Thermal runaway fume and gas treatment apparatus and electric device

Abstract

The present application discloses a thermal runaway fume and gas treatment apparatus and an electric device. The thermal runaway fume and gas treatment apparatus mixes thermal runaway fumes and gases generated by a lithium ion battery with a safety gas to form a mixed gas, and then discharges the mixed gas to an external environment, thereby eliminating the possibility of explosion after the thermal runaway fumes and gases are discharged to the external environment.

Description

A thermal runaway flue gas treatment device and electrical equipment Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a thermal runaway flue gas treatment device and electrical equipment. Background Technology

[0002] Lithium-ion batteries, as a highly efficient and portable energy storage device, have a wide range of applications. They are mainly used in electric vehicles, energy storage devices, aerospace, and other fields.

[0003] However, lithium-ion batteries may experience thermal runaway due to mechanical, electrical, and thermal abuse, as well as their inherent defects. If thermal runaway occurs and is not effectively handled, it can cause safety accidents and threaten the personal safety of people in the vicinity. Furthermore, the fumes from thermal runaway contain flammable gases, and if not dealt with in time, the probability of combustion and explosion is relatively high.

[0004] Application content

[0005] To address the safety hazards posed by thermal runaway in existing lithium-ion batteries, this application provides the following solutions for thermal runaway flue gas treatment devices and electrical equipment. These devices mix the thermal runaway flue gas generated by lithium-ion batteries with a safety gas to form a mixed gas before releasing it into the external environment, thereby avoiding the possibility of an explosion after the thermal runaway flue gas is released into the external environment.

[0006] The thermal runaway flue gas treatment device for the first scheme is as follows:

[0007] The thermal runaway gas treatment device of this solution mixes the thermal runaway gas generated by the lithium-ion battery with a safety gas to form a mixed gas before releasing it into the external environment. The concentration of flammable gas in the mixed gas is below the lower explosive limit. Before releasing the thermal runaway gas generated after a battery thermal runaway into the external environment, this application mixes it with a safety gas to dilute the concentration of flammable gas in the thermal runaway gas. This concentration ensures that the flammable gas concentration is below the lower explosive limit, thereby avoiding the possibility of an explosion after the thermal runaway gas is released into the external environment.

[0008] Specifically, the thermal runaway flue gas treatment device used in this solution includes a mixed exhaust unit, which has the following three forms:

[0009] The first configuration is as follows: The mixed exhaust unit includes a three-way pipe assembly and a primary exhaust fan. The three-way pipe assembly includes three interconnected pipes: a first pipe, a second pipe, and a third pipe. The first pipe serves as the mixed gas exhaust pipe and is equipped with a primary exhaust fan. The second pipe is used to introduce thermal runaway gas, and the third pipe is used to introduce safety gas. When the device is operating, if thermal runaway of the battery is detected, the primary exhaust fan starts working. The thermal runaway gas and outside air enter the first pipe to form a mixed gas, which is then discharged into the external environment through the first pipe. By pre-setting the diameters of the second and third pipes, the concentration of combustible gas after the air and thermal runaway gas mixture is controlled to be below the lower explosive limit before being discharged into the external environment through the first pipe. In this first configuration, a secondary exhaust fan can be installed on the third pipe. By activating the secondary exhaust fan, the gas flow rate per unit time in the third pipe can be increased, rapidly reducing the concentration of combustible gas in the mixed gas and further improving the safety of the mixed gas discharged into the external environment.

[0010] The second form is as follows: The mixed exhaust unit includes a mixing chamber, a safety gas source, and a mixed gas exhaust pipe. The mixing chamber is equipped with a thermal runaway flue gas inlet and a mixed gas exhaust outlet, with the mixed gas exhaust pipe installed at the exhaust outlet. The safety gas source injects inert gas into the mixing chamber. During operation, when thermal runaway of the battery is detected, the thermal runaway flue gas enters the mixing chamber. Simultaneously, the safety gas source injects safety gas into the mixing chamber, controlling the injection amount to ensure that the concentration of combustible gas after mixing with the thermal runaway flue gas is below the lower explosive limit before being safely discharged into the external environment through the mixed gas exhaust pipe. Further, the safety gas can be carbon dioxide or nitrogen.

[0011] The third type is as follows: The mixed exhaust unit includes a mixing chamber, a mixed gas exhaust pipe, and a blower; the mixing chamber is equipped with a thermal runaway flue gas inlet and a mixed gas exhaust outlet, and the mixed gas exhaust pipe is installed at the mixed gas exhaust outlet; the blower injects air into the mixing chamber. When the device is running, if thermal runaway of the battery is detected, the thermal runaway flue gas enters the mixing chamber, and at the same time, the blower blows in air, controlling the amount of air injected so that the concentration of combustible gas after mixing with the thermal runaway flue gas is below the lower explosive limit, and then it is discharged to the external environment through the mixed gas exhaust pipe.

[0012] The second aspect of this solution provides an electrical device including multiple individual batteries, a thermal runaway emission pipeline, and a thermal runaway flue gas treatment device as described in the first aspect. The thermal runaway emission pipeline includes a main pipe and multiple branch pipes. Each individual battery is connected to a branch pipe via the main pipe, and the branch pipe covers the explosion vent of the individual battery. The thermal runaway flue gas outlet of the main pipe is connected to a mixed exhaust unit. In this electrical device, the thermal runaway flue gas is discharged to the thermal runaway flue gas treatment system via branch pipes and the main pipe, eliminating the possibility that the electrolyte ejected from a thermal runaway individual battery might come into contact with adjacent individual batteries, thus avoiding the problem of thermal runaway propagation caused by short circuits or abnormal chemical reactions in adjacent individual batteries.

[0013] Furthermore, the aforementioned multiple individual batteries are located inside a housing, while the mixed exhaust unit is located outside the housing. The main pipe in the thermal runaway exhaust pipeline transports the thermal runaway flue gas to the outside of the housing and then into the mixed exhaust unit.

[0014] The third aspect of this solution provides another type of electrical equipment, including an energy storage cabinet, multiple battery packs, a thermal runaway emission pipeline, and a thermal runaway flue gas treatment device as described in the first aspect; the thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe; multiple battery packs are installed inside the energy storage cabinet; the mixed exhaust unit is located outside the energy storage cabinet; the battery pack includes a housing, a venting pipeline, and multiple individual batteries; multiple individual batteries are located inside a housing, and multiple flue gas inlets on the venting pipeline cover the venting section of each individual battery, and the flue gas outlet of the venting pipeline is connected to the flue gas outlet of the battery pack; the thermal runaway flue gas is sequentially transported from the venting pipeline, branch pipes, and main pipe to the mixed exhaust unit to mix with the safety gas.

[0015] In this electrical equipment, thermal runaway fumes are discharged to the outside of the battery pack through a venting pipe. This eliminates the possibility that electrolyte ejected from a single cell during thermal runaway might come into contact with adjacent cells, preventing the spread of thermal runaway within the battery pack caused by short circuits or abnormal chemical reactions in nearby cells. Furthermore, the branch and main pipes discharge thermal runaway fumes outside the energy storage cabinet, eliminating the possibility that ejected electrolyte might come into contact with electrical components inside the cabinet. This prevents corrosion of these components by the electrolyte and avoids the spread of thermal runaway within the cabinet caused by short circuits in the electrical components.

[0016] Furthermore, the aforementioned mixed exhaust unit is located above the energy storage cabinet, with the mixed gas outlet of the mixed exhaust unit facing the sky and at least 1 meter away from the top of the energy storage cabinet. This arrangement of the thermal runaway flue gas treatment device further ensures the safety of the mixed gas after it is discharged from the energy storage cabinet.

[0017] The second option for thermal runaway flue gas treatment is as follows:

[0018] The thermal runaway flue gas treatment device of this solution is used for lithium-ion batteries, including a purification tank and a mixed exhaust unit. The purification tank contains a purification agent. After the battery experiences thermal runaway, the carbonates and solid particles carried in the thermal runaway flue gas are filtered by the purification agent. The gas is partially discharged from the purification tank and then enters the mixed exhaust unit. The mixed exhaust unit mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas that is then discharged into the external environment. The concentration of combustible gas in the mixed gas is below the lower explosive limit.

[0019] This application utilizes a purification tank to first purify the carbonates (which may be in vapor or liquid form) carried by the thermal runaway flue gas, preventing further decomposition reactions and reducing the content of flammable gases in the flue gas. The remaining unpurified flue gas then exits the purification tank and enters a mixing exhaust unit. This unit thoroughly mixes the purified flue gas with a safety gas to form a mixed gas. The concentration of flammable gases in this mixed gas is reduced to below the lower explosive limit, avoiding the risk of combustion and explosion after the flue gas is released into the external environment. It also significantly reduces the air pollution caused by directly releasing the flue gas into the external environment. Furthermore, the post-purification mixing step further reduces the flammable gas content in the flue gas entering the mixing exhaust unit, further lowering the flammable gas content in the mixed gas after mixing with the safety gas. This increases the likelihood that the flammable gas remains below the lower explosive limit, making emissions safer.

