Battery module, battery pack and electric vehicle

Abstract

The embodiment of the utility model provides a battery module, a battery pack and an electric vehicle, and relates to the technical field of batteries. The battery module comprises a plurality of battery cells, a lower shell and a heat insulation layer, wherein an anti-explosion valve is arranged at the bottom of each battery cell. The lower shell is used for placing a plurality of battery cells, the lower shell is provided with a pressure relief cavity, the lower shell is provided with a plurality of pressure relief holes, and the plurality of pressure relief holes are communicated with the pressure relief cavity; and each pressure relief hole corresponds to an anti-explosion valve of one battery cell. The heat insulation layer is arranged between the lower shell and the battery cell; the heat insulation layer is provided with a plurality of breaking areas, and each breaking area corresponds to the anti-explosion valve of one battery cell. The heat insulation layer is arranged between the battery cell and the lower shell, so that effective heat insulation between the battery cell and the lower shell can be realized. In addition, the heat insulation layer is provided with the breaking area, so that gas can conveniently break through the heat insulation layer to enter the pressure relief cavity of the lower shell. According to the battery module, the battery pack and the electric vehicle, effective heat insulation between the battery cells and the shell can be realized on the premise of preventing the battery cells from being out of control.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery module, a battery pack and an electric vehicle. Background Art

[0002] Battery thermal runaway and thermal diffusion have always been technical problems for the safety of vehicles and energy storage batteries. At present, as long as a single battery cell experiences thermal runaway, it may cause more batteries to experience chain thermal runaway, which may cause combustion or even explosion accidents, endangering the safety of personnel, vehicles and the environment. Most of the current battery thermal runaway systems are designed with a bottom plate as a support plate. The support plate has a hole at the battery cell explosion-proof valve to discharge the jet and high-temperature gas ejected during thermal runaway of the battery cell directly into the cavity at the bottom of the battery box.

[0003] However, current battery thermal runaway systems cannot achieve effective thermal insulation between the battery cell and the shell. Utility Model Content

[0004] The utility model provides a battery module, a battery pack and an electric vehicle, which can achieve effective heat insulation between a battery core and a shell while preventing the battery core from losing control.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] An embodiment of the utility model provides a battery module, which includes:

[0007] A plurality of battery cells, each of which has an explosion-proof valve at the bottom;

[0008] A lower shell, the lower shell is used to place the plurality of battery cells, the lower shell has a pressure relief chamber, the lower shell is provided with a plurality of pressure relief holes, the plurality of pressure relief holes are all connected to the pressure relief chamber; and each of the pressure relief holes corresponds to the explosion-proof valve of one of the battery cells;

[0009] A heat-insulating layer is arranged between the lower shell and the battery core; the heat-insulating layer is provided with a plurality of rupture zones, each of which corresponds to an explosion-proof valve of the battery core.

[0010] In an optional embodiment, the ruptured area is connected to other areas of the thermal insulation layer via a tear line.

[0011] In an optional embodiment, the area of ​​the pressure relief hole is larger than the area of ​​the rupture zone.

[0012] In an optional embodiment, the battery module further includes a support plate, which is disposed between the lower shell and the battery cell; the support plate is provided with a plurality of through holes, and each of the through holes corresponds to the explosion-proof valve of one of the battery cells.

[0013] In an optional embodiment, the battery module further includes a temperature-resistant gauze, and the temperature-resistant gauze is arranged between the support plate and the thermal insulation layer.

[0014] In an optional embodiment, the lower shell is provided with a plurality of reinforcing ribs, the plurality of reinforcing ribs are arranged at intervals between the pressure relief holes, and the plurality of reinforcing ribs all protrude toward the pressure relief cavity.

[0015] In an optional embodiment, the lower shell includes a shell body and a pressure relief partition, the shell body is connected to the pressure relief partition, the shell body and the pressure relief partition form the pressure relief chamber, and the pressure relief partition is provided with a plurality of the pressure relief holes.

[0016] In an optional embodiment, the lower shell is further provided with at least one exhaust channel, the exhaust channel is communicated with the pressure relief chamber, and the exhaust channel is used to discharge the gas in the pressure relief chamber out of the lower shell.

[0017] An embodiment of the utility model further provides a battery pack, comprising the battery module in any of the above embodiments.

[0018] An embodiment of the utility model further provides an electric vehicle, comprising a vehicle body and the battery pack in the above embodiment, wherein the battery pack is arranged in the vehicle body.

