Box body and battery module

Abstract

The utility model discloses a box body and a battery module. The box body comprises an upper cover assembly, a lower cover assembly and two end covers. The device is characterized by further comprising two side plates, the upper end faces of the side plates are connected with the upper cover assembly in a screw connection mode, and the lower end faces of the side plates are connected with the lower cover assembly in a screw connection mode. The box body is composed of the upper cover assembly, the lower cover assembly, the two end covers and the two side plates, and compared with the prior art that the side wall of the box body is formed by splicing the upper cover assembly and the lower cover assembly, the strength is better.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, and in particular relates to a box and a battery module. Background Art

[0002] The application areas of lithium-ion batteries are very wide, covering many fields from electronic products to electric vehicles, energy storage systems, aerospace and so on.

[0003] In order to meet the demand for large-capacity use, multiple lithium-ion batteries are generally connected in series or in parallel or in a combination of series and parallel to form a battery pack for use.

[0004] For example, Chinese patent publication number CN220569864U discloses a battery module, which includes a box body and a plurality of single cells arranged in the box body and insulated from the box body; the box body includes an upper cover assembly, a lower cover assembly and two end covers; a thermal runaway flue gas exhaust channel is provided in the upper cover assembly; and a heat exchange medium circulation channel is provided in the lower cover assembly.

[0005] The upper cover assembly and the lower cover assembly are both composed of a horizontal plate and two vertical plates. The two side walls of the box in the patent are actually composed of the vertical plates of the upper cover assembly and the vertical plates of the lower cover assembly spliced together and connected by screws.

[0006] In this structure, the side walls are formed by splicing the upper cover assembly and the lower cover assembly, which results in poor strength at the side walls of the box. Summary of the Invention

[0007] In order to solve the problem that the side walls of the existing battery module are constructed by splicing an upper cover assembly and a lower cover assembly, resulting in poor strength at the side walls of the box body, the first aspect of the present invention provides a box body.

[0008] The box body includes an upper cover assembly, a lower cover assembly and two end covers; it is characterized in that it also includes two side panels; the upper end surfaces of the side panels are connected to the upper cover assembly by screw connections, and the lower end surfaces of the side panels are connected to the lower cover assembly by screw connections.

[0009] The box body of the present invention is composed of an upper cover assembly, a lower cover assembly, two end covers and two side panels. Compared with the prior art in which the side walls of the box body are composed of an upper cover assembly and a lower cover assembly, the box body has better strength.

[0010] Furthermore, the upper cover assembly includes a first horizontal plate and a first vertical tube;

[0011] A fire protection medium channel is provided inside the first horizontal plate;

[0012] The number of the first vertical tubes is consistent with the number of the single cells, and one end of the first vertical tube is fixed to the first horizontal plate and communicates with the fire-fighting medium channel, and the other end of the first vertical tube faces the lower cover assembly;

[0013] The first horizontal plate is provided with two first grooves, and the tops of the side plates are used to be embedded therein.

[0014] Furthermore, the lower cover assembly includes a second horizontal plate and ribs;

[0015] A heat exchange medium circulation channel is provided inside the second horizontal plate;

[0016] The ribs include at least two ribs, which are placed on the surface of the second horizontal plate close to the upper cover assembly and are arranged orthogonally to the side plates. The two ends of the ribs are fixed to the side plates only by screw connection.

[0017] The second horizontal plate is provided with two second grooves, and the bottoms of the side plates are embedded in the second grooves.

[0018] The second aspect of the present invention provides a battery module, comprising the box body described in the first aspect, and a plurality of single cells arranged in the box body; an insulating top cover is buckled and installed on the top of each single cell; the second vertical tube of the insulating top cover is plugged into the first vertical tube to form an explosion relief channel; a sealing layer is provided between the insulating top cover and the top of the single cell.

[0019] The utility model has ingeniously designed the box body of the battery module. The upper cover component constituting the box body serves as the fire protection passage of the battery module, and the lower cover component constituting the box body serves as the heat exchange medium circulation passage of the battery module. Thus, the battery module can utilize the heat exchange medium to control the temperature of each single cell in the battery module during operation without increasing the volume of the battery module, thereby ensuring the uniformity of each single cell and reducing the probability of thermal runaway. At the same time, when a single cell in the battery module experiences thermal runaway, the fire protection medium passage and the explosion relief passage can be used to inject the fire protection medium into the single cell experiencing thermal runaway. The fire protection medium can absorb and cool the thermal runaway smoke released by the single cell, thereby reducing the risk of thermal runaway and improving the safety of the battery module.

