Battery pack

Abstract

The utility model provides a battery pack, which mainly solves the problem that potential safety hazards are generated after thermal runaway smoke in the existing battery pack is exhausted. 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 an isolation bin through a partition plate. First isolation liquid is arranged in the battery compartment, and the battery module is arranged in the first isolation liquid; second isolation liquid is arranged in the isolation bin; when the battery module in the battery compartment is subjected to thermal runaway, the first isolation liquid prevents thermal runaway flue gas in the battery compartment from influencing the single batteries which are not subjected to thermal runaway, and meanwhile, the first isolation liquid enters the thermal runaway single batteries to prevent the thermal runaway single batteries from continuously generating thermal runaway; the thermal runaway flue gas in the battery bin enters the isolation bin through the flue gas channel, and the second isolation liquid cools the thermal runaway flue gas, so that the discharged thermal runaway flue gas is not easy to burn, and the safety of the battery pack during use is improved.

Description

Technical Field

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

[0002] With the widespread application of lithium-ion batteries, the safe use of lithium-ion batteries has also attracted attention. Due to the high concentration of multiple lithium-ion batteries in the battery pack, under the influence of factors such as overcharge, over-discharge, overheating, and mechanical collision of lithium-ion batteries, the battery diaphragm collapses and internal short circuits occur, resulting in thermal runaway, which may eventually lead to internal fire in the battery, and in severe cases, cause explosions, posing safety hazards.

[0003] When a lithium-ion battery is in complete thermal runaway, the temperature inside the battery can reach over 500°C. The gases generated during the thermal runaway process cause the internal pressure of the battery to increase, causing the battery shell to expand and rupture, spraying and releasing the evaporated electrolyte and reaction gases inside the battery to form thermal runaway flue gas. The above-mentioned thermal runaway flue gas includes combustible gases such as hydrogen, carbon monoxide, methane, and ethylene. When the thermal runaway flue gas is discharged out of the battery pack, the combustible gas comes into contact with the air and burns. The flames and heat generated during the combustion can easily cause the combustion of the batteries and thermal runaway flue gas in the battery pack, resulting in more intense combustion or explosion and other safety hazards. Summary of the invention

[0004] In order to solve the potential safety hazard caused by the exhaust of smoke due to thermal runaway in a battery pack, the utility model provides a battery pack.

[0005] In order to achieve the above object, the technical solution of the utility model is:

[0006] A battery pack comprises a case and a battery module; the inner cavity of the case is divided into a battery compartment and an isolation compartment by a partition, and a smoke passage connecting the battery compartment and the isolation compartment is provided on the partition; a first isolation liquid is provided in the battery compartment, and the battery module is arranged in the first isolation liquid, and the first isolation liquid is an insulating and non-flammable liquid; a second isolation liquid is provided in the isolation compartment, and a smoke outlet is provided on the isolation compartment, and the second isolation liquid is a non-flammable liquid; when thermal runaway occurs in the battery module in the battery compartment, the thermal runaway smoke enters the isolation compartment through the smoke passage, passes through the second isolation liquid in the isolation compartment, and is discharged through the smoke outlet.

[0007] Furthermore, the smoke channel is located on the top of the partition and is connected to a smoke pipeline, and the outlet of the smoke pipeline is immersed in the second isolation liquid.

[0008] Furthermore, an isolation membrane is provided on the smoke channel, and the pressure bearing capacity of the isolation membrane is smaller than the pressure bearing capacity of the explosion relief membrane of the battery cell in the battery module.

[0009] Furthermore, the filling height of the first isolation liquid can submerge the poles of each single battery in the battery module.

[0010] Furthermore, the smoke outlet is arranged at the top of the isolation chamber and is located on a side away from the battery chamber.

[0011] Furthermore, an exhaust valve is provided on the smoke outlet.

[0012] Furthermore, the first isolation liquid and the second isolation liquid are the same liquid.

[0013] Furthermore, the first isolation liquid is a fluorinated liquid.

[0014] Furthermore, the battery module includes a plurality of single cells connected in series. Along the arrangement direction of the single cells in the battery module, two side walls of the battery compartment are respectively provided with T-shaped positioning blocks for positioning each single cell, and the bottom of the T-shaped positioning blocks is also provided with a supporting boss for supporting each single cell.

[0015] Furthermore, a heat insulation plate is provided between each single battery in the battery module.

