WO2023094130A1

WO2023094130A1 - Battery handling structure

Info

Publication number: WO2023094130A1
Application number: PCT/EP2022/080699
Authority: WO
Inventors: Bengt Andersson
Original assignee: Composite Technologies Sweden Ab
Priority date: 2021-11-24
Filing date: 2022-11-03
Publication date: 2023-06-01
Also published as: SE545775C2; SE2151429A1

Abstract

The invention relates to a safety structure (10) for handling batteries that risk self- ignition, comprising an enclosure (12), at least one enclosed chamber (20) arranged inside said enclosure in which a battery (22) can be placed, an outlet (28) in the chamber (20) for hot flue gas from a self-ignited battery, a gas treatment channel (30) arranged inside said enclosure (12) and fluidly connected to said outlet (28) of said chamber (20) and with an outlet (46) for treated gas from said enclosure (12), at least one gas treatment material element (36) provided in said gas treatment channel (30) for treatment of the hot flue gas, a cooling channel (48) arranged inside said enclosure (12), provided with an inlet (50) and an outlet (52) in said enclosure (12) for a cooling media flowing in said cooling channel (48), said cooling channel (48) being connected to said gas treatment channel (30) for providing a heat exchange, cooling the flue gas in the gas treatment channel (30).

Description

BATTERY HANDLING STRUCTURE

TECHNICAL AREA

The present invention relates to a safety structure for handling batteries, and in particular batteries for which there is a risk of self-ignition.

BACKGROUND OF INVENTION

There is an ever increasing focus on battery-operated equipment and vehicles and in particular the development of electrically driven vehicles such as cars, lorries, mopeds and scooters, mainly due to environmental aspects and reducing the CO2 emissions from combustion engines.

Rechargeable batteries used for the above purposes often contain lithium and or other materials that may form redox reactions and these batteries may sometimes malfunction such that a chain redox reaction, a thermal runaway, is started, which destroys the battery. Since these batteries contain flammable substances and large amounts of toxic gases may be produced if they bum, it is important that the batteries are stored in a safe place, both when stationary and also during transportation, so that the heat and the gases are prevented from entering the environment.

However, there is a risk that batteries may malfunction also during use, and in many environments and for many vehicles, it is very important that the heat and fire from self-ignited batteries are prevented to spread in the vehicle. This may for example be important in ships and boats, trains, lorries, mining vehicles, just to mention a few. Another area that is growing is battery stations that can be used for charging vehicles or are placed adjacent or in buildings and are used for storing electricity from for example photovoltaic panels or wind generators. It is also here important that malfunctioning batteries that self-ignite do not cause damage or fire to the buildings that they are connected to.

Some solutions have been developed that can handle storing and transportation of this type of batteries. US 2019/0280259 discloses a transportation device for batteries having an external case. Inside the case, an inner tank is placed, in which a battery can be placed via an opening in the case. The opening is closed with an air- tight lid. The transportation device is further provided with a ventilation opening that communicates with a flow path from the inner tank. A heat absorption material is arranged along the flow path.

If a battery in the inner tank ignites, the hot gases produced flow along the flow path and are cooled by the heat absorption material. In this regard, the external walls of the external case are heat conductive and function as radiation surfaces for the heat. The heat absorption material consists of plaster that reacts above an activation temperature and gives off steam. The heat absorption material also reacts with acids present in the gases such that the acids are bound. The steam may also split hydrogen.

A drawback with this solution is that the outer wall surfaces of the external case will heat up due to the heat from the heat absorption material and even if the heat might not be so high as to ignite other objects, persons may get injured if in contact with the external case during a fire.

DE 10 2012 019 676 discloses a battery transport container having an inner case of flexible material that can expand and flex if a battery explodes. The inner case may further comprise an intumescent material that can act as a catalyst against poisonous gases. The inner case is further provided with a flexible gas conduit for transporting hot gases from the inner case. The gas conduit may be provided with a filter and a cooling cartridge through which the hot gases pass.

