Battery pack and electric vehicle

Abstract

The utility model provides a battery pack and an electric vehicle, and mainly solves the problem of potential safety hazards caused by thermal runaway of the battery pack. The battery pack comprises a box body and a battery module, 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; a first through hole and a second through hole are formed in the partition plate; a three-way pipe is arranged in the fire-fighting bin, a first port of the three-way pipe is connected with the first through hole, a second port of the three-way pipe is provided with a first one-way valve, and a third port of the three-way pipe is connected with a smoke outlet in the box body; and the second through hole is connected with a second one-way valve. When thermal runaway happens to a battery module in the battery bin, thermal runaway smoke enters the fire-fighting bin through the first one-way valve, when the pressure in the battery bin reaches a certain value, the explosion venting part on the smoke exhaust port is opened, the thermal runaway smoke is exhausted out of the battery pack, and fire-fighting liquid in the fire-fighting bin enters the battery bin through the second one-way valve; and the battery module is cooled and extinguished, so that the spreading of thermal runaway is avoided, and the safety of the battery pack is improved.

Description

Technical Field

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

[0002] With the wide application of lithium-ion batteries, the safe use of lithium-ion batteries has also attracted attention. Since a plurality of lithium-ion batteries in the battery pack are highly concentrated, under the influence of factors such as overcharging, over-discharging, overheating, and mechanical collision of the lithium-ion batteries, the battery diaphragm collapses and internal short circuits are caused, thereby resulting in thermal runaway, which may ultimately cause the battery to catch fire inside and even cause an explosion in severe cases, posing a safety hazard. Summary of the Invention

[0003] In order to solve the problem of safety hazards caused by thermal runaway of the battery pack, the utility model provides a battery pack and an electric vehicle.

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

[0005] A battery pack includes a box body and a battery module; the inner cavity of the box body is separated into a battery compartment and a fire protection compartment by a partition; the battery module is arranged in the battery compartment; there is fire protection liquid in the fire protection compartment; the partition is provided with a first through hole and a second through hole; a three-way pipe is arranged in the fire protection compartment, a first port of the three-way pipe is connected to the first through hole, a first one-way valve for allowing the hot runaway smoke in the battery compartment to enter the fire protection compartment is arranged at a second port of the three-way pipe, a third port of the three-way pipe is connected to a smoke exhaust port on the box body, and a pressure relief part is arranged on the smoke exhaust port; a second one-way valve for allowing the fire protection liquid in the fire protection compartment to enter the battery compartment is connected to the second through hole; the opening pressures of the first one-way valve and the second one-way valve meet the following conditions: before the pressure relief part on the smoke exhaust port opens, the first one-way valve can open, and the hot runaway smoke in the battery compartment enters the fire protection compartment through the first one-way valve; after the pressure relief part on the smoke exhaust port opens, the second one-way valve can open, and the fire protection liquid in the fire protection compartment enters the battery compartment through the second one-way valve.

[0006] Further, a smoke exhaust pipe is connected to the smoke exhaust port, and the length of the smoke exhaust pipe is greater than 0.2 m.

[0007] Further, the outlet of the smoke exhaust pipe is arranged downward.

[0008] Further, the initial pressures of the fire protection compartment and the battery compartment are the same, and at the same time, the opening pressures of the first one-way valve and the second one-way valve are the same.

[0009] Further, the opening pressure of the pressure relief part is 0.3 MP, and the opening pressures of the first one-way valve and the second one-way valve are both 0.1 MP.

[0010] Further, the smoke exhaust port is arranged at the top of the box body, and the explosion venting part on the smoke exhaust port is an explosion venting film.

[0011] Further, the fire extinguishing liquid is fluorinated liquid or water.

[0012] Further, the battery compartment is filled with a flame retardant material, and the battery module is coated in the flame retardant fuel.

[0013] The present utility model also provides an electric vehicle, including the above battery pack, and the battery pack is arranged on the frame of the electric vehicle.