[0020] Furthermore, the aforementioned purifying agent is an alkaline solution, which is used to filter acidic gases and carbonates in the thermal runaway flue gas. Since acidic gases such as carbonates, hydrogen sulfide, hydrogen fluoride, and CO2 in the thermal runaway flue gas are heavier than air, they tend to sink within the purification tank. Therefore, they will neutralize with the alkaline solution in the purifying agent, preventing the potential for carbonate overflow to cause thermal runaway in nearby batteries. This also avoids environmental pollution and personal injury caused by the emission of hydrogen sulfide, hydrogen fluoride, and CO2. Additionally, due to the presence of the purification tank, some solid particles in the thermal runaway flue gas can also settle into the purification tank due to gravity.

[0021] Furthermore, the above-mentioned alkaline solution is a 0.1 mol / L NaOH solution.

[0022] Furthermore, the aforementioned mixed exhaust unit includes a main pipe and at least one branch pipe; the main pipe is installed vertically, with its lower end connected to the thermal runaway flue gas inlet of the purification tank, and its upper end serving as the mixed gas outlet. One end of the branch pipe is connected to the main pipe, and the other end serves as a safety gas inlet. Since hydrogen and carbon monoxide have the highest concentrations of combustible gases in the thermal runaway flue gas, and tend to rise within the purification tank before being discharged into the main pipe, rapidly injecting safety gas into the main pipe through the branch pipe can reduce the concentration of combustible gases such as hydrogen and carbon monoxide to below the lower explosive limit, thus avoiding potential combustion and explosion problems caused by directly discharging the thermal runaway flue gas.

[0023] Furthermore, in order to fully mix the thermal runaway flue gas and the safety gas, the main pipe consists of a first pipe section, a mixing section, and a second pipe section from top to bottom; there are two or more branch pipes, evenly distributed along the circumference; the inner diameter of the mixing section is greater than the inner diameter of the second pipe section, which is greater than the inner diameter of the first pipe section.

[0024] Furthermore, to save on the cost of handling thermal runaway flue gas, the aforementioned safety gas is air; to increase the air injection volume and velocity, as well as the mixing speed of air and thermal runaway flue gas in the main pipe, the safety gas inlet of the aforementioned branch pipe is equipped with a non-powered exhaust fan. The non-powered exhaust fan is installed in a manner that ensures only ambient air can enter the main pipe.

[0025] The second aspect of this solution provides an electrical device, including multiple individual batteries, a thermal runaway emission pipeline, and a thermal runaway flue gas treatment device as described in the first aspect; the thermal runaway flue gas treatment device includes a purification tank and a mixed exhaust unit; the thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each individual battery is connected to a branch pipe, and the branch pipe covers the explosion vent of the individual battery; the thermal runaway flue gas outlet of the main pipe is connected to the purification tank; a mixed exhaust unit is installed on the top of the purification tank.

[0026] In this electrical equipment, thermal runaway flue gas is discharged to the mixed exhaust unit through branch pipes and a main pipe. This eliminates the possibility that electrolyte ejected from a single thermal runaway cell may come into contact with adjacent cells, preventing the spread of thermal runaway caused by short circuits or abnormal chemical reactions in nearby cells. Simultaneously, the purification tank removes carbonates (which may be in vapor or liquid form) carried by the thermal runaway flue gas, preventing further decomposition and reducing the content of flammable gases in the flue gas. Next, the mixed exhaust unit thoroughly mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas. The concentration of flammable gases in this mixed gas is reduced to below the lower explosive limit, avoiding the risk of combustion and explosion after the thermal runaway flue gas is discharged into the external environment. This also significantly reduces the pollution of the atmosphere caused by the direct discharge of thermal runaway flue gas into the external environment.

[0027] Finally, in the step of purification followed by mixing, the purification process can reduce the content of combustible gases in the thermal runaway flue gas entering the mixing and emission unit to a certain extent, further reducing the content of combustible gases in the mixed gas after mixing with the safe gas, thereby increasing the possibility that the combustible gases are below the lower explosive limit, making the emission safer. Furthermore, the aforementioned multiple individual batteries are located within a housing, while the purification tank and mixing and exhaust unit are located outside the housing. The main pipe in the thermal runaway emission pipeline transports the thermal runaway flue gas outside the housing before it enters the purification tank.

[0028] The third aspect of this solution provides an electrical device, including an energy storage cabinet, a thermal runaway emission pipeline, multiple battery packs, and the aforementioned thermal runaway flue gas treatment device. The thermal runaway flue gas treatment device includes a purification tank and a mixing exhaust unit. The thermal runaway emission pipeline includes a main pipe and multiple branch pipes. Each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe. Multiple battery packs are installed inside the energy storage cabinet. At least the mixing exhaust unit in the thermal runaway flue gas treatment device is located outside the energy storage cabinet. The battery pack includes a housing, a venting pipeline, and multiple individual batteries. Multiple individual batteries are located within a housing. Multiple flue gas inlets on the venting pipeline cover the venting section of each individual battery, and the flue gas outlet of the venting pipeline is connected to the flue gas outlet of the battery pack. The thermal runaway flue gas is sequentially transported from the venting pipeline, branch pipes, and main pipe to the purification tank, where the carbonate and solid particles carried in the thermal runaway flue gas are filtered. The gaseous portion of the thermal runaway flue gas enters the mixing exhaust unit and mixes with the safety gas.

[0029] In this electrical equipment, thermal runaway fumes are discharged to the outside of the battery pack through a venting pipe. This eliminates the possibility that electrolyte ejected from a single cell during thermal runaway might come into contact with adjacent cells, preventing the spread of thermal runaway within the battery pack caused by short circuits or abnormal chemical reactions in nearby cells. Furthermore, the branch and main pipes discharge thermal runaway fumes outside the energy storage cabinet, eliminating the possibility that ejected electrolyte might come into contact with electrical components inside the cabinet. This prevents corrosion of these components by the electrolyte and avoids the spread of thermal runaway within the cabinet caused by short circuits in the electrical components. Meanwhile, purifying the carbonates (which may be in vapor or liquid form) carried by the thermal runaway flue gas through the purification tank can prevent the carbonates from continuing to decompose, thereby reducing the content of combustible gases in the thermal runaway flue gas. Then, the mixing exhaust unit fully mixes the purified thermal runaway flue gas with the safety gas to form a mixed gas. The concentration of combustible gases in this mixed gas is reduced to below the lower explosive limit, avoiding the risk of combustion and explosion after the thermal runaway flue gas is discharged into the external environment. At the same time, it also greatly reduces the pollution of the atmosphere caused by the direct discharge of thermal runaway flue gas into the external environment.

[0030] Finally, in the step of purification followed by mixing, the purification process can reduce the content of combustible gas in the thermal runaway flue gas entering the mixing emission unit to a certain extent, further reducing the content of combustible gas in the mixed gas after mixing with the safe gas, thereby increasing the possibility that the combustible gas is below the lower explosive limit, making the emission safer.

[0031] Furthermore, the aforementioned mixed emission unit is located above the energy storage cabinet, with its mixed gas outlet facing the sky and at least 1 meter above the top of the energy storage cabinet. This arrangement of the mixed emission unit further ensures the safety of the mixed gas after it is emitted from the energy storage cabinet.

[0032] The third option for thermal runaway flue gas treatment is as follows:

[0033] This thermal runaway gas treatment device is applied to lithium iron phosphate batteries and includes a thermal runaway emission pipeline and a mixing exhaust unit, which is a mixer. The thermal runaway emission pipeline is used to transport the thermal runaway gas generated by the thermal runaway of the lithium iron phosphate battery to the mixer. The mixer is used to mix the thermal runaway gas with a safety gas to form a mixed gas before it is discharged to the external environment. The volume ratio of the thermal runaway gas to the safety gas in the mixed gas is less than 1:7. This application discharges the thermal runaway gas generated after the battery experiences thermal runaway into the mixer via the emission pipeline. The mixer mixes the thermal runaway gas with the safety gas to form a mixed gas, and the concentration of combustible gas in the mixed gas is significantly reduced compared to the original concentration of combustible gas in the thermal runaway gas, thereby reducing or even avoiding the possibility of explosion and combustion after the mixed gas is discharged to the external environment.

[0034] Furthermore, there are no ignition sources within a 1-meter radius of the mixed flue gas outlet of the mixer. These ignition sources could include electrical components, lighters, cigarette butts, and objects prone to static electricity. Because the mixed gas is further diluted in the atmosphere after being discharged, the concentration of combustible gases within the mixed gas is further reduced, thereby improving the safety of the mixed gas after it is released into the external environment.