[0020] Furthermore, in order to prevent the gap between the insulating top cover and the top of the single cell from causing thermal runaway smoke to leak from the gap, and the firefighting medium injected into the inner cavity of the single cell from leaking from the gap, thereby posing a safety hazard to the battery module, the present invention provides a sealing layer between the insulating top cover and the top of the single cell.

[0021] Furthermore, the sealing layer is a double-sided adhesive sheet. Using the double-sided adhesive sheet as the sealing layer is not only convenient for sealing and installation, but also inexpensive.

[0022] Furthermore, in order to accurately and quickly monitor thermal runaway, a TVOC detection device is provided in the above-mentioned box.

[0023] Furthermore, the first horizontal plate of the upper cover assembly is provided with a threaded hole communicating with the fire protection medium channel; the TVOC detection device is fixed to the first horizontal plate by a threaded connection;

[0024] The TVOC detection device includes a fixed sleeve, a TVOC probe and a waterproof breathable membrane; the outer surface of the fixed sleeve is provided with an external thread that matches the threaded hole, one end of the fixed sleeve is open, and the other end is provided with a waterproof breathable membrane; the TVOC probe is embedded in the fixed sleeve, the sensing end of the TVOC probe is close to the waterproof breathable membrane, and the wiring end of the TVOC probe is close to the open end. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the appearance diagram of the battery module;

[0026] Figure 2 It is the structural diagram of the cylinder;

[0027] Figure 3 It is a structural diagram of the upper cover assembly;

[0028] Figure 4 This is the structural diagram of the side panel;

[0029] Figure 5 is a structural diagram of the lower cover assembly;

[0030] Figure 6 A cross-sectional view of the battery module from a first perspective;

[0031] Figure 7 is a cross-sectional view of the battery module from a second perspective;

[0032] Figure 8 A cross-sectional view of the battery module from a third perspective;

[0033] Figure 9 This is a structural diagram of the insulating top cover;

[0034] Figure 10 This is the structural diagram of the insulation fixing frame;

[0035] Figure 11 This is a cross-sectional view of the TVOC detection device.

[0036] The reference numerals are as follows:

[0037] 1- box body, 2- end cover, 3- upper cover assembly, 4- lower cover assembly, 5- side panel, 6- first horizontal plate, 7- first vertical tube, 8- fire protection medium channel, 9- first mounting hole, 10- first groove, 11- second horizontal plate, 12- rib, 13- heat exchange medium circulation channel, 14- second mounting hole, 15- second groove, 16- single battery, 17- insulating top cover, 18- second vertical tube, 19- pole avoidance hole, 20- insulating fixing frame, 21- annular sealing ring, 22- TVOC detection device, 23- fixing sleeve, 24- TVOC probe, 25- waterproof breathable membrane, 26- main control circuit board, 27- accommodating cavity, 28- signal output terminal. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments. Obviously, the embodiments described are only some embodiments, not all embodiments. Based on the following embodiments, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this utility model.

[0039] It should also be noted that the terms "upper, lower, inner, and outer" used herein to indicate positions or locations are based on those shown in the accompanying drawings and are intended solely to simplify the description. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the technical solution. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In this utility model, unless otherwise specified or limited, the terms "mounted, connected, and connected" should be understood broadly. For example, they can refer to fixed connection, detachable connection, or integral connection. They can also refer to mechanical connection, electrical connection, direct connection, indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0041] The battery module of the present invention mainly includes a housing and a plurality of single cells. The single cells can be connected in series, in parallel, or in a mixed connection of series and parallel. This can be adjusted at any time according to actual needs. In this embodiment, the single cells are all connected in series.

[0042] The single cells of this embodiment are commercially available square-shell lithium-ion batteries, and the number of single cells can be increased or decreased according to the specifications required by the battery module.

[0043] 1. Cabinet

[0044] like Figures 1 to 2 As shown, in this embodiment, the box body 1 includes an end cover 2, an upper cover assembly 3, a lower cover assembly 4 and two side panels 5;

[0045] Two end covers 2, an upper cover assembly 3, a lower cover assembly 4, and two side panels 5 are connected to form a box body 1;

[0046] Among them, the upper end surfaces of the two side panels 5 are connected to the upper cover assembly 3 by screw connection, and the lower end surfaces of the two side panels 5 are connected to the lower cover assembly 4 by screw connection, thereby forming a cylinder with open ends at the front and back, and the two end covers 2 are fixed and sealed to the two open ends of the cylinder by screw connection.

