Cover for containing a lithium battery fire

Abstract

The aim of the invention is to provide a device for containing a lithium battery fire, suitable for electric personal transporters, which is easily transportable from one place to another without endangering the safety of the user, and limits the ecological impact associated with the commercialization thereof. The solution proposed by the invention is a cover (1) characterized in that it comprises a flexible envelope (11) so as to allow it to be folded, and a frame (12) configured to stiffen the envelope so as to create an air gap at least 1 cm thick between the envelope and at least part of an item of equipment (2) arranged inside the cavity (111) of the envelope, the air gap extending over an area at least equal to 60% of the total outer surface area of the at least part of the item of equipment, and also to allow the envelope to be folded.

Description

Lithium battery fire containment cover Technical field of the invention

[0001] The present invention relates to the technical field of lithium battery fire containment devices, and more particularly, to foldable covers for containing a lithium battery fire in an electrically powered personal mobility device. State of the art

[0002] Electric personal mobility devices such as electric scooters, personal transporters, Segways, hoverboards, electric unicycles, electric bikes, and others have become commonplace in many homes in recent years. These devices are generally equipped with lithium batteries. However, these batteries can be prone to thermal runaway, leading to a fire in minutes, or even seconds, that rapidly releases a significant amount of heat. Furthermore, the combustion of such lithium batteries cannot be stopped by conventional fire extinguishers. Therefore, it is necessary to contain the fire and wait for several hours for it to burn itself out once the fuel is exhausted.

[0003] The civil aviation sector has been interested in the problems of lithium battery fires in portable electronic devices that passengers are likely to bring on board an aircraft. Several solutions, both flexible and rigid, have been proposed, notably in documents WO 2014 / 116354 A1 (B. Burkett), US 11,247,083 B2 (Cellblock), US 2022 / 0355137 A1 (Innovint Aircraft Interior), US 2020 / 0330805 A1 (Bags).

[0004] However, these devices are designed for portable electronic device batteries and are not sized to contain a lithium battery fire in an electric personal mobility device. Indeed, a mobile phone or tablet battery is generally capable of storing a few watt-hours of energy, a laptop battery a few tens of watt-hours, while an electric personal mobility device battery can store one or several hundred watt-hours, or even several thousand watt-hours. As demonstrated in the study entitled "Toxic Gases from Fire in Electric Vehicles" (O. Willstrand et al.), the greater the amount of energy stored in the battery, the greater the amount of heat released during a fire.Therefore, the various designs proposed in these documents are not applicable to the field of electrically powered personal mobility devices.

[0005] In particular, the rollable or foldable pouch design shown in US patent 2020 / 0330805 A1 (Bags) is only feasible if the fires this pouch is designed to withstand release significantly less energy than battery fires in personal mobility devices. Therefore, it is possible to design pouches with walls thin enough to allow rolling or folding.

[0006] US patents 2022 / 0024674 A1 (Cellblock) and 2017 / 0237054 A1 (TM Mast) address the issue of batteries capable of storing a large amount of energy. Each patent proposes a metal container equipped with a layer of thermal insulation. However, these containers can only hold the battery. Therefore, using such containers requires systematically removing the battery from the personal mobility device after each use and then placing it in the container. This procedure may seem cumbersome to a user who might be tempted to skip it, thus endangering themselves. Furthermore, the steel containers are heavy and bulky, making them difficult for the user to transport to a destination when using their personal mobility device to travel between multiple locations.

[0007] Document GB 2549454 A (JLGilbert) attempts to address these drawbacks by proposing a lightweight rigid box equipped with shoulder straps so that it can be carried like a backpack. The rigid box is sized to hold a Segway. This highly conceptual document provides virtually no design details for this box. Furthermore, this solution is not without its disadvantages. Indeed, the rigid box is quite bulky, and its flat side walls can be highly susceptible to crosswinds when the user is carrying the box on their back, potentially posing a danger. Additionally, when not in use, the box is bulky, making it difficult to store and taking up unnecessary space in the user's home. Finally, the industrial packaging of such a box requires a large cardboard box.Its large size limits the number of boxes that can be placed on a pallet, requires significant storage space, and also limits the number of units that can be transported per shipment. This logistics method has a significant cost, not only financial but especially environmental. Indeed, the larger the boxes, the greater the waste. Furthermore, the fewer units are transported per shipment, the greater the number of shipments required, and consequently, the higher the fuel consumption and associated CO2 emissions.

