Battery pack and electric vehicle

Abstract

The utility model provides a battery pack and an electric vehicle, and mainly solves the problem that potential safety hazards exist in exhaust of thermal runaway smoke after thermal runaway of an existing battery pack. The battery pack comprises a box body, a battery module, a cooling and filtering device and an ignition device, an inner cavity of the box body is divided into a battery bin and a fire-fighting bin through a partition plate. The battery module is arranged in the battery compartment; the cooling and filtering device is arranged in the fire-fighting bin, and the ignition device is installed on the box body. Before the thermal runaway flue gas is ignited by the ignition device, the cooling and filtering device cools the thermal runaway flue gas so as to reduce the temperature of the thermal runaway flue gas, meanwhile, the cooling and filtering device treats electrolyte and impurities carried in the thermal runaway flue gas, and when the treated thermal runaway flue gas enters the ignition device to be combusted, combustion flames are stable, so that the thermal runaway flue gas is ignited by the ignition device. And the defects of flame splashing, flame instability and the like generated when electrolyte and impurities in the thermal runaway flue gas are combusted together with combustible gas are overcome.

Description

Technical Field

[0001] The utility model belongs to the field of electric vehicle battery safety, and particularly relates to a battery pack and an electric vehicle. Background Art

[0002] The battery pack is an important part of an electric vehicle, mainly providing driving power for the electric vehicle. In order to pursue higher endurance, multiple single cells are closely arranged in the box body of the battery pack. The high-density arrangement makes the safety and thermal stability of the battery pack poor. At the same time, under the influence of factors such as overcharging, over-discharging, overheating, and mechanical collision, it is easy to cause the breakdown of the battery separator and internal short circuit of each single cell in the battery pack, resulting in thermal runaway of the battery pack. When the battery pack undergoes thermal runaway, a large amount of thermal runaway flue gas will be generated. After the high-temperature and high-pressure thermal runaway flue gas is discharged from the battery pack, it will pose a safety hazard. Summary of the Invention

[0003] To solve the problem that there is a safety hazard in the discharge of thermal runaway flue gas after the thermal runaway of the existing electric vehicle battery pack, the utility model provides a battery pack and an electric vehicle.

[0004] To achieve the above purpose, the technical solution of the utility model is as follows:

[0005] A battery pack includes a box body, a battery module, a cooling and filtering device, and an ignition device; the inner cavity of the box body is divided into a battery compartment and a fire protection compartment by a partition board; the battery module is arranged in the battery compartment; the cooling and filtering device is arranged in the fire protection compartment and includes at least one cooling and filtering tank. The flue gas inlet of the cooling and filtering tank is used to connect with the explosion vent on the partition board, and the flue gas outlet is connected with the ignition device; there is coolant in the cooling and filtering tank, which is used for cooling and filtering the thermal runaway flue gas discharged from the battery compartment; the ignition device is installed on the box body and is used for igniting the thermal runaway flue gas processed by the cooling and filtering tank.

[0006] Further, one-way valves are arranged at both the flue gas inlet and the flue gas outlet of the cooling and filtering tank.

[0007] Further, a shunt pipe is arranged in the cooling and filtering tank for shunting the thermal runaway flue gas entering the cooling and filtering tank.

[0008] Further, a filter plate is arranged in the battery compartment for filtering the thermal runaway flue gas discharged from the battery compartment.

[0009] Further, a flame retardant material is filled in the battery compartment, and the battery module is coated in the flame retardant fuel.

[0010] Further, an installation pipe connected to the outlet of the cooling and filtering tank is provided on the side wall of the box body; the ignition device includes a connection housing, an ignition assembly, and a flame arrester; one end of the connection housing is connected to the installation pipe, and the other end of the connection housing is connected to the flame arrester located outside the box body. A combustion area is formed between the flame arrester and the top plate of the connection housing. The connection housing is provided with a flue gas passage for delivering the thermally out-of-control flue gas to the combustion area, and the ignition assembly is used to ignite the thermally out-of-control flue gas in the combustion area.

[0011] Further, the connection housing is provided with a plurality of flue gas passages, and the flue gas passages are through holes provided on the side wall of the connection housing and longitudinally penetrating through the connection housing. The plurality of flue gas passages are all communicated with the combustion area and are used to disperse and introduce the thermally out-of-control flue gas into the combustion area.

[0012] Further, the flue gas passage includes a mixing passage and a first passage arranged in sequence. The mixing passage is communicated with the combustion area, and an oxygen mixing port communicated with the external environment is provided on the mixing passage.

[0013] Further, a protective housing is provided inside the connection housing. The ignition assembly includes a trigger and an igniter; the igniter includes an ignition needle, a high-voltage package, and a circuit board. The ignition needle is arranged in the combustion area, the high-voltage package and the circuit board are integrated in the protective housing, and the trigger is arranged at the end of the protective housing.

[0014] Further, the flame arrester includes a plurality of flame arrester mesh covers nested in sequence, and each flame arrester mesh cover is formed by metal wire weaving.

[0015] The present utility model also provides an electric vehicle, which includes the above battery pack, and the battery pack is arranged under the footrest of the electric vehicle.