[0047] Specifically, if Figure 3 As shown, in this embodiment, the upper cover assembly includes a first horizontal plate 6 and a first vertical tube 7. In order to ensure the strength and temperature resistance of the first horizontal plate 6, the first horizontal plate 6 is made of metal. Considering the cost and weight, the first horizontal plate 6 is made of aluminum in this embodiment.

[0048] See also Figure 8 A fire-fighting medium channel 8 is integrally formed in the first horizontal plate 6 (the first horizontal plate is usually integrally formed by extrusion or casting. In order to form a closed fire-fighting medium channel, a blocking plate needs to be welded to each end of the extruded or cast first horizontal plate), and a plurality of first vertical pipes 7 are provided on the first horizontal plate 6, and one end of the first vertical pipe 7 is fixed on the first horizontal plate 6 and connected to the fire-fighting medium channel 8, and the other end of the first vertical pipe 7 faces the lower cover assembly 4; the fire-fighting medium adopts a liquid medium, and water or a mixture of water and ethylene glycol can be selected.

[0049] The first horizontal plate 6 is also provided with a first mounting hole 9 for mounting a fire-fighting medium inlet joint and a fire-fighting medium outlet joint;

[0050] In order to improve the connection strength and sealing between the side panel and the upper cover assembly 3, in this embodiment, two first grooves 10 are provided on the first horizontal plate 6, and the first grooves 10 are used for the top of the side panel to be embedded therein.

[0051] like Figure 5 As shown, the lower cover assembly 4 includes a second horizontal plate 11 and ribs 12; see Figure 8As shown, a heat exchange medium circulation channel 13 is provided inside the second horizontal plate 11 (the second horizontal plate is usually formed in one piece by extrusion or casting. In order to form a closed heat exchange medium circulation channel, a blocking plate needs to be welded to each end of the extruded or cast second horizontal plate). The temperature of each single battery is controlled by the heat exchange medium flowing in the heat exchange medium circulation channel 13. There are many options for heat exchange medium, which can be air, liquid or phase change material. The temperature control effect of air is poorer than that of liquid and phase change material. When used here, the phase change material is more expensive than liquid, and the temperature control effect is not stable enough. Therefore, the preferred heat exchange medium in this embodiment is liquid, which can be any one of water, mineral oil and ethylene glycol;

[0052] At least two ribs 12 are placed on the surface of the second horizontal plate 11 near the upper cover assembly 3 and are arranged orthogonally to the side panels 5. The ends of the ribs 12 are fixed to the side panels 5 only by screws. The main purposes of the provision of the ribs 12 are as follows: first, to limit the position of the single battery cells in the box; second, to enhance the strength of the lower cover assembly and the connection strength between the lower cover assembly and the side panels.

[0053] The second horizontal plate 11 is further provided with a second mounting hole 14 for mounting a heat exchange medium inlet joint and a heat exchange medium outlet joint;

[0054] In order to improve the connection strength and sealing performance between the side panel 5 and the lower cover assembly 4, in this embodiment, two second grooves 15 are provided on the second horizontal plate, and the second grooves 15 are used for the bottom of the side panel to be embedded therein.

[0055] It should also be noted that: in this embodiment, the integrally formed heat exchange medium flow channel 13 is S-shaped, which can improve the heat exchange effect.

[0056] 2. Battery Module

[0057] Based on the above box structure, this embodiment also provides a battery module using the above box, such as Figure 1 、 Figures 6 to 8 As shown, the battery module includes a box body 1 and a plurality of single cells 16 arranged in the box body;

[0058] like Figure 9As shown, in the present invention, an insulating top cover 17 is fastened and installed on the top of each single cell 16, and a second vertical tube 18 is provided on the insulating top cover 17. The second vertical tube 18 is plugged into the first vertical tube 18 of the upper cover assembly 3 to form an explosion relief channel for the single cell 16; when a single cell in the battery module experiences thermal runaway, a fire protection medium can be injected into the single cell experiencing thermal runaway through the fire protection medium channel and the explosion relief channel. The fire protection medium can absorb and cool the thermal runaway smoke released by the single cell, thereby reducing the risk of thermal runaway and improving the safety of the battery module;

[0059] The individual cells are insulated from the upper cover assembly 3 by an insulating top cover 17, which is made of a non-metallic insulating material, such as ABS or nylon. The insulating top cover 17 comprises a square plate and sidewalls extending downwardly from the four sides of the square plate. To avoid the poles on the individual cells, the insulating top cover 17 is provided with pole-avoidance holes 19 for the poles of the individual cells 16 to extend outward. The use of the insulating top cover 17 not only insulates the individual cells 16 from the upper cover assembly 3, but also insulates the individual cells 16 on both sides of the housing 1 from the housing sidewalls, and also insulates adjacent individual cells 16 connected in series from each other.