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

[0017] 1. In the battery pack of the utility model, the inner cavity of the box includes a battery compartment and an isolation compartment. The battery compartment contains an insulating and non-flammable first isolation liquid, and the isolation compartment contains a non-flammable second isolation liquid. The battery module is immersed in the first isolation liquid. When the battery module is working normally, the first isolation liquid transfers the heat generated by the battery module during operation to the box body for heat dissipation. At the same time, the first isolation liquid also provides insulation protection for the battery module to avoid short circuits between adjacent single cells. When any single cell in the battery module experiences thermal runaway, the first isolation liquid isolates and protects the battery module to prevent the thermal runaway smoke in the battery compartment from affecting the single cells that have not experienced thermal runaway, and the first isolation liquid can also enter the thermal runaway single cells to prevent the thermal runaway batteries from continuing to experience thermal runaway and prevent the spread of thermal runaway. The second isolation liquid in the isolation compartment cools the thermal runaway smoke discharged from the battery compartment so that the vaporized electrolyte in the thermal runaway smoke is cooled and liquefied, achieving gas-liquid separation and reducing the probability of combustion after the thermal runaway smoke is discharged. At the same time, the second isolation liquid cools the thermal runaway smoke to reduce the temperature of the thermal runaway smoke discharged from the box, making it less likely to burn or explode, thereby improving the safety of the battery pack when in use.

[0018] 2. In the battery pack of the utility model, the smoke channel is located at the top of the partition, and the smoke channel is connected to a smoke pipe, and the outlet of the smoke pipe is immersed in the second isolation liquid. This arrangement allows the thermal runaway smoke in the battery compartment to be discharged from the battery compartment more smoothly and quickly, avoiding the accumulation of thermal runaway smoke in the battery compartment.

[0019] 3. In the battery pack of the utility model, an isolation membrane is provided on the smoke channel, and the pressure bearing capacity of the isolation membrane is smaller than the pressure bearing capacity of the battery cell explosion venting membrane in the battery module, so that the isolation membrane can be opened in time when the battery is thermally runaway. When the battery module is working normally, the isolation membrane seals the battery compartment to prevent the second isolation liquid in the isolation compartment from flowing with the first isolation liquid in the battery compartment, which will affect the battery module.

[0020] 4. In the battery pack of the utility model, the filling height of the first isolation liquid can submerge the poles of each single cell in the battery module, so that each single cell can be submerged in the first isolation liquid. At this time, the first isolation liquid can fully contact the top, bottom and side walls of each single cell, and each part of the single cell can contact with the first isolation liquid for heat transfer, and the temperature uniformity of each part of the single cell is better.

[0021] 5. In the battery pack of the utility model, the smoke outlet is arranged at the top of the isolation compartment and is located on the side away from the battery compartment. This arrangement can increase the distance between the thermal runaway smoke and the battery module after it is discharged, and further avoid the influence of the discharged thermal runaway smoke on the battery module in the battery compartment.

[0022] 6. In the battery pack of the utility model, in order to facilitate the manufacture of the battery pack, the second isolation liquid adopts the same insulating non-flammable liquid as the first isolation liquid.

[0023] 7. In the battery pack of the utility model, along the arrangement direction of each single battery, T-shaped positioning blocks for positioning and installing each single battery are respectively provided on the two side walls of the battery compartment. The T-shaped positioning blocks not only position each single battery in its arrangement direction, but also position it in a direction perpendicular to the arrangement direction, so as to achieve reliable installation of each single battery and prevent the battery module from shaking in the box and colliding with the inner wall of the box.

[0024] 8. In the battery pack of the utility model, a heat insulation board is provided between each single battery in the battery module, and the heat insulation board insulates each single battery to avoid heat transfer between adjacent single batteries. At the same time, the heat insulation board can also suppress the deformation of the shells of two adjacent single batteries due to expansion, avoiding the safety hazards such as leakage, internal short circuit and thermal runaway caused by swelling and deformation, thereby improving the safety and reliability of the entire battery module.

[0025] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a schematic structural diagram of a battery pack according to an embodiment;

[0028] Figure 2 is a schematic structural diagram of a battery module in a battery pack of an embodiment;

[0029] Figure 3 It is a schematic diagram of the structure of the box body in the battery pack of the embodiment;

[0030] Figure 4 A schematic diagram of a battery pack in an embodiment filled with a first isolation liquid and a second isolation liquid;

[0031] Figure 5 is a cross-sectional view of a battery pack of an embodiment;

[0032] Figure 6 Schematic diagram of installing an exhaust valve in a battery pack of an embodiment.

