BATTERY BOX BODY AND BATTERY MODULE

The present application provides a battery box body and a battery module. The battery box body incudes a base plate assembly and a side beam assembly, where the base plate assembly is divided into a first region and a second region. Where a first pressure relief cavity is defined by an outer plate and an inner plate of the base plate assembly, the battery cells are occluded on a portion of a cavity wall of the first pressure relief cavity. A second pressure relief cavity is defined by the support plate and the inner plate, and other portion of the cavity wall of the first pressure relief cavity is communicated with the second pressure relief cavity. A third pressure relief cavity is defined by an inner cavity of the side beam assembly, the side beam assembly is installed with a pressure relief valve communicated with the third pressure relief cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application Serial No. 202210419599.7, filed on Apr. 20, 2022. The aforementioned application is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present application relates to the field of power batteries, for example, to a battery box body and a battery module.

BACKGROUND

A battery box body of a large cylindrical battery includes an accommodating cavity configured to accommodate battery cells, and is provided with a pressure relief valve. When a thermal runaway occurs in the battery cells, substances enter the pressure relief valve from the accommodating cavity. A pressure relief path is relatively short, and cooling effect is not ideal during a pressure relief process. High-temperature substances sprayed are easy to burn and heat spread, resulting in fire hazards.

SUMMARY

The present application provides a battery box body and a battery module to reduce a temperature of high-temperature substances, so that the temperature of the high-temperature substances is lower than an ignition point when the high-temperature substances reach at a pressure relief valve, thereby preventing from firing and improving safety and reliability.

A battery box body is provided, including a base plate assembly and a side beam assembly disposed surrounding the base plate assembly, where the base plate assembly is divided into a first region and a second region, battery cells are disposed in the first region, and a support plate is disposed in the second region;the base plate assembly includes an outer plate and an inner plate, a first pressure relief cavity is defined by the outer plate and the inner plate, and the battery cells are occluded on a portion of a cavity wall of the first pressure relief cavity;a second pressure relief cavity is defined by the support plate and the inner plate, and other portion of the cavity wall of the first pressure relief cavity is communicated with the second pressure relief cavity; anda third pressure relief cavity is defined by an inner cavity of the side beam assembly, the second pressure relief cavity is communicated with the third pressure relief cavity, and the side beam assembly is stalled with a pressure relief valve communicated with the third pressure relief cavity.

A battery module is provided, including battery cells and the battery box body mentioned above, wherein the battery cells are disposed in the first region.

In the above figures:1. Base plate assembly;11. Outer plate;12. Inner plate;121. Carrier plate;1211. First through hole;122. Spacing plate;13. Strainer plate;1A. First pressure relief cavity;2. Side beam assembly;21. Isolation wall;22. First side beam;23. Second side beam;231. Horizontal side beam;2311. Pressure relief valve;232. Vertical side beam;24. Third side beam;25. Fourth side beam;2A. Third pressure relief cavity;3. Support plate;3A. Second pressure relief cavity;4. Pressure relief valves;5. Connection plate;6. Fastener;7. Fixing member;8. First crossbeam;9. Second crossbeam;M. First region; N. Second region.

DETAILED DESCRIPTION OF THE EMBODIMENT

The technical solutions in the embodiments of the present application will be described hereafter with reference to the accompanying drawings, the described embodiments are only a part of embodiments of the present application.

In description of the present application, unless otherwise specified and defined, terms “connected with”, “connected” and “fixed” should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or a whole; it may be a mechanical connection or an electrical connection; it may be a directly connection or an indirectly connection through an intermediate media; and it may be an internal connection of two components or an interaction relationship between two components. For those skilled in the art, meanings of the above terms in the present application can be understood according to situations.

In the present application, unless otherwise specified and defined, a first feature is disposed “on” or “under” a second feature may include a direct contact between the first feature and the second feature, or a contact between the first feature and the second feature through other features rather than the direct contact. Moreover, that the first feature is disposed “up”, “above” and “on” the second feature includes that the first feature is right above or obliquely above the second feature, or only indicate that a horizontal height of the first feature is greater than a horizontal height of the second feature. That the first feature is disposed “under”, “below”, or “underneath” of the second feature include that the first feature is right below or obliquely below the second feature, or only indicate that the horizontal height of the first feature is less than the horizontal height of the second feature.