[0035] Specifically, the thermal runaway flue gas treatment device used in this application has various forms. Preferably, the thermal runaway flue gas treatment device used in this application specifically includes a mixing exhaust unit, which is a mixer. The mixer includes a converging pipe section, a straight pipe section, and a diffuser section connected sequentially from bottom to top. The lower port of the converging pipe section serves as a safety gas inlet, and the upper port of the diffuser section serves as a mixed gas outlet. The portion of the thermal runaway emission pipeline near the flue gas outlet is located in the converging pipe section, and the flow direction of the thermal runaway flue gas in the portion of the pipe section is from bottom to top.

[0036] When thermal runaway flue gas is discharged into the mixer, because the outlet of the thermal runaway discharge pipeline is located in the converging section and the thermal runaway flue gas is ejected upwards, a low-pressure zone is generated at the outlet of the thermal runaway discharge pipeline due to the setting of the straight section and the converging section. At this time, the low-pressure zone will attract the safety gas entering from the lower port of the converging section. The thermal runaway flue gas and the safety gas mix rapidly, which greatly reduces the concentration of combustible gas in the thermal runaway flue gas. Moreover, the mixer can accelerate the mixing speed of thermal runaway flue gas and safety gas without the need for an additional power source, thereby reducing the cost of thermal runaway flue gas treatment.

[0037] Furthermore, in order to save on the cost of treating thermal runaway flue gas, the aforementioned safety gas is air.

[0038] Furthermore, to increase the air injection volume and velocity, as well as the mixing speed of air and thermal runaway flue gas within the mixer, the thermal runaway flue gas treatment device also includes a non-powered exhaust fan; the non-powered exhaust fan is installed at the lower port of the convergence pipe section. The installation method of the non-powered exhaust fan must ensure that only ambient air can enter the mixer.

[0039] Furthermore, to enhance safety, the thermal runaway flue gas treatment device also includes a safety gas source connected to a safety gas inlet, wherein the safety gas source is filled with carbon dioxide or nitrogen.

[0040] The second aspect of this solution provides an electrical device including multiple individual batteries and a thermal runaway gas treatment device. The thermal runaway gas treatment device includes a mixing exhaust unit and a thermal runaway emission pipeline. The mixing exhaust unit is a mixer. The thermal runaway emission pipeline includes a main pipe and multiple branch pipes. Each individual battery is connected to a branch pipe, which covers the explosion vent of the individual battery. The thermal runaway gas outlet of the main pipe is connected to the mixer of the thermal runaway gas treatment device. In this electrical device, the thermal runaway gas is discharged to the mixer through the branch pipes and the main pipe, eliminating the possibility that the electrolyte ejected from a thermal runaway individual battery may come into contact with adjacent individual batteries, thus avoiding the problem of thermal runaway propagation caused by short circuits or abnormal chemical reactions in adjacent individual batteries.

[0041] Furthermore, the aforementioned multiple individual cells are located inside a housing, while the mixer is located outside the housing. The main pipe in the thermal runaway emission pipeline transports the thermal runaway flue gas to the outside of the housing and then into the mixer.

[0042] The third aspect of this solution provides another type of electrical equipment, including an energy storage cabinet, multiple battery packs, and the aforementioned thermal runaway flue gas treatment device; the thermal runaway flue gas treatment device includes a mixing exhaust unit and a thermal runaway emission pipeline; the mixing exhaust unit is a mixer; the thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe; multiple battery packs are installed inside the energy storage cabinet; the mixer is located outside the energy storage cabinet; the battery pack includes a housing, a venting pipeline, and multiple individual batteries; multiple individual batteries are located inside a housing, and multiple flue gas inlets on the venting pipeline cover the venting section of each individual battery, and the flue gas outlet of the venting pipeline is connected to the flue gas outlet of the battery pack; the thermal runaway flue gas is sequentially transported from the venting pipeline, branch pipes, and main pipe to the mixer to mix with the safety gas.

[0043] In this electrical equipment, thermal runaway fumes are discharged to the outside of the battery pack through a venting pipe. This eliminates the possibility that electrolyte ejected from a single cell during thermal runaway might come into contact with adjacent cells, preventing the spread of thermal runaway within the battery pack caused by short circuits or abnormal chemical reactions in nearby cells. Furthermore, the branch and main pipes discharge thermal runaway fumes outside the energy storage cabinet, eliminating the possibility that ejected electrolyte might come into contact with electrical components inside the cabinet. This prevents corrosion of these components by the electrolyte and avoids the spread of thermal runaway within the cabinet caused by short circuits in the electrical components.

[0044] Furthermore, the mixer is located above the energy storage cabinet, with its mixed gas outlet facing the sky and at least 1 meter above the top of the cabinet. This arrangement further ensures the safety of the mixed gas after it exits the energy storage cabinet. Attached Figure Description

[0045] Figure 1 is a structural schematic diagram of Embodiment 1;

[0046] Figure 2 is a structural schematic diagram of Example 2;

[0047] Figure 3 is a structural schematic diagram of Example 3;

[0048] Figure 4 is a structural principle diagram of Example 4;

[0049] Figure 5 is a structural principle diagram of Example 5.

[0050] Figure 6 is a structural schematic diagram of Example 6;

[0051] Figure 7 is a structural schematic diagram of Example 7;

[0052] Figure 8 is a structural schematic diagram of Example 8;

[0053] Figure 9 is a structural schematic diagram of Example 9;

[0054] Figure 10 is a structural schematic diagram of Embodiment 10;

[0055] Figure 11 is a structural schematic diagram of Embodiment 11;

[0056] Figure 12 is a structural schematic diagram of Embodiment 12;

[0057] Figure 13 is a structural schematic diagram of Example 13;

[0058] Figure 14 is a structural principle diagram of Example 14.

[0059] The attached diagram is labeled as follows: 100-Mixed exhaust unit, 110-Main pipe, 111-Branch pipe, 112-First pipe section, 113-Mixing section, 114-Second pipe section, 115-Non-powered exhaust fan, 201-Converging pipe section, 202-Straight pipe section, 203-Diffusive pipe section, 1-T-way pipe assembly, 2-First-stage exhaust fan, 11-First pipeline, 12-Second pipeline, 13-Third pipeline, 14-Second-stage exhaust fan, 15-Mixing chamber, 16-Safety gas source, 17-Mixed gas emission pipe, 18-Blower, 200-Battery pack, 300-Thermal runaway emission pipeline, 301-Branch pipe, 302-Main pipe, 400-Single battery cell, 500-Shell, 600-Energy storage cabinet, 700-Explosion relief pipeline, 800-Purification tank. Detailed Implementation

[0060] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0061] The phrase "other embodiments" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this application, "a plurality of" means two or more, unless otherwise expressly and specifically defined.

[0062] In this specification, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection, an indirect connection via an intermediate component, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0063] Furthermore, it should be noted in the description of this application 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 accompanying drawings, and is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0064] When a battery experiences thermal runaway, the existing methods for handling thermal runaway are as follows:

[0065] Measure 1: This measure is currently widely used. Specifically, it uses fire-fighting media such as heptafluoropropane, perfluorohexanone, fine water mist, and aerosol to suppress thermal runaway. However, this method has high fire-fighting costs, especially when combined with the widely used perfluorohexanone fire extinguishing medium, which will cause a sharp increase in the cost of handling thermal runaway.

[0066] Measure 2: Existing technologies have proposed a relatively cost-effective method for large-scale energy storage power generation stations. Since the external environment of the station is relatively open, when the battery experiences thermal runaway, the thermal runaway flue gas can be directly discharged into the external environment. However, the application of this solution has significant limitations. For example, if this solution is applied to electric vehicle charging stations, industrial and commercial energy storage, etc., the external environment of these scenarios is relatively complex, and equipment such as photovoltaic panels and charging piles may generate static electricity, which could lead to a greater risk of danger.

[0067] Since both of the above methods have their own problems, this application provides a thermal runaway flue gas treatment device. The device mixes the thermal runaway flue gas generated by the battery with a safety gas to form a mixed gas before discharging it into the external environment. The concentration of combustible gas in the mixed gas is reduced to below the lower explosive limit.

[0068] It should be noted that:

[0069] 1. A battery can be a commercially available single cell, such as a prismatic lithium-ion battery, a pouch battery, or a cylindrical battery; it can also be a battery pack, which is generally composed of multiple single cells connected in series, parallel, or mixed connections; or it can be a high-capacity battery proposed in the prior art, which is composed of multiple single cells connected in parallel, and the multiple single cells are in a shared electrolyte system.

[0070] 2. The composition and explosion limits of the thermal runaway fumes from lithium-ion batteries are shown in the table below:

[0071] The analysis in the table above shows that, except for carbon dioxide, all other gases in the thermal runaway flue gas from the battery are flammable gases. Among them, hydrogen has the highest concentration (around 39.3%), which is more than 6 times that of carbon monoxide, more than 5 times that of methane, more than 7 times that of ethylene, and tens or even hundreds of times that of other hydrocarbon gases. In addition, the lowest explosive limit of hydrogen is 4.0%, which is about 1 / 3 of that of carbon monoxide, 4 / 5 of that of methane, 1.5 times that of ethylene, and 1.4 to 2.8 times that of other hydrocarbon gases.