The drawback with both the above solutions is that they are designed exclusively for handling single batteries and the inner dimensions are chosen in relation to specific battery sizes, which limits the flexibility to handle multiple batteries of different sizes.

None of the shown solutions can further handle neither batteries that are active, i.e. that are charged and/or de-charged, nor transporting and storing of vehicles with batteries that may self-ignite due to damage, such as for example an electric car that has been involved in a traffic accident.

There is thus room for improvements in this technical area. BRIEF DESCRIPTION OF INVENTION

The aim of the present invention is to remedy the drawbacks of the state of the art solutions. This aim is obtained with the features of the independent patent claim. Preferable embodiments of the invention will form the subjects of the dependent patent claims.

In the following description of the invention, the word battery will be used in many instances. It is to be understood that this word comprises many different types of rechargeable batteries using different materials. Especially materials, and combinations of materials, used in batteries that can cause redox reactions with or without the presence of oxygen are of importance and should be handled with the present invention. It is also to be understood that this word comprises individual cells, clusters of battery cells, such as battery modules, battery packs and a plurality of these. In this context, the battery or batteries may be stand-alone units as well as batteries installed in vehicles.

According to the invention a safety structure for handling batteries that risk selfignition is provided, comprising an enclosure, at least one enclosed chamber in which a battery can be placed arranged inside said enclosure, an outlet in the chamber for hot flue gas from a self-ignited battery, a gas treatment channel arranged inside said enclosure and fluidly connected to said outlet of said chamber and with an outlet for treated gas from said enclosure, at least one, and preferably several, gas treatment material elements provided in said gas treatment channel for treatment of the hot flue gas, a cooling channel arranged inside said enclosure, provided with an inlet and an outlet in said enclosure for a cooling media flowing in said cooling channel, said cooling channel being connected to said gas treatment channel for providing a heat exchange, cooling the flue gas in the gas treatment channel.

With this design, a very effective treatment of hot flue gases is obtained with an active cooling of the gases while flowing through the at least one gas treatment material element. Further, the enclosure may comprise a plurality of enclosed chambers in which batteries can be placed. Hereby several batteries may be placed in one enclosure such as a container or the like. In this regard, the chambers may be of different sizes for accommodating different types and sizes of batteries. The chamber may also be arranged large enough to accommodate a vehicle such as an electric car. This is an advantage for instance when handling electric cars that have been involved in car incidents or crashes, where there is a risk that the battery pack of the vehicle has been damaged. A suitable truck provided with the chamber may then load the damaged vehicle into the enclosure for transport to a service and repair facility in a safe way. Should the battery pack of the vehicle self-ignite, the device according to the invention will handle the heat and the gases in a very safe, reliable and environmentally friendly way.

According to one aspect, if more than one chamber is arranged in the enclosure, each chamber may be connected to a separate gas treatment channel and wherein each gas treatment channel is connected to a separate cooling chamber or to a common cooling chamber. As an alternative, the chambers may be connected to a common gas treatment channel, in turn connected to a common cooling chamber. Common piping may then be arranged from each chamber to the gas treatment chamber.

In order to prevent other batteries from being ignited when one battery ignites, each chamber may be provided with a lid or valve allowing gas to flow out of the chamber but preventing gas to flow into the chamber. Thereby all chambers not containing an ignited battery will be closed, reducing the risk of fire spreading to batteries in other chambers. The solution also ensures that oxygen cannot enter the chamber with the ignited battery since the enclosure is air-tight apart from the connection with the gas treatment channel, and when gas is flowing out of the chamber, no air can enter, and if the gas flow drops, the valve is closed.