[0014] Compared with the prior art, the technical solution of the present utility model has the following advantages:

[0015] 1. In the battery pack of the present utility model, the inner cavity of the box body includes a battery compartment and a fire protection compartment. There is fire extinguishing liquid in the fire protection compartment. When thermal runaway occurs in the battery module in the battery compartment, the thermal runaway smoke enters the fire protection compartment through the first one-way valve, squeezing the fire extinguishing liquid in the fire protection compartment; when the pressure in the battery compartment reaches a certain value, the explosion venting part on the smoke exhaust port opens, and the thermal runaway smoke is discharged from the battery pack. At this time, the fire extinguishing liquid in the fire protection compartment enters the battery compartment through the second one-way valve to cool down and extinguish the fire of the battery module, so as to avoid the spread of thermal runaway and improve the safety of the battery pack.

[0016] At the same time, the present utility model installs the first one-way valve and the second one-way valve in the box body. The first one-way valve and the second one-way valve are used in cooperation. When thermal runaway occurs in the battery module, the fire extinguishing liquid in the fire protection compartment can be squeezed into the battery compartment in a timely and reliable manner. Compared with the electrical signal triggering methods such as setting temperature sensors or pressure sensors, the mechanical triggering method of the first one-way valve and the second one-way valve has a reliable opening method and can maintain high reliability during the long-term use of the battery pack.

[0017] 2. A smoke pipe is connected to the smoke exhaust port of the battery pack of the present utility model. The smoke pipe is a pipe with a certain length. The smoke pipe spatially isolates the discharged thermal runaway smoke from the battery pack, so that there is a certain safety distance between the discharged thermal runaway smoke and the battery pack, avoiding the influence of the discharged thermal runaway smoke on the battery module in the box body.

[0018] 3. In the battery pack of the present utility model, the outlet of the smoke pipe is arranged downward, so that the thermal runaway smoke can be discharged smoothly and in a timely manner. At the same time, the outlet of the smoke pipe is arranged downward, so that its exhaust direction is towards the ground, avoiding the discharged thermal runaway air flow from burning passengers or damaging the electric vehicle.

[0019] 4. In the battery pack of the present utility model, when selecting the first one-way valve and the second one-way valve, the opening pressure P0 of the pressure relief part is greater than the opening pressure P1 of the first one-way valve and the opening pressure P2 of the second one-way valve, and the first one-way valve and the second one-way valve adopt valves with the same opening pressure. This kind of setting facilitates cost control during procurement and assembly, and also facilitates on-site assembly, avoiding potential hazards caused by installation errors.

[0020] 5. In the battery pack of the present utility model, the smoke exhaust port is arranged at the top of the box body and on the side far from the battery compartment. This kind of setting enables the hot runaway smoke to be discharged smoothly. At the same time, it can also increase the distance between the discharged hot runaway smoke and the battery module, further avoiding the influence of the discharged hot runaway smoke on the battery module in the battery compartment.

[0021] 6. In the battery pack of the present utility model, the battery compartment is filled with a flame retardant material, and the battery module is coated in the flame retardant fuel. The flame retardant material not only prevents the spread of hot runaway in the battery compartment, but also further avoids the combustion of the battery compartment.

[0022] Other advantages, objectives, and features of the present utility model will be partially reflected by the following description, and partially will also be understood by those skilled in the art through the research and practice of the present utility model. Brief Description of the Drawings

[0023] 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 following drawings 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.

[0024] Figure 1 It is a schematic structural diagram of the battery pack in Embodiment 1 of the present utility model;

[0025] Figure 2 It is a schematic diagram of the fire compartment in Embodiment 1 of the present utility model filled with fire extinguishing liquid;

[0026] Figure 3 It is a cross-section of the battery pack in Embodiment 1 of the present utility model Figure 1 ;

[0027] Figure 4 It is a cross-section of the battery pack in Embodiment 1 of the present utility model Figure 2 ;

[0028] Figure 5 It is a schematic diagram of the battery pack (with a smoke pipeline) in Embodiment 1 of the present utility model;

[0029] Figure 6Schematic diagram of the electric vehicle according to Embodiment 2 of the present utility model;

[0030] Figure 7 Installation schematic diagram of the battery pack on the electric vehicle according to Embodiment 2 of the present utility model Figure 1 ;

[0031] Figure 8 Installation schematic diagram of the battery pack on the electric vehicle according to Embodiment 2 of the present utility model Figure 2 。

[0032] Reference numerals: 100 - battery pack, 200 - electric vehicle, 1 - box body, 2 - battery module, 3 - fire extinguishing liquid, 4 - three - way pipe, 5 - first check valve, 6 - second check valve, 7 - smoke exhaust pipeline, 11 - partition board, 12 - battery compartment, 13 - fire protection compartment, 14 - smoke exhaust port, 15 - explosion venting part, 21 - single cell, 22 - battery management system, 111 - first through hole, 112 - second through hole. Detailed implementation manners

[0033] To make the above - mentioned objects, features and advantages of the present utility model more obvious and understandable, the following detailed description of the specific implementation manners of the present utility model is made in conjunction with the accompanying drawings of the specification. Obviously, the described embodiments are 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.