[0008] Therefore, the invention aims to provide a lithium battery fire containment device, suitable for electrically powered personal mobility devices, easily transportable from one place to another without endangering the user's safety, and limiting the ecological impact related to its marketing. Disclosure of the invention

[0009] The solution proposed by the invention is a lithium battery fire containment cover comprising an envelope having a housing configured to receive at least part of equipment comprising at least one lithium battery, said envelope being configured to at least withstand a fire of a lithium battery capable of storing an amount of energy equal to 100 Wh.This cover is remarkable in that: The cover is flexible so as to allow its folding, The cover also includes a frame configured to: Rigidify the cover so as to create an air gap, at least 1 cm thick, between the cover and at least one part of the equipment, and extending over an area at least equal to 60% of the area of ​​a total external surface of at least one part of the equipment, when at least one part of the equipment is arranged inside the housing, Allow the cover to be folded when the housing is devoid of at least one part of the equipment.

[0010] Thus, the proposed cover allows for the containment of a lithium battery fire in an electric personal mobility device, while being easily transportable from one location to another without compromising user safety, and while minimizing the environmental impact of its distribution. Indeed, the air gap created by the frame provides an additional layer of thermal insulation. Air is, in fact, an excellent thermal insulator. This additional layer of insulation allows for a reduction in the cover's thickness compared to one that would be in direct contact with the personal mobility device. This reduced thickness results in a cover that is flexible enough to be folded.The frame is also designed to prevent the flexible cover from sagging on a personal mobility device inside the housing, while still allowing the cover to fold when the housing is empty. The frame and cover thus act synergistically, each helping the other achieve its purpose and vice versa. Furthermore, once folded, the cover's size is significantly reduced. It can therefore be easily stored and transported in a standard backpack, which offers much less wind resistance than the rigid box of the prior art. User safety is thus ensured.

[0011] According to an advantageous feature of the invention which allows both the limitation of the spread of smoke from the fire, said smoke being very toxic to humans, and the limitation of the increase in pressure inside the dwelling due to the gas release resulting from the fire and the increase in heat in the dwelling, the cover includes a controlled smoke extraction device.

[0012] According to another advantageous feature of the invention which allows for the creation of a chimney suitable for guiding the extraction of smoke and limiting the pressure rise inside the dwelling, the controlled smoke extraction device includes an extraction orifice provided in the envelope.

[0013] According to yet another advantageous feature of the invention which limits the release of potentially toxic elements from the bag, the controlled smoke extraction device includes a filter arranged at the extraction orifice so as to filter certain elements of the smoke.

[0014] According to yet another advantageous feature of the invention which allows limiting the amount of heat released from the cover, the latter includes a fire attenuation device.

[0015] According to yet another advantageous feature of the invention allowing the controlled release of a mitigating agent inside the dwelling, the fire mitigation device comprises: At least one pocket arranged inside the envelope, Granules, based on mineral material, arranged inside said at least one pocket, A discharge opening on each pocket, said discharge opening being configured to allow the discharge of said granules arranged in said associated pocket, towards the air gap, A hot-melt wire arranged at the discharge opening of each pocket so as to close said associated pocket, said hot-melt wire being configured to melt, when subjected to a temperature rise due to the fire of a lithium battery, so as to allow the opening of said associated pocket and the discharge of said granules through said discharge opening.

[0016] According to yet another advantageous feature of the invention enabling the mitigation of a lithium battery fire, the granules are made of vermiculite.

[0017] According to yet another advantageous feature of the invention for providing a fire-resistant casing for a lithium battery of a personal mobility device, said casing comprises at least one textile layer of silicone-coated glass fabric, or silica fabric, or silica needle-punched felt.

[0018] According to yet another advantageous feature of the invention which allows the user to be warned that a fire is starting so that he can take steps to take shelter, the cover includes a device for warning people.

[0019] According to yet another advantageous feature of the invention enabling the user to be warned effectively, the warning device for persons comprises: A detection element configured to detect the start of a fire in a lithium battery, A signaling element configured to emit a warning signal when the detection element detects the start of a fire. Description of the figures

[0020] Other features and advantages of the invention will become apparent from the following description of particular embodiments of the invention, given by way of example, but not limitation, with reference to the accompanying drawings in which: is a schematic view of a first example of an embodiment of a cover of the invention adapted to an electric scooter; is a schematic cross-sectional view of the cover, shown in the figure, unfolded and without an electric scooter; is a schematic cross-sectional view of the cover, shown in the figure, unfolded and in which an electric scooter is arranged; is a schematic cross-sectional view of the cover, shown in the figure, unfolded and in which an electric scooter is arranged, after opening the pockets of the attenuation device; is a schematic cross-sectional view of the cover, shown in the figure, without an electric scooter and folded so as to allow its storage. Detailed description

[0021] The invention relates to a cover (1) for containing a lithium battery fire. A lithium battery is defined as any electrochemical accumulator whose reaction is based on the lithium element.