[0033] Figure numerals: 1-box, 2-battery module, 3-first isolation liquid, 4-second isolation liquid, 5-exhaust valve, 11-partition, 12-battery compartment, 13-isolation compartment, 14-smoke channel, 15-smoke outlet, 16-smoke pipeline, 17-isolation membrane, 121-T-type positioning block, 122-support boss, 21-single battery, 22-connecting terminal, 23-battery management system, 24-heat insulation board. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary persons in the field without creative work should fall within the scope of protection of the utility model.

[0035] The "other embodiments" that appear in different places in this specification do not all refer to the same embodiment, nor are they separate or selective embodiments that are mutually exclusive with other embodiments. In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of this utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically limited.

[0036] In the description of this specification, unless otherwise clearly specified 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 a direct connection, an indirect connection through an intermediate, or the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0037] At the same time, in the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top, bottom, inside and outside" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as a limitation on the present invention.

[0038] Existing battery packs generally include multiple single cells, which are closely arranged in the box of the battery pack. Thermal runaway is prone to occur in the battery pack during use or when it is overcharged, over-discharged, or mechanically collided. When the battery is in thermal runaway, a series of chemical reactions will occur inside, releasing a large amount of heat and gas, such as: SEI film decomposition reaction (90-120°C), negative electrode and electrolyte reaction (100-350°C), electrolyte decomposition reaction (110-300°C), diaphragm shrinkage and melting reaction (>130°C), positive electrode and electrolyte reaction (200-300°C) and adhesive decomposition reaction (200-300°C), etc., and a large amount of thermal runaway smoke is generated, which contains combustible gases such as hydrogen, CO, CO2, and methane. The thermal runaway smoke is discharged from the box of the battery pack, and it is easy to burn after gathering. The flame and heat generated during combustion will affect the single cells in the battery pack, causing more intense combustion.

[0039] Based on this, the utility model fills a first isolation liquid and a second isolation liquid in the battery pack. The first isolation liquid is an insulating and non-flammable liquid, and the second isolation liquid is a non-flammable liquid. When the battery module is in thermal runaway, the first isolation liquid isolates and protects the battery module in the battery compartment to prevent the thermal runaway smoke in the battery compartment from affecting the single battery cells that have not experienced thermal runaway. At the same time, the first isolation liquid enters the thermal runaway single battery to prevent the thermal runaway battery from continuing to experience thermal runaway. The second isolation liquid performs gas-liquid separation and cooling on the thermal runaway smoke discharged from the battery compartment, so that the thermal runaway smoke discharged from the box is not easy to burn or explode, thereby improving the safety of the battery pack when in use.

[0040] like Figures 1 to 4 As shown, the battery pack provided in this embodiment includes a box body 1 and a battery module 2. The battery module 2 is arranged in the box body 1 and is the power supply body of the battery pack. The box body 1 is mainly used to integrate and install the battery module 2, and also provides safety protection for the battery module 2 to prevent the battery module 2 from impact, vibration, falling, etc. in the external environment.

[0041] like Figure 2 As shown, the battery module 2 mainly includes a battery management system 23, a terminal 22 and a plurality of single cells 21. The plurality of single cells 21 are arranged in series to meet different capacity requirements. The single cells 21 can be existing single cylindrical batteries, square shell batteries, and soft-pack batteries. For example, it includes 15 105Ah lithium iron phosphate square shell batteries, the electrical connection method is 1P15S, the parameters after assembly are 48V / 105Ah, the capacity is 5KWh, etc. The battery management system 23 (BMS) mainly monitors the working status of each single cell 21. During installation, the battery management system 23 can be set inside the box 1 or outside the box 1. When it is set inside the box 1, the connection with the single cell 21 is more convenient and reliable. When it is set outside the box 1, it is convenient for later maintenance and replacement.

[0042] The battery module 2 is electrically connected to an external circuit or an electrical device via a terminal block 22. The terminal block 22 can be disposed on the housing 1 and exposed to the housing 1 for easy charging and discharging. During installation, the terminal block 22 can be fixedly connected to the housing 1 and cannot be detached from the housing 1, or it can be detachably connected to the housing 1. Figure 2 As shown, the above-mentioned terminal 22 and battery management system 23 (BMS) are integrated on the same side outside the box 1 and are fixedly installed.

