Sealed battery pack

Abstract

The present application discloses a sealed battery pack, comprising a closed box and at least one heat dissipation duct system; a battery cell installation cavity is provided in the closed box, and a battery cell is installed in the battery cell installation cavity; an inlet connected to the battery cell installation cavity is provided on the heat dissipation duct system; an outlet connected to the external environment of the closed box is provided on the heat dissipation duct system; the heat dissipation duct system is used to cool the gas released during the thermal runaway of the battery cell; in the sealed battery pack of the present invention, when the gas released during the thermal runaway of the battery cell enters from the inlet and moves toward the outlet, the heat of the gas is transferred to the surface of the closed box through the heat dissipation duct system, so that the temperature of the gas gradually decreases, and finally the gas is discharged outside the sealed battery pack, thereby reducing the risk of combustion after the gas meets fresh air.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a sealed battery pack. Background Art

[0002] In thermal runaway, the high temperature of power batteries will cause the decomposition of the negative electrode SEI film (solid electrolyte interface film), the decomposition of the positive electrode active material and the oxidation of the electrolyte, generating a large amount of gas and heat, causing the gas pressure inside the lithium-ion battery to rise sharply, causing the battery pressure relief valve to open, and a large amount of high-temperature, flammable and toxic gas to be released from the battery, which will seriously damage personal and property safety. As the size and capacity of power batteries continue to increase, the gas released by thermal runaway will often increase exponentially.

[0003] The existing power battery sealed box is generally equipped with a pressure relief valve. When the high pressure in the box reaches a certain level, the pressure relief valve will rupture and open, and the toxic and flammable high-pressure gas in the box will be directly released from the pressure relief valve into the surrounding air. These high-temperature flammable gases are discharged into the air and come into contact with a large amount of fresh air from the outside, which can easily cause combustion accidents. Summary of the invention

[0004] The main purpose of the present invention is to provide a sealed battery pack, aiming to solve the problem that the combustible gas generated by the power battery during thermal runaway will burn when it encounters fresh air due to its high temperature.

[0005] In order to achieve the above-mentioned object, the present invention provides a sealed battery pack including a closed box and at least one heat dissipation pipeline system;

[0006] A battery cell installation cavity is provided in the closed box, and a battery cell is installed in the battery cell installation cavity;

[0007] The heat dissipation duct system is provided with an inlet connected to the battery cell installation cavity;

[0008] The heat dissipation pipe system is provided with an outlet connected to the external environment of the closed box;

[0009] Among them, the heat dissipation pipe system is used to cool the gas released during thermal runaway of the battery cell.

[0010] Furthermore, the closed box includes a frame composed of profiles, the middle of the profile is a hollow channel, the hollow channels are interconnected to form a connected cavity, and the connected cavity is a heat dissipation pipeline system.

[0011] Furthermore, the closed box includes a frame composed of profiles, the middle part of the profile is a hollow channel, the hollow channels are interconnected to form a connected cavity, and a sealing piece is provided in the connected cavity. The sealing piece guides and separates the connected cavity to form a unidirectional flow channel, and the unidirectional flow channel is a heat dissipation pipe system.

[0012] Furthermore, the closed box includes a frame composed of profiles, the middle of the profiles is a hollow channel, communication pipes are connected between the profiles, and the communication pipes connect the profiles to each other to form a connected cavity, and the connected cavity is the heat dissipation pipe system.

[0013] Furthermore, the heat dissipation pipe system is installed inside the closed box, and the heat dissipation pipe system and the closed box are connected in a heat-conducting manner.

[0014] Furthermore, the heat dissipation pipeline system is arranged on the outer wall of the closed box.

[0015] Furthermore, fins are provided in the hollow channel.

[0016] Furthermore, fins are provided on the inner wall of the heat dissipation pipe system.

[0017] Furthermore, it also includes a pressure relief exhaust valve, which is arranged at the inlet, outlet or the middle of the heat dissipation pipeline system.

[0018] Furthermore, when the pressure relief exhaust valve is arranged at the inlet or in the middle of the heat dissipation pipeline system, a blocking net is arranged at the outlet.

[0019] In the sealed battery pack of the present invention, during the process in which the gas released by the thermal runaway of the battery cell enters from the inlet of the heat dissipation pipe system and moves toward the outlet, the heat of the high-temperature gas released by the thermal runaway is continuously transferred to the heat dissipation pipe system, so that the temperature of the gas gradually decreases and is finally discharged outside the sealed battery pack, thereby reducing the risk of combustion of the gas released by the thermal runaway after encountering fresh air. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the arrangement of a heat dissipation channel system in a sealed battery pack according to an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of the arrangement of a heat dissipation channel system in a sealed battery pack according to a second embodiment of the present invention;

[0022] Figure 3 is a three-dimensional schematic diagram of the arrangement of a heat dissipation channel system in a sealed battery pack according to a second embodiment of the present invention;

[0023] Figure 4 is a partial enlarged view of the arrangement of the heat dissipation channel system in the sealed battery pack according to the second embodiment of the present invention;

[0024] Figure 5 is a schematic diagram of the arrangement of a heat dissipation channel system in a sealed battery pack according to a third embodiment of the present invention;

[0025] Figure 6 It is a three-dimensional schematic diagram of the arrangement of the heat dissipation channel system in the sealed battery pack according to the fourth embodiment of the present invention.