According to a further aspect, the connection between the gas treatment channel and the cooling chamber may preferably comprise corrugated, waved and/or profiled surfaces in order to increase the heat exchanging surface. Moreover, the treatment channel and the cooling channel may preferably extend generally vertically in the enclosure, providing generally vertical flow of flue gases and cooling media. The gas treatment material elements may comprise granular lime as treatment material, having good treatment properties for handling flue gases from batteries such as batteries containing lithium. Further, the gas treatment material elements may comprise a number of plates positioned generally perpendicular to a flow of flue gases, where the plates are provided with a plurality of passages and wherein the granular lime is placed on the plates. The plates may in this regard comprise perforations or stretch or expanded metal. The plates may further comprise bags containing the granular lime, having a mesh size preventing the granular lime to fall through the plates or be blown away by the gas flow. Moreover, the granular lime may be placed on the plates leaving an area uncovered for reducing pressure drop of the gas over the plates.

According to another aspect, the cooling channel may comprise gaseous or fluid cooling media and in this regard, the media may be forced through the cooling channel with a flow force element.

The present invention may be utilized in any situation where there is a risk of thermal runaway and concerns all batteries that are stored or used for running all sorts of devices and vehicles. For instance, buildings that contain batteries, either back-up batteries in computer halls, storage batteries connected to renewal energy such as wind or solar power may use the present invention. Regarding the term battery used in this description, it is to be understood that the invention also covers a battery or several batteries placed in another device. For instance, a chamber as described may be designed to accommodate a vehicle powered with batteries. As an example, an enclosure with a chamber may be provided on a truck and in case of an accident with an electrically driven vehicle, the whole vehicle with its batteries may be placed in the chamber, minimizing the risk of injuries due to thermal runaway of the batteries of the damaged vehicle. Another example are computers and other electronic equipment that may be stored in one or several chambers of an enclosure according to the invention during transport by for example airplanes or busses.

These and other aspects of, and advantages with, the present invention will become apparent from the following detailed description of the invention and from the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

In the following detailed description of the invention, reference will be made to the accompanying drawings, of which

Fig. 1 is a schematic perspective view of a safety structure of one embodiment of the invention,

Fig.2 is a schematic side view of a safety structure according to Fig. 1 , slightly modified,

Fig. 3 is a detailed view of flue gas treatment elements comprised in the safety structure of Fig. 2,

Fig. 4 shows schematically a variant of a safety structure seen from above,

Fig. 5 is a schematic side view of a further variant of a safety structure, and

Fig. 6 shows an example of a safety structure according to the invention arranged mobile on a truck and designed to accommodate and transport a vehicle.

DETAILED DESCRIPTION OF THE INVENTION

In the drawings a safety structure 10 for handling batteries is shown. In the embodiment shown in Figs. 1 and 2, the structure comprises an outer limiter that may be an enclosure 12 such as a container provided with side walls 14, a bottom 16 and a roof 18. The container 12 is preferably made of fire resistant material such as steel. Inside the container a number of chambers 20 can be placed, in which batteries 22, comprising a number of battery cells, that might self-ignite may be placed. Here it is to be understood that not only batteries, but also equipment, vehicles and all sorts of devices containing batteries that might self-ignite may be placed in the chambers. In this regard, the chamber or chambers 20 may be arranged with lids 24 for facilitating insertion of the batteries 22. The lid 24 is preferably provided with suitable locking elements (not shown). The chambers 20 may be of different sizes for accommodating different battery sizes. The chambers 20 are preferably provided with a fire-protective and heat insulation 26 of a suitable material and are air-tight.

One preferable type of material that can be used for the insulation and fire protection comprises basalt fibre, perlite and soluble glass, which is marketed under the trade name ExpanCore®, having excellent fire and heat resistant properties and providing compact solutions with flexibility for specific applications. However, it is to be understood that other types of material that provide fire protection and insulation such as stone wool may be used as alternatives.

The, or each, chamber 20 is provided with an outlet 28 for flue gas emitting from the battery inside the chamber 20. The outlet 28 may be provided with a lid or valve 29 for opening and closing each outlet 28. The valve could be manually operated or be in the form of a check valve, only allowing gas out from the chamber but preventing gas from other chambers to enter.