[0022] Referring to the figures, the cover (1) includes an envelope (11). The latter has a housing (111) configured to receive at least part of a device (2) comprising at least one lithium battery (24).

[0023] The equipment (2) may be an electrically powered personal mobility device, hereinafter referred to as "personal mobility device" for the sake of simplicity, but which shall only be interpreted as a personal mobility device equipped with an electrical motor. The personal mobility device may, in particular, be an electric scooter as shown in Figures 1 and 2. In other embodiments, the personal mobility device may be a patrol vehicle, a Segway, a Segway, a Segway, a Segway, an electric bicycle, or any other electrically powered personal mobility device suitable for a person skilled in the art.

[0024] In one embodiment, the equipment (2) is a lithium battery (24). This may be the case, for example, when the lithium battery (24) can be detached from the personal mobility device for recharging. Once the lithium battery (24) is detached, the personal mobility device no longer presents a risk; only the lithium battery itself poses a risk. Therefore, in such cases, it may be advantageous to have a smaller enclosure (11) with a compartment (111) configured to receive the lithium battery (24) alone.

[0025] In one embodiment, the equipment (2) is a carton, or a pallet, containing one or more lithium batteries (24). In particular, this carton, or pallet, can package one or more electrical devices equipped with a lithium battery (24), for example, one or more personal mobility devices. It is thus possible to contain lithium battery fires in a personal mobility device while it is still packaged. The carton, or pallet, can also package several electronic devices, each containing a lithium battery (24) capable of storing a quantity of energy of a few watt-hours, or a few tens of watt-hours, the cumulative energy of all the batteries in the carton, or pallet, being greater than or equal to 100 Wh.

[0026] The housing (111) can then have a shape and dimensions adapted to at least part of the equipment (2) that it is intended to receive. The lithium battery (24) is preferably arranged in at least part of the equipment (2) intended to be received in the housing (111).

[0027] In a first embodiment of the housing (111), it can be configured to receive only part of the equipment (2). This may be the case, in particular, when the equipment (2) comprises a body and a steering column (25) extending more than 50 cm above said body and at the end of which a handlebar (25) is arranged. This is, for example, the case for the housing (111) shown in the figures. Indeed, in this embodiment, the housing (111) is configured to receive the wheels (21), the axles (22), the platform (23), and the lithium battery (24) of the scooter. The lithium battery (24) can, for example, be arranged inside the platform (23). The steering column (25) and the handlebar (26), on the other hand, are arranged outside the housing (111). This can also be the case for a patrol unit.

[0028] In a second embodiment of the housing (111), the latter can be configured to receive the equipment (2) in its entirety. This may be the case, in particular, when the equipment (2) is a cardboard box or a pallet. This may also be the case when the equipment is a personal mobility device without a steering column and handlebars, such as a Segway, a Segway skateboard, or a self-balancing unicycle.

[0029] The casing (11) is configured to withstand at least a fire in a lithium battery capable of storing 100 Wh of energy. For the purposes of this invention, "withstand" means that the thermal conductivity of the casing is the same at the end of the event as at the beginning. Advantageously, the casing (11) can be configured to withstand at least a fire in a lithium battery capable of storing 350 Wh of energy. Preferably, the casing (11) can be configured to withstand at least a fire in a lithium battery capable of storing 500 Wh of energy. Advantageously, the casing (11) can be configured to withstand at least a temperature of 800°C for 10 minutes, then a temperature of 200°C for 10 hours.Preferably, the envelope (11) can be configured to withstand at least a temperature of 1200°C for 1 hour, then a temperature of 600°C for 20 hours, then a temperature of 200°C for 30 hours.

[0030] The envelope (11) may have a thermal conductivity less than or equal to 0.07 Wm-1.k-1. Advantageously, the envelope may have a thermal conductivity less than or equal to 0.04 Wm-1.k-1. Preferably, the envelope may have a thermal conductivity less than or equal to 0.02 Wm-1.k-1.

[0031] The envelope (11) is flexible so as to allow its folding. For the purposes of this invention, "flexible so as to allow its folding" means that, for a strip of the envelope (11) 50 cm long and 10 cm wide, detached from the rest of said envelope, the upper surface of one half of the length of said strip can be folded over the upper surface of the second half of the length of said strip, so that the two said upper surfaces can be in contact over at least 80% of the area of ​​one or the other of said upper surfaces.