[0026] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0028] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "said", "above", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements, units, modules, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, units, modules, components, and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0029] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0030] Reference Figure 1-6 In one embodiment of the present invention, the sealed battery pack includes a closed box and a heat dissipation duct system 2; the closed box is provided with a cell installation cavity, and the cell is installed in the cell installation cavity; the heat dissipation duct system 2 is provided with an inlet 201 connected to the cell installation cavity; the heat dissipation duct system 2 is provided with an outlet 202 connected to the external environment of the closed box. The heat dissipation duct system 2 is used to cool the gas released during the thermal runaway process of the cell.

[0031] If there is no heat dissipation pipeline system 2, a pressure relief valve is directly provided on the closed box. When the battery cell releases gas due to thermal runaway, the closed box can also play a role in heat dissipation before the pressure relief valve is broken. However, when the pressure relief valve is broken, the high-temperature gas will rush out directly from the closed box, causing safety hazards.

[0032] The present invention uses the heat dissipation duct system 2 to detect the environment inside the sealed battery pack 100 without sensors, so there is no need for a corresponding control circuit; there is no traditional complex smoke removal and fire extinguishing system, so the structure of the sealed battery pack 100 is lightweight and simple.

[0033] In this embodiment, as the gas released by thermal runaway of the battery cell enters from the inlet 201 and moves toward the outlet 202, the temperature of the gas gradually decreases and is finally discharged out of the sealed battery pack 100, thereby reducing the risk of combustion of the gas after encountering fresh air.

[0034] Reference Figure 1 In one embodiment, the closed box includes a frame 1 composed of a profile, the middle of the profile is a hollow channel, the hollow channels are interconnected to form a connected cavity, and the connected cavity is a heat dissipation pipeline system 2.

[0035] The frame 1 is a cubic structure, and an inlet 201 and an outlet 202 are arranged on the frame 1 to form a heat dissipation pipe system 2. The gas released by the thermal runaway of the sealed battery pack 100 is cooled by the frame 1, and the temperature of the gas is reduced before the gas contacts the fresh air. In the specific process, the heat of the gas is transferred to the frame 1, and then transferred to the surface of the closed box. The heat is dissipated by the closed box, which accelerates the speed at which the temperature of the gas released by the thermal runaway of the battery cell drops. The frame 1 realizes both mechanical support and heat dissipation, and the space utilization rate is high. Even if the thermal runaway of the sealed battery pack 100 is very severe, and the heat dissipation pipe system 2 cannot continuously cool the released gas to below the ignition point, it can also buy a certain amount of precious emergency processing time for the user.

[0036] Reference Figure 2-4 In one embodiment, the closed box includes a frame 1 composed of a profile, the middle part of the profile is a hollow channel, the hollow channels are connected to each other to form a connected cavity, a plugging member 3 is provided in the connected cavity, the plugging member 3 guides and separates the connected cavity to form a unidirectional flow channel, and the unidirectional flow channel is a heat dissipation pipeline system 2. An inlet 201 and an outlet 202 are provided on the connected cavity, and the gas released by thermal runaway enters from the inlet 201 and then continuously cools down in the connected cavity, and finally is discharged from the outlet 202.

[0037] Compared with using the entire frame 1 structure as the heat dissipation pipeline system 2, the plugging member 3 separates the connected cavities to form a unidirectional flow channel, and the movement of the gas in the unidirectional long flow channel forms a gradual cooling effect. The frame 1 structure itself is used as the heat dissipation basis, and the cooling effect of the gas generated by thermal runaway is achieved under the premise of minimal structural changes to the existing sealed battery pack 100.

[0038] In one embodiment, the closed box includes a frame 1 composed of profiles, the middle part of the profiles is a hollow channel, and when the hollow channels are not connected to each other to form a connected cavity, a communication pipe needs to be introduced. The communication pipe is arranged between the profiles, and the communication pipe connects the profiles to each other to form a connected cavity; the connected cavity is a heat dissipation pipe system. The above-mentioned hollow channels are not connected to each other to form a connected cavity mainly because the connection between the profiles is in an open state or a blocked state.

[0039] Reference Figure 5 In one embodiment, the heat dissipation pipe system 2 is set up inside the closed box, and the heat dissipation pipe system 2 is connected to the closed box by heat conduction. When the closed box itself cannot be used to form the heat dissipation pipe system 2 due to structural limitations, the heat dissipation pipe system 2 is set up in the closed box and abuts against the closed box to form a good heat conduction connection. After the heat of the gas released during the thermal runaway process is transferred to the heat dissipation pipe system 2, the heat dissipation pipe system 2 transfers the heat to the surface of the closed box to cool the gas. In implementation, the heat dissipation pipe system 2 and the closed box are coated with thermal conductive glue or welded together to ensure high-quality heat conduction between the two.