The, or each, outlet 28 is in fluid communication with a generally vertically extending gas treatment channel 30. In this regard, if more than one chamber 20 is provided, each outlet may be connected to a separate flue treatment channel. As an alternative, each outlet 28 may be connected to a common generally vertically extending gas treatment channel 30 if several chambers 20 are provided.

Independent of the design with one or several chambers, the flue treatment channel 30 preferably comprises a first wall section 32 facing the interior of the container. The first wall section 32 is preferably provided with heat insulating material 26 that could be of a type mentioned above. The flue treatment channel 30 is further comprises a second wall section 34. The second wall section 34 is not provided with insulating material but is instead intended to function as a heat exchange layer. In this regard, the second wall section 34 is preferably corrugated, waved, profiled in order to increase the heat exchanging surface. Along the path of the flue treatment channel 30, a plurality of gas treatment material elements 36 are provided. The gas treatment material elements 36 may comprise a number of different components that are able to treat and clean the flue gases. One preferable material is granular lime. The granular lime may be placed such that the flue gases pass through it. In this regard, it is important that the over pressure is not too high.

One way of solving this is to arrange a number of surfaces along the path of the flue gases inside the flue treatment channel. For instance, plates 38 with perforations or plates of stretch or expanded metal may be used, Fig. 3. The plates are preferably attached to both wall sections. In order to ensure that the granular lime 40 does not fall through the perforations of the plates 38 or be blown away by the gas flow, the granulate may be placed in bags 42 made of a fire-resistant material such as steel cloth with a density or mesh size that can hold the granules. In order to handle pressure issues, the bags 42 of lime granulate may be placed on the plates such that gaps 44 are provided. The gaps 44 are preferably positioned close to alternating wall sections as seen in Fig. 3, reducing the risk of a volume of the flue gas just passing the treatment material elements 36. At an upper part of the gas treatment channel 30 an outlet 46 for treated gases is provided, for instance in the roof 18 of the container 12.

The second wall section 34 is placed with a distance from one of the side walls 14 of the container 12, creating a vertical cooling passage or channel 48 between them. The second wall section 34 could be attached to the container wall 14 with for instance plates of expanded metal 49, stabilizing the second wall. The expanded metal allows a flow of media through the cooling channel and also acts as a heat transfer from the second wall. The side wall 14 is provided with an inlet 50 to the cooling channel 48 at a lower section. At an upper part of the cooling channel 48, an outlet 52 is provided, for instance in the roof 18 of the container 12. Further, the second wall section 34 may be provided with a passage 54, fluidly connecting the upper part of the cooling channel 48 with the upper part of the flue treatment channel 30.

The function is intended as follows. If a battery 22 inside a chamber 20 sustains a self-ignition and thermal runaway, large amounts of hot flue gas will be created. The gas is then led through the outlet 28 of the chamber 20 and into the flue treatment channel 30. If several chambers are used, the valves 29 in the outlets to the chambers of batteries that have not ignited are closed to protect them from the fire. The flue gas then flows upwards through the flue treatment channel 30 and through the gas treatment material elements 36 where the components of the gas interact with the granular lime, thereby removing toxic elements in the gas. While flowing through the flue treatment channel 30, the hot gases are cooled when exposed to the profiled second wall section 34, whereby the second wall section 34 functions as a heat exchanger because cool air is flowing in the cooling channel 48 on the other side of the second wall section 34. Since the plates 38 of the gas treatment material elements 36 are attached to the second wall section, they will aid in the heat transfer from the hot gases flowing through the plates 38 to the second wall section 34. The treated and cooled gases are then led from the flue treatment channel 30 and through the outlet 46. The passage 54 between the cooling channel 48 and flue gas treatment channel 30 provides a mixing of air with the treated gases before release into the atmosphere.