[0016] Compared with the prior art, the technical solution of the present utility model has the following advantages:

[0017] 1. The utility model integrates a cooling and filtering device and an ignition device on the battery pack of an electric vehicle. When any single battery in the battery pack has a thermal runaway, the ignition device performs a controllable ignition treatment on the thermal runaway flue gas to avoid potential safety hazards caused by the discharge of the thermal runaway flue gas. Before the thermal runaway flue gas is ignited by the ignition device, the cooling and filtering device cools the thermal runaway flue gas to reduce its temperature, thereby preventing the high-temperature thermal runaway flue gas from damaging the parts in the ignition device. At the same time, the cooling and filtering device treats the electrolyte and impurities carried in the thermal runaway flue gas so that the treated thermal runaway flue gas becomes a gaseous substance. When the gaseous thermal runaway flue gas enters the ignition device for combustion, the combustion flame is relatively stable, avoiding defects such as flame splashing and unstable flame when the electrolyte and impurities in the thermal runaway flue gas burn together with combustible gases. In addition, after being cooled and filtered in the cooling and filtering device, the thermal runaway flue gas is discharged at a relatively stable flow rate, avoiding potential safety hazards such as sudden increase in instantaneous pressure of the thermal runaway flue gas, inability to be ignited in time, or sudden increase in combustion flame, and improving the safety of the battery pack during use.

[0018] 2. In the battery pack of the utility model, one-way valves are provided at both the flue gas inlet and the flue gas outlet of the cooling and filtering tank. The two one-way valves prevent the coolant in the cooling and filtering tank from entering the battery compartment and the ignition device, thus avoiding damage to the battery compartment and the ignition device. At the same time, the two one-way valves also prevent the coolant in the cooling and filtering tank from volatilizing. Therefore, after the battery pack is used for a long time, the coolant in the cooling and filtering device can continuously maintain a better treatment effect.

[0019] 3. In the battery pack of the utility model, a shunt pipe is provided in the cooling and filtering tank. The shunt pipe scatters and divides the thermal runaway flue gas, and the divided thermal runaway flue gas fully contacts the coolant in the cooling and filtering tank, thereby improving the treatment effect of the cooling and filtering tank and making the treatment of the thermal runaway flue gas more thorough.

[0020] 4. In the battery pack of the utility model, a filter plate is provided in the battery compartment. The filter plate treats the solid impurities in the thermal runaway flue gas in the battery compartment, further improving the treatment effect of the impurities in the thermal runaway flue gas.

[0021] 5. In the battery pack of the utility model, the connecting housing of the ignition device has a plurality of flue gas channels. The plurality of flue gas channels disperse and introduce the thermal runaway flue gas into the combustion zone, and the thermal runaway flue gas is dispersed and ignited, which can effectively reduce the flame height when the thermal runaway flue gas burns, so as to control the combustion flame within a certain height range and improve the safety of the entire ignition device during use.

[0022] 6. In the battery pack of the utility model, the flue gas channels are through holes provided on the side wall of the connecting housing and penetrating longitudinally. The flue gas channels with this structure are relatively simple to manufacture and process, and the outer shape of the connecting housing is also relatively beautiful.

[0023] 7. In the battery pack of the present utility model, the flue gas passage includes a mixing passage and a first passage that are connected in sequence from top to bottom. The oxygen mixing port transports external air into the mixing passage, where it is mixed with the thermal runaway flue gas input from the first passage and then transported to the combustion area for combustion. This way of mixing thermal runaway flue gas and oxygen before ignition makes the combustion of thermal runaway flue gas more complete, and the height of the combustion flame is further reduced.

[0024] 8. In the battery pack of the present utility model, the flame arrester includes a plurality of fireproof mesh covers nested in sequence. This flame arrester can not only prevent the combustion flame from overflowing but also isolate the heat generated during combustion, thereby further improving the safety of the ignition device during use.

[0025] Other advantages, objectives, and features of the present utility model will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present utility model. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Structural schematic diagram of the battery pack (two covers) in Embodiment 1;

[0028] Figure 2 Structural schematic diagram of the battery pack (one cover) in Embodiment 1;

[0029] Figure 3 Structural schematic diagram of the battery pack (omitting the cover) in Embodiment 1;

[0030] Figure 4 Structural schematic diagram of the cooling and filtering tank in Embodiment 1;

[0031] Figure 5 Explosion diagram of the battery pack in Embodiment 1;

[0032] Figure 6 Cross-sectional view of the ignition device in Embodiment 1;

[0033] Figure 7 For Figure 6 Partial enlarged view;

[0034] Figure 8 Cross-sectional view of the connection housing of the ignition device in Embodiment 1;

[0035] Figure 9 It is a schematic structural diagram of the battery pack in Embodiment 2;

[0036] Figure 10 It is a schematic structural diagram of the ignition device in Embodiment 2;

[0037] Figure 11 It is a cross-sectional view of the ignition device in Embodiment 2;

[0038] Figure 12 It is a schematic structural diagram of the electric vehicle in Embodiment 3;

[0039] Figure 13 It is a schematic installation diagram of the battery pack in the electric vehicle in Embodiment 3.

[0040] Reference numerals: 1 - box body, 2 - battery module, 3 - cooling and filtering device, 4 - ignition device, 5 - electric vehicle, 11 - partition board, 12 - cover plate, 13 - explosion vent, 14 - installation pipe, 15 - filter plate, 21 - single battery, 22 - battery management system, 31 - cooling and filtering tank, 32 - flue gas inlet, 33 - flue gas outlet, 34 - check valve, 35 - shunt pipe, 41 - connection housing, 42 - combustion area, 43 - ignition assembly, 44 - flame arrester, 45 - flue gas channel, 451 - first channel, 452 - mixing channel, 453 - oxygen mixing port, 411 - top plate, 412 - cylinder body, 413 - protective shell, 414 - connecting pipe, 415 - annular channel, 416 - flue gas cavity, 417 - smoke passing through hole, 431 - ignition needle, 432 - high-voltage package, 433 - circuit board, 434 - dry battery, 435 - trigger, 51 - footrest. Detailed implementation manners

[0041] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will describe in detail the specific implementation manners of the present utility model with reference to the accompanying drawings of the specification. Obviously, the described embodiments are a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0042] "In other embodiments" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that mutually excludes other embodiments. In the description of this specification, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. In the description of the present utility model, "a plurality" means two or more, unless otherwise specifically defined.