[0072] Studies have shown that the various combustible gases in the thermal runaway flue gas of lithium iron phosphate batteries can be considered as a whole, and the lower explosion limit of the combustible gases is 6.8%. In other words, by mixing the safe gas with the thermal runaway flue gas to form a mixed gas, as long as the concentration of combustible gases is reduced to below 6.8%, safe emissions can be achieved.

[0073] Furthermore, based on the values ​​in the table above, we can conclude that when a safe gas is mixed with thermal runaway flue gas to form a mixed gas, as long as the concentration of hydrogen in the thermal runaway flue gas is reduced to below 4.0%, it can be characterized that the concentration of the remaining combustible gases in the mixed gas has also been reduced to below the lower explosive limit.

[0074] 3. Safety gases can be inert gases such as nitrogen, carbon dioxide, or air. Using inert gases or carbon dioxide as safety gases provides higher safety than using air. However, since safety gases are used in larger quantities, using air as a safety gas results in lower operating costs compared to using inert gases or carbon dioxide.

[0075] 4. The external environment mentioned in the text refers to the atmospheric environment. Ideally, it should be a relatively open, spacious environment.

[0076] Example 1

[0077] This embodiment provides a thermal runaway flue gas treatment device, the safe gas used in the thermal runaway flue gas treatment device is air; as shown in Figure 1, the thermal runaway flue gas treatment device includes a mixing exhaust unit 100, the mixing exhaust unit 100 includes a three-way pipe assembly 1 and a primary exhaust fan 2; the three-way pipe assembly 1 includes a first pipe 11, a second pipe 12 and a third pipe 13 that are interconnected; the first pipe 11 serves as a mixed gas discharge pipe and the primary exhaust fan 2 is installed on the first pipe 11; the second pipe 12 is used to introduce thermal runaway flue gas, and the third pipe is used to introduce air.

[0078] When the device is in operation, if thermal runaway of the battery is detected, the primary exhaust fan 2 starts working. The thermal runaway flue gas and outside air enter the first pipe 11 to form a mixed gas, which is then discharged into the external environment through the first pipe 11. By pre-setting the pipe diameters of the second pipe 12 and the third pipe 13, as well as the exhaust volume of the primary exhaust fan, the concentration of the combustible gas after the air and thermal runaway flue gas mixture is controlled to be below the lower explosive limit before being discharged into the external environment through the first pipe 11.

[0079] Preferably, to ensure a sufficient amount of air mixes with the thermal runaway flue gas per unit time, a secondary exhaust fan 14 is installed on the third pipeline 13. By turning on the secondary exhaust fan 14, the gas flow rate in the third pipeline 13 per unit time can be increased, which can quickly reduce the concentration of combustible gas in the mixed gas and further improve the safety of the mixed gas discharged into the external environment.

[0080] In some other embodiments, the third conduit 13 may also be connected to a safe gas source containing carbon dioxide or inert gas.

[0081] Example 2

[0082] This embodiment provides a thermal runaway flue gas treatment device, as shown in Figure 2. The thermal runaway flue gas treatment device includes a mixing exhaust unit 100, which includes a mixing chamber 15, a safety gas source 16, and a mixed gas discharge pipe 17. The mixing chamber 15 is provided with a thermal runaway flue gas inlet and a mixed gas discharge outlet, and the mixed gas discharge pipe 17 is installed at the mixed gas discharge outlet. The safety gas source 16 injects inert gas or carbon dioxide into the mixing chamber. When the device is operating, when thermal runaway of the battery is detected, the thermal runaway flue gas enters the mixing chamber, and at the same time, the safety gas source 16 injects safety gas into the mixing chamber. The amount of safety gas injected and the size of the thermal runaway flue gas inlet are controlled so that the concentration of combustible gas after mixing with the thermal runaway flue gas is below the lower explosive limit before being discharged to the external environment through the mixed gas discharge pipe 17. In this embodiment, carbon dioxide is preferably used as the safety gas in the safety gas source.

[0083] Example 3

[0084] This embodiment provides a thermal runaway flue gas treatment device, as shown in Figure 3. The device includes a mixing exhaust unit 100, which comprises a mixing chamber 15, a mixed gas discharge pipe 17, and a blower 18. The mixing chamber 15 has a thermal runaway flue gas inlet and a mixed gas discharge outlet, and the mixed gas discharge pipe 17 is installed at the mixed gas discharge outlet. The blower 18 injects air into the mixing chamber 15. During operation, when thermal runaway of the battery is detected, the thermal runaway flue gas enters the mixing chamber, and simultaneously, the blower 18 blows air into the mixing chamber. The amount of air injected is controlled so that the concentration of combustible gas after mixing with the thermal runaway flue gas is below the lower explosive limit before being discharged into the external environment through the mixed gas discharge pipe 17.

[0085] Example 4

[0086] This embodiment provides an electrical device that uses only one battery pack 200. As shown in Figure 4, the electrical device mainly includes a battery pack composed of multiple individual batteries 400 connected in series, parallel, or mixed, a thermal runaway emission pipeline 300, and a thermal runaway flue gas treatment device as described in embodiments 1 to 3. The thermal runaway emission pipeline 300 includes a main pipe 302 and multiple branch pipes 301. Each individual battery 400 is connected to a branch pipe 301, and the branch pipe 301 covers the explosion vent of the individual battery. The thermal runaway flue gas outlet of the main pipe 302 is connected to the thermal runaway flue gas treatment device.

[0087] In some embodiments, multiple individual cells 400 in the battery pack 200 are located inside a housing 500, and the thermal runaway flue gas treatment device is located outside the housing 500. The main pipe 302 in the thermal runaway emission pipeline 300 delivers the thermal runaway flue gas to the outside of the housing 500 and then into the thermal runaway flue gas treatment device.

[0088] Example 5

[0089] This embodiment provides an electrical device, which is actually an energy storage device (which can be a residential energy storage, industrial and commercial energy storage, or a power generation-side energy storage device); as shown in Figure 5, the electrical device includes an energy storage cabinet 600, multiple battery packs 200, a thermal runaway emission pipeline 300, and a thermal runaway flue gas treatment device as described in Embodiments 1 to 3.

[0090] Multiple battery packs 200 are installed inside the energy storage cabinet 600; the thermal runaway flue gas treatment device is located outside the energy storage cabinet 600; the thermal runaway emission pipeline 300 includes a main pipe 302 and multiple branch pipes 301; each battery pack 200 has a branch pipe 301 connected to the flue gas outlet of the main pipe 302; the battery pack 200 includes a housing 500, an explosion relief pipeline 700 and multiple individual batteries 400; the multiple individual batteries 400 are located inside a housing 500, multiple flue gas inlets on the explosion relief pipeline 700 cover the explosion relief part of each individual battery 400, and the flue gas outlet of the explosion relief pipeline 700 is connected to the flue gas outlet of the battery pack.

[0091] When any single cell in a battery pack experiences thermal runaway, the thermal runaway gas first exits the battery pack 200 through the explosion relief pipe 700, and then sequentially exits through the branch pipe 301 and the main pipe 302 to the thermal runaway gas treatment device outside the energy storage cabinet 600. Finally, the thermal runaway gas and the safety gas are mixed to form a mixed gas that is discharged into the external environment. The safety gas injected into the thermal runaway gas treatment device must ensure that the concentration of combustible gas in the mixed gas is reduced to below the lower explosive limit.

[0092] Preferably, in this embodiment, the thermal runaway gas treatment device is located above the energy storage cabinet, with the mixed gas outlet of the thermal runaway gas treatment device facing the sky and at least 1 meter away from the top of the energy storage cabinet. This arrangement of the thermal runaway gas treatment device further ensures the safety of the mixed gas after it is discharged from the energy storage cabinet.

[0093] It should be noted that the explosion relief pipe 700 in this embodiment is actually similar in structure to the thermal runaway discharge pipe in embodiment 4, and also includes branch pipes and main pipes; in some other embodiments, a pipe can also be fixed to the top of each individual cell and cover the explosion relief part of each individual cell.

[0094] In some other embodiments, the explosion relief pipe 700 may not be installed in the battery pack. The thermal runaway flue gas can be discharged directly to the mixing chamber outside the energy storage cabinet 600 through the thermal runaway emission pipe after passing through the battery pack shell. However, this method may cause the thermal runaway to spread in the battery pack shell, which has certain safety hazards.

[0095] In some other embodiments, in order to make the thermal runaway discharge pipeline structure more compact and thus ensure the energy density of the energy storage cabinet, the main pipe in the thermal runaway discharge pipeline may adopt a support frame that supports multiple battery packs.

[0096] This application provides a second solution for a thermal runaway flue gas treatment device. This device filters the carbonate and solid particles carried in the thermal runaway flue gas after the battery experiences thermal runaway using a purifying agent in a purifying tank. After the gas is discharged from the purifying tank, it enters and mixes with a safe gas to form a mixed gas (the concentration of combustible gas in the mixed gas is reduced to below the lower explosive limit) before being discharged into the external environment.