[0019] The battery module, battery pack and electric vehicle of the present utility model have the following beneficial effects:

[0020] The battery module includes multiple battery cells, a lower shell and a heat-insulating layer, and an explosion-proof valve is provided at the bottom of each battery cell. The pressure of the gas inside the battery cell can be controlled by providing the explosion-proof valve of the battery cell. When gas is generated inside the lithium battery, the explosion-proof valve of the battery cell can control the pressure of the gas inside the battery through its own pressure control device to keep it within a safe range, thereby preventing accidents such as explosion and fire caused by excessive expansion of the battery. The lower shell is used to place multiple battery cells, and the lower shell has a pressure relief cavity. The lower shell is provided with multiple pressure relief holes, and the multiple pressure relief holes are connected to the pressure relief cavity; and each pressure relief hole corresponds to an explosion-proof valve of a battery cell. By providing the pressure relief holes and the pressure relief cavity, it can be ensured that when the explosion-proof valve of the battery cell is opened, the excess gas in the battery cell is discharged. The heat-insulating layer is provided between the lower shell and the battery cell; the heat-insulating layer is provided with multiple rupture zones, and each rupture zone corresponds to an explosion-proof valve of the battery cell. By providing the heat-insulating layer between the battery cell and the lower shell, effective heat insulation between the battery cell and the lower shell can be achieved. Furthermore, providing a rupture zone in the heat insulation layer also facilitates the gas to break through the heat insulation layer and enter the pressure relief cavity of the lower shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of a battery module provided in an embodiment of the present utility model;

[0023] Figure 2 An exploded schematic diagram of a battery module provided in an embodiment of the utility model;

[0024] Figure 3 A schematic diagram of a lower housing provided in an embodiment of the utility model;

[0025] Figure 4 A schematic diagram of a heat insulation layer provided in an embodiment of the present utility model;

[0026] Figure 5 It is a partial enlarged schematic diagram of A provided in an embodiment of the utility model;

[0027] Figure 6 A partial cross-sectional schematic diagram of a battery module provided in an embodiment of the utility model;

[0028] Figure 7 It is a partial enlarged schematic diagram of point B provided in the embodiment of the utility model.

[0029] Icon: 1000-battery module; 100-battery cell; 200-lower shell; 210-shell body; 211-exhaust channel; 220-pressure relief baffle; 221-pressure relief hole; 222-reinforcement rib; 230-pressure relief chamber; 300-insulation layer; 310-rupture zone; 320-tear line; 400-support plate; 410-through hole; 500-heat-resistant gauze. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used. It is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present utility model.

[0034] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0035] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0036] Battery thermal runaway and thermal diffusion have always been technical problems for the safety of vehicles and energy storage batteries. At present, as long as a single battery cell experiences thermal runaway, it may cause more battery cells to experience chain thermal runaway, which may cause combustion or even explosion accidents, endangering the safety of personnel, vehicles and the environment. Most of the current battery thermal runaway systems are designed with a bottom plate as a support plate. The support plate has a hole at the battery cell explosion-proof valve to discharge the jet and high-temperature gas ejected during thermal runaway of the battery cell directly into the cavity at the bottom of the battery case. However, the current battery thermal runaway system cannot achieve effective heat insulation between the battery cell and the shell.

[0037] Based on this, please refer to Figure 1 and Figure 2 The battery module 1000, battery pack and electric vehicle provided in this embodiment can effectively improve the above-mentioned technical problems. The electric vehicle includes a vehicle body and a battery pack, the battery pack is arranged in the vehicle body, and the battery pack provides electric energy for the vehicle body to realize various functions of the vehicle body.

[0038] The battery pack in this embodiment includes a battery module 1000. According to the functional requirements of the battery pack, the battery pack may also include a liquid cooling system, a BMS (battery management system), etc. The liquid cooling system may be provided between adjacent battery cells 100 of the battery module 1000, and the battery management system is electrically connected to the battery cell 100. In addition, the battery pack may also include other structural devices, which are not limited here.

[0039] The structure of the battery module 1000 is described in detail below.