[0060] In order to prevent the gap between the insulating top cover and the top of the single cell from causing thermal runaway smoke to leak from the gap, and the fire-fighting medium injected into the inner cavity of the single cell from leaking from the gap, which would cause safety hazards to the battery module, the utility model provides a sealing layer between the insulating top cover and the top of the single cell.

[0061] In this embodiment, the sealing layer is a double-sided adhesive sheet provided between the insulating top cover and the top of the single cell. During installation, the double-sided adhesive sheet is first bonded to the insulating top cover, and then the insulating top cover is bonded to the top of the single cell through the other bonding surface of the double-sided adhesive sheet. The shape and size of the double-sided adhesive sheet are substantially consistent with those of the top of the single cell. In addition, in order to avoid the single cell poles and the explosion relief channel, the double-sided adhesive sheet is provided with pole avoidance holes and channel avoidance holes.

[0062] In some other embodiments, the sealing layer may also be made of sealant. However, compared with double-sided adhesive sheets, the thickness of the sealant layer is difficult to control and the operation is relatively difficult.

[0063] The bottom of each battery cell 16 is fixed to the lower cover assembly 4 via an insulating frame 20, which insulates the bottom of each battery cell 16 from the lower cover assembly 4. The insulating frame 20 comprises a rectangular frame that conforms to the shape of the battery cell 16. The side walls of the rectangular frame are provided with two ears for connecting to the lower cover assembly 4. The bottom of the battery cell 16 can be insulated from the lower cover assembly 4 by adding a thin insulating pad or applying an insulating layer to the lower cover assembly.

[0064] In order to further reduce the manufacturing cost and assembly times of the insulating top cover 17 and the insulating fixing frame 20, the present embodiment optimizes the structure. Multiple single cells 16 can also share one insulating top cover 17 and one insulating fixing frame 20. In the present embodiment, two single cells connected in series and located in the same straight line share one insulating top cover 17 and one insulating fixing frame 20.

[0065] In some other embodiments, partitions and insulating sealants can be added to the box body to achieve positioning and insulation of single cells. However, this method requires the installation of partitions on the upper cover assembly or the lower cover assembly, and also requires a process of pouring insulating sealant, which makes the production of the entire battery module more troublesome and the structure more complicated.

[0066] In this embodiment, the second vertical tube 18 is integrally formed on the insulating top cover 17. The orthographic projection of the second vertical tube 18 on the single cell top cover covers the area of the explosion-proof membrane, and the gap between the first vertical tube 7 and the second vertical tube 18 remains sealed from the outside.

[0067] The plug-in connection between the first vertical tube 7 and the second vertical tube 18 makes it easy to complete the assembly of the explosion relief channel and the communication with the fire medium channel 8 during the box assembly process. The assembly process is simple, and the second vertical tube 18 is integrally formed on the insulating top cover 17, which means that the second vertical tube 18 also has good insulation performance.

[0068] In some other embodiments, a pipe may be used, and its two ends may be welded to the upper cover assembly and the single cell top cover to form an explosion relief channel. However, this method is relatively difficult to process.

[0069] In this embodiment, Figure 8 As shown, an annular sealing ring 21 is provided on the top surface of the top cover of the single cell 16. The upper surface of the annular sealing ring 21 is used to closely contact the end of the first vertical tube 7 inside the second vertical tube 18 (alternatively, this contact surface can be designed as a concave-convex mating labyrinth seal structure). This prevents the escape of thermal runaway smoke and ensures the airtightness of the explosion venting channel. In some other embodiments, an additional sealing ring can be added in the gap between the first vertical tube 7 and the second vertical tube 18, but this arrangement can make the insertion process between the two less smooth.

[0070] In this embodiment, in order to make the first vertical tube 7 and the second vertical tube 18 plug-in and fit more smoothly, the inner portions of the first vertical tube 7 and the second vertical tube 18 are at least partially tapered.

[0071] In order to accurately monitor thermal runaway, Figure 6As shown, the box is equipped with a TVOC detection device 22. When a single battery in the box experiences thermal runaway, the TVOC detection device 22 can monitor the gas composition of the thermal runaway smoke, thereby triggering the injection of firefighting media into the cavity of the runaway single battery, thereby suppressing the thermal runaway. At the same time, because the TVOC detection device monitors volatile gases, it can also detect when a single battery leaks, triggering the battery module alarm and controlling the battery module to stop operation, and start maintenance on the battery module.