[0097] It should be noted that:

[0098] 1. Lithium-ion batteries can be commercially available single cells, such as prismatic lithium-ion batteries, pouch batteries, and cylindrical batteries; they can also be battery packs, which are generally composed of multiple single cells connected in series, parallel, or mixed connections; or they can be high-capacity batteries as proposed in the prior art, which are composed of multiple single cells connected in parallel, and the multiple single cells are in a shared electrolyte system.

[0099] 2. During thermal runaway, a series of violent chemical reactions occur inside the lithium-ion battery, generating a large amount of heat and flammable and toxic gases. These gases include, but are not limited to, hydrogen (H2), carbon monoxide (CO), methane (CH4), and other hydrocarbons. When these gases mix with air within a specific concentration range, they may form an explosive mixture.

[0100] The explosion limits refer to the concentration range within which thermally runaway flue gas, when mixed with air, can explode upon contact with an ignition source. This range typically has a lower limit and an upper limit, known as the lower explosive limit (LEL) and the upper explosive limit (UEL), respectively. When the concentration of combustible gas is below the LEL, the mixture is too lean to support combustion; when the concentration is above the UEL, the mixture is too rich, lacking sufficient oxygen, and also unable to support combustion.

[0101] Experimental results show that the lower explosive limit of the mixed gas generated during thermal runaway of lithium iron phosphate batteries is 6.80%, and the upper explosive limit is 40.63%. This means that when the concentration of the mixed gas is below 6.80%, an explosion will not occur; and when the concentration is above 40.63%, an explosion will also not occur. An explosion is only possible within the concentration range of 6.80% to 40.63%.

[0102] In addition to gases such as hydrogen, CO, and methane, thermal runaway flue gas also contains carbonates (carbonates are generally in vapor or liquid form). If carbonates are not treated, they will undergo a series of decomposition reactions, which will continue to produce a large amount of harmful and flammable gases.

[0103] 3. Safety gases can be inert gases such as nitrogen, carbon dioxide, or air. Using inert gases or carbon dioxide as safety gases offers higher safety than using air. However, due to the large volume of safety gases used, using air as a safety gas is less expensive than using inert gases or carbon dioxide.

[0104] 4. The external environment mentioned in the text refers to the atmospheric environment. Ideally, it should be a relatively open, spacious environment.

[0105] Example 6

[0106] This embodiment provides a thermal runaway flue gas treatment device, as shown in Figure 6. The thermal runaway flue gas treatment device includes a purification tank 800 and a mixing exhaust unit 100. The purification tank 800 contains a purifying agent, and the purification tank 800 is provided with a thermal runaway flue gas inlet and a thermal runaway flue gas outlet. In this embodiment, the purifying agent is injected into the purification tank 800 in advance. In some other embodiments, the purifying agent can also be introduced into the purification tank by spraying when the thermal runaway flue gas enters the purification tank.

[0107] After a thermal runaway occurs in the battery, the thermal runaway flue gas is transported to the purification tank 800 through the thermal runaway emission pipeline 300. The carbonate and solid particles carried in the thermal runaway flue gas are filtered by the purifying agent, and part of the gas is discharged from the purification tank 800 and enters the mixed exhaust unit. Preferably, a section of the thermal runaway emission pipeline 300 is inserted into the purification tank 800 from the thermal runaway flue gas inlet and is immersed in the purifying agent (the opening of the section of the thermal runaway emission pipeline 300 is as close as possible to the bottom of the purification tank). The thermal runaway flue gas outlet of the purification tank 800 is used to connect with the mixed exhaust unit 100.

[0108] In this embodiment, the purification tank 800 contains an alkaline solution, which may be an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, etc. This alkaline solution can not only dissolve the carbonate in the flue gas from the thermal runaway of the battery, but also has a good treatment effect on acidic gases such as CO2 and HF.

[0109] Taking NaOH solution as an example, when thermal runaway flue gas is transported to NaOH solution, the NaOH solution reacts with acidic substances such as carbonates, CO2, and HF in the flue gas. For example, carbonates react with NaOH solution: CHOOCR + NaOH = RCOONa + CHOH; CO2 reacts with NaOH solution: 2NaOH + CO2 = Na2CO3 + H2O; subsequently, CO2 also reacts: Na2CO3 + CO2 + H2O = 2NaHCO3; HF reacts with NaOH solution: NaOH + HF = NaF + H2O. Through these reactions, the carbonates and acidic gases in the thermal runaway flue gas are neutralized, significantly reducing subsequent treatment costs.

[0110] Extensive battery thermal runaway experiments were conducted, and the effects of water and different concentrations of NaOH solution on the treatment of thermal runaway flue gas were compared. It was found that the gas volume collected after treatment with 0.05–0.5 mol / L NaOH solution was the smallest, the effect was significant after treatment with 0.1–0.2 mol / L NaOH solution, and the effect was the best after treatment with 0.1 mol / L NaOH solution.

[0111] Table 1. Unprocessed runaway data of fully charged 32650 batteries

[0112] Table 2 Results of treatment with NaOH solutions of different concentrations

[0113] Based on the above experimental data, it was found that the volume of gas collected after the thermal runaway of a fully charged 32650 battery without any treatment was 4L. When the thermal runaway gas from a fully charged 32650 battery was passed through a NaOH solution with a concentration of 0.5 mol / L or higher, the collected gas volume was generally greater than 2L, indicating unsatisfactory treatment results. Passing the thermal runaway gas from a fully charged 32650 battery through a NaOH solution of 0.05–0.5 mol / L resulted in a smaller gas volume, all below 2L. Treatment with 0.1–0.2 mol / L sodium hydroxide showed significant effects, with the smallest collected gas volume (approximately 1L) after treatment with 0.1 mol / L sodium hydroxide, demonstrating the best effect. Therefore, a 0.05–0.5 mol / L NaOH solution has a good treatment effect on the thermal runaway gas from a battery.

[0114] Besides alkaline solutions, the principle of "like dissolves like" can be used to treat carbonate liquids or vapors carried in thermal runaway flue gas using organic substances. The organic solvent can be at least one of ester solvents, alcohol solvents, or aldehyde solvents. Specifically, the ester solvent can be methyl salicylate or diethyl phthalate, and the alcohol solvent can be isoamyl alcohol, benzyl alcohol, isobutanol, or isooctanol. However, the adsorption capacity of these organic substances for carbonates is weaker than that of alkaline solutions, and they also cannot absorb acidic gases.

[0115] The mixed exhaust unit 100 mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas that is then discharged into the external environment; the concentration of combustible gas in the mixed gas is reduced to below the lower limit of the explosion limit.

[0116] In this embodiment, the mixed exhaust unit 100 includes a main pipe 110 and at least one branch pipe 111. The main pipe 110 is installed vertically, and its lower end is connected to the thermal runaway flue gas inlet of the purification tank 800. The upper end of the main pipe 110 serves as the mixed gas outlet. One end of the branch pipe 111 is connected to the main pipe 110, and the other end serves as the safety gas inlet. While the purified thermal runaway flue gas enters the main pipe 110, the branch pipe 111 injects a large amount of safety gas into the main pipe 110, so that the concentration of combustible gas in the formed mixed gas is reduced to below the lower explosive limit and then safely discharged to the external environment.

[0117] Preferably, in order to provide a sufficiently large space within the main pipe 110 for mixing the thermal runaway flue gas and the safety gas, in this embodiment, the main pipe 110 includes, from top to bottom, a first pipe section 112, a mixing section 113, and a second pipe section 114, with the inner diameter of the mixing section 113 > the inner diameter of the second pipe section 114 > the inner diameter of the first pipe section 112; in order to allow as much safety gas as possible to enter the main pipe 110, in this embodiment, two or more branch pipes 111 can be provided on the main pipe 110, and they can be evenly distributed along the circumferential direction.

[0118] Preferably, in this embodiment, air is used as the safety gas while also considering cost savings.

[0119] Preferably, in this embodiment, a non-powered exhaust fan 115 is provided at the safety gas inlet of the branch pipe 111. The non-powered exhaust fan 115 is installed in a way that ensures that only ambient air can enter the main pipe. The non-powered exhaust fan 115 can increase the amount of ambient air entering the main pipe 110 per unit time. At the same time, the non-powered exhaust fan 115 has no additional electrical components, which can also avoid the occurrence of danger.

[0120] Example 7

[0121] This embodiment provides a thermal runaway flue gas treatment device, which differs from Embodiment 6 in that the mixed exhaust unit 100 is different. As shown in Figure 7, the mixed exhaust unit 100 includes a three-way pipe assembly 1 and a primary exhaust fan 2. The three-way pipe assembly 1 includes a first pipe 11, a second pipe 12, and a third pipe 13 that are interconnected. The first pipe 11 serves as a mixed gas discharge pipe and the primary exhaust fan 2 is installed on the first pipe 11. The second pipe 12 is used to connect with the thermal runaway flue gas outlet of the purification tank, and the third pipe 13 is used to introduce air.