[0032] In a first embodiment of the casing (11), the casing can be a single layer. The layer can be made of a material classified in fire reaction category M0 according to standard NF P92-507. The layer may include a textile. This textile can be a glass fabric, a silica fabric, a silica needle-punched felt, a glass needle-punched felt, or any other textile suitable to those skilled in the art. The textile can be coated with a polymer, for example, silicone. Advantageously, the layer can be made of silicone-coated glass fabric. Alternatively, the textile can be coated with a vermiculite coating. The textile can be coated, on its side adjacent to the housing (111), with a hydrophobic coating.This layer can, in particular, be made of hydrophobic polymer, for example, acrylic, epoxy, polyethylene, polystyrene, vinyl chloride, polyvinyl chloride, polytetrafluoroethylene, polydimethylsiloxane, polyester, or polyurethane. Advantageously, the layer can be made of polyurethane-coated fiberglass fabric. The layer can have a thickness of between 0.3 mm and 5 mm. Preferably, the layer can have a thickness of 0.4 mm.

[0033] In a second embodiment, the casing (11) may be multilayered. At least one of the layers, preferably all of the layers, may be made of a material classified in fire reaction category M0 according to standard NF P92-507. One or more layers may comprise a textile of the same type as those described above. The textile of one or more layers may be coated with a polymer, or alternatively with a vermiculite coating, as described above. The textile of one or more layers may be coated with a hydrophobic coating, for example, hydrophobic polytetrafluoroethylene, as described above. Advantageously, the textile of the layer adjacent to the housing (111) may be coated, on its side adjacent to the housing (111), with the hydrophobic coating.Alternatively, the layer adjacent to the housing (111) can be made of a hydrophobic polymer, for example, acrylic, epoxy, polyethylene, polystyrene, vinyl chloride, polyvinyl chloride, polytetrafluoroethylene, polydimethylsiloxane, polyester, or polyurethane. This hydrophobic layer protects the other layers of the casing (11) from dirt accumulated on the equipment (2), and in particular on the wheels of a personal mobility device. The interior of the casing (11) can thus be cleaned more easily. Advantageously, the layer adjacent to the housing (111) can be made of polyurethane-coated fiberglass fabric. Each layer can have a thickness of between 0.3 mm and 5 mm. When a layer is made of felt, for example, silica needle-punched felt or glass needle-punched felt, said layer can have a thickness of between 4 mm and 10 mm.Preferably, at least one layer may have a thickness of 0.4 mm. Preferably, the envelope (11) comprises three layers.

[0034] The casing (11) can also be impermeable to at least a portion of the fumes produced by a lithium battery fire. In this case, the material of the single-layer casing (11), or of one or more layers of the multi-layer casing (11), can be selected for its impermeability to at least a portion of the fumes produced by a lithium battery fire.

[0035] According to a multilayer embodiment, the casing (11) comprises at least one inner layer contiguous to the housing (111) made of polyurethane-coated fiberglass fabric and classified in fire reaction category M0 according to standard NF P92-507. The inner layer has, for example, a thickness of between 0.3 mm and 1 mm, advantageously between 0.3 mm and 0.5 mm. The casing (11) may then comprise an intermediate layer, contiguous to the inner layer, made of felt classified in fire reaction category M0 according to standard NF P92-507. The felt is advantageously a needle-punched fiberglass felt. The intermediate layer has, for example, a thickness of between 4 mm and 7 mm. The casing (11) may then comprise an outer layer, contiguous to the intermediate layer, made of felt classified as a material composed of modacrylic, combed cotton, and a carbon fiber mesh.Apart from carbon fiber, the material may contain at least 50% modacrylic, advantageously 55% modacrylic. Apart from carbon fiber, the material may contain at least 40% combed cotton, advantageously 45% combed cotton. The carbon fiber mesh may have square cells with sides between 4 mm and 6 mm, advantageously 5 mm. The outer layer has, for example, a thickness between 0.5 mm and 1 mm, advantageously between 0.5 mm and 0.7 mm.