[0072] In this embodiment, the first horizontal plate 6 of the upper cover assembly 3 is provided with a threaded hole communicating with the fire medium channel; the TVOC detection device 22 is fixed to the first horizontal plate 6 by a threaded connection; Figure 11 As shown, the TVOC detection device 22 includes a fixing sleeve 23, a TVOC probe 24 and a waterproof breathable membrane 25; the outer surface of the fixing sleeve 23 is provided with an external thread that matches the threaded hole, one end of the fixing sleeve 23 is open, and the other end is provided with a waterproof breathable membrane 25; the TVOC probe 24 is embedded in the fixing sleeve, the sensing end of the TVOC probe 24 is close to the waterproof breathable membrane 25, and the wiring end of the TVOC probe 24 is close to the open end.

[0073] The TVOC detection device 22 directly detects the thermal runaway smoke in the fire medium channel. Compared with setting the TVOC detection device 22 in the box to detect the thermal runaway smoke, the thermal runaway smoke is easier to detect because the volume of the fire medium channel is much smaller than the volume inside the box.

[0074] In addition, since the TVOC detection device 22 is provided with a waterproof breathable membrane, it can ensure that the thermal runaway smoke passes through the waterproof breathable membrane and is detected by the TVOC probe, while avoiding the problem of the fire protection medium acting on the TVOC probe and causing the TVOC probe to fail.

[0075] In this embodiment, Figure 6 As shown, to ensure good sealing and insulation, a sealing insulating gasket is provided between the end cap 2 and the open end of the barrel. A main control circuit board 26 housing a cavity 27 is located between one of the two end caps 2 and the individual battery cells. Signal output terminals 28 are provided on the main control circuit board 26, at least partially extending outside the end cap 2. The placement of the main control circuit board 26 within the end cap 2 not only improves the integrity of the battery module but also reduces the impact of the external environment on the circuitry within the battery module.

Claims

1. A box body, comprising an upper cover assembly, a lower cover assembly and two end covers; characterized in that: It also includes two side panels; the upper end surfaces of the side panels are connected to the upper cover assembly by screw connection, and the lower end surfaces of the side panels are connected to the lower cover assembly by screw connection.

2. The box according to claim 1, characterized in that: The upper cover assembly includes a first horizontal plate and a first vertical tube; A fire protection medium channel is provided inside the first horizontal plate; The number of the first vertical tubes is consistent with the number of the single cells, and one end of the first vertical tube is fixed to the first horizontal plate and communicates with the fire-fighting medium channel, and the other end of the first vertical tube faces the lower cover assembly; The first horizontal plate is provided with two first grooves, and the tops of the side plates are used to be embedded therein.

3. The box according to claim 1 or 2, characterized in that: The lower cover assembly includes a second horizontal plate and ribs; A heat exchange medium circulation channel is provided inside the second horizontal plate; The ribs include at least two ribs, which are placed on the surface of the second horizontal plate close to the upper cover assembly and are arranged orthogonally to the side plates. The two ends of the ribs are fixed to the side plates only by screw connection. The second horizontal plate is provided with two second grooves, and the bottoms of the side plates are embedded in the second grooves.

4. A battery module, characterized in that: The invention comprises a box as claimed in claim 2, and a plurality of single cells arranged in the box; an insulating top cover is fastened and mounted on the top of each single cell; the second vertical tube of the insulating top cover is connected to the first vertical tube to form an explosion relief channel; A sealing layer is provided between the insulating top cover and the top of the single battery.

5. A battery module according to claim 4, characterized in that: The sealing layer is a double-sided adhesive sheet.

6. A battery module according to claim 4 or 5, characterized in that: A TVOC detection device is provided in the box.

7. A battery module according to claim 6, characterized in that: The first horizontal plate of the upper cover assembly is provided with a threaded hole communicating with the fire protection medium channel; the TVOC detection device is fixed to the first horizontal plate by a threaded connection; The TVOC detection device includes a fixed sleeve, a TVOC probe and a waterproof breathable membrane; the fixed sleeve is provided with an external thread that matches the threaded hole, one end of the fixed sleeve is open, and the other end is provided with a waterproof breathable membrane; The TVOC probe is embedded in the fixing sleeve, the sensing end of the TVOC probe is close to the waterproof breathable membrane, and the wiring end of the TVOC probe is close to the open end.

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