[0122] When the device is in operation, if thermal runaway of the battery is detected, the primary exhaust fan 2 starts working. The thermal runaway flue gas and outside air enter the first pipe 11 to form a mixed gas, which is then discharged into the external environment through the first pipe 11. By pre-setting the pipe diameters of the second pipe 12 and the third pipe 13, as well as the exhaust volume of the primary exhaust fan 2, the concentration of the combustible gas after the air and thermal runaway flue gas mixture is controlled to be below the minimum explosive limit before being discharged into the external environment through the first pipe 11.

[0123] Preferably, to ensure a sufficient amount of air mixes with the thermal runaway flue gas per unit time, a secondary exhaust fan 14 is installed on the third pipeline 13. By turning on the secondary exhaust fan 14, the gas flow rate in the third pipeline 13 per unit time can be increased, which can quickly reduce the concentration of combustible gas in the mixed gas and further improve the safety of the mixed gas discharged into the external environment.

[0124] In some other embodiments, the third conduit 13 may also be connected to a safe gas source containing carbon dioxide or inert gas.

[0125] Example 8

[0126] This embodiment provides an electrical device that uses only one battery pack 200. As shown in Figure 8, the electrical device mainly includes a battery pack composed of multiple individual batteries 400 connected in series, parallel, or mixed, a thermal runaway emission pipeline 300, and a thermal runaway flue gas treatment device as described in embodiments 2 to 6. The thermal runaway emission pipeline 300 includes a main pipe 302 and multiple branch pipes 301. Each individual battery 400 is connected to a branch pipe 301, and the branch pipe 301 covers the explosion vent of the individual battery. The thermal runaway flue gas outlet of the main pipe 302 is connected to the purification tank 800 of the thermal runaway flue gas treatment device.

[0127] In some embodiments, multiple individual cells 400 in the battery pack 200 are located inside a housing 500, and the thermal runaway flue gas treatment device is located outside the housing 500. The main pipe 302 in the thermal runaway emission pipeline 300 transports the thermal runaway flue gas to the outside of the housing 500 and then into the purification tank 800 of the thermal runaway flue gas treatment device.

[0128] Example 9

[0129] This embodiment provides an electrical device, which is actually an energy storage device (which can be a residential energy storage, industrial and commercial energy storage, or a power generation-side energy storage device); as shown in Figure 9, the electrical device includes an energy storage cabinet 600, multiple battery packs 200, a thermal runaway emission pipeline 300, and a thermal runaway flue gas treatment device as described in embodiments 2 to 6.

[0130] Multiple battery packs 200 are installed inside the energy storage cabinet 600; at least one mixed emission unit in the thermal runaway flue gas treatment device is located outside the energy storage cabinet 600; the thermal runaway emission pipeline 300 includes a main pipe 302 and multiple branch pipes 301; each battery pack 200 has a branch pipe 301 connected between its flue gas outlet and the main pipe 302; the battery pack 200 includes a housing 500, a deflation pipeline 700, and multiple individual batteries 400; the multiple individual batteries 400 are located inside a housing 500, and multiple flue gas inlets on the deflation pipeline 700 cover the deflation section of each individual battery 400, and the flue gas outlet of the deflation pipeline 700 is connected to the flue gas outlet of the battery pack;

[0131] When any single cell in a battery pack experiences thermal runaway, the thermal runaway gas is first discharged from the battery pack through the explosion relief pipeline, and then sequentially discharged from the branch pipe and the main pipe to the thermal runaway flue gas treatment device. The thermal runaway flue gas treatment device purifies and mixes the thermal runaway flue gas to form a mixed gas that is discharged into the external environment.

[0132] Preferably, in this embodiment, the mixing and emission unit is located above the energy storage cabinet, with the mixed gas outlet of the mixing and emission unit facing the sky and at least 1 meter away from the top of the energy storage cabinet. This arrangement of the mixing and emission unit further ensures the safety of the mixed gas after it is emitted from the energy storage cabinet.

[0133] It should be noted that the explosion relief pipeline in this embodiment is actually similar in structure to the thermal runaway discharge pipeline in embodiment 9, and also includes branch pipes and main pipes; in some other embodiments, a pipeline can also be fixed to the top of each individual cell and cover the explosion relief part of each individual cell.

[0134] In some other embodiments, the battery pack may not have a venting pipe. The thermal runaway gas can be discharged directly to the mixed exhaust unit outside the energy storage cabinet through the thermal runaway exhaust pipe after passing through the battery pack housing. However, this method may cause the thermal runaway to spread inside the battery pack housing, which poses a certain safety hazard.

[0135] In some other embodiments, in order to make the thermal runaway discharge pipeline structure more compact and thus ensure the energy density of the energy storage cabinet, the main pipe in the thermal runaway discharge pipeline may adopt a support frame that supports multiple battery packs.

[0136] This application also provides a third solution for a thermal runaway flue gas treatment device applied to lithium iron phosphate batteries, including a thermal runaway emission pipeline and a mixing exhaust unit, wherein the mixing exhaust unit is a mixer; the thermal runaway emission pipeline is used to transport the thermal runaway flue gas generated by the thermal runaway of the lithium iron phosphate battery to the mixer, and the mixer is used to mix the thermal runaway flue gas with a safety gas to form a mixed gas before discharging it to the external environment; wherein the volume ratio of the thermal runaway flue gas to the safety gas in the mixed gas is less than 1:7. This application mixes the thermal runaway flue gas and the safety gas through a mixer, which significantly reduces the concentration of combustible gas, thereby reducing or even avoiding the problem of explosion and combustion after the thermal runaway flue gas is discharged to the external environment.

[0137] It should be noted that:

[0138] 1. A battery can be a commercially available single cell, such as a prismatic lithium-ion battery, a pouch battery, or a cylindrical battery; it can also be a battery pack, which is generally composed of multiple single cells connected in series, parallel, or mixed connections; or it can be a high-capacity battery proposed in the prior art, which is composed of multiple single cells connected in parallel, and the multiple single cells are in a shared electrolyte system.

[0139] 2. During thermal runaway, a series of violent chemical reactions occur inside the lithium iron phosphate battery, generating a large amount of heat and flammable and toxic gases. These gases include, but are not limited to, hydrogen (H2), carbon monoxide (CO), methane (CH4), and other hydrocarbons. When these gases mix with air within a specific concentration range, they may form an explosive mixture.

[0140] 3. Safety gases can be inert gases such as nitrogen, carbon dioxide, or air. Using inert gases or carbon dioxide as safety gases offers higher safety than using air. However, due to the large volume of safety gases used, using air as a safety gas is less expensive than using inert gases or carbon dioxide.

[0141] 4. The external environment mentioned in the text refers to the atmospheric environment. Ideally, it should be a relatively open, spacious environment.

[0142] Example 10

[0143] This embodiment provides a thermal runaway flue gas treatment device, in which air is used as the safety gas. As shown in Figure 10, the thermal runaway flue gas treatment device includes a thermal runaway emission pipeline 300 and a mixing exhaust unit 100. The mixing exhaust unit 100 is a mixer with a tubular structure, including a converging pipe section 201, a straight pipe section 202, and a diffuser section 203 connected sequentially from bottom to top. The lower port of the converging pipe section 201 serves as the safety gas inlet, and the upper port of the diffuser section 203 serves as the mixed gas outlet. A portion of the thermal runaway emission pipeline near the flue gas outlet is located in the converging pipe section 201, and the flow direction of the thermal runaway flue gas in the portion of the pipe section is from bottom to top.

[0144] When a battery experiences thermal runaway, the runaway gas flows through the thermal runaway emission pipeline to the mixer. Due to the arrangement of the straight and converging pipe sections, a low-pressure zone is created at the outlet of the thermal runaway emission pipeline. This low-pressure zone attracts safety gas entering from the lower port of the converging pipe section. The thermal runaway gas and safety gas mix rapidly and are then discharged into the external environment through the upper port of the diffuser section. This significantly reduces the concentration of combustible gases in the thermal runaway gas. Furthermore, this mixer can accelerate the mixing speed of the thermal runaway gas and safety gas without requiring an additional power source, reducing the cost of thermal runaway gas treatment. To ensure the correct ratio of safety gas to thermal runaway gas entering the mixer, the diameter of the section of the thermal runaway emission pipeline near the gas outlet and the diameter of each section in the mixer can be pre-set, thereby controlling the volume ratio of thermal runaway gas to safety gas to maintain below 1:8 for safe emission.

[0145] In some other embodiments, a non-powered exhaust fan can also be installed at the lower port of the converging pipe section 201. The installation method of the non-powered exhaust fan needs to ensure that only ambient air can enter the mixer. The non-powered exhaust fan can increase the amount of ambient air entering the main pipe per unit time. At the same time, the non-powered exhaust fan has no additional electrical components, which can also avoid the occurrence of danger.

[0146] In some other embodiments, the lower port of the converging tube section 201 may also be connected to a safety gas source, wherein the safety gas in the safety gas source is carbon dioxide or nitrogen.