[0034] In this specification, "other embodiments" appearing in different places do not all refer to the same embodiment, nor are they separate or alternative embodiments that are mutually exclusive with 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 specifying 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.

[0035] In the description of this specification, unless otherwise clearly defined and limited, 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, or indirectly connected through an intermediate member, or it can be the internal communication of two components. For those of ordinary skill in the art, the specific meaning of the above - mentioned terms in the present utility model can be understood according to specific circumstances.

[0036] Meanwhile, 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 element 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.

[0037] Existing battery packs generally include multiple single cells, and the multiple single cells are closely arranged in the box body of the battery pack. During the use of the battery pack, or during overcharging, over-discharging, and mechanical collisions, thermal runaway is likely to occur. When thermal runaway occurs in the battery, a series of chemical reactions will occur inside, releasing a large amount of heat and gas, posing a safety hazard. Based on this, the present utility model provides a fire protection chamber in the battery pack, and there is fire protection liquid in the fire protection chamber. When thermal runaway occurs in the battery pack, the fire protection liquid enters the battery chamber to prevent the spread of thermal runaway and deal with the battery with thermal runaway in the battery chamber, so as to improve the safety of the battery pack during use.

[0038] At the same time, the present utility model installs a first one-way valve and a second one-way valve in the box body. The thermal runaway smoke in the battery chamber is introduced into the fire protection chamber through the first one-way valve to squeeze the fire protection liquid in the fire protection chamber. When the thermal runaway smoke in the battery chamber is discharged, a pressure difference is generated between the fire protection chamber and the battery chamber, and the fire protection liquid in the fire protection chamber enters the battery chamber through the second one-way valve, and then fire protection measures such as cooling and extinguishing the battery module in the battery chamber are carried out. It can be seen that the first one-way valve and the second one-way valve are used in cooperation. When thermal runaway occurs in the battery module, the fire protection liquid in the fire protection chamber can be squeezed into the battery chamber in a timely and reliable manner. Compared with the electrical signal triggering methods such as setting temperature sensors or pressure sensors, the mechanical triggering method of the first one-way valve and the second one-way valve has a reliable opening method and can maintain high reliability during the long-term use of the battery pack.

[0039] Embodiment 1

[0040] As Figures 1 to 4 shown, the battery pack 100 provided in this embodiment includes a box body 1 and a battery module 2. The inner cavity of the box body 1 is divided into a battery chamber 12 and a fire protection chamber 13 by a partition 11; the battery module 2 is arranged in the battery chamber 12 and is the power supply main body of the battery pack 100; there is fire protection liquid 3 in the fire protection chamber 13 to provide safety protection for the battery pack 100.

[0041] The above-mentioned box body 1 is an enclosed box body, which mainly integrally installs the battery module 2 and also provides safety protection for the battery module 2, so that the battery module 2 is protected from impacts, vibrations, drops, 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 addition, to avoid the risk of short circuit between the battery module 2 in the box body 1 and external devices, the above-mentioned box body 1 is generally made of an insulating material with relatively high stiffness.

[0042] As Figure 2 shown, the battery module 2 mainly includes a battery management system 22, a wiring terminal, and a plurality of single cells 21. The plurality of single cells 21 are connected in series to meet different capacity requirements. The single cell 21 can be an existing single cylindrical battery, a square shell battery, or a soft pack battery. The battery module 2 is electrically connected to an external circuit or an electrical device through the wiring terminal. The wiring terminal can be arranged on the box body 1 and exposed outside the box body 1 for convenient charging and discharging. During installation, the wiring terminal can be fixedly connected to the box body 1 and is non-removable from the box body 1, or can be detachably connected to the box body 1. The battery management system 22 (BMS) mainly monitors the working states of the single cells 21. During installation, the battery management system 22 can be arranged inside the box body 1 or outside the box body 1. When arranged inside the box body 1, the connection with the single cells 21 is more convenient and reliable. When arranged outside the box body 1, it is convenient for later maintenance and replacement.