[0043] The box 1 of the battery pack is a closed box. The shape and size of the box 1 can be designed to be convenient for placement according to the application scenario of the battery module 2, such as a cylinder, prism, cube, etc. In actual use, for the convenience of installation and placement, the shape of the box 1 is preferably a cuboid. In addition, in order to avoid the risk of short circuit between the battery module 2 in the box 1 and external equipment, the box 1 is generally made of insulating material and a material with high rigidity.

[0044] like Figure 3 As shown, the inner cavity of the box body 1 in this embodiment is divided into a battery compartment 12 and an isolation compartment 13 by a partition 11. In order to ensure the strength and sealing of the box body 1, the box body 1 and the partition are generally manufactured by extrusion or stamping. The battery compartment 12 is filled with a first isolation liquid 3, and each single battery 21 is placed in the first isolation liquid 3 in the battery compartment 12. The isolation compartment 13 is filled with a second isolation liquid 4.

[0045] In the specific configuration, the battery compartment 12 and the isolation compartment 13 can be arranged left and right, or front and back, depending on the usage scenario and size of the battery pack. In addition, the partition 11 is provided with a smoke passage 14 connecting the battery compartment 12 and the isolation compartment 13. When a single battery in the battery compartment 12 undergoes thermal runaway, the thermal runaway smoke in the battery compartment 12 is transported to the isolation compartment 13 and then discharged.

[0046] In addition, a positioning structure may be provided on the battery compartment 12 to facilitate positioning and installation of the battery module 2 and to prevent the battery module 2 from shaking significantly in the box 1. The positioning structure is as follows:

[0047] First, the battery compartment 12 is provided with a plurality of positioning grooves corresponding to the single battery cells 21 one by one, and the positioning grooves are positioning structures, and each single battery cell 21 is inserted into the corresponding positioning groove;

[0048] Second, if Figure 2 and Figure 3 As shown, along the arrangement direction of each single battery 21, a plurality of T-shaped positioning blocks 121 are respectively provided on the two side walls of the battery compartment 12, and each single battery 21 is arranged between adjacent T-shaped positioning blocks 121. The T-shaped positioning blocks 121 not only position each single battery 21 in the arrangement direction, but also position each single battery 21 in a direction perpendicular to the arrangement direction, so as to achieve reliable installation of each single battery 21. At this time, a supporting boss 122 for supporting each single battery can be provided at the bottom of the above-mentioned T-shaped positioning block 121, and each single battery 21 is placed on the supporting boss 122, so that a channel is formed between the bottom of each single battery 21 and the bottom plate of the battery compartment 12, so that the bottom of each single battery 21 can be fully in contact with the first isolation liquid 3.

[0049] like Figure 2As shown, in this embodiment, a heat insulation board 24 may be provided between each single cell 21 in the battery module 2, and the heat insulation board 24 may be specifically a foam board or the like. Since the battery module is connected in series, when one of the single cells 21 is in thermal runaway, the electrical connection between the single cells 21 is disconnected. At the same time, since there is a heat insulation board 24 between each single cell, the heat insulation board 24 insulates each single cell 21 to avoid heat transfer between adjacent single cells 21, which can effectively prevent heat spread. Therefore, the thermal runaway single cell 21 will not affect other single cells 21 in the battery compartment 12. In addition, the heat insulation board 24 can also suppress the deformation of the shell of two adjacent single cells due to expansion, avoid the safety hazards such as leakage, internal short circuit and thermal runaway caused by bulging deformation, and improve the safety and reliability of the entire battery module.

[0050] like Figure 4 and Figure 5 As shown, in this embodiment, the battery compartment 12 is filled with a first isolation liquid 3, which is mainly an insulating and non-flammable liquid, and has the following functions:

[0051] First, the battery module 2 is isolated and protected to prevent the thermal runaway smoke in the battery compartment 12 from affecting the single battery cells that have not experienced thermal runaway;

[0052] Second, each single battery 21 is insulated to prevent a short circuit between adjacent single batteries 21;

[0053] Third, after any single cell 21 goes into thermal runaway, the first isolation liquid 3 enters the single cell in thermal runaway to prevent the single cell in thermal runaway from continuing to go into thermal runaway;

[0054] Fourth, when each single cell 21 is working normally, each single cell 21 is immersed in the first isolation liquid 3. The first isolation liquid 3 processes the heat generated by the single cell 21 when working, so that each single cell 21 in the battery compartment 12 is in a balanced temperature environment, avoiding large temperature differences between the single cells 21, thereby reducing the risk of thermal runaway and improving the safety of the battery pack.