[0043] In the description of this specification, unless otherwise clearly specified and defined, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, indirectly connected through an intermediate member, or the internal communication of two components. For those of ordinary skill in the art, the specific meaning of the above terms in this application can be understood according to specific circumstances.

[0044] At the same time, in the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "top, bottom, inner, and outer" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0045] The battery pack is an important part of an electric vehicle, mainly providing driving power for the electric vehicle. Existing battery packs generally include multiple single cells (the single cells can be existing single cylindrical cells, square shell cells, soft-pack cells, etc.) and a battery management system. The multiple single cells are connected in series, parallel, or in series-parallel in a box to meet different capacity requirements of the battery pack. The battery management system is mainly used to maintain and manage each single cell to prevent phenomena such as overcharging and over-discharging. During the use of the above multiple single cells, or during overcharging, over-discharging, and mechanical collisions, thermal runaway is likely to occur, generating thermal runaway smoke. This thermal runaway smoke accumulates outside the battery pack, posing a safety hazard.

[0046] Based on this, the present utility model provides a battery pack, which is integrally integrated with a cooling and filtering device and an ignition device. The ignition device performs a controllable ignition treatment on the thermal runaway smoke to avoid the safety hazard caused by the discharge of the thermal runaway smoke. Before the thermal runaway smoke is ignited by the ignition device, the cooling and filtering device cools the thermal runaway smoke to reduce the temperature of the thermal runaway smoke, thereby avoiding damage to the parts in the ignition device by the high-temperature thermal runaway smoke. At the same time, the cooling and filtering device treats the electrolyte and impurities carried in the thermal runaway smoke so that the treated thermal runaway smoke is a gaseous substance. When the gaseous thermal runaway smoke enters the ignition device for combustion, the combustion flame is relatively stable, avoiding defects such as flame splashing and unstable flame when the electrolyte and impurities in the thermal runaway smoke burn together with the combustible gas. In addition, after the thermal runaway smoke is cooled and filtered in the cooling and filtering device, it is discharged at a relatively stable flow rate, avoiding the sudden increase in the instantaneous pressure of the thermal runaway smoke, the safety hazard that the thermal runaway smoke cannot be ignited in time or the combustion flame suddenly becomes larger, and improving the safety of the battery pack during use.

[0047] Embodiment 1

[0048] As Figures 1 to 8As shown in the figure, this embodiment provides a battery pack, which includes a box body 1, a battery module 2, a cooling and filtering device 3, and an ignition device 4. The inner cavity of the box body 1 is divided into a battery compartment and a fire protection compartment by a partition 11. The battery module 2 is the power supply main body of the battery pack and is arranged in the battery compartment. The cooling and filtering device 3 is arranged in the fire protection compartment and includes at least one cooling and filtering tank 31. The cooling and filtering tank 31 is provided with a flue gas inlet 32 and a flue gas outlet 33. The flue gas inlet 32 is connected to the explosion vent 13 on the partition 11, and the flue gas outlet 33 is connected to the ignition device 4. The cooling and filtering tank 31 contains a coolant for cooling and filtering the thermal runaway flue gas discharged from the battery compartment. The ignition device 4 is installed on the box body 1 for igniting the thermal runaway flue gas processed by the cooling and filtering tank 31.

[0049] In this embodiment, a set of cooling and filtering device 3 and an ignition device 4 are added to the box body 1 of the existing battery pack. When a single battery in the battery pack undergoes thermal runaway, the thermal runaway flue gas first enters the cooling and filtering tank 31 for cooling and filtering to completely remove the electrolyte and solid impurities, and then the ignition device 4 is started to controllably ignite the cooled and filtered thermal runaway flue gas, thereby reducing the safety hazard of the battery pack's thermal runaway.

[0050] As Figure 3 shown in the figure, the box body 1 in this embodiment is a closed box body, which mainly integrally installs the battery module 2, the cooling and filtering device 3, and the ignition device 4, and also provides safety protection for the battery module 2 to prevent the battery module 2 from being impacted, vibrated, dropped, etc. in the external environment. The shape and size of the box body 1 can be designed according to the application scenario of the battery module 2 into a shape convenient for placement, such as a cylinder, a prism, a cube, etc. In actual use, for the convenience of installation and placement, the box body 1 is generally a rectangular shell. In addition, to avoid the risk of short circuit between the battery module 2 in the box body 1 and external devices, the above box body 1 is generally made of an insulating material with high stiffness.

[0051] As Figure 3 and Figure 5 shown in the figure, the inner cavity of the above box body 1 is divided into a battery compartment and a fire protection compartment by a partition 11. When specifically setting, the battery compartment and the fire protection compartment can be arranged side by side or one above the other, and are specifically set according to the use scenario and size of the battery pack. The box body 1 in this embodiment can be specifically realized by the following structure:

[0052] First, as Figure 2 and Figure 3 shown in the figure, the rectangular shell is a structure with an open top. The partition 11 is integrally formed with the rectangular shell, and the open end of the rectangular shell is sealed by a cover plate 12.

[0053] Second, as Figure 1 and Figure 5As shown in the figure, the rectangular housing has an open top end. The partition 11 is integrally formed with the rectangular housing. The open end of the rectangular housing is sealed by two cover plates 12. One cover plate 12 seals the battery compartment, and the other cover plate 12 seals the fire compartment. In the structure of the housing 1 with such two cover plates 12, it is convenient to assemble and repair the devices in the battery compartment and the fire compartment respectively.