[0147] Example 11

[0148] This embodiment provides a thermal runaway flue gas treatment device, which uses air as the safety gas; the difference between this embodiment and embodiment 10 is that the mixed exhaust unit 100 used is different.

[0149] As shown in Figure 11, the mixed exhaust unit 100 is a mixer with another structure, including a three-way pipe assembly 1 and a primary exhaust fan 2; the three-way pipe assembly 1 includes a first pipe 11, a second pipe 12 and a third pipe 13 that are interconnected; the first pipe 11 serves as the mixed flue gas exhaust pipe and the primary exhaust fan 2 is installed on the first pipe 11; the second pipe 12 is used to connect with the thermal runaway exhaust pipe 300, and the third pipe 13 is used to introduce air.

[0150] When the device is in operation, if thermal runaway of the battery is detected, the primary exhaust fan 2 starts working. The thermal runaway flue gas and outside air enter the first pipe 11 to form a mixed gas, which is then discharged into the external environment through the first pipe 11. By pre-setting the diameter of the second pipe 12 and the third pipe 13, the volume ratio of thermal runaway flue gas to safety gas is controlled to be maintained below 1:7 before being discharged into the external environment through the first pipe 11.

[0151] Preferably, to ensure a sufficient amount of air mixes with the thermal runaway flue gas per unit time, a secondary exhaust fan 14 is installed on the third pipeline 13. By turning on the secondary exhaust fan 14, the gas flow rate in the third pipeline 13 per unit time can be increased, which can quickly reduce the concentration of combustible gas in the mixed gas and further improve the safety of the mixed gas discharged into the external environment.

[0152] In some other embodiments, the third conduit 13 may also be connected to a safe gas source containing carbon dioxide or inert gas.

[0153] Example 12

[0154] This embodiment provides a thermal runaway flue gas treatment device. This embodiment differs from Embodiment 10 in that it uses a different mixing exhaust unit 100. As shown in Figure 12, the mixing exhaust unit is a mixer with a different structure, including a mixing chamber 15, a safety gas source 16, and a mixed gas discharge pipe 17. The mixing chamber 15 is provided with a thermal runaway flue gas inlet and a mixed gas outlet, and the mixed gas discharge pipe 17 is installed at the mixed gas outlet. The safety gas source 16 injects inert gas or carbon dioxide into the mixing chamber. When the device is operating, if thermal runaway of the battery is detected, the thermal runaway flue gas enters the mixing chamber. Simultaneously, the safety gas source 16 injects safety gas into the mixing chamber, controlling the injection amount of safety gas and the diameter of the thermal runaway flue gas inlet to maintain the volume ratio of thermal runaway flue gas to safety gas below 1:7 before safely discharging it into the external environment through the mixed gas discharge pipe 17. In this embodiment, the safety gas source is carbon dioxide.

[0155] Example 13

[0156] This embodiment provides an electrical device that uses only one battery pack 200. As shown in Figure 13, the electrical device mainly includes a battery pack composed of multiple individual batteries 400 connected in series, parallel or mixed, and a thermal runaway flue gas treatment device as described in embodiments 3 to 10.

[0157] The thermal runaway flue gas treatment device includes a mixing exhaust unit 100 and a thermal runaway emission pipeline 300; the thermal runaway emission pipeline 300 includes a main pipe 302 and multiple branch pipes 301; each individual battery 400 is connected to a branch pipe 301 between itself and the main pipe, and the branch pipe 301 covers the explosion vent of the individual battery; the thermal runaway flue gas outlet of the main pipe 302 is connected to the mixer.

[0158] In some embodiments, multiple individual cells 400 in the battery pack 200 are located inside a housing 500, and the mixed exhaust unit 100 is located outside the housing 500. The main pipe 302 in the thermal runaway exhaust pipeline 300 delivers the thermal runaway flue gas to the outside of the housing 500 and then enters the mixed exhaust unit 100 to mix with the safety gas before safely discharging it into the external environment.

[0159] Example 14

[0160] This embodiment provides an electrical device, which is actually an energy storage device (which can be a residential energy storage, industrial and commercial energy storage, or a power generation-side energy storage device); as shown in Figure 14, the electrical device includes an energy storage cabinet 600, multiple battery packs 200, and a thermal runaway flue gas treatment device as described in embodiments 3 to 10.

[0161] The thermal runaway flue gas treatment device includes a mixed exhaust unit 100 and a thermal runaway emission pipeline 300; multiple battery packs 400 are installed inside an energy storage cabinet 600; the mixed exhaust unit 100 in the thermal runaway flue gas treatment device is located outside the energy storage cabinet 600; the thermal runaway emission pipeline 300 includes a main pipe 302 and multiple branch pipes 301; each battery pack 200 has a branch pipe 301 connected between its flue gas outlet and the main pipe 302; the thermal runaway flue gas is transported to the outside of the housing 500 and then enters the thermal runaway emission pipeline 300; the battery pack 200 includes a housing 500, an explosion relief pipeline 700 and multiple individual batteries 400; the multiple individual batteries 400 are located inside a housing 500, multiple flue gas inlets on the explosion relief pipeline 700 cover the explosion relief part of each individual battery 400, and the flue gas outlet of the explosion relief pipeline 700 is connected to the flue gas outlet of the battery pack.

[0162] When any single cell in a battery pack experiences thermal runaway, the thermal runaway gas is first discharged from the battery pack through the explosion relief pipe 700, and then sequentially discharged from the branch pipe and the main pipe to the mixer outside the energy storage cabinet. Finally, the thermal runaway gas and the safety gas are mixed to form a mixed gas that is safely discharged to the external environment.

[0163] Preferably, in this embodiment, the mixer is located above the energy storage cabinet, with the mixed gas outlet of the mixer facing the sky and at least 1 meter away from the top of the energy storage cabinet. This arrangement of the mixer further ensures the safety of the mixed gas after it is discharged from the energy storage cabinet.

[0164] It should be noted that: in this embodiment, the explosion relief pipe 700 is actually similar in structure to the thermal runaway discharge pipe in embodiment 13, and also includes branch pipes and main pipes; in some other embodiments, a pipe can also be fixed to the top of each individual cell and cover the explosion relief part of each individual cell.

[0165] In some other embodiments, the explosion relief pipe 700 may not be installed in the battery pack. The thermal runaway flue gas can be discharged directly to the mixer outside the energy storage cabinet through the thermal runaway emission pipe after passing through the battery pack housing. However, this method may cause the thermal runaway to spread inside the battery pack housing, which poses a certain safety hazard.

[0166] In some other embodiments, in order to make the thermal runaway discharge pipeline structure more compact and thus ensure the energy density of the energy storage cabinet, the main pipe in the thermal runaway discharge pipeline may adopt a support frame that supports multiple battery packs.

Claims

A thermal runaway flue gas treatment device for lithium-ion batteries, characterized in that... It includes a mixed exhaust unit, which mixes the thermal runaway fumes generated by the lithium-ion battery with safety gases to form a mixed gas before releasing it into the external environment. The thermal runaway flue gas treatment device according to claim 1 is characterized in that, The concentration of combustible gas in the mixture is reduced to below the lower explosive limit. The thermal runaway flue gas treatment device according to claim 2 is characterized in that, The mixed exhaust unit includes a three-way pipe assembly and a primary exhaust fan; the three-way pipe assembly includes a first pipe, a second pipe, and a third pipe that are interconnected; the first pipe serves as the mixed gas exhaust pipe and the primary exhaust fan is installed on the first pipe; the second pipe is used to introduce thermal runaway flue gas, and the third pipe is used to introduce safety gas. The thermal runaway flue gas treatment device according to claim 3 is characterized in that, A secondary exhaust fan is installed on the third pipeline. The thermal runaway flue gas treatment device according to claim 2 is characterized in that, The mixed exhaust unit includes a mixing chamber, a mixed gas exhaust pipe, and a blower; the mixing chamber is equipped with a thermal runaway flue gas inlet and a mixed gas exhaust outlet, and the mixed gas exhaust pipe is installed at the mixed gas exhaust outlet; the blower injects air into the mixing chamber. The thermal runaway flue gas treatment device according to claim 2 is characterized in that, The mixed exhaust unit includes a mixing chamber, a safety gas source, and a mixed gas exhaust pipe; the mixing chamber is equipped with a thermal runaway flue gas inlet and a mixed gas exhaust outlet, and the mixed gas exhaust pipe is installed at the mixed gas exhaust outlet; the safety gas source injects safety gas into the mixing chamber. The thermal runaway flue gas treatment device according to claim 6 is characterized in that, The safety gas in the safety gas source is carbon dioxide or nitrogen. The thermal runaway flue gas treatment device according to claim 1 is characterized in that, It also includes a purification tank containing a purification agent. After the lithium-ion battery experiences thermal runaway, the carbonates and solid particles carried in the thermal runaway flue gas are filtered by the purification agent. The gas is partially discharged from the purification tank and then enters the mixing exhaust unit. The mixing exhaust unit mixes the purified thermal runaway flue gas with a safety gas to form a mixed gas, which is then discharged to the external environment. The concentration of combustible gas in the mixed gas is below the lower explosive limit. The thermal runaway flue gas treatment device according to claim 8 is characterized in that, The purifying agent is an alkaline solution, which is used to filter out carbonates and acidic gases carried in the thermal runaway flue gas. The thermal runaway flue gas treatment device according to claim 9 is characterized in that, The alkaline solution is a 0.1 mol / L NaOH solution. The thermal runaway flue gas treatment apparatus according to any one of claims 8 to 10 is characterized in that, The mixed exhaust unit includes a main pipe and at least one branch pipe; the main pipe is installed vertically, the lower end of the main pipe is connected to the thermal runaway flue gas inlet of the purification tank, the upper end of the main pipe serves as the mixed gas outlet, one end of the branch pipe is connected to the main pipe, and the other end serves as the safety gas inlet. The thermal runaway flue gas treatment device according to claim 11 is characterized in that, The main pipe includes, from top to bottom, a first pipe section, a mixing section, and a second pipe section; there are two or more branch pipes, which are evenly distributed along the circumference; the inner diameter of the mixing section is greater than the inner diameter of the second pipe section, which is greater than the inner diameter of the first pipe section. The thermal runaway flue gas treatment device according to claim 11 is characterized in that, The safety gas is air; the safety gas inlet of the branch pipe is equipped with a non-powered exhaust fan. According to claim 1, the thermal runaway flue gas treatment device uses a lithium iron phosphate battery, characterized in that... It also includes a thermal runaway emission pipeline, and the mixed exhaust unit is a mixer; the thermal runaway emission pipeline is used to transport the thermal runaway flue gas generated by the thermal runaway of the lithium iron phosphate battery to the mixer, and the mixer is used to mix the thermal runaway flue gas with the safety gas to form a mixed gas before it is discharged to the external environment; wherein, the volume ratio of thermal runaway flue gas to safety gas in the mixed gas is less than 1:

7. The thermal runaway flue gas treatment device according to claim 14 is characterized in that, There is no ignition source within a 1m radius of the outlet of the mixed flue gas from the mixer. The thermal runaway flue gas treatment device according to claim 14 or 15 is characterized in that, The mixer has a tubular structure; the mixer includes a converging pipe section, a straight pipe section and a diffuser section connected sequentially from bottom to top. The lower port of the converging pipe section serves as the safety gas inlet and the upper port of the diffuser section serves as the mixed gas outlet. The part of the thermal runaway emission pipeline near the flue gas outlet is located in the converging pipe section, and the flow direction of the thermal runaway flue gas in the part of the pipe section is from bottom to top. The thermal runaway flue gas treatment device according to claim 16 is characterized in that, The safety gas is air. The thermal runaway flue gas treatment device according to claim 17 is characterized in that, It also includes a non-powered exhaust fan; the non-powered exhaust fan is installed at the lower port of the convergence pipe section. The thermal runaway flue gas treatment device according to claim 16 is characterized in that, It also includes a safety gas source connected to the safety gas inlet, which is filled with carbon dioxide or nitrogen. An electrical appliance, characterized in that, The device includes multiple individual cells and a thermal runaway gas treatment device as described in any one of claims 14 to 19; the thermal runaway gas treatment device includes a mixing exhaust unit and a thermal runaway emission pipeline; the mixing exhaust unit is a mixer; the thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each individual cell is connected to a branch pipe, and the branch pipe covers the explosion vent of the individual cell; the thermal runaway gas outlet of the main pipe is connected to the mixer of the thermal runaway gas treatment device. The electrical equipment according to claim 20 is characterized in that, The multiple individual cells are located inside a housing, and the mixer is located outside the housing. The main pipe in the thermal runaway emission pipeline delivers the thermal runaway flue gas to the outside of the housing and then into the mixer. An electrical appliance, characterized in that, The device includes an energy storage cabinet, multiple battery packs, and a thermal runaway gas treatment device as described in any one of claims 14 to 19. The thermal runaway gas treatment device includes a mixing exhaust unit and a thermal runaway emission pipeline. The mixing exhaust unit includes a mixer. The thermal runaway emission pipeline includes a main pipe and multiple branch pipes. Each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe. The multiple battery packs are installed inside the energy storage cabinet. The mixer is located outside the energy storage cabinet. Each battery pack includes a housing, a venting pipeline, and multiple individual batteries. The multiple individual batteries are located within a housing. Multiple flue gas inlets on the venting pipeline cover the venting section of each individual battery, and the flue gas outlet of the venting pipeline is connected to the flue gas outlet of the battery pack. The thermal runaway gas is sequentially transported from the venting pipeline, branch pipes, and main pipe to the mixer to mix with a safety gas. The electrical equipment according to claim 22 is characterized in that, The mixer is located above the energy storage cabinet, with the mixed gas outlet of the mixer facing the sky and at least 1 meter away from the top of the energy storage cabinet. An electrical appliance, characterized in that, It includes multiple individual cells, a thermal runaway emission pipeline, and a thermal runaway flue gas treatment device as described in any one of claims 2 to 7; the thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each individual cell is connected to a branch pipe, and the branch pipe covers the explosion vent of the individual cell; the thermal runaway flue gas outlet of the main pipe is connected to a mixed exhaust unit. The electrical equipment according to claim 24 is characterized in that, The multiple individual cells are located inside a housing, and the thermal runaway flue gas treatment device is located outside the housing. The main pipe in the thermal runaway emission pipeline transports the thermal runaway flue gas to the outside of the housing and then into the thermal runaway flue gas treatment device. An electrical appliance, characterized in that, The device includes an energy storage cabinet, multiple battery packs, a thermal runaway emission pipeline, and a thermal runaway flue gas treatment device as described in any one of claims 2 to 7. The thermal runaway emission pipeline includes a main pipe and multiple branch pipes. Each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe. The multiple battery packs are installed inside the energy storage cabinet. The thermal runaway flue gas treatment device is located outside the energy storage cabinet. Each battery pack includes a housing, a venting pipeline, and multiple individual batteries. The multiple individual batteries are located within a housing. Multiple flue gas inlets on the venting pipeline cover the venting section of each individual battery, and the flue gas outlet of the venting pipeline is connected to the flue gas outlet of the battery pack. The thermal runaway flue gas is sequentially transported from the venting pipeline, branch pipes, and main pipe to a mixing exhaust unit to mix with a safety gas. The electrical equipment according to claim 26 is characterized in that, The mixed exhaust unit is located above the energy storage cabinet, with the mixed gas outlet of the mixed exhaust unit facing the sky and at least 1 meter away from the top of the energy storage cabinet. An electrical appliance, characterized in that, The device includes multiple individual cells, a thermal runaway emission pipeline, and a thermal runaway flue gas treatment device as described in any one of claims 8 to 13; the thermal runaway flue gas treatment device includes a purification tank and a mixed exhaust unit; the thermal runaway emission pipeline includes a main pipe and multiple branch pipes; each individual cell is connected to a branch pipe, and the branch pipe covers the explosion vent of the individual cell; the thermal runaway flue gas outlet of the main pipe is connected to the purification tank; a mixed exhaust unit is installed on the top of the purification tank. The electrical equipment according to claim 28 is characterized in that, The multiple individual batteries are located inside a housing, while the purification tank and the mixed exhaust unit are located outside the housing. The main pipe in the thermal runaway emission pipeline transports the thermal runaway flue gas to the outside of the housing and then into the purification tank. An electrical appliance, characterized in that, The device includes an energy storage cabinet, multiple battery packs, a thermal runaway emission pipeline, and a thermal runaway flue gas treatment device as described in any one of claims 8 to 13. The thermal runaway flue gas treatment device includes a purification tank and a mixing exhaust unit. The thermal runaway emission pipeline includes a main pipe and multiple branch pipes. Each battery pack's flue gas outlet is connected to a branch pipe between itself and the main pipe. Multiple battery packs are installed inside the energy storage cabinet. At least the mixing exhaust unit in the thermal runaway flue gas treatment device is located outside the energy storage cabinet. Each battery pack includes a housing, a venting pipeline, and multiple individual batteries. Multiple individual batteries are located within a housing. Multiple flue gas inlets on the venting pipeline cover the venting section of each individual battery, and the flue gas outlet of the venting pipeline is connected to the flue gas outlet of the battery pack. The thermal runaway flue gas is sequentially transported from the venting pipeline, branch pipes, and main pipe to the purification tank, where carbonates and solid particles carried in the thermal runaway flue gas are filtered. The gaseous portion of the thermal runaway flue gas enters the mixing exhaust unit and mixes with a safety gas. The electrical equipment according to claim 30 is characterized in that, The mixed exhaust unit is located above the energy storage cabinet, with the mixed gas outlet of the mixed exhaust unit facing the sky and at least 1 meter away from the top of the energy storage cabinet.

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