[0043] In this embodiment, the capacity requirements of the battery pack are met by a plurality of series-connected cylinders. The cylindrical batteries are installed in the battery compartment 12 through brackets. In addition, a positioning structure can also be provided in the battery compartment 12 to position and install the battery module 2, and at the same time, it also prevents the battery module 2 from shaking significantly inside the box body 1. In addition, a flame-retardant material can also be filled in the above-mentioned battery compartment 12, and the battery module 2 is coated with the flame-retardant fuel. The flame-retardant material not only prevents the spread of thermal runaway in the battery compartment 12, but also further prevents the battery compartment 12 from catching fire.

[0044] As Figure 2 shown, the inner cavity of the box body 1 in this embodiment is separated by a partition 11 into a battery compartment 12 and a fire protection compartment 13. When specifically arranged, the battery compartment 12 and the fire protection compartment 13 can be arranged side by side or one above the other, and are specifically arranged according to the use scenario and size of the battery pack 100.

[0045] In this embodiment, during actual use, for convenient installation and placement, the box body 1 is generally a rectangular shell. At this time, the box body 1 can specifically adopt the following several structures:

[0046] First, the rectangular housing has a structure with one end open. The open end of the rectangular housing is sealed by a cover plate. At the same time, a detachable partition 11 is provided inside the rectangular housing. Among them, the cavity between the partition 11 and the bottom plate of the rectangular housing is the battery compartment 12, and the cavity between the cover plate and the partition 11 is the fire protection compartment 13;

[0047] Second, the rectangular housing has a structure with both ends open. Among them, one open end is sealed by a first cover plate, and the other open end is sealed by a second cover plate. A partition 11 is integrally provided inside the cavity of the rectangular housing. The cavity between the first cover plate and the partition 11 is the fire protection compartment 13, and the cavity between the second end cover and the partition 11 is the battery compartment 12.

[0048] In the first box structure described above, after all components are installed, when replacing and repairing the devices in the battery compartment 12, it is necessary to remove all the devices in the fire protection compartment 13 and the partition 11 before proceeding. In addition, when the partition 11 is detachably connected, there will inevitably be a gap between the partition 11 and the inner wall of the box body 1. When the partition 11 and the box body 1 are used for a long time, it is possible that the fire protection liquid 3 in the fire protection compartment 13 leaks into the battery compartment 12. Therefore, the second box structure is a better structure. The second box structure not only facilitates the installation of the devices in the fire protection compartment 13 and the battery compartment 12, but also avoids the above leakage problem, and at the same time the whole box body 1 is easy to process and manufacture.

[0049] In this embodiment, a smoke exhaust port 14 is provided on the fire protection compartment 13 of the box body 1 for exhausting the thermal runaway smoke in the battery compartment 12. A pressure relief part 15 is also provided on the smoke exhaust port 14. The pressure relief part 15 specifically adopts a pressure relief membrane or a pressure relief valve, etc. When the battery pack 100 is in normal use, the smoke exhaust port 14 is sealed. When the single battery 21 in the battery compartment 12 has a thermal runaway, when the pressure in the battery compartment 12 reaches a certain value, the pressure relief part 15 is opened, and the thermal runaway smoke is discharged through the smoke exhaust port 14. In this embodiment, the above-mentioned smoke exhaust port 14 is provided at the top of the fire protection compartment 13 and on the side far from the battery compartment 12. This setting makes it difficult for the fire protection liquid in the fire protection compartment 13 to leak from the smoke exhaust port, and at the same time enables the thermal runaway smoke in the battery compartment 12 to be discharged from the battery compartment 12 more smoothly and quickly, avoiding the accumulation of thermal runaway smoke in the battery compartment 12.