[0055] like Figure 5 As shown, when the first isolation liquid 3 is filled, its filling height is preferably able to submerge the poles of each single battery 21. At this time, when each single battery 21 has thermal runaway and explodes from the top, the first isolation liquid 3 can promptly handle the single battery 21 in thermal runaway. In addition, after the first isolation liquid 3 submerges each single battery 21, the first isolation liquid 3 can fully contact the top, bottom and side wall of each single battery 21, and each part of the single battery 21 can contact the first isolation liquid 3 for heat transfer, and the temperature uniformity of the single battery 21 itself is good.

[0056] In this embodiment, the first isolation liquid 3 can be an insulating and non-flammable liquid such as fluorinated liquid or silicone oil, and the silicone oil can be a non-conductive and non-flammable liquid such as methyl silicone oil and dimethyl silicone oil.

[0057] like Figure 4 and Figure 5 As shown, in this embodiment, the isolation chamber 13 is filled with a second isolation liquid 4, and the second isolation liquid 4 is mainly a non-flammable liquid, which mainly has the following functions:

[0058] First, the thermal runaway flue gas is cooled so that the vaporized electrolyte in the thermal runaway flue gas is cooled and liquefied, achieving gas-liquid separation. The discharged thermal runaway flue gas does not contain electrolyte, reducing the probability of combustion of the thermal runaway flue gas.

[0059] Second, the thermal runaway flue gas is cooled, which reduces the temperature of the thermal runaway flue gas after it is discharged, further reducing the probability of combustion.

[0060] When the second isolation liquid 4 is filled in the isolation chamber 13, it can be fully filled or partially filled, as long as the thermal runaway flue gas discharged from the flue gas channel 14 can be discharged after passing through the second isolation liquid 4. The second isolation liquid 4 can specifically be a non-flammable and non-conductive liquid similar to the first isolation liquid 3, and other non-flammable liquids can also be used.

[0061] When the battery pack of this embodiment is filled, the second isolation liquid 4 and the first isolation liquid 3 can use the same liquid to facilitate the production of the battery pack. At the same time, the second isolation liquid 4 uses an insulating and non-flammable liquid to further ensure the safety of the battery module 2 during thermal runaway.

[0062] like Figure 2 and Figure 3As shown, in order to facilitate the discharge of the thermal runaway smoke in the battery compartment 12, the smoke channel 14 is located at the top of the partition 11. At the same time, the smoke channel 14 is connected to a smoke pipe 16, the inlet of the smoke pipe 16 is connected to the smoke channel 14, and the outlet of the smoke channel 14 is immersed in the second isolation liquid 4. This arrangement enables the thermal runaway smoke in the battery compartment 12 to be discharged from the battery compartment 12 relatively smoothly and quickly, and avoids the thermal runaway smoke from accumulating in the battery compartment 12. In addition, an isolation membrane 17 can also be provided on the above-mentioned smoke channel 14. The pressure bearing capacity of the isolation membrane 17 is less than the pressure bearing capacity of the battery monomer explosion relief membrane in the battery module. The isolation membrane 17 opens when the pressure in the battery compartment 12 reaches the threshold value, and the thermal runaway smoke in the battery compartment 12 is transported to the isolation compartment 13. The main function of the isolation membrane 17 is to seal the battery compartment 12 to prevent the second isolation liquid 4 in the isolation compartment 13 and the first isolation liquid 3 in the battery compartment 12 from flowing in series, which affects the battery module. At the same time, since the single cells 21 are connected in series and there are heat insulation plates 24 between the single cells 21, when a single cell 21 in the battery compartment 12 is in thermal runaway, it is difficult to trigger thermal runaway of other single cells 21. At the same time, since the eruption of thermal runaway smoke from a single cell 21 is only for the initial moment (after the thermal runaway smoke is ejected, the first isolation liquid 3 is immediately poured into the shell of the thermal runaway single cell 21, and no thermal runaway smoke will continue to be generated), the pressure of the thermal runaway smoke in the battery compartment is relatively small. At this time, the opening pressure of the above-mentioned isolation membrane 17 is relatively small, generally less than 0.1Mpa, so that the thermal runaway smoke can smoothly open the isolation membrane 17, so that the thermal runaway smoke can enter the isolation compartment.