[0036] According to a multilayer embodiment, the casing (11) comprises at least one inner layer contiguous with the housing (111) and similar to the inner layer of the embodiment described in the preceding paragraph. The casing (11) includes a first intermediate layer, contiguous with the inner layer, and similar to the intermediate layer of the embodiment described in the preceding paragraph. The casing (11) then comprises one or more stacks of two additional intermediate layers: a first additional intermediate layer, similar to the inner layer and contiguous with the preceding intermediate layer, and a second additional intermediate layer similar to the first intermediate layer and contiguous with the first additional intermediate layer. The casing (11) then comprises an outer layer, contiguous with the last intermediate layer, and similar to the outer layer of the embodiment described in the preceding paragraph.

[0037] The layers of the multi-layered envelope can be joined together by means of stitching. The stitching can be done using Kevlar thread.

[0038] The casing (11) may include an insertion opening (112). This opening is configured to allow the insertion or removal of at least a portion of the equipment (2) into the housing (111). The insertion opening (112) may be opened or closed, as required, by means of a zipper (113). Alternatively, or in combination, the insertion opening (112) may be opened or closed, as required, by means of a hook-and-loop fastener and / or a magnetic fastener and / or a snap buttonhole and / or straps and / or any other opening and closing device suitable to a person skilled in the art. The insertion opening (112) may preferably be arranged on a front face of the casing so as to allow the insertion or removal of at least a portion of the equipment (2) into the housing (111) in a horizontal translational movement.In particular, when the equipment (2) is a personal mobility device, the insertion opening (112) can be configured to allow the insertion or extraction of at least a portion of the equipment (2) into the housing (111) by rolling the equipment (2) forward or backward. In alternative embodiments, the insertion opening (112) can be located at any other place suitable to a person skilled in the art. In some embodiments, the housing (11) may have multiple insertion openings (112).

[0039] As shown in the figures, the cover (1) also includes a frame (12). Referring to the figure, the frame (12) is configured to stiffen the casing (11) so as to create an air gap (13) between the casing (11) and at least a portion of the equipment (2) when said equipment is arranged inside the housing (11). The air gap (13) thus formed can be used for its natural thermal insulation properties in the event of a fire in the lithium battery (24).

[0040] The air gap (13) has a thickness of at least 1 cm. Advantageously, the air gap has a thickness of at least 3 cm. Preferably, the air gap (13) has a thickness of at least 5 cm. The air gap (13) extends over an area at least equal to 60% of the total exterior surface area of ​​at least a portion of the equipment (2). Advantageously, the air gap (13) may extend over an area at least equal to 70% of the total exterior surface area of ​​at least a portion of the equipment (2). Preferably, the air gap (13) may extend over an area at least equal to 80% of the total exterior surface area of ​​at least a portion of the equipment (2).

[0041] The air gap (13) may have an upper portion. This upper portion may have a thickness of at least 3 cm, advantageously at least 5 cm, preferably at least 10 cm. The upper portion of the air gap (13) may extend over an area of ​​at least 60%, advantageously at least 70%, preferably at least 80%, of the total area of ​​at least a portion of the equipment (2).

[0042] The air blade (13) may have a right lateral portion and a left lateral portion. These may have a thickness of at least 2 cm, advantageously at least 4 cm, preferably at least 7 cm. The right lateral portion, respectively the left lateral portion, of the air blade (13) may extend over an area of ​​at least 60%, advantageously at least 70%, preferably at least 80%, of the total right lateral area, respectively of the total left lateral area, of at least a portion of the equipment (2).

[0043] The frame (12) is configured to allow the casing (11) to fold when the housing (111) is devoid of at least part of the equipment (2). In particular, the frame (12) can be configured to allow the casing (11) to fold, such that the external volume of the casing (11), once folded, is at least 50% less, advantageously at least 60% less, preferably at least 70% less, than the external volume of the casing (11) when unfolded.

[0044] To achieve this, the frame (12) may comprise, as schematically shown in Figures a, a series of independent hoops arranged along the envelope (11) so as to keep the upper part of said envelope separated from the lower part of said envelope, and to keep the right lateral part of said envelope separated from the left lateral part of said envelope. Each hoop may be separated from the next hoop so as to define an intermediate part of the envelope (11), said intermediate part being able to be either stretched between the two hoops that frame it, as schematically shown in Figures a, or folded between the two said hoops so as to form one or more folds (115), as schematically shown in Figure 1.In particular, the intermediate section can be stretched between the two hoops that frame it by tension exerted by at least one part of the equipment (2) on two ends of the casing (11) as shown in the figures. The hoops may have a diameter between 1.5 mm and 15 mm. For an embodiment in which the equipment (2) is a personal mobility device, the hoops may preferably have a diameter between 1.5 mm and 5 mm.

