filter.

[0009] The battery module according to the present invention is characterized by having an internal emission containment volume that contains emissions in the event of extreme thermal runaway of a battery cell, preventing them from diffusing outside the module and damaging other storage battery cells. This internal containment volume contains emission particles while opening to the outside through a particle filter to release internal pressure. Therefore, even if thermal runaway occurs, the battery module can continue to operate normally and minimize loss of energy capacity.

[0010] Furthermore, the side casing surrounds the battery, providing mechanical reinforcement and maintaining uniform temperature. In this way, the battery module has a compact structure with excellent thermal conductivity during normal operation.

[0011] In one embodiment, the external thermal protection plate comprises a first metal sheet attached to the cover of the battery cell and having cutouts around the battery poles, a second metal sheet attached to the first metal sheet and forming, together with the first metal sheet, an internal emission containment volume common to all of the battery cells, and at least one particle filter positioned at a lateral end of the external thermal protection plate and opening into the internal emission containment volume.

[0012] In this embodiment, the second metal sheet of each external heat protection plate is advantageously coated on one of its internal surfaces with a heat protection sheet.

[0013] In another embodiment, the central mechanical support plate includes a plurality of independent internal emission containment volumes on the lateral assembly face of the battery module, each emission containment volume associated with the same battery cell, each comprising a plurality of pockets formed around the poles of that battery cell, and opening to the outside at each end via a manifold feeding a particulate filter.

[0014] In this other embodiment, the external thermal protection plate may have a plurality of internal emission containment volumes independent of one another on the surface opposite the lateral assembly surface of the battery module, each emission containment volume being associated with the same battery cell and comprising a plurality of pockets formed around the poles of that battery cell, and opening to the outside at each end via a manifold that feeds into a particulate filter.

[0015] In this case, the pocket of emission containment volume is advantageously covered with a thermal protection material.

[0016] In either embodiment, the heating system of the central mechanical support plate can include an electrical resistance at each location facing the battery cells.

[0017] Furthermore, the bus bars of the battery cells are welded to the battery poles and electrically connected to the battery poles by connecting wires covered with thermal and electrical insulating layers.

[0018] Additionally, an external thermal protection plate may be coupled to the cooling system, and the central mechanical support plate and the external thermal protection plate may be made of aluminum.

[0019] Another object of the invention is a battery for an extraterrestrial vehicle comprising at least two battery modules as described above, electrically coupled to one another at their respective lateral assembly faces and mechanically assembled to one another.

[0020] Other characteristics and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, which show exemplary, non-limiting embodiments of the invention. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram of a battery according to the present invention. [Figure 2]FIG. 2 is a longitudinal cross-sectional view of the battery of FIG. [Figure 3] FIG. 3 is an exploded perspective view showing a battery cell of a battery module according to the present invention. [Figure 4] FIG. 4 is a partially exploded perspective view of the battery module according to the first embodiment of the present invention. [Figure 5] FIG. 5 is an enlarged view of FIG. [Figure 6] FIG. 6 is a longitudinal cross-sectional view of a portion of the module of FIG. 4, showing the ejector manifold. [Figure 7] FIG. 7 is a partially exploded perspective view of a battery module according to a second embodiment of the present invention. [Figure 8] FIG. 8 is a partially exploded perspective view of a battery module according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a diagram showing how the bus bars of the battery cells are electrically connected to the poles of the battery. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention relates to modules for space lithium-ion batteries, such as those found on extraterrestrial vehicles.

[0023] In known manner, the battery 2a, 2b of an extraterrestrial vehicle such as that shown in Figures 1 and 2 is constructed from a plurality of electrically coupled and mechanically assembled battery modules 4a, 4b stacked one on top of the other.

[0024] The battery modules 4a, 4b are sandwiched between two external thermal protection side plates 6a, 6b made of a material with low thermal resistance and able to withstand the high temperatures of the emissions, for example aluminium.

[0025] Each external thermal protection plate 6a, 6b is fitted with one or more thermal systems for cooling by heat pipes 8 with variable or constant conductance (or thermal bridges with low thermal resistance) or for heating by electrical resistors (not shown in Figures 1 and 2).

[0026] At one of the two end faces, the batteries 2a, 2b further comprise a power connector 10 and a fixed support 12.

[0027] Each battery module 4a, 4b is composed of a plurality of battery cells 14 that are mechanically assembled and electrically connected.

[0028] FIG. 3 shows an example of the structure of a battery cell 14 for manufacturing a battery module according to the present invention.

[0029] The battery cell 14 shown in this figure comprises a central body 16 that forms a support to which a plurality of batteries 18 are attached. More specifically, the batteries 18 are arranged in pairs, with the batteries arranged on either side of the central body 16. The central body 16 also acts as a thermal bridge to distribute heat throughout the batteries.