[0054] As Figure 3 shown in the figure, the battery module 2 in the battery compartment mainly includes a battery management system 22, a terminal block, and a plurality of single cells 21. The plurality of single cells 21 are connected in series to meet different capacity requirements. The single cells 21 can be existing single cylindrical cells, square shell cells, or soft package cells. In this embodiment, the capacity requirements of the battery pack are met by a plurality of series-connected cylinders. The battery module 2 is electrically connected to an external circuit or an electrical device through the terminal block. The terminal block can be arranged on the housing 1 and exposed outside the housing 1 for convenient charging and discharging. The battery management system 22 (BMS) mainly monitors the working states of the single cells 21.

[0055] In addition, a positioning structure can be provided in the battery compartment to position and install the battery module 2, and at the same time, it also prevents the battery module 2 from shaking significantly in the housing 1. In addition, a flame retardant material can be filled in the above-mentioned battery compartment, and the battery module 2 is coated in the flame retardant fuel. The flame retardant material not only prevents the spread of thermal runaway in the battery compartment, but also further prevents the battery compartment from catching fire.

[0056] As Figure 3 shown in the figure, in this embodiment, a filter plate 15 can also be provided in the battery compartment. The filter plate 15 is specifically a foam copper plate. The thermal runaway smoke in the battery compartment first passes through the filter plate 15, and then is discharged from the battery compartment through the explosion vent 13. The filter plate 15 filters the electrolyte and solid impurities in the thermal runaway smoke. The filtered thermal runaway smoke is discharged into the cooling and filtering tank 31 through the explosion vent 13 for further treatment, thereby improving the treatment effect on the thermal runaway smoke.

[0057] The cooling and filtering device 3 in this embodiment includes at least one cooling and filtering tank 31. The number of cooling and filtering tanks 31 can be set according to the number and requirements of the single cells 21 in the battery pack. Each cooling and filtering tank 31 is provided with a flue gas inlet 32 and a flue gas outlet 33. If there are multiple cooling and filtering tanks 31, the flue gas inlets 32 and flue gas outlets 33 of adjacent cooling and filtering tanks 31 can be connected in series through pipelines. After series connection, the flue gas inlet 32 of the first cooling and filtering tank 31 is connected to the explosion vent 13 on the partition plate 11, and the flue gas outlet 33 of the last cooling and filtering tank 31 is connected to the ignition device 4. In actual use, considering cost and installation space, generally one cooling and filtering tank 31 is the best. At this time, the flue gas inlet 32 of this cooling and filtering tank 31 is connected to the explosion vent 13 on the partition plate 11, and the flue gas outlet 33 is connected to the ignition device 4.

[0058] In this embodiment, the shape of the cooling and filtering tank 31 is not limited, and it can be a rectangular tank body, a circular tank body, an elliptical tank body, etc. The best is to use a circular tank body, and the circular tank body has good pressure-bearing performance. The cooling and filtering tank 31 is filled with a coolant, and the coolant is a liquid such as water, alkali solution, fluorinated liquid, etc. The coolant cools the heat runaway flue gas discharged from the battery compartment. At the same time, when the heat runaway flue gas passes through the coolant, the electrolyte and impurities carried in the heat runaway flue gas are filtered and retained in the coolant, which can effectively avoid problems such as flame splash and flame overflow caused by the simultaneous combustion of the electrolyte and impurities with the combustible gas. If the coolant is an alkali solution, the alkali solution can not only remove the solid impurities and electrolyte in the heat runaway flue gas, but also adsorb part of the heat runaway flue gas, so that the subsequent ignition device 4 can fully process the remaining heat runaway flue gas.

[0059] When the flue gas inlets 32 and flue gas outlets 33 on each of the above-mentioned cooling and filtering tanks 31 are specifically set, the flue gas inlet 32 is generally set at the bottom of the cooling and filtering tank 31. At this time, the heat runaway flue gas can smoothly pass through the coolant, and then the coolant can fully process the heat runaway flue gas. The flue gas outlet 33 is generally set at the top of the cooling and filtering tank 31. At this time, the gas in the heat runaway flue gas can smoothly discharge from the cooling and filtering tank 31. At the same time, the heat runaway flue gas is not likely to carry out the liquid and impurities in the cooling and filtering tank 31 out of the cooling and filtering tank 31.

[0060] Such as Figure 3As shown in the figure, when the cooling and filtering tank 31 in this embodiment is specifically connected, check valves 34 are provided at both the flue gas inlet 32 and the flue gas outlet 33 of the cooling and filtering tank 31. The two check valves 34 prevent the coolant in the cooling and filtering tank 31 from flowing into the battery compartment and the ignition device 4, which may damage the battery modules in the battery compartment and the ignition device 4. At the same time, the two check valves 34 can also seal the coolant in the cooling and filtering tank 31 to prevent the coolant from volatilizing. After the battery pack is used for a long time, the coolant in the cooling and filtering device 3 can continuously maintain a better treatment effect. In addition, the check valve 34 at the flue gas outlet 33 can ensure the flow direction of the thermal runaway flue gas and prevent the occurrence of backfire phenomenon.