[0063] The smoke outlet 15 on the isolation chamber 13 is mainly used to discharge the thermal runaway smoke. Figure 1 As shown, in this embodiment, the smoke outlet 15 is arranged at the top of the isolation chamber 13 and is located on the side away from the battery chamber 12. This arrangement increases the distance between the thermal runaway smoke and the battery module 2 after it is discharged, and further avoids the thermal runaway smoke after it is discharged from affecting the battery module 2 in the battery chamber 12. In addition, Figure 6 As shown, an exhaust valve 5 may also be provided on the smoke outlet 15. The exhaust valve 5 is specifically a pressure valve or an explosion relief valve. When the battery pack is in normal use, the smoke outlet 15 is sealed to prevent the second isolation liquid 4 from flowing out of the box body when the battery pack is transported or moved. When the single battery 21 in the battery compartment 12 has thermal runaway, the exhaust valve 5 is opened by the thermal runaway smoke with a certain pressure to allow the thermal runaway smoke to be discharged from the box body 1.

[0064] When the above-mentioned battery pack is manufactured, first, each single cell 21 is placed in the battery compartment 12, and electrical connections are made between each single cell 21, as well as between each single cell 21 and the battery management system 23 and the terminal 22. Secondly, the isolation membrane 17 and the flue gas pipeline 16 are connected to the flue gas channel 14; then, the first isolation liquid 3 and the second isolation liquid 4 are filled in the battery compartment 12 and the isolation compartment 13 respectively, and finally the open end of the box body 1 is sealed with a cover.

[0065] When the battery pack is working normally, the first isolation liquid 3 in the battery compartment 12 processes the heat generated by each single cell 21, and the temperature uniformity at different positions of each single cell is good. At the same time, the temperature uniformity of the entire battery module is also high. In addition, the first isolation liquid 3 provides insulation protection for each single cell 21 to prevent short circuits between each single cell. When a single cell 21 in the battery compartment 12 has thermal runaway, the thermal runaway battery generates thermal runaway smoke, and the thermal runaway smoke diffuses on the top of the battery compartment 12. When the thermal runaway smoke pressure of the battery compartment 12 reaches a certain value, the isolation membrane 17 at the smoke channel 14 ruptures, and the thermal runaway smoke enters the isolation compartment 13, and is discharged outside the box 1 after passing through the second isolation liquid 4 in the isolation compartment 13. Due to the presence of the first isolation liquid 3 and the second isolation liquid 4, the thermal runaway smoke discharged outside the box 1 will not affect the single cell 21 in the box 1 and the thermal runaway smoke in the box 1.

Claims

1. A battery pack, characterized in that: Including box and battery module; The inner cavity of the box is divided into a battery compartment and an isolation compartment by a partition, and a smoke passage connecting the battery compartment and the isolation compartment is provided on the partition; The battery compartment has a first isolation liquid, the battery module is arranged in the first isolation liquid, and the first isolation liquid is an insulating and non-flammable liquid; The isolation chamber contains a second isolation liquid, and a smoke outlet is provided on the isolation chamber, and the second isolation liquid is a non-flammable liquid; When thermal runaway occurs in the battery module in the battery compartment, the thermal runaway smoke enters the isolation compartment through the smoke channel, passes through the second isolation liquid in the isolation compartment, and is discharged through the smoke outlet.

2. The battery pack according to claim 1, characterized in that: The smoke channel is located on the top of the partition and is connected to a smoke pipeline, the outlet of which is immersed in the second isolation liquid.

3. The battery pack according to claim 2, characterized in that: An isolation membrane is provided on the smoke channel, and the pressure bearing capacity of the isolation membrane is smaller than the pressure bearing capacity of the explosion relief membrane of the battery cell in the battery module.

4. The battery pack according to claim 1, characterized in that: The filling height of the first isolation liquid can submerge the poles of each single battery in the battery module.

5. The battery pack according to claim 1, characterized in that: The smoke outlet is arranged on the top of the isolation chamber and is located on a side away from the battery chamber.

6. The battery pack according to claim 5, characterized in that: The smoke outlet is provided with an exhaust valve.

7. The battery pack according to any one of claims 1 to 6, characterized in that: The first isolation liquid and the second isolation liquid are the same liquid.

8. The battery pack according to claim 7, characterized in that: The first isolation liquid is a fluorinated liquid.

9. The battery pack according to claim 8, characterized in that: The battery module includes a plurality of single cells connected in series. Along the arrangement direction of the single cells in the battery module, two side walls of the battery compartment are respectively provided with T-shaped positioning blocks for positioning the single cells. The bottom of the T-shaped positioning blocks is also provided with supporting bosses for supporting the single cells.

10. The battery pack according to claim 9, characterized in that: A heat insulation plate is arranged between each single battery in the battery module.

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