The above solution may be modified in a number of ways. For instance, the inlet 50 or the outlet 52 of the cooling channel 48 may be provided with forced flow elements such as fans 60, Fig. 3, for creating a forced air flow, thereby increasing the heat exchanging effect. If a fluid is used as cooling media, pumps may be provided for creating a forced flow. In this regard, it is of course possible to use other media than air for cooling. For instance, the cooling channel may constitute or comprise water pipes or channels in contact with the second wall section for providing the heat exchange effect. Further, the chambers may be provided with anchoring elements 56 for securing batteries during transportation of the container 12.

Moreover, the outlets 28 from the chambers may be connected to a common piping 62, Fig. 4. In this way several of the walls of the enclosure 12 may be used for providing both treatment channels 30 as well as cooling channels 48. In this regard, also the roof may be provided with treatment and cooling channels. In order to automate the process, the chambers may be provided with temperature sensors and/or smoke detectors. If one battery ignites, this is detected and the valves in the outlets of the other battery chambers are closed to protect them. If a fan or a pump is used for the cooling media, this may be activated for creating a flow of cooling media in the cooling channel(s). The enclosure may further be provided with doors 80 for loading and unloading of batteries. Further, if really large batteries are stored, that might produce very large amounts of flue gas when ignited, further gas treatment elements may be placed on the container and connected to the outlet for further gas flue treatment.

Fig. 5 shows a further embodiment of the invention. Here the treatment channel and the cooling channel are arranged with the same function and similar design as a plate heat exchanger. As seen in Fig. 5, hot flue gases leaving the outlet are first flowing upwards through a first flue treatment channel 30¹, then downwards though a second flue treatment channel 30" and then upwards through a third flue treatment channel 30¹¹¹ before exiting the enclosure through the outlet 46. As seen, the first and the second treatment channels are provided with gas treatment material elements 36. It is however to be understood that also the third flue treatment channel may be provided with gas treatment material elements 36, or that only the first flue treatment channel is arranged with gas treatment material elements 36.

Further, cooling media enters through inlet 50 and flows upwards though a first cooling channel 48¹, downwards through a second cooling channel 48" and then upwards through a third cooling channel 48¹" before exiting outlet 52. This will provide an effective cooling of the flue gases. The design of the heat exchanger in Fig. 5 has a counter flow of the flue gases and the cooling media. It is of course to be understood that the flow of the cooling media could be arranged in the opposite direction with a parallel flow with incoming cooling media through the outlet 52 and outgoing cooling media through the inlet 50. Further, even if the interface between the gas treatment channels and the cooling channels are shown with flat surfaces, it is of course to be understood that the surfaces could be corrugated, waved, profiled as described above.

As mentioned above, the solution can be further expanded to handle whole vehicles that need to be transported in a safe way. Figure 6 shows an example of a truck 90 provided with an enclosure 12. The enclosure 12 could for example be a transport container that is releasably attached to the truck 90. The inside of the container is covered with heat insulating material, forming the chamber 20. The container/chamber has a size to accommodate a whole vehicle 92 comprising a battery pack 22. This may for example be the case where an electric vehicle has been damaged in a traffic accident and needs to be removed from the accident scene and transported to service and repair facilities. Due to the accident, the batteries may have been damaged or affected such that there is a risk that they might ignite and cause a fire.

For this purpose, the vehicle is placed in chamber 20 of the enclosure or container 12 via doors 80 in the end of the container. This may either be by an appropriate ramp and winch up to the container, or that the truck is provided with a crane so that the container may be lifted down to the ground. In the latter case, the container may then be off-loaded at a service and repair site.

Even though the gas treatment channel or channels have been shown to extend generally vertically in the embodiments, it is to be understood that the gas treatment channel may extend in other directions and/or with bends, depending on installation prerequisites. The bags of granulate may then be fixedly attached to structures inside the gas treatment channel for providing the function as described above.