[0040] Figure 1 A schematic diagram of a battery module 1000 provided in an embodiment of the present utility model; Figure 2 FIG. 1 is an exploded schematic diagram of a battery module 1000 provided in an embodiment of the present utility model. Figure 1 and Figure 2 As shown, the battery module 1000 includes a plurality of battery cells 100, a lower shell 200 and a heat-insulating layer 300, and an explosion-proof valve is arranged at the bottom of each battery cell 100. The lower shell 200 is used to place a plurality of battery cells 100, and the lower shell 200 has a pressure relief chamber 230, and the lower shell 200 is provided with a plurality of pressure relief holes 221, and the plurality of pressure relief holes 221 are all connected to the pressure relief chamber 230; and each pressure relief hole 221 corresponds to an explosion-proof valve of a battery cell 100. The heat-insulating layer 300 is arranged between the lower shell 200 and the battery cell 100; the heat-insulating layer 300 is provided with a plurality of rupture zones 310, and each rupture zone 310 corresponds to an explosion-proof valve of a battery cell 100. The rupture zones 310, the pressure relief holes 221 and the explosion-proof valves of the battery cells 100 are all in one-to-one correspondence, which can realize independent exhaust of a single battery cell 100, and independent thermal insulation of thermal runaway between adjacent battery cells 100 without interfering with each other.

[0041] The explosion-proof valve of the battery cell 100 can control the pressure of the gas inside the battery cell 100. When gas is generated inside the lithium battery, the explosion-proof valve of the battery cell 100 can control the pressure of the gas inside the battery through its own pressure control device to keep it within a safe range, thereby preventing the battery from exploding or catching fire due to excessive expansion. In existing cylindrical shell battery structures, the explosion-proof valve is mostly distributed on the top of the battery. In this area, there are more types of functional parts such as connecting pieces, monitors, and heat insulation. The height space of the area is limited. When a single battery cell 100 has thermal runaway, it is difficult to form an effective guiding channel to block or inhibit heat diffusion, resulting in more battery cells 100 experiencing chain thermal runaway, endangering the safety of personnel, vehicles, and the environment. By setting the explosion-proof valve at the bottom of the battery cell 100, the problem of limited space can be solved.

[0042] In order to match the explosion-proof valve at the bottom of the battery cell 100, it is convenient to discharge the gas inside the battery cell 100 out of the battery cell 100. Figure 3 , and combined with Figure 2 , Figure 3Schematic diagram of the lower shell 200 provided in the embodiment of the utility model. In this embodiment, a plurality of pressure relief holes 221 corresponding to the explosion-proof valve of the battery cell 100 are opened in the lower shell 200, and the lower shell 200 has a pressure relief chamber 230. When the explosion-proof valve at the bottom of the battery cell 100 is opened, the gas can flow into the pressure relief chamber 230 along the pressure relief hole 221, thereby ensuring that the excess gas in the battery cell 100 is discharged. In addition, in order to achieve effective heat insulation between the battery cell 100 and the lower shell 200, the battery module 1000 in this embodiment is provided with an insulation layer 300 between the battery cell 100 and the lower shell 200. In addition, the rupture zone 310 provided in the insulation layer 300 is also convenient for the gas to break through the insulation layer 300 and enter the pressure relief chamber 230 of the lower shell 200. The battery module 1000, the battery pack and the electric vehicle can achieve effective heat insulation between the battery cell 100 and the shell under the premise of preventing the battery cell 100 from losing control. Specifically, the heat insulation layer 300 can be made of polyurethane foam, silicone foam, polyimide and other materials, as long as they can provide heat insulation effect. The specific material used for the heat insulation layer 300 is not limited here.

[0043] In order to facilitate the opening of the pressure relief hole 221, form the pressure relief cavity 230, and simplify the processing of the lower shell 200, please refer to Figure 3 The lower shell 200 in this embodiment includes a shell body 210 and a pressure relief partition 220. The shell body 210 is connected to the pressure relief partition 220. The shell body 210 and the pressure relief partition 220 form a pressure relief cavity 230. The pressure relief partition 220 is provided with a plurality of pressure relief holes 221. Of course, the lower shell 200 can also be designed as an integral structure or other structural forms, as long as the lower shell 200 has the pressure relief cavity 230 and the pressure relief holes 221, which is not limited here.

[0044] In order to improve the structural strength of the lower housing 200, please continue to refer to Figure 3 The lower shell 200 in this embodiment is provided with a plurality of reinforcing ribs 222, which are arranged at intervals between the pressure relief holes 221, and the plurality of reinforcing ribs 222 all protrude toward the pressure relief chamber 230. Specifically, in this embodiment, a plurality of reinforcing ribs 222 are provided on the pressure relief baffle 220 to increase the structural strength of the pressure relief baffle 220 and prevent the pressure relief baffle 220 from being damaged due to excessive pressure of the ejected material and the high-temperature gas.

[0045] Please continue reading Figure 3 In this embodiment, the lower housing 200 is further provided with at least one exhaust channel 211, which is connected to the pressure relief chamber 230 and is used to discharge the gas in the pressure relief chamber 230 out of the lower housing 200. Specifically, in this embodiment, each column of pressure relief holes 221 is provided with an exhaust channel 211 to achieve rapid pressure relief.