[0045] The frame (12) can be made of metal, for example, stainless steel, tungsten, molybdenum, niobium and tantalum, titanium, or an alloy of these materials, ceramic, fiberglass, for example, silicon carbide, or any other material suitable to a person skilled in the art.

[0046] The casing (11) may include loops (114) configured to hold the frame (12) in position inside or outside the casing. The loops (114) may be attached to one or more layers of the casing (11) by means of stitching, snap fasteners, or any other means suitable to those skilled in the art. The stitching may be made using Kevlar thread. In one embodiment, one or more loops are formed by a portion of webbing attached to the outside of the casing (11). Advantageously, the portion of webbing is attached to the casing (11) by means of stitching arranged along the longitudinal edges of said portion of webbing. The central portion of the webbing, between said longitudinal stitching, then forms a space for the passage of a hoop of the frame (12). Advantageously, the longitudinal stitching does not penetrate the inner layer of the casing (11).Alternatively, the loops (114) may be formed by one or more inner layers, with perforations provided on said inner layer(s) allowing the reinforcement to alternately pass in front of or behind said inner layer(s). The loops may also take any other form suitable to those skilled in the art. In alternative embodiments, the reinforcement (12) may be held in position on the envelope (11) by means of hooks fixed to said envelope, rings fixed to said envelope, or any other fastening means suitable to those skilled in the art. The reinforcement (12) may be held in position on the envelope (11) by a permanent fastening system or by a removable fastening system. In the latter case, the reinforcement (12) may be separated from the envelope (11) so as to facilitate folding said envelope.

[0047] In one embodiment of the frame (12), the frame may comprise a series of inflatable hoops arranged along the casing (11). The inflatable hoops are preferably arranged on the outside of the casing. Thus arranged, the inflatable hoops are subjected to a temperature lower than the temperature inside the casing (11) when a fire occurs in the lithium battery (24) inside the casing. The inflatable hoops may be independent of each other or connected by inflatable crossbars. Once inflated, the inflatable hoops are capable of keeping the upper part of the casing separate from the lower part of the casing, and of keeping the right side of the casing separate from the left side of the casing.When the cover (1) is not in use, the inflatable hoops and crossbars can be deflated to facilitate folding the cover (11). The inflatable hoops and crossbars may have airtight walls. These walls may be made of polyvinyl chloride, rubber, or any other material suitable to those skilled in the art. The inflatable hoops and crossbars can be inflated or deflated via a valve. When inflated, the inflatable hoops and crossbars may have a diameter of between 20 mm and 50 mm.

[0048] The enclosure (11) may include an emergency longitudinal opening. This opening is configured to allow the enclosure (11) to be placed over at least part of the equipment (2) when the equipment is already in a fire condition and is not already inside the housing (111). The emergency longitudinal opening may be opened or closed as required by means of a zipper and / or a hook-and-loop fastener and / or a magnetic closure and / or a snap fastener and / or straps and / or any other opening and closing device suitable to a person skilled in the art. The emergency longitudinal opening may preferably be located on a lower or side face of the enclosure (11) so as to allow the lower portion of the enclosure to be opened and the enclosure to be placed over the equipment (2).

[0049] The cover (1) may include a controlled smoke extraction device. Indeed, a lithium battery fire quickly produces a large quantity of smoke. This smoke, trapped within the cover (11), along with the rapid temperature increase inside the housing (111), leads to a rapid increase in pressure within the housing (111). The controlled smoke extraction device can therefore extract the smoke in such a way as to reduce the pressure inside the housing (111) and prevent a potential explosion of the cover. Furthermore, since this smoke may contain elements potentially toxic to humans, the controlled smoke extraction device can direct the smoke to a specific location to prevent it from dispersing too quickly into the surrounding air.

[0050] The controlled smoke extraction device may include an extraction opening (14) provided in the casing (11). The extraction opening (14) may have a diameter between 1 cm and 15 cm. In an embodiment in which the equipment (2) is a personal mobility device comprising a steering column (25) and handlebars (26) arranged outside the housing (111), the extraction opening (14) may be arranged on the casing (11) so as to allow the steering column (25) to protrude, as in the schematic example shown in Figures 1 and 2. In some embodiments, the controlled smoke extraction device may include several extraction openings (14) provided in the casing (11).

[0051] The controlled smoke extraction system may also include a filter. This filter may be positioned at the extraction opening(s) (14) to filter out certain elements of the smoke. This filter, or these filters, may, for example, be quartz microfiber filters.