[0061] When a check valve 34 is provided at the flue gas inlet 32 of the cooling and filtering tank 31, the explosion vent 13 on the partition 11 is directly connected to the check valve 34, and the explosion vent 13 is sealed through the check valve 34; if no check valve 34 is provided at the flue gas inlet 32 of the cooling and filtering tank 31, an explosion-proof part is provided on the explosion vent 13 of the partition 11, and the explosion-proof part can specifically be an explosion-proof membrane or an explosion-proof valve. At the same time, the installation height of the explosion vent is greater than the liquid level height of the coolant in the cooling and filtering tank 31. When the battery pack is in normal use, the explosion-proof part seals the explosion vent 13. When a single battery 21 in the battery compartment undergoes thermal runaway and the pressure in the battery compartment reaches a certain value, the explosion-proof part is opened, and the thermal runaway flue gas is discharged through the explosion vent 13. Similarly, if no check valve 34 is provided at the flue gas outlet 33 of the cooling and filtering tank 31, at this time, the installation height of the ignition device 4 is greater than the liquid level height of the coolant in the cooling and filtering tank 31 to prevent the coolant in the cooling and filtering tank 31 from entering the ignition device 4.

[0062] As Figure 4 shown in the figure, to further improve the treatment effect of the coolant on the thermal runaway flue gas, a shunt pipe 35 is provided in the cooling and filtering tank 31 in this embodiment. The inlet of the shunt pipe 35 is connected to the flue gas inlet 32, and the outlet is immersed in the coolant. At the same time, a plurality of through holes are opened on the side wall of the shunt pipe 35, and the thermal runaway flue gas is dispersed in the coolant through the plurality of through holes on the shunt pipe 35. The shunt pipe 35 breaks up and shunts the thermal runaway flue gas. After the shunted thermal runaway flue gas is fully contacted with the coolant in the cooling and filtering tank 31, the treatment effect of the cooling and filtering tank 31 is improved, and the treatment of the thermal runaway flue gas is more thorough. It should be noted that when there is a shunt pipe 35 in the cooling and filtering tank 31, the flue gas inlet 32 can be provided at the top or side wall of the cooling and filtering tank 31.

[0063] Based on the above structure, the cooling and filtering tank 31 in this embodiment has the following functions:

[0064] First, when the thermal runaway flue gas passes through the cooling and filtering tank 31, the peak pressure of the thermal runaway flue gas decreases. When the subsequent ignition device 4 ignites, the flame is relatively stable. At the same time, it also avoids the sudden increase in the instantaneous pressure of the thermal runaway flue gas, and the safety hazards that the thermal runaway flue gas cannot be ignited in time or the combustion flame suddenly becomes larger.

[0065] Second, the electrolyte and impurities carried in the thermal runaway flue gas are filtered, so that the treated thermal runaway flue gas is a gaseous substance. When the gaseous thermal runaway flue gas enters the ignition device 4 for combustion, the combustion flame is relatively stable, avoiding defects such as flame splashing and unstable flame when the electrolyte and impurities in the thermal runaway flue gas burn together with the combustible gas, and improving the safety of the thermal runaway flue gas during combustion.

[0066] Third, the thermal runaway flue gas discharged from the battery compartment is cooled to remove the high-temperature property of the thermal runaway flue gas, avoiding damage to the components in the ignition device 4 caused by the high-temperature thermal runaway flue gas.

[0067] As Figure 5 shown, in this embodiment, the ignition device 4 is connected to the flue gas outlet 33 of the cooling and filtering tank 31, and the ignition device 4 ignites the thermal runaway flue gas treated by the cooling and filtering tank 31. When the ignition device 4 is installed, an installation pipe 14 connected to the outlet of the cooling and filtering tank 31 is provided on the side wall of the box body 1, and the ignition device 4 is fixed on the box body 1 through the installation pipe 14.

[0068] As Figure 3 、 Figures 5 to 8 shown, the ignition device 4 in this embodiment mainly includes a connecting shell 41, a flame arrester 44 and an ignition assembly 43; one end of the connecting shell 41 is connected to the installation pipe 14, and the other end of the connecting shell 41 is connected to the flame arrester 44. The flame arrester 44 is located outside the box body and forms a combustion area 42 with the top plate 411 of the connecting shell 41. The combustion area 42 provides a combustion space for the combustion of the thermal runaway flue gas. At the same time, a flue gas channel 45 communicating with the combustion area 42 is provided on the connecting shell 41, and the flue gas channel 45 conveys the thermal runaway flue gas into the combustion area 42, and the ignition assembly 43 is used to ignite the thermal runaway flue gas in the combustion area 42.

[0069] As Figure 7 and Figure 8As shown in the figure, in this embodiment, the connection housing 41 includes a cylinder body 412, a top plate 411 and a connecting pipe 414. The cylinder body 412 has a structure with one end open and the other end having a bottom plate. The open end of the cylinder body 412 is connected to the installation pipe 14, and the bottom plate of the cylinder body 412 is connected to the top plate 411 through the connecting pipe 414. At the same time, a smoke passing through hole 417 is provided on the bottom plate of the cylinder body 412. At this time, the smoke passage 45 of the connection housing 41 is mainly formed by the inner cavity of the cylinder body 412, the smoke passing through hole 417, and the inner cavity of the connecting pipe 414 that are connected in sequence. After the heat runaway smoke flows out from the smoke outlet 33 of the cooling and filtering tank 31 and enters the installation pipe 14, it enters the inner cavity of the cylinder body 412 through the installation pipe 14, then enters the connecting pipe 414 through the smoke passing through hole 417, and finally enters the combustion area 42 through the through hole on the top plate 411 and is ignited by the ignition assembly 43.

[0070] In addition, a plurality of oxygen mixing ports 453 are provided on the side wall of the above-mentioned connecting pipe 414. The oxygen mixing ports 453 introduce external air into the connecting pipe 414. The heat runaway smoke and the external air are mixed in the connecting pipe and then enter the combustion area 42 together, thereby realizing the stable and safe combustion of the heat runaway smoke.