[0046] The above-mentioned “heat insulation layer 300 is provided with a plurality of collapse zones 310”, for details, please refer to Figure 4 and Figure 5 , Figure 4 A schematic diagram of a heat insulation layer 300 provided in an embodiment of the present utility model; Figure 5 This is a partial enlarged schematic diagram of point A provided in an embodiment of the utility model. In this embodiment, the rupture zone 310 is connected to other areas of the insulation layer 300 by a tear line 320. Because there is a tear line 320 between the rupture zone 310 and the gas area of ​​the insulation layer 300, when the explosion-proof valve is opened, the impact force of the gas can easily break open the rupture zone 310, and the rupture zone 310 is separated from other areas of the insulation layer 300, and the ejected material passes through the insulation layer 300 into the pressure relief chamber 230 to discharge the battery cell 100. Of course, the tear line 320 may not be designed between the rupture zone 310 and other areas of the insulation layer 300, and the rupture zone 310 may also be designed to be relatively thin, so that the ejected material in the explosion-proof valve can be broken open and enter the pressure relief chamber 230.

[0047] Figure 6 A partial cross-sectional schematic diagram of a battery module 1000 provided in an embodiment of the present utility model; Figure 7 This is a partial enlarged schematic diagram of B provided in the embodiment of the utility model, please refer to Figure 7 , and combined with Figure 6 In order to prevent the rupture zone 310 from blocking the pressure relief hole 221, the area of ​​the pressure relief hole 221 in this embodiment is larger than the area of ​​the rupture zone 310. Of course, the area size of the pressure relief hole 221 may also be equal to the area size of the rupture zone 310, which is not limited here. Since most explosion-proof valves are circular, the pressure relief hole 221 in this embodiment may be designed to be circular, and the rupture zone 310 may also be designed to be circular, that is, the diameter of the pressure relief hole 221 here is larger than the diameter of the circular hole in the rupture zone 310. Of course, the pressure relief hole 221 and the rupture zone 310 may also be designed to be other shapes, as long as they can be set corresponding to the explosion-proof valve, which is not limited here.

[0048] In order to further achieve effective heat insulation between the battery cell 100 and the lower housing 200, please refer to Figure 7 , and combined with Figure 6 The battery module 1000 in this embodiment further includes a support plate 400, which is disposed between the lower housing 200 and the battery cell 100; the support plate 400 is provided with a plurality of through holes 410, each of which corresponds to an explosion-proof valve of the battery cell 100. By adding a support plate 400 between the thermal insulation layer 300 and the battery cell 100, non-contact thermal insulation between the battery cell 100 and the thermal insulation layer 300 can be achieved, the battery cell 100 is out of contact with the thermal insulation layer 300, and the direct heat transfer path is blocked, thereby improving the thermal insulation effect between the battery cell 100 and the lower housing 200.

[0049] Please continue reading Figure 7 , and combined with Figure 6 In order to prevent the ejected material and high-temperature gas from rebounding due to the ejection pressure and damaging the thermal insulation layer 300 and the battery cell 100, the battery module 1000 in this embodiment also includes a heat-resistant gauze 500, which is arranged between the support plate 400 and the thermal insulation layer 300. When the explosion-proof valve of the battery cell 100 is opened, the ejected material and high-temperature gas in the battery cell 100 are discharged, and break through the rupture area 310 under the action of high pressure, opening the thermal insulation layer 300, and the ejected material enters the pressure relief chamber 230. The internal air pressure of the pressure relief chamber 230 increases, which will compress the thermal insulation layer 300 of the battery cell 100. The addition of the heat-resistant gauze 500 can play a supporting role for the thermal insulation layer 300, and can also play a role of blocking and sealing, blocking the ejected material and high-temperature gas, thereby protecting the thermal insulation layer 300 and the battery cell 100.

[0050] According to a battery module 1000 provided in this embodiment, its working principle is as follows:

[0051] When the battery cell 100 is in thermal runaway, the explosion-proof valve of the battery cell 100 opens, and the high-temperature and high-pressure ejecta rushes through the heat-resistant gauze 500, and impacts the ruptured area 310 of the insulation layer 300 with the tear line 320 under the action of high pressure. The tear line 320 helps the ruptured area 310 to tear and detach under force. After the insulation layer 300 is opened, the ejecta enters the pressure relief chamber 230, and the air pressure in the pressure relief chamber 230 increases, which in turn presses the insulation layer 300 of the adjacent battery cell 100. The heat-resistant gauze 500 can support the insulation layer 300, and can also play a role in blocking and sealing, blocking the ejecta and high-temperature gas, thereby protecting the insulation layer 300 and the battery cell 100. Finally, the ejecta and high-temperature gas in the pressure relief chamber 230 can be discharged from the shell through the exhaust channel 211.