The embodiment provides a battery module, including an electrical component, battery cells, and a battery box body. Both the electrical component and the battery cells are accommodated in the battery box body. In order to prevent individual battery cell in the battery module from runaway to damage other battery cells, the electrical component, and control systems, etc., the embodiment provides a battery box body.

As shown inFIG.1toFIG.3, the battery box body includes a base plate assembly1and a side beam assembly2disposed surrounding the base plate assembly1, where the base plate assembly1is divided into a first region M and a second region N, the battery cells are disposed in the first region M, and a support plate3is disposed in the second region N. The base plate assembly1includes an outer plate11and an inner plate12, where a first pressure relief cavity1A is defined by the outer plate11and the inner plate12, the battery cells are occluded on a portion of a cavity wall of the first pressure relief cavity1A. A second pressure relief cavity3A is defined by the support plate3and the inner plate12, and other portion of the cavity wall of the first pressure relief cavity1A is communicated with the second pressure relief cavity3A. A third pressure relief cavity2A is defined by an inner cavity of the side beam assembly2, the second pressure relief cavity3A is communicated with the third pressure relief cavity2A, and the side beam assembly2is installed with a pressure relief valve4communicated with the third pressure relief cavity2A.

When a thermal runaway occurs in one or more of the battery cells, high-temperature substances sprayed from the battery cells where the thermal runaway occurs are diffused in the first pressure relief cavity1A, and a first pressure relief layer formed by the first pressure relief cavity1A is separated from a battery cell layer where the battery cells are located, so as to ensure that other battery cells on an upper layer of the inner plate12are not affected during a pressure relief process, thereby preventing other battery cells from being affected. A pressure relief channel is defined by the first pressure relief cavity1A, the second pressure relief cavity3A, and the third pressure relief cavity2A, and after passing through the pressure relief channel, the high-temperature substances are relieved through a pressure relief valve4. When the high-temperature substances pass through the first pressure relief cavity1A, the second pressure relief cavity3A, and the third pressure relief cavity2A, three pressure relief cavity structures respectively take away a large amount of heat to form three times of cooling, and when the high-temperature substances reach at the pressure relief valve4of the box body, a temperature of the high-temperature substances are lower than an ignition point to prevent fire, which is more safe and reliable.

As shown inFIG.4, the inner plate12includes a carrier plate121and a spacing plate122, where each of the battery cells is occluded at a side of a corresponding one of first through hole1211defined in the carrier plate121, and the high-temperature substances sprayed from the battery cells where the thermal runaway occurs enter the first pressure relief cavity1A through the first through holes1211and are diffused, so as to realize that the first pressure relief cavity1A is separated from the battery cells. In the embodiment, the battery cells are cylindrical battery cells, the first through holes1211are circular holes, a bottom area of each of the cylindrical battery cells is not less than a cross-sectional area of a corresponding one of the first through holes1211, to ensure that the high-temperature substances enter the first pressure relief cavity1A as much as possible, and to prevent leakage of the substances from affecting other battery cells. A plurality of first through holes1211are disposed in the carrier plate121and arranged in a form such as a plurality of rows or a matrix, so that the carrier plate121is a honeycomb plate.

In other embodiments, the battery cells may also be square battery cells, etc., and structures such as the carrier plate121and the first through holes1211may be disposed accordingly, the embodiment is not limited thereto.

As shown inFIG.3andFIG.4, the second pressure relief cavity3A is defined by the spacing plate122and the support plate3, and the first pressure relief cavity1A is communicated with the second pressure relief cavity3A through second through holes defined in the spacing plate122. A strainer plate13is disposed on the second through holes defined in the spacing plate122, and a plurality of smaller holes are defined on the strainer plate13to prevent large particulate substances from entering the second pressure relief cavity3A, thereby preventing the pressure relief channel from being blocked by the high-temperature substances sprayed from the battery cells, and resulting in unsmooth pressure relief. The high-temperature substances are filtered through the strainer plate13, and the strainer plate13may be replaced periodically in a later period. In the embodiment, a phase change material layer is affixed on the strainer plate13, and the temperature of the high-temperature substances may be reduced through the phase change material layer.

The outer plate11is a steel plate with a high melting point, is not easy to melt, and may reduce the temperature of the high-temperature substances.