[0071] As Figure 6 and Figure 7 shown in the figure, in this embodiment, the ignition assembly 43 mainly includes a trigger 435 and an igniter; the igniter is used to ignite the heat runaway smoke in the combustion area 42. The above-mentioned igniter can be realized by different structures. For example, an existing arc igniter or a resistance wire igniter can be used. In this embodiment, an arc igniter can be specifically used. The arc igniter can be specifically powered by a dry battery 434 or an external circuit. The above-mentioned arc igniter specifically includes an ignition needle 431, a high-voltage package 432, a circuit board 433, etc. During specific installation, the ignition needle 431 is installed in the combustion area 42, and the high-voltage package 432 and the circuit board 433 are integrated together and installed outside the combustion area 42 to avoid damage to them caused by the combustion flame or heat of the heat runaway smoke. For example, the above-mentioned high-voltage package 432 and the circuit board 433 can be integrated in the fire protection compartment of the box body 1.

[0072] As Figure 7 and Figure 8 shown in the figure, in this embodiment, a protective shell 413 is provided in the cavity after the installation pipe 14 is connected to the cylinder body 412. The high-voltage package 432, the circuit board 433 and the dry battery 434 of the above-mentioned igniter can be arranged in the inner cavity of the protective shell 413. This installation method can not only protect the high-voltage package 432, the circuit board 433, the dry battery 434 and the trigger 435 from being damaged during use or transportation when they are installed outside the connection housing 41, but also realize the integrated installation of each device, reducing the installation space of the entire device.

[0073] After adding the above-mentioned protective case 413, an annular channel 415 is formed between the outer side wall of the protective case 413 and the inner side wall of the cylinder 412. At the same time, a flue gas cavity 416 communicating with the annular channel 415 is formed between the end of the cylinder 412 and the bottom plate of the protective case 413. The flue gas cavity 416 is communicated with the connecting pipe 414 through a smoke passing through hole 417 provided on the bottom plate of the cylinder 412. At this time, the flue gas channel 45 is mainly composed of an annular channel 415, a flue gas cavity 416, a smoke passing through hole 417, and the inner cavity of the connecting pipe 414 that are connected in sequence.

[0074] The above-mentioned trigger 435 is used to start the igniter when the thermal runaway flue gas passes through the connecting housing 41. The trigger 435 can specifically adopt a sensor. When the battery pack undergoes thermal runaway and generates thermal runaway flue gas, the sensor monitors the flow rate, pressure, temperature, gas composition, etc. of the thermal runaway flue gas in real time. When the monitored data exceeds the threshold, a signal is sent to the igniter, thereby starting ignition. The sensor in this embodiment can specifically adopt an air flow sensor, a flow sensor, a pressure sensor, a temperature sensor, etc. The air flow sensor can specifically adopt an e-cigarette microphone head, etc. As Figure 7 shown, when the trigger 435 is specifically installed, the air flow sensor is arranged inside the connecting housing 41 or at the bottom of the protective case 413, and can directly receive the direct impact trigger of the thermal runaway flue gas, ensuring that the igniter can be triggered in a timely and reliable manner after the battery undergoes thermal runaway. The flow sensor, pressure sensor, or temperature sensor can be installed at the flue gas outlet 33 of the cooling and filtering tank 31 to start the igniter in a timely manner when the thermal runaway flue gas passes through the cooling and filtering tank 31.

[0075] As Figure 5 and Figure 6 shown, in this embodiment, the flame arrester 44 forms a combustion zone 42 when the thermal runaway flue gas burns safely. The flame arrester 44 prevents the surrounding substances from being damaged by the high temperature during the combustion of the thermal runaway flue gas, and at the same time can also prevent rainwater from entering the ignition head. The flame arrester 44 can be realized by the following structure:

[0076] The flame arrester 44 in this embodiment is a conical tube structure. One end of the conical tube is fixed on the connecting housing 41. The conical tube is a pipeline with a certain length, ensuring that the flue gas burns fully in the conical tube. Its length can effectively ensure that when the combustion is intense, the flame during the combustion of the thermal runaway flue gas will not overflow.

[0077] When the above-mentioned flame arrester 44 is installed, it can be directly sleeved on the outside of the connecting housing 41. At this time, an annular connecting boss is provided on the outside of the connecting housing 41, and there is an external thread on the annular connecting boss. The inner wall of the flame arrester 44 has an internal thread, and the flame arrester 44 is threadedly connected with the annular connecting protrusion. Or, a connecting plate can also be provided at the open end of the bottom of the flame arrester 44, and the flame arrester 44 is fixed to the top plate 411 of the connecting housing 41 through the connecting plate and bolts.

[0078] Example 2

[0079] The battery pack in this embodiment is similar in structure to the battery pack in Embodiment 1. The difference from the battery pack in Embodiment 1 is that the ignition device structure in this embodiment is different.

[0080] As Figures 9 to 11 shown, the ignition device 4 in this embodiment mainly includes a connecting housing 41, a flame arrester 44 and an ignition assembly 43; the flame arrester 44 is located outside the box body, is connected to the connecting housing 41, and forms a combustion area 42 with the top plate 411 of the connecting housing 41. The combustion area 42 provides a combustion space for the combustion of the thermal runaway flue gas; the connecting housing 41 is arranged in the installation pipe 14, and a plurality of flue gas channels 45 communicating with the combustion area 42 are arranged on the connecting housing 41. The flue gas channels 45 convey the thermal runaway flue gas into the combustion area 42; the ignition assembly 43 is used to ignite the thermal runaway flue gas in the combustion area 42.