[0050] Such as Figures 2 to 4As shown in the figure, the inner cavity of the box body 1 in this embodiment is separated by a partition 11 into a battery compartment 12 and a fire compartment 13. The partition 11 is provided with a first through hole 111 and a second through hole 112. A three-way pipe 4 is arranged in the fire compartment 13. The first port of the three-way pipe 4 is connected to the first through hole 111. A first one-way valve 5 is arranged at the second port of the three-way pipe 4. When the pressure in the battery compartment 12 is greater than the pressure in the fire compartment 13 and the pressure difference between the battery compartment 12 and the fire compartment 13 is greater than the opening pressure of the first one-way valve 5, the thermal runaway flue gas in the battery compartment 12 enters the fire compartment 13 through the first one-way valve 5. The third port of the three-way pipe 4 is connected to the smoke exhaust port 14 on the box body 1, and a pressure relief part 15 is arranged on the smoke exhaust port 14. A second one-way valve 6 is connected to the second through hole 112, and the second one-way valve 6 is installed in the battery compartment. When the pressure in the fire compartment 13 is greater than the pressure in the battery compartment 12 and the pressure difference between the inner cavities of the fire compartment 13 and the battery compartment 12 is greater than the opening pressure of the second one-way valve 6, the second one-way valve 6 opens, and the fire extinguishing liquid 3 in the fire compartment 13 enters the battery compartment 12 through the second one-way valve 6.

[0051] To ensure the sealing performance between the fire compartment 13 and the battery compartment 12, during specific installation, when the second one-way valve 6 is connected to the second through hole 112 on the partition 11, a gasket needs to be installed to ensure the seal at the connection. When the three-way pipe 4 is connected to the first through hole 111, the sealing performance here also needs to be ensured. Specifically, the seal can also be achieved by using a gasket, or the three-way pipe 4 can be welded to the first through hole 111 of the partition 11.

[0052] When a thermal runaway occurs in the battery module in the battery compartment 12, the thermal runaway flue gas first enters the fire compartment 13 through the first one-way valve 5. At this time, the pressure relief part 15 is in the unopened state. When the pressure in the battery compartment 12 exceeds the opening pressure of the pressure relief part 15, the pressure relief part 15 opens to relieve the pressure of the battery compartment 12. After the thermal runaway flue gas in the battery compartment 12 is discharged, the pressure in the fire compartment 13 is greater than the pressure in the battery compartment 12. At this time, the second one-way valve 6 opens, enabling the fire extinguishing liquid in the fire compartment 13 to smoothly enter the battery compartment 12.

[0053] The selection of the opening pressure P0 of the above-mentioned pressure relief part 15, the opening pressure P1 of the first one-way valve 5, and the opening pressure P2 of the second one-way valve 6 is as follows:

[0054] If the initial pressure Px of the fire compartment 13 is the same as the initial pressure value Pd of the battery compartment 12, at this time, the opening pressure P0 of the pressure relief part 15 > Px + P1; the opening pressure P1 of the first one-way valve 5 needs to meet the following conditions: 0 < P1 < the opening pressure P0 of the pressure relief part 15; the opening pressure P2 of the second one-way valve 6 needs to meet the following conditions: 0 < P2 < the opening pressure P0 of the pressure relief part 15;

[0055] If the initial pressure Px of the fire protection chamber 13 is greater than the initial pressure value Pd of the battery chamber 12, at this time, the opening pressure P0 of the explosion venting part 15 > Px + P1; then the opening pressure P1 of the first one-way valve 5 needs to meet the following conditions: 0 < P1 < the opening pressure P0 of the explosion venting part 15; the opening pressure P2 of the second one-way valve 6 needs to meet the following conditions: Px - Pd < P2 < the opening pressure P0 of the explosion venting part 15;

[0056] If the initial pressure Px of the fire protection chamber 13 is less than the initial pressure value Pd of the battery chamber 12, and the opening pressure P0 of the explosion venting part 15 > Px + P1, then the opening pressure P1 of the first one-way valve 5 needs to meet the following conditions: Pd - Px < P1 < the opening pressure P0 of the explosion venting part 15; the opening pressure P2 of the second one-way valve 6 needs to meet the following conditions: 0 < P2 < the opening pressure P0 of the explosion venting part 15;

[0057] In summary, regardless of the initial pressure value Pd in the battery chamber 12 and the initial pressure Px in the fire protection chamber 13, the opening pressure P1 of the first one-way valve 5 and the opening pressure P2 of the second one-way valve 6 both need to be less than the opening pressure P0 of the explosion venting part 15. At the same time, the opening pressures of the first one-way valve 5 and the second one-way valve 6 meet the following conditions: before the explosion venting part 15 on the smoke exhaust port opens, the first one-way valve 5 can open, and the thermal runaway smoke in the battery chamber 12 enters the fire protection chamber 13 through the first one-way valve 5. After the explosion venting part 15 on the smoke exhaust port opens, the second one-way valve 6 can open, and the fire protection liquid in the fire protection chamber 13 enters the battery chamber 12 through the second one-way valve.