As shown inFIG.5, isolation walls21are disposed in the third pressure relief cavity2A, so that the third pressure relief cavity2A includes a plurality of cavities communicated with each other, and a plurality of isolation walls21may be arranged in parallel and at intervals to form an s-shaped cavity. Alternatively, the plurality of isolation walls21are arranged at intervals, and the isolation walls21may have included angles to form the plurality of cavities, holes are defined in the isolation walls21, and the cavities are communicated with each other. Alternatively, the plurality of isolation walls21are disposed with different shapes, such as one or a combined shape of T-shaped, L-shaped, a plurality of continuous L-shaped, cross-shaped, and concave-shaped, ect., so that the third pressure relief cavity2A forms a “labyrinth” cavity structure, and a structural shape and a splicing shape of the isolation walls21may be referred to related art to form a labyrinth with a simple shape or a complex shape, the embodiment is not limited thereto. When the high-temperature substances flow in the third pressure relief cavity2A, a length of the third pressure relief cavity2A is increased, and pressure relief time is prolonged, thereby reducing the temperature of the high-temperature substances.

As shown inFIG.4andFIG.5, a cross section of the second region N is an isosceles trapezoid, the side beam assembly2includes a first side beam22and second side beams23symmetrically communicated with both ends of the first side beam22, pressure relief holes2311are defined in the second side beams22, and the second pressure relief cavity3A is communicated with the third pressure relief cavity2A through the pressure relief holes2311. The pressure relief holes2311are defined on two symmetrical second side beams23, the high-temperature substances are respectively output from the two second side beams23to two sides to disperse the high-temperature substances, which is beneficial to reduce the temperature.

As shown inFIG.5, each of the second side beams23has an L-shaped cross section, and includes a horizontal side beam231and a vertical side beam232communicated with each other. The horizontal side beam231is located in the second region N, and the second pressure relief cavity3A is communicated with the horizontal side beam231. The length of the third pressure relief cavity2A is prolonged by disposing the L-shaped side beam assembly2. In the embodiment, the horizontal side beam231is provided with a plurality of cavities arranged along a horizontal direction, the vertical side beam232is provided with a plurality of cavities arranged along a vertical direction, and the isolation walls21are provided with openings to communicate between the cavities.

The two second side beams23are symmetrical along a symmetrical plane, two pressure relief valves4are provided and installed on the side beam assembly2and located at a side of the first region M away from the second region N to prolong a conveying path of the high-temperature substances, and the two pressure relief valves4are symmetrical along the symmetrical plane. That is, the two side beams23and the two pressure relief valves4are symmetrical along the same symmetrical plane, so that pressure relief pressure of each of the two pressure relief valves4is reduced to improve reliability.

As shown inFIG.4, the side beam assembly2further includes a fourth side beam25parallel to the first side beam22, and a third side beam24to connect the second side beam23with the fourth side beam25, where the pressure relief valve4is installed on the fourth side beam25, and a output path of the high-temperature substances in the third pressure relief cavity2A is defined by the second side beam23, the third side beam24, the fourth side beam25, and the pressure relief valves4located on a corresponding side.

As shown inFIG.3, the battery box body further includes a connection plate5and a fastener6, where the fastener6passes through the connection plate5, the base plate assembly1, and the side beam assembly2in sequence, so that the connection plate5, the base plate assembly1, and the side beam assembly2are connected with each other.

As shown inFIG.4, the battery box body further includes a first crossbeam8, where the first crossbeam8is configured to divide the first region M into a plurality of installation regions, and each of the installation regions is configured to install a group of the battery cells, so that the battery cells are de-modular in groups, a number of components is reduced, and cost is reduced; and the first cross beam8is connected to the base plate assembly1and the side beam assembly2by a fixing member7to improve structural strength. The fixing member7may be a combination of a long screw and a nut, where the long screw penetrates through the base plate assembly1and the first cross beam8, the nut abuts against a side of the base plate assembly1away from the first cross beam8. In the embodiment, the first crossbeam8is a cross beam. In the embodiment, the cross beam divides the first region M into four installation regions to improve the structural strength. In other embodiments, a plurality of first crossbeams8may be provided to divide the first region M into eight installation regions or more. The plurality of first crossbeams8may be arranged in parallel and at intervals, so that the plurality of installation regions may be arranged in a row or a column according to usage requirements, the embodiment is not limited to thereto.

As shown inFIG.4, the battery box body further includes a second crossbeam9, where the second crossbeam9is provided to separate the first region M from the second region N, and the second region N is configured to install the electrical component, so as to prevent the electrical component, a control system and the like from being damaged when the thermal runaway occurs in the battery cells. Similarly, the second crossbeam9may also be connected to the base plate assembly1by the fixing member7.