It is to be understood that the embodiments described above and shown in the drawings are to be regarded only as illustrative examples and that the invention may be modified in many ways within the scope of the patent claims.

Claims

PATENT CLAIMS

1 . Safety structure (10) for handling batteries that risk self-ignition, comprising

- an enclosure (12),

- at least one enclosed chamber (20) arranged inside said enclosure in which a battery (22) can be placed,

- an outlet (28) in the chamber (20) for hot flue gas from a self-ignited battery,

- a gas treatment channel (30) arranged inside said enclosure (12) and fluidly connected to said outlet (28) of said chamber (20) and with an outlet (46) for treated gas from said enclosure (12),

- at least one gas treatment material element (36) provided in said gas treatment channel (30) for treatment of the hot flue gas,

- a cooling channel (48) arranged inside said enclosure (12), provided with an inlet (50) and an outlet (52) in said enclosure (12) for a cooling media flowing in said cooling channel (48), said cooling channel (48) being connected to said gas treatment channel (30) for providing a heat exchange, cooling the flue gas in the gas treatment channel (30).

2. Safety structure according to claim 1 , wherein several gas treatment material elements (36) are provided in said gas treatment channel (30).

3. Safety structure according to claim 1 or 2, wherein said enclosure (12) comprises a plurality of enclosed chambers (20) in which batteries can be placed.

4. Safety structure according to claim 3, wherein each chamber (20) is connected to a separate gas treatment channel (30) and wherein each gas treatment channel is connected to a separate cooling chamber (48) or to a common cooling chamber.

5. Safety structure according to claim 3, wherein the chambers (20) are connected to a common gas treatment channel (30), in turn connected to a common cooling channel (48).

6. Safety structure according to claim 5, wherein each chamber (20) is provided with a lid or valve (29) allowing gas to flow out of the chamber but preventing gas to flow into the chamber.

7. Safety structure according to any of the preceding claims, wherein the connection (34) between the gas treatment channel (30) and the cooling chamber (48) comprises corrugated, waved and/or profiled surfaces in order to increase the heat exchanging surface.

8. Safety structure according to any of the preceding claims, wherein said gas treatment channel (30) and said cooling channel (48) .extend generally vertically in said enclosure, providing generally vertical flow of flue gases and cooling media.

9. Safety structure according to claim 8, wherein the gas treatment channel (30¹, 30", 30¹¹¹) and the cooling channel (48¹, 48", 48¹") are arranged in sections that are placed in parallel to form a function of a plate heat exchanger.

10. Safety structure according to any of the preceding claims, wherein said gas treatment material elements (36) comprise granular lime (40) as treatment material.

11 . Safety structure according to claim 10, wherein said gas treatment material elements comprise a number of plates (38) positioned generally perpendicular to a flow of flue gases, said plates being provided with a plurality of passages and wherein the granular lime is placed on said plates.

12. Safety structure according to claim 11 , wherein said plates (48) further comprise bags (42) containing the granular lime, having a mesh size preventing the granular lime to fall through the plates or be blown away by the gas flow.

13. Safety structure according to any of the claim 11 - 12, wherein the granular lime (40) is placed on the plates leaving an area (44) uncovered for reducing pressure drop of the gas over the plates. Safety structure according to any of the preceding claims, wherein the cooling channel (48) comprises gaseous or fluid cooling media. Safety structure according to claim 14, wherein the media is forced through the cooling channel (48) with a flow force element (60). Safety structure according to any of the preceding claims, wherein the chamber (20) and at least sections of the gas treatment channel are covered with fire-resistant and -insulating material (26). Safety structure according to claim 16, wherein the material (26) comprises basalt fibre, perlite and soluble glass, for instance ExpanCore®. Safety structure according to any of the preceding claims, wherein the battery is arranged in a vehicle and the chamber (20) is designed to accommodate a vehicle.