[0030] In the exemplary embodiment of Figure 4, the batteries 18 are cylindrical. Alternatively, they can be prismatic.

[0031] Furthermore, for each pole 22 of the battery, two bus bars 20 (also called interconnect bars) are attached and electrically connected to each other.

[0032] The busbars 20 are plates of conductive material with circular cutouts 24 facing the poles 22 of the battery, and are screwed at each longitudinal end to the central body 16 .

[0033] As shown in more detail in FIG. 9, each busbar 20 is electrically connected to a pole 22 of the battery by a connecting wire 26, the cross section of which is adjusted to melt above a certain current amplitude.

[0034] The connecting wires 26 are welded (eg ultrasonically welded) to the battery poles and poles 22 and are covered with several layers of thermal, electrical and fire-resistant insulating material.

[0035] In the example shown in FIG. 3, the connecting wire is covered with circular pellets 28 made of aerogel and glass fiber (for thermal and electrical protection) and circular mica pellets 30 (for fire protection).

[0036] The battery cell 14 is made of a material that can withstand high temperatures of around 1200°C (e.g., G-10 / FR-4, a thermosetting laminate made of an epoxy resin binder and continuous filament glass fabric), and also includes two covers 32 that cover the busbars 20 and are fixed to the busbars 20 with multiple screws 33.

[0037] Furthermore, two side casings 34 are attached to opposite side surfaces of the battery and fixed to the central body 16 of the battery cell 14 by a number of screws 36 .

[0038] More specifically, the inside of the side casing 34 has a shape complementary to that of the battery, allowing it to fit snugly against the battery. In this manner, the battery of cells is sandwiched between the side casing and the central body, providing mechanical support for the battery and enabling it to withstand vibration and shock.

[0039] The insertion of a flexible element (not shown), for example a flexible electrically insulating and thermally conductive material, between the battery 18 and the side casing 34 and central body 16 has the advantage of providing uniform contact to the battery.

[0040] Next, a first embodiment of a battery 2a according to the present invention will be described with reference to FIGS.

[0041] In this example, the battery 2a comprises two battery modules 4a sandwiched between two external thermal protection plates 6a, each battery module 4a being formed by 16 battery cells 14 as previously described.

[0042] Of course, the number of battery cells per battery module may vary, and the number of battery modules forming the battery may also vary.

[0043] The two battery modules 4a are assembled together at one of their sides (hereinafter referred to as the lateral assembly face), which side is opposite to the two external thermal protection plates 6a.

[0044] In this first embodiment, each battery module 4a further comprises a central mechanical support plate 38a attached to the battery cell covers 32 on the lateral assembly face side of the module.

[0045] As shown in more detail in FIG. 5, this central mechanical support plate 38a includes a plurality of separate internal emission containment volumes 40 on the surface facing the lateral assembly surfaces of the corresponding battery modules.

[0046] More specifically, each of these emission containment volumes 40 is associated with and common to the same battery cell 14 and comprises a number of pockets 42 intended to be arranged around the poles of that battery.

[0047] At the two longitudinal ends of the battery cell, each emission containment volume 40 opens to a manifold 44 that feeds a particulate filter 46, which in turn opens to the outside for venting filtered gases.

[0048] Similarly, the external thermal protection plate 6a of the battery module 4a in this first embodiment includes a plurality of mutually independent internal emission containment volumes 48 (see FIG. 6) on the surface opposite the side assembly surface of the module.

[0049] Each of these emission containment volumes 48 is common to and associated with the same battery cell and comprises a number of pockets 50 intended to be arranged around the poles of that battery.

[0050] As shown in FIG. 6, at the two longitudinal ends of the battery cell, the emission containment volumes 48 each open into a manifold 52 that feeds a particulate filter 54 .

[0051] Typically, the particulate filters 46, 54 contain stainless steel wool, glass fibers or wool or the like to relieve pressure while absorbing all of the kinetic energy of the emissions.

[0052] In this way, in the event of extreme thermal runaway in one of the battery cells of the battery module, the emissions will spread within the corresponding emission containment volume 40, 48, preventing the emissions from spreading outside the module and damaging other battery cells.

[0053] According to an advantageous embodiment, the pockets 42, 50 of each of these emission containment volumes 40, 48 are lined with a thermal protection material (eg, fiberglass).

[0054] In this first embodiment, a central mechanical support plate 38a attached to the cover of the battery cell is provided with a heating system on the side facing the cover.

[0055] These heating systems typically consist of electrical resistors 56 each positioned opposite a battery cell 14 of the corresponding battery module.

[0056] Next, a second embodiment of a battery 2b according to the present invention will be described with reference to FIGS.

[0057] In this second example, the battery 2b also comprises two battery modules 4b sandwiched between two external thermal protection plates 6b, each battery module 4b being formed by 16 battery cells as previously described.