[0052] The cover (11) may include a fire suppression device. This device may be configured to release fire suppression material onto the equipment (2) when a fire occurs in the lithium battery (24). The suppression material may be liquid, viscous, or solid. In particular, the suppression material may be mineral-based. Preferably, the suppression material may be vermiculite.

[0053] With reference to the figures, the fire mitigation device may include at least one pocket (15) provided inside the envelope (11).

[0054] The pocket(s) (15) may be single-layered or multi-layered and made of materials similar to the envelope (11). The layer(s) may have a thickness of between 0.1 mm and 2 mm. Each pocket. The pocket(s) are preferably attached to the upper part of the envelope (11). The pocket(s) (15) may be attached to the envelope (11) by a permanent fastening system, for example, by sewing, gluing, or any other fastening method suitable to those skilled in the art. The seams may be made using Kevlar thread. In an alternative embodiment, the pocket(s) may be attached to the envelope (11) by a removable fastening system, for example, snap fasteners, hook and loop fasteners, or any other fastening method suitable to those skilled in the art. The pocket(s) may thus be separated from the envelope (11) so as to allow the envelope to be folded.

[0055] When the fire suppression system has a single pouch (15), this pouch may extend along the length of the casing (11). The pouch may have a capacity of between 1 L and 10 L. Preferably, the pouch (15) extends over at least 20%, preferably at least 50%, of the length of the casing (11). When the fire suppression system has several pouches (15), these may be arranged regularly along the casing (11). Preferably, the pouches (15) extend, cumulatively, over at least 20%, preferably at least 50%, of the length of the casing (11). Each pouch (15) may have a capacity of between 0.2 L and 2.5 L. The pockets (15) can advantageously be arranged so as to permit the folding of the envelope (11) while they are fixed to said envelope.In particular, the pockets (15) can be arranged on the envelope (11) so as to allow their folding under the hoops of the frame (12) when folding said envelope, as schematically shown in the figure.

[0056] Granules (16) may be arranged inside said at least one pouch (15). These granules (16) may be mineral-based. The mineral material may include silicon dioxide. The mineral material may also include sodium oxide, and / or calcium oxide, and / or alumina, and / or magnesia, and / or any other component suitable to those skilled in the art. Preferably, the granules (16) may be made of vermiculite. The granules (16) may be a mixture of granules of different materials. The granules (16) may be spherical, cylindrical, pebbly, or any other shape suitable to those skilled in the art. The granules (16) may all be substantially the same size, or may comprise different granules of different sizes. The granules (16) can have a diameter between 0.25 mm and 25 mm, preferably between 5 mm and 10 mm.

[0057] Each pouch (15) may then include a discharge opening (151). This opening may be configured to allow the discharge of the granules (16) arranged in the associated pouch (15) towards the air gap (13). The discharge opening (151) has a shape and dimensions that allow the granules (16) to be discharged. The discharge opening (151) may, for example, be in the form of a slot formed in a lower wall of the pouch (5). The slot may have a length between 5 cm and 1 m, preferably between 5 cm and 20 cm. In one embodiment, each pouch (15) may include several discharge openings (151) conforming to the one described above.

[0058] A hot-melt wire can be arranged at the discharge opening (151) of each pouch (15) to close the associated pouch. The hot-melt wire can close the discharge opening (151) by stitching the edges of the discharge opening (151) together, the stitching being made using the hot-melt wire. The hot-melt wire can be configured to melt when subjected to a temperature rise due to the ignition of the lithium battery (24), so as to allow the associated pouch (15) to open and the granules (16) to be discharged through the discharge opening (151). In practice, the hot-melt wire can be configured to melt at a temperature between 50°C and 100°C. The hot-melt wire can be made of a heat-fusible material, for example, a copolyester or a copolyamide. The figure shows the pockets (15) closed by the hot melt wire, before the latter melts.The figure shows the open pockets (15), once the hot melt wire has melted, the granules (16) having flowed towards the air blade (13) through the discharge opening (151) so that said granules cover part of the upper surface of the equipment (2) at the level of the battery (24).

[0059] In one embodiment, the pouch(es) may include, in its layer(s), at least one hot-melt portion. This portion may be configured to melt when subjected to a temperature rise due to the ignition of the lithium battery (24), so as to allow the granules (16) arranged in the associated pouch (15) to be discharged into the air gap (13). In practice, the hot-melt portion may be configured to melt at a temperature between 50°C and 100°C. The hot-melt portion may be made of a hot-melt material, for example, a copolyester or a copolyamide. In one embodiment, the layer, or all the layers, of the pouch(es) (15) are hot-melt.