[0081] As Figures 9 to 11 shown, the connecting housing 41 in this embodiment is a cylindrical structure with a top plate 411. The top plate 411 and the flame arrester 44 above the top plate 411 form a combustion area 42. A plurality of flue gas channels 45 are arranged on the side wall of the connecting housing 41. The flue gas channels 45 are through holes arranged on the side wall of the connecting housing 41 and longitudinally penetrating through the connecting housing 41. A plurality of flue gas channels 45 penetrate through in the longitudinal direction of the cylinder and communicate with the combustion area 42 at the top of the connecting housing 41. In this embodiment, a plurality of flue gas channels 45 are arranged on the connecting housing 41, and a plurality of flue gas channels 45 are all communicated with the combustion area 42, which are used to disperse and introduce the thermal runaway flue gas into the combustion area 42. The plurality of flue gas channels 45 disperse and introduce the thermal runaway flue gas into the combustion area 42, and the thermal runaway flue gas is dispersed and burned in the combustion area 42. Compared with the centralized single combustion point, the combustion flame of the dispersed combustion is relatively small, which can reduce the flame height when the thermal runaway flue gas burns, control the flame height of the thermal runaway flue gas combustion within a certain range, and improve the safety when the entire thermal runaway flue gas is ignited.

[0082] As Figure 11 shown, the above-mentioned flue gas channel 45 can be mainly realized in the following ways:

[0083] First, a plurality of convex ribs extending along the length direction are arranged on the side wall of the connecting housing 41. The flue gas channel 45 is a through hole arranged on the convex rib and longitudinally penetrating. During specific processing, since the flue gas channel 45 is processed on the convex rib, the requirement for the side wall thickness of the connecting housing 41 is relatively low;

[0084] Second, a plurality of through holes longitudinally penetrating are processed on the side wall of the connecting housing 41 to form the flue gas channel 45; when processing the flue gas channel 45 with this kind of structure, it is required that the side wall of the connecting housing 41 has a certain thickness;

[0085] Among the above various structural forms, the second structure which is relatively simple in manufacturing and processing is preferably selected. During specific processing, the number of flue gas channels 45 is 4 to 10, preferably 5 to 6. The multiple flue gas channels 45 can be evenly distributed along the circumference of the connecting housing 41, and are preferably arranged in a circular shape with the longitudinal axis of the connecting housing 41 as the center. This setting enables multiple uniformly dispersed combustion points to be formed when the thermal runaway flue gas is ignited, and the combustion flame heights of the respective dispersed combustion points are relatively uniform.

[0086] As Figure 11 shown, to further reduce the flame height during the combustion of the thermal runaway flue gas, the thermal runaway flue gas and oxygen can be mixed before ignition. At the same time, after passing through the mixed oxygen, the combustion of the thermal runaway flue gas is more complete. Specifically, the above flue gas channel 45 can include a first channel 451 and a mixing channel 452 that are connected in sequence. The mixing channel 452 is connected to the combustion zone 42. The mixing channel 452 is provided with an oxygen mixing port 453 communicating with the external environment. The oxygen mixing port 453 conveys the external air into the mixing channel 452, mixes it with the thermal runaway flue gas input from the first channel 451, and then conveys it to the combustion zone 42.

[0087] Preferably, the central axes of the above first channel 451 and mixing channel 452 are coaxial. The cross-sectional size of the first channel 451 is smaller than that of the mixing channel 452, and the length of the first channel 451 is greater than that of the mixing channel 452. This setting can not only increase the size of the oxygen mixing port 453 and ensure the oxygen mixing ratio of the thermal runaway flue gas. At the same time, since both the first channel 451 and the mixing channel 452 are structures similar to capillary tubes, the capillary tubes can increase the flow velocity of the thermal runaway flue gas, ensure better oxygen mixing of the thermal runaway flue gas, and better oxygen mixing makes the combustion of the thermal runaway flue gas more complete, reducing the generation of yellow fire and even enabling flameless combustion.

[0088] During actual processing, since the size of the mixing channel 452 is larger than that of the first channel 451, the preferred solution in this embodiment is: the first channel 451 is formed by a through hole provided on the side wall of the connecting housing 41; the mixing channel 452 is formed by a through hole provided on the rib of the connecting housing 41. This structure can not only ensure the strength of the connecting housing 41, but also increase the number of oxygen mixing ports 453 by arranging the mixing channel 452 on the rib.

[0089] In this embodiment, the ignition assembly 43 mainly includes a trigger and an igniter; the igniter is used to ignite the thermal runaway flue gas in the combustion area 42, and the trigger is used to start the igniter when the thermal runaway flue gas passes through the connection housing 41. The specific structures and installation methods of the trigger and the igniter are the same as those in Embodiment 1, and will not be described in detail in this embodiment. In this embodiment, since the flue gas passage 45 is preferably arranged on the side wall of the connection housing 41, at this time, the connection housing 41 can be processed into a hollow structure, and the high-voltage package, circuit board and dry battery of the above igniter can be arranged in the inner cavity of the connection housing 41.

[0090] In this embodiment, the flame arrester 44 is located outside the box body and has a combustion area 42 when the thermal runaway flue gas burns safely. The flame arrester 44 prevents the surrounding substances from being scalded by the high temperature during the combustion of the thermal runaway flue gas, and can also prevent rainwater from entering the igniter head. The flame arrester 44 can be realized by the following structures:

[0091] First, the flame arrester 44 is a cylindrical structure with an open bottom, and air holes are provided on the side wall and the top of the cylinder. To maintain aesthetics and installation convenience, the shape of the flame arrester 44 is preferably the same as that of the connection housing 41. The flame arrester 44 can not only prevent the flame from overflowing, but also isolate the heat generated during combustion;

[0092] Second, as Figure 11 shown, the flame arrester 44 includes a plurality of flame arrester mesh covers nested in sequence. Each flame arrester mesh cover is formed by weaving metal wires, specifically by weaving heat-insulating iron wire meshes; when the thermal runaway flue gas enters the combustion area 42 and is ignited by the ignition assembly 43, a combustion flame will be generated. Under normal circumstances, the combustion flame has a relatively high combustion temperature, and the longer the combustion flame lasts, the higher the temperature will be, and it is very easy to burn through a single-layer flame arrester mesh cover. Therefore, two or more layers of flame arrester mesh covers are designed, so as to ensure that the combustion flame burns inside the flame arrester mesh cover. The multi-layer flame arrester mesh cover can effectively reduce the probability that the high-temperature flame burns through the mesh cover and the flame overflows. In addition, the multi-layer flame arrester mesh cover can also isolate the heat generated during the combustion of the thermal runaway flue gas and improve the safety of the device during use.