[0058] After the battery pack is manufactured, the initial pressure Px of the fire protection chamber 13 and the initial pressure Pd of the battery chamber 12 are generally the same. At this time, when selecting the first one-way valve 5 and the second one-way valve 6, the opening pressure P0 of the explosion venting part 15 is greater than P1 and P2, and the opening pressure P1 of the first one-way valve 5 is the same as the opening pressure P2 of the second one-way valve 6. The first one-way valve 5 and the second one-way valve 6 adopt valves with the same opening pressure. This kind of setting is convenient for cost control during procurement and assembly, and is also convenient for on-site assembly, avoiding potential hazards caused by installation errors. In this embodiment, the opening pressure P0 of the explosion venting part on the smoke exhaust port can be 0.3MP, and the opening pressures P1 of the first one-way valve 5 and P2 of the second one-way valve 6 can both be 0.1MP.

[0059] In this embodiment, the fire protection chamber 13 is filled with the fire protection liquid 3, and the requirement for its filling amount is: it can extinguish the fire of the battery module 2 in the battery chamber 12. The above-mentioned fire protection liquid 3 can specifically adopt fire protection liquids such as fluorinated liquid and water. After any single battery 21 has a thermal runaway, the fire protection liquid 3 enters the battery chamber 12 to prevent the continuous thermal runaway; at the same time, the fire protection liquid 3 can also cool the thermal runaway smoke, reducing the temperature of the thermal runaway smoke after it is discharged, and further reducing the probability of its combustion.

[0060] As Figure 5 shown, for the convenience of discharging the hot - runaway flue gas in the battery compartment 12, a flue gas pipeline 7 is connected to the smoke exhaust port 14. The inlet of the flue gas pipeline 7 is connected to the smoke exhaust port 14, and the flue gas pipeline 7 is a pipeline with a certain length, which safely isolates the battery pack 100 from the discharged hot - runaway flue gas, so that the discharged hot - runaway flue gas will not affect the battery pack 100. Specifically, when setting, it is relatively better that the length of the flue gas pipeline 7 is greater than 0.2m. This kind of setting increases the distance between the discharged hot - runaway flue gas and the battery module 2, and further avoids the discharged hot - runaway flue gas from affecting the battery module 2 in the battery compartment 12.

[0061] When manufacturing the above - mentioned battery pack 100, first, place each single - cell battery 21 in the battery compartment 12, and conduct electrical connections between the single - cell batteries 21, as well as the connections between each single - cell battery 21 and the battery management system 22 and the terminal. Secondly, install the second one - way valve 6, the three - way pipe 4, and the first one - way valve 5, etc. Subsequently, fill the fire - fighting liquid 3 in the fire - fighting compartment 13, and finally seal the open end of the box body 1 with a cover plate.

[0062] After the battery pack is manufactured, the pressure in the battery compartment 12 is generally the same as the pressure in the fire - fighting compartment 13. When one or more batteries in the battery pack 100 undergo thermal runaway, the hot - runaway flue gas passes through the first through - hole 111 on the partition 11 and enters the three - way pipe 4. At this time, the pressure in the battery compartment 12 is greater than the pressure in the fire - fighting compartment 13. When the pressure difference between the inner cavities of the battery compartment 12 and the fire - fighting compartment 13 is greater than the opening pressure of the first one - way valve 5, the first one - way valve 5 opens, and the hot - runaway flue gas in the battery compartment 12 enters the fire - fighting compartment 13 through the first one - way valve 5. At this time, since the opening pressure of the explosion - venting part 15 is greater than the opening pressure (0.1MP) of the first one - way valve 5, the hot - runaway flue gas will not be discharged through the explosion - venting part 15 on the smoke exhaust port 14 of the box body 1; as the hot - runaway flue gas in the battery compartment 12 continuously increases, the hot - runaway flue gas in the fire - fighting compartment 13 also continuously increases. When the pressure in the battery compartment 12 continues to rise to the opening pressure (0.3MP) of the explosion - venting part 15 on the smoke exhaust port 14, the explosion - venting part 15 on the box body smoke exhaust port 14 opens, the battery compartment 12 relieves pressure, and the hot - runaway flue gas in the battery compartment 12 is discharged through the smoke exhaust port 14. As the hot - runaway flue gas in the battery compartment 12 gradually discharges, when the pressure in the battery compartment 12 is less than the pressure in the fire - fighting compartment 13, and the pressure difference between the fire - fighting compartment 13 and the battery compartment 12 is greater than the opening pressure (0.1MP) of the second one - way valve 6, the second one - way valve 6 opens, and the fire - fighting liquid 3 in the fire - fighting compartment 13 enters the battery compartment 12 to cool and extinguish the fire of the battery module 2 in the battery compartment 12, etc., to prevent the spread of thermal runaway of the battery module 2.