[0060] In one embodiment of the fire suppression device, the device includes a reservoir of a liquid, viscous, or foamy suppression agent. The fire suppression device also includes one or more tubes configured to guide the suppression agent from the reservoir to the air gap (13) such that the suppression agent covers a portion of the upper surface of the equipment (2) at the level of the battery (24). The fire suppression device includes a mechanism for drawing the suppression agent out of the reservoir, into the tube(s), when a fire in the battery (24) is detected. This mechanism may be a valve when the reservoir is pressurized. In one embodiment, this mechanism may be a pump.

[0061] The enclosure (1) may include a warning device for people. The warning device may, firstly, include a detection device configured to detect the start of a lithium battery fire. The detection device may include a thermal sensor configured to detect a temperature rise inside the housing (111) above a thermal threshold characteristic of a lithium battery fire. The thermal threshold may, for example, be 50°C. The detection device may include an infrared camera configured to detect a temperature rise above the thermal threshold for at least part of the equipment (2). The detection device may include a smoke detector inside the housing (111). The detection device may include any other means of detecting a lithium battery fire suitable to a person skilled in the art.The detection device may include one of the detection means described above, or a combination of several of these means.

[0062] The warning device for people may include a signaling device configured to emit a warning signal when the detection device detects the start of a fire. The signaling device may include an audible alarm. This alarm may be integrated into the cover (1) and take the form of a beeper or a loudspeaker. The audible alarm may also be separate from the cover (1) and take the form of a speaker connected to a wireless network, for example, the speakerphone of a phone or tablet. In this case, the warning device may include a wireless network connection chip. The signaling device may include a visual alarm. This alarm may be integrated into the cover (1) and take the form of a light.The visual warning device may also be located outside the cover (1) and take the form of a screen connected to a wireless network, for example, a phone or tablet screen. The warning device may include any other signaling means suitable to a person skilled in the art. The warning device may include one of the signaling means described above, or a combination of several of these means.

[0063] When the equipment (2) is a personal mobility device, the cover (1) may include a charger configured to charge the lithium battery (24) of said equipment when the latter is arranged inside the housing (111).

[0064] The cover may include one or more storage pockets arranged on the outside of the envelope (11). The storage pocket(s) may be sewn onto the envelope (11). They are preferably made of the same material as the envelope (11).

Claims

A lithium battery fire containment cover comprising an enclosure (11) having a housing (111) configured to receive at least a portion of equipment comprising at least one lithium battery (24), said enclosure being configured to at least withstand a fire of a lithium battery capable of storing an amount of energy equal to 100 Wh, characterized in that: said enclosure is flexible so as to allow its folding; said cover also comprises a frame (12) configured to: stiffen said enclosure so as to create an air gap (13), at least 1 cm thick, between said enclosure and said at least a portion of said equipment, and extending over an area at least equal to 60% of the total external surface area of ​​said at least a portion of said equipment, when said at least a portion of said equipment is arranged inside said housing.To allow the folding of said envelope when said housing is devoid of at least some part of said equipment. Cover according to claim 1 characterized in that it comprises a controlled smoke extraction device. Cover according to claim 2 characterized in that the controlled smoke extraction device includes an extraction orifice (14) provided in the envelope (11). Cover according to claim 3 characterized in that the controlled smoke extraction device includes a filter arranged at the extraction orifice (14) so ​​as to filter certain elements of the smoke. Cover according to one of the preceding claims characterized in that it includes a fire attenuation device. A cover according to claim 5 characterized in that the fire attenuation device comprises: At least one pocket (15) provided inside the cover (11), Granules (16), based on mineral material, arranged inside said at least one pocket, A discharge opening (151) on each pocket (15), said discharge opening being configured to allow the discharge of said granules arranged in said associated pocket, towards the air gap (13), A hot-melt wire arranged at the discharge opening (151) of each pocket (15), so as to close said associated pocket, said hot-melt wire being configured to melt, when subjected to a temperature rise due to the fire of a lithium battery, so as to allow the opening of said associated pocket and the discharge of said granules through said discharge opening. Cover according to claim 6 characterized in that the granules (16) are made of vermiculite. Cover according to any one of the preceding claims characterized in that the cover (11) comprises at least one textile layer of silicone-coated glass fabric, or silica fabric, or silica needle-punched felt. Cover according to one of the preceding claims characterized in that it includes a device for warning people. Cover according to claim 9 characterized in that the person warning device comprises: A detection element configured to detect a start of fire in a lithium battery, A signaling element configured to emit a warning signal when the detection element detects a start of fire.

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