[0058] Each battery module 4b further includes a central mechanical support plate 38b that is attached to the battery cell covers 32 on the lateral assembly face of the module.

[0059] The central mechanical support plate 38b includes a heating system on the side opposite the battery cell covers, which typically includes electrical resistors 56 positioned opposite each battery cell of the corresponding battery module.

[0060] In this second embodiment, each external thermal protection plate 6b comprises in particular a first metal sheet 60 attached to the cover 32 of a battery cell and having cutouts 62 around the poles of the respective battery.

[0061] The external thermal protection plate 6b further comprises a second metal sheet 64 attached to the first metal sheet 60 and forming, together with the latter, an internal emission containment volume (not shown) common to all battery cells.

[0062] Thus, in contrast to the first embodiment, the emission containment volume is not individualized for each battery cell, but is here common to all battery cells within the same battery module.

[0063] At the two side edges of the outer thermal protection plate 6b, this emission containment volume opens to the outside via particle filters 68.

[0064] Thus, if one of the battery cells of the battery module experiences extreme thermal runaway, the emissions will spread within the corresponding common emission containment volume, thereby containing the emissions and preventing their propagation outside the battery module.

[0065] According to an advantageous configuration, the second metal sheet 64 of each external thermal protection plate 6b is coated on its inner surface with a thermal protection sheet (not shown), for example made from glass fiber, to ensure resistance to very high temperatures.

Claims

1. A battery module (4a; 4b) for an extraterrestrial vehicle, comprising: A plurality of mechanically assembled and electrically connected battery cells (14), each battery cell comprising: a central body (16) forming the support; a plurality of batteries (18) arranged in pairs on either side of said central body; two bus bars (20) attached to respective poles (22) of the battery (18) and electrically connecting the battery; two covers (32) attached to the busbars; two side casings (34) attached to opposite sides of the battery and fixed to the central body; a plurality of battery cells (14) comprising: a central mechanical support plate (38a; 38b) attached to the cover (32) of the battery cell (14) on the side of a lateral assembly face of the battery module, the central mechanical support plate (38a; 38b) comprising a heating system (56) on the opposite side of the cover; an external thermal protection plate (6a; 6b) attached to the cover of the battery cell opposite the lateral assembly face of the battery module and defining, together with the cover, at least one internal emission containment volume (48) that opens to the outside via a particle filter (54; 68).

2. The external heat protection plate (6b) a first metal sheet (60) attached to the cover of the battery cell and having cutouts (62) around the poles of the battery; a second metal sheet (64) attached to the first metal sheet (60) and forming, together with the first metal sheet, an internal emission containment volume common to all of the battery cells; 2. The battery module (4b) according to claim 1, further comprising at least one particle filter (68) disposed at a lateral end of the outer thermal protection plate (6b) and opening into the interior of the inner emission containment volume.

3. 3. The battery module (4b) according to claim 2, wherein the second metal sheet (64) of the outer thermal protection plate (6b) is covered on its inner surface with a thermal protection sheet.

4. 2. The battery module (4a) of claim 1, wherein the central mechanical support plate (38a) comprises a plurality of mutually independent internal emission containment volumes (40) on a lateral assembly face of the battery module, each emission containment volume being associated with the same battery cell (14), comprising a plurality of pockets (42) formed around the poles (22) of that battery cell, and opening to the outside at each end via a manifold (44) feeding a particle filter (46).

5. 5. The battery module (4a) of claim 4, wherein the external thermal protection plate (6a) includes, on a side opposite a lateral assembly face of the battery module, a plurality of mutually independent internal emission containment volumes (48), each emission containment volume associated with the same battery cell (14), including a plurality of pockets (50) formed around the poles (22) of that battery cell, and opening to the outside at each end via a manifold (52) feeding a particle filter (54).

6. 6. The battery module (4a) of claim 5, wherein the pockets (42, 50) of the emission containment volume are covered with a thermal protection material.

7. 7. The battery module (4a; 4b) according to any one of claims 1 to 6, wherein the heating system of the central mechanical support plate comprises electrical resistors (56) arranged opposite each battery cell.

8. 8. The battery module (4a; 4b) according to claim 1, wherein the busbars (20) of the battery cells (18) are electrically connected to the poles (22) of the battery by connecting wires (28) welded to the poles and covered with a thermal and electrical insulating layer (28).

9. The battery module (4a; 4b) according to any one of claims 1 to 8, wherein the external thermal protection plate (6a; 6b) is coupled to a cooling system (8).

10. The battery module (4a; 4b) according to any one of claims 1 to 9, wherein the central mechanical support plate (38a; 38b) and the external thermal protection plates (6a; 6b) are made of aluminium.

11. A battery (2a; 2b) for an extraterrestrial vehicle, comprising at least two battery modules (4a; 4b) according to any one of claims 1 to 10, electrically coupled to one another and mechanically assembled at respective lateral assembly faces.

Images