[0063] Embodiment 2

[0064] As Figures 6 to 8As shown in the figure, this embodiment provides an electric vehicle 200, which includes the battery pack 100 in Embodiment 1. When in use, the battery pack 100 is installed on the vehicle body of the electric vehicle 200 and is used to supply power to the electrical devices of the electric vehicle 200. The battery pack 100 can be installed under the seat of the electric vehicle 200. After installation, the outlet of the smoke pipe 7 is located at the position of the rear wheel of the electric vehicle, and the outlet of the smoke pipe 7 faces downward, having a safety distance from the driver.

[0065] When the battery pack 100 is being charged, it can be removed from the electric vehicle 200 and placed in a charging cabinet for charging, or it can be directly placed on the electric vehicle 200 for charging on a charging pile. When any single battery 21 in the battery pack 100 undergoes thermal runaway during the charging process, the battery management system 22 monitors the abnormal state of the battery pack 100 and issues a warning message (the warning light flashes or the buzzer sounds an alarm). At the same time, the fire extinguishing liquid in the fire compartment 13 provides safety protection for the thermal runaway battery module 2.

Claims

1. A battery pack, characterized in that, It includes a box body and a battery module; The inner cavity of the box body is separated into a battery compartment and a fire compartment by a partition; the battery module is arranged in the battery compartment; there is fire extinguishing liquid in the fire compartment; The partition is provided with a first through hole and a second through hole; a three-way pipe is arranged in the fire compartment, the first port of the three-way pipe is connected to the first through hole, a first one-way valve for allowing the hot runaway smoke in the battery compartment to enter the fire compartment is arranged at the second port of the three-way pipe, the third port of the three-way pipe is connected to the smoke exhaust port on the box body, and a pressure relief part is arranged on the smoke exhaust port; a second one-way valve for allowing the fire extinguishing liquid in the fire compartment to enter the battery compartment is connected to the second through hole; The opening pressures of the first one-way valve and the second one-way valve meet the following conditions; before the pressure relief part on the smoke exhaust port opens, the first one-way valve can open, and the hot runaway smoke in the battery compartment enters the fire compartment through the first one-way valve; after the pressure relief part on the smoke exhaust port opens, the second one-way valve can open, and the fire extinguishing liquid in the fire compartment enters the battery compartment through the second one-way valve.

2. The battery pack according to claim 1, characterized in that, A smoke pipe is connected to the smoke exhaust port, and the length of the smoke pipe is greater than 0.2 m.

3. The battery pack according to claim 2, wherein, The outlet of the smoke pipe is arranged downward.

4. The battery pack according to claim 1, characterized in that, The initial pressures of the fire compartment and the battery compartment are the same, and at the same time, the opening pressures of the first one-way valve and the second one-way valve are the same.

5. The battery pack according to claim 4, characterized in that, The opening pressure of the pressure relief part is 0.3 MP, and the opening pressures of the first one-way valve and the second one-way valve are both 0.1 MP.

6. The battery pack according to claim 5, characterized in that, The smoke exhaust port is arranged at the top of the box body, and the pressure relief part on the smoke exhaust port is a pressure relief membrane.

7. The battery pack according to claim 1, wherein The fire extinguishing liquid is fluorinated liquid or water.

8. The battery pack according to claim 7, wherein The battery compartment is filled with a flame retardant material, and the battery module is coated in the flame retardant fuel.

9. An electric vehicle, characterized in that, It includes the battery pack according to any one of claims 1 to 8, and the battery pack is arranged on the frame of an electric vehicle.

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