[0052] In summary, the battery module 1000 includes a plurality of battery cells 100, a lower shell 200 and a heat-insulating layer 300, and an explosion-proof valve is arranged at the bottom of each battery cell 100. The lower shell 200 is used to place a plurality of battery cells 100, and the lower shell 200 has a pressure relief chamber 230, and the lower shell 200 is provided with a plurality of pressure relief holes 221, and the plurality of pressure relief holes 221 are all connected to the pressure relief chamber 230; and each pressure relief hole 221 corresponds to an explosion-proof valve of a battery cell 100. The heat-insulating layer 300 is arranged between the lower shell 200 and the battery cell 100; the heat-insulating layer 300 is provided with a plurality of rupture areas 310, and each rupture area 310 corresponds to an explosion-proof valve of a battery cell 100. By arranging the pressure relief holes 221 and the pressure relief chamber 230, it can be ensured that when the explosion-proof valve of the battery cell 100 is opened, the excess gas in the battery cell 100 is discharged. By providing the heat insulating layer 300 between the battery cell 100 and the lower shell 200, effective heat insulation between the battery cell 100 and the lower shell 200 can be achieved. Moreover, providing the collapse zone 310 in the heat insulating layer 300 also facilitates the gas to break through the heat insulating layer 300 and enter the pressure relief cavity 230 of the lower shell 200. The battery module 1000, the battery pack and the electric vehicle can achieve effective heat insulation between the battery cell 100 and the shell while preventing the battery cell 100 from losing control.

[0053] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

Claims

1. A battery module, characterized in that: include: A plurality of battery cells (100), each of the battery cells (100) being provided with an explosion-proof valve at the bottom; A lower shell (200), the lower shell (200) being used to place a plurality of the battery cells (100), the lower shell (200) having a pressure relief chamber (230), the lower shell (200) being provided with a plurality of pressure relief holes (221), the plurality of pressure relief holes (221) being all in communication with the pressure relief chamber (230); and each of the pressure relief holes (221) corresponds to the explosion-proof valve of one of the battery cells (100); A heat insulation layer (300), the heat insulation layer (300) being arranged between the lower shell (200) and the battery cell (100); the heat insulation layer (300) being provided with a plurality of rupture zones (310), each of the rupture zones (310) corresponding to an explosion-proof valve of the battery cell (100).

2. The battery module according to claim 1, characterized in that: The ruptured area (310) is connected to other areas of the thermal insulation layer (300) via a tear line (320).

3. The battery module according to claim 1, characterized in that: The area of ​​the pressure relief hole (221) is greater than the area of ​​the rupture zone (310).

4. The battery module according to claim 1, characterized in that: The battery module (1000) further comprises a support plate (400), wherein the support plate (400) is arranged between the lower shell (200) and the battery cell (100); the support plate (400) is provided with a plurality of through holes (410), and each of the through holes (410) corresponds to the explosion-proof valve of one of the battery cells (100).

5. The battery module according to claim 4, characterized in that: The battery module (1000) further comprises a temperature-resistant gauze (500), wherein the temperature-resistant gauze (500) is arranged between the support plate (400) and the heat insulation layer (300).

6. The battery module according to claim 1, characterized in that: The lower shell (200) is provided with a plurality of reinforcing ribs (222), the plurality of reinforcing ribs (222) are arranged at intervals between the pressure relief holes (221), and the plurality of reinforcing ribs (222) all protrude toward the pressure relief chamber (230).

7. The battery module according to claim 1, characterized in that: The lower shell (200) comprises a shell body (210) and a pressure relief baffle (220); the shell body (210) is connected to the pressure relief baffle (220); the shell body (210) and the pressure relief baffle (220) enclose the pressure relief chamber (230); and the pressure relief baffle (220) is provided with a plurality of pressure relief holes (221).

8. The battery module according to claim 1, characterized in that: The lower shell (200) is further provided with at least one exhaust channel (211), the exhaust channel (211) being in communication with the pressure relief chamber (230), and the exhaust channel (211) being used to discharge the gas in the pressure relief chamber (230) out of the lower shell (200).

9. A battery pack, characterized in that: A battery module (1000) comprising any one of claims 1 to 8.

10. An electric vehicle, characterized in that: It comprises a vehicle body and the battery pack according to claim 9, wherein the battery pack is arranged in the vehicle body.

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