[0093] When the above flame arrester 4 is installed, it can be directly sleeved on the outside of the connection housing U. At this time, an annular connection boss is provided on the outside of the connection housing 41, and there is an external thread on the annular connection boss. The inner wall of the flame arrester 44 has an internal thread, and the flame arrester 44 is threadedly connected to the annular connection protrusion. Alternatively, a connecting plate can also be provided at the open end of the bottom of the flame arrester 44, and the flame arrester 44 is fixed to the top plate A11 of the connection housing 41 through the connecting plate and bolts.

[0094] Embodiment 3

[0095] This embodiment provides an electric vehicle, which includes the battery pack in Embodiment 1 or Embodiment 2. The battery pack is installed on the electric vehicle 5 to supply power to the electrical devices of the electric vehicle 5 and at the same time provide driving power for the electric vehicle.

[0096] In this embodiment, the electric vehicle 5 integrates the cooling and filtering device 3 and the ignition device 4 on the battery pack of the electric vehicle 5. When a thermal runaway occurs in the battery pack of the electric vehicle 5 and thermal runaway flue gas is generated, the thermal runaway flue gas enters the cooling and filtering device 3. After being processed in the cooling and filtering device 3, it enters the ignition device 4. The ignition device 4 performs a safe and controllable ignition treatment on the remaining thermal runaway flue gas to reduce the safety hazards generated after the thermal runaway of the battery pack.

[0097] As Figure 12 and Figure 13 shown, during specific installation, the battery pack can be installed under the seat of the electric vehicle 5 or under the footrest 51. At this time, the flame arrester 44 of the ignition device 4 is located on one side of the rear wheel of the electric vehicle 5 to prevent the discharged thermal runaway airflow from burning passengers or causing damage to the electric vehicle 5.

Claims

1. A battery pack, characterized in that, It includes a box body, a battery module, a cooling and filtering device, and an ignition device; The inner cavity of the box body is separated into a battery compartment and a fire protection compartment by a partition board; The battery module is arranged in the battery compartment; The cooling and filtering device is arranged in the fire protection compartment and includes at least one cooling and filtering tank. The flue gas inlet of the cooling and filtering tank is used to connect with the explosion vent on the partition board, and the flue gas outlet is connected with the ignition device; there is coolant in the cooling and filtering tank, which is used for cooling and filtering the thermally out-of-control flue gas discharged from the battery compartment; The ignition device is installed on the box body and is used for igniting the thermally out-of-control flue gas processed by the cooling and filtering tank.

2. The battery pack according to claim 1, wherein One-way valves are arranged at both the flue gas inlet and the flue gas outlet of the cooling and filtering tank.

3. The battery pack according to claim 2, wherein A shunt pipe is arranged in the cooling and filtering tank and is used for shunting the thermally out-of-control flue gas entering the cooling and filtering tank.

4. The battery pack according to claim 1, characterized in that, A filter plate is arranged in the battery compartment and is used for filtering the thermally out-of-control flue gas discharged from the battery compartment.

5. The battery pack according to claim 4, characterized in that, The battery compartment is filled with a flame retardant material, and the battery module is coated in the flame retardant fuel.

6. The battery pack according to any one of claims 1 to 5, characterized in that An installation pipe connected to the outlet of the cooling and filtering tank is arranged on the side wall of the box body; the ignition device includes a connection housing, an ignition component, and a flame arrester; one end of the connection housing is connected to the installation pipe, and the other end of the connection housing is connected to the flame arrester located outside the box body. A combustion area is formed between the flame arrester and the top plate of the connection housing. The connection housing is provided with a flue gas passage for transporting the thermally out-of-control flue gas to the combustion area, and the ignition component is used for igniting the thermally out-of-control flue gas in the combustion area.

7. The battery pack according to claim 6, wherein, The connection housing is provided with a plurality of flue gas passages, and the flue gas passages are through holes arranged on the side wall of the connection housing and longitudinally penetrating through the connection housing. A plurality of flue gas passages are all communicated with the combustion area and are used for dispersedly introducing the thermally out-of-control flue gas into the combustion area.

8. The battery pack according to claim 7, characterized in that, The flue gas passage includes a mixing passage and a first passage arranged in sequence. The mixing passage is communicated with the combustion area, and an oxygen mixing port communicated with the external environment is arranged on the mixing passage.

9. The battery pack according to claim 8, characterized in that, A protective housing is arranged in the connection housing. The ignition component includes a trigger and an igniter; the igniter includes an ignition needle, a high-voltage package, and a circuit board. The ignition needle is arranged in the combustion area, the high-voltage package and the circuit board are integrated in the protective housing, and the trigger is arranged at the end of the protective housing.

10. The battery pack according to claim 6, characterized in that, The flame arrester includes a plurality of flame arrester mesh covers nested in sequence, and each flame arrester mesh cover is formed by metal wire weaving.

11. An electric vehicle, characterized in that, [[ID=

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