[0040] Reference Figure 6 In one embodiment, the heat dissipation pipe system 2 is arranged on the outer wall of the closed box, the inlet 201 of the heat dissipation pipe system 2 is connected to the battery cell installation cavity, and the outlet 202 of the heat dissipation pipe system 2 is connected to the external environment of the closed box. The battery cell releases gas due to thermal runaway, and the gas begins to cool down after entering the heat dissipation pipe system 2 from the inlet 201; in particular, the heat dissipation pipe system 2 is arranged on the outer wall of the closed box to have good heat exchange with natural air, so that the heat dissipation pipe system 2 can have a better cooling effect. The heat dissipation pipe system 2 and the outer wall of the closed box can also form a heat-conducting connection, such as the heat dissipation pipe system 2 against the outer wall of the box or a heat-conducting layer such as a heat-conducting glue is arranged between the heat dissipation pipe system 2 and the outer wall of the box, or the heat dissipation pipe system 2 is welded to the outer wall of the box, so that the heat of the heat dissipation pipe system 2 is dissipated through the surface of the closed box. In implementation, the heat dissipation pipe system 2 can be a heat dissipation system formed by a tortuous arrangement of heat dissipation pipes, or it can be a heat dissipation fin pipe system with an air-conducting inner cavity.

[0041] In one embodiment, fins are provided in the hollow channel. The fins in the hollow channel enhance the heat exchange effect between the gas and the profile, and the profile transfers the heat to the surface of the closed box after heating up, thereby enhancing heat dissipation.

[0042] In one embodiment, fins are provided on the inner wall of the heat dissipation pipe system. The fins on the inner wall of the heat dissipation pipe system enhance the heat exchange effect between the gas and the heat dissipation pipe system. After the heat dissipation pipe system is heated up, the heat is transferred to the surface of the closed box to achieve enhanced heat dissipation.

[0043] In one embodiment, the sealed battery pack 100 further includes a pressure relief exhaust valve, which is disposed at the inlet 201, the outlet 202 or the middle of the heat dissipation pipe system 2. When the sealed battery pack 100 is under negative pressure or does not reach the rated positive pressure, the pressure relief exhaust valve isolates the outside air from entering the sealed battery pack 100, ensuring that the environment in the sealed battery pack 100 is not disturbed by the outside world. When the battery cell has thermal runaway and releases gas, and reaches the rated positive pressure, the pressure relief exhaust valve is opened, and the gas is discharged after cooling through the heat dissipation pipe system 2.

[0044] In one embodiment, when the pressure relief exhaust valve is disposed at the inlet 201 or the middle of the heat dissipation pipe system 2, a blocking net is disposed at the outlet 202. When there is no pressure relief exhaust valve as a barrier at the outlet of the heat dissipation pipe system 2, the blocking net can prevent foreign matter from entering the heat dissipation pipe system 2, thereby ensuring that the heat dissipation pipe system 2 can work normally.

[0045] In summary, in the sealed battery pack of the present invention, the gas released by the thermal runaway of the battery cell enters from the inlet of the heat dissipation pipe system and moves toward the outlet. The heat of the high-temperature gas released by the thermal runaway is continuously transferred to the heat dissipation pipe system, so that the temperature of the gas gradually decreases and is finally discharged from the sealed battery pack, thereby reducing the risk of combustion of the gas released by the thermal runaway after encountering fresh air.

[0046] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A sealed battery pack, characterized in that: The sealed battery pack includes a closed box and at least one heat dissipation duct system; A battery cell installation cavity is provided in the closed box, and a battery cell is installed in the battery cell installation cavity; The heat dissipation pipeline system is provided with an inlet connected to the battery cell installation cavity; The heat dissipation pipeline system is provided with an outlet connected to the external environment of the closed box; Wherein, the heat dissipation pipeline system is used to cool the gas released during the thermal runaway process of the battery cell; The closed box includes a frame composed of profiles, the middle of the profile is a hollow channel, the hollow channels are interconnected to form a connected cavity, and the connected cavity is the heat dissipation pipeline system; The closed box includes a frame composed of profiles, the middle part of the profile is a hollow channel, the hollow channels are connected to each other to form a connected cavity, a plugging piece is provided in the connected cavity, the plugging piece guides and separates the connected cavity to form a unidirectional flow channel, and the unidirectional flow channel is the heat dissipation pipeline system; The closed box includes a frame composed of profiles, the middle of the profiles is a hollow channel, and communication pipes are connected between the profiles. The communication pipes connect the profiles to each other to form a connected cavity, and the connected cavity is the heat dissipation pipeline system.

2. The sealed battery pack according to claim 1, characterized in that: Fins are arranged in the hollow channel.

3. The sealed battery pack according to claim 1, characterized in that: The inner wall of the heat dissipation pipeline system is provided with fins.

4. The sealed battery pack according to any one of claims 1 to 3, characterized in that: It also includes a pressure relief exhaust valve, which is arranged at the inlet, the outlet or the middle of the heat dissipation pipeline system.

5. The sealed battery pack according to claim 4, characterized in that: When the pressure relief exhaust valve is arranged at the inlet or in the middle of the heat dissipation pipeline system, a blocking net is arranged at the outlet.

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