Patent Publication Number: US-2022231370-A1

Title: Fireproof component, battery pack, and device using battery as power supply

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of PCT Patent Application No. PCT/CN2020/114930, entitled “FIREPROOF MEMBER, BATTERY PACK, AND DEVICE USING BATTERIES AS POWER SOURCE” filed on Sep. 12, 2020, which claims priority to Chinese Patent Application No. 201921689873.2, filed with the State Intellectual Property Office of the People&#39;s Republic of China on Oct. 10, 2019, and entitled “FIREPROOF COMPONENT, BATTERY PACK, AND DEVICE USING BATTERY AS POWER SUPPLY”, all of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments of this application relate to the technical field of batteries, and in particular, to a fireproof component, a battery pack, and a device using a battery as a power supply. 
     BACKGROUND 
     An electric vehicle primarily uses a high voltage provided by a battery pack as a power source. Currently, with the development of the new-energy electric vehicle industry, higher requirements are imposed on the safety of the battery in the battery pack in the entire industry. That is because, if the battery in the battery pack is affected by factors such as a short circuit and a high temperature when the battery pack is in use, a high-pressure gas is prone to be generated inside the battery and is prone to cause thermal runaway and accidents such as a fire or explosion. 
     To slow down the spread of thermal runaway of the battery to avoid the accidents such as a fire or explosion, an existing battery pack is generally equipped with a fireproof component. The fireproof component is generally a mica board, fireproof cloth, or the like. When the mica board, the fireproof cloth, and the like are fastened into the battery pack by bolts, a joint between the fireproof component and the battery pack is prone to incur problems such as crushing and cracking under a locking effect of the bolts. 
     SUMMARY 
     In view of the problems existent in the background technologies, an objective of this application is to provide a fireproof component, a battery pack, and a device using a battery as a power supply. The fireproof component is simply structured and easily moldable, thereby improving production efficiency. When the fireproof component is applied to the battery pack, problems such as crushing and cracking of the fireproof component are avoided, thereby improving safety and reliability of the battery pack. 
     To achieve the foregoing objective, this application provides a fireproof component for use in a battery pack. The fireproof component includes a main body and a frame. The frame includes a body portion, an extension portion, and an opening. An inner peripheral face of the body portion defines the opening. The extension portion is located circumferentially outside the body portion and connected to an outer peripheral face of the body portion. The extension portion extends along a third direction that is perpendicular to a plane defined by the frame and protrudes beyond the body portion. The main body covers the opening of the frame and is connected to the body portion. The main body and the frame are parts independent of each other, and the connection between the fireproof component and the battery module is implemented by screwing of the frame to the battery module, without a need to fix the main body to the battery module, thereby avoiding the problems such as crushing and cracking of the main body in a case of fixing the main body to the battery module, and improving safety of the fireproof component. 
     In the third direction, the main body is located at one side of the body portion of the frame; or the main body is accommodated in the opening. 
     In the third direction, the main body is located at one side of the body portion of the frame. A first connecting hole is disposed on the body portion, a second connecting hole is disposed on the main body, and the main body is connected to the body portion through the second connecting hole and the first connecting hole, thereby implementing a connection between the main body and the frame. 
     A third connecting hole is further disposed on the body portion of the frame, and the third connecting hole is disposed close to the extension portion in contrast with the first connecting hole. An avoidance notch is further disposed on the main body, and the avoidance notch is configured to expose the third connecting hole out of the main body. In this way, when the body portion of the frame is fixedly connected to the battery module through the third connecting hole, because the main body is not fixedly connected to the battery module directly, the main body is prevented from being damaged in a connecting process, thereby ensuring reliability of the connection between the fireproof component and the battery module. 
     The main body is a mica board. The mica board is resistant to a high temperature, thereby improving the high-temperature resistance of the main body. 
     The frame includes a plurality of connecting pieces. The plurality of connecting pieces are spliced together in tandem. Each of the connecting pieces includes a first plate portion and a second plate portion. The second plate portion extends along the third direction and protrudes beyond the first plate portion. The first plate portions of all the connecting pieces constitute the body portion of the frame, and the second plate portions of all the connecting pieces constitute the extension portion of the frame. The plurality of connecting pieces are spliced in tandem to form the frame. When a connecting piece in the frame is damaged, the connecting piece is replaceable without a need to replace the entire frame, thereby reducing replacement cost. 
     Each of the connecting pieces is a sheet metal part. The sheet metal part is formed by stamping, of which the technical process is mature, thereby helping to improve the production efficiency of the frame. 
     Along a circumferential direction of the frame, a positioning slot is disposed at an end of one of two adjacent connecting pieces, and the positioning slot accommodates an end of the other of the two adjacent connecting pieces. The positioning slot facilitates positioning of the two adjacent connecting pieces during installation. 
     The plurality of connecting pieces include two first connecting pieces and two second connecting pieces. The two first connecting pieces are spaced apart in a first direction, the two second connecting pieces are spaced apart in a second direction, and each of the second connecting pieces is connected to the two first connecting pieces. 
     This application further provides a battery pack, including a battery module and the foregoing fireproof component. A main body of the fireproof component and a body portion of a frame are located above the battery module. An extension portion is located circumferentially outside the battery module. The body portion of the frame is fixedly connected to the battery module. The battery module is fixed to the frame. In this way, the battery module is fixed to the fireproof component, thereby avoiding the problems such as crushing and cracking caused by a fixed connection between the battery module and the main body. 
     The battery module includes a plurality of batteries, and an explosion-proof valve is disposed in each of the batteries. A thickness of a part that is of the main body of the fireproof component and that corresponds to the explosion-proof valve is greater than a thickness of a part that is of the main body and that is located outside the explosion-proof valve, thereby preventing a high-temperature and high-pressure gas expelled out of the explosion-proof valve of the battery from crushing the main body when the battery module is thermally runaway. 
     The battery module is plural in number, and a plurality of battery modules are arranged in at least one row of module cells. The fireproof component is disposed on each row of module cells. 
     This application further provides a device that uses a battery as a power supply. The device includes a power source. The power source is configured to provide a driving force for the device. The foregoing battery pack configured to provide electrical energy to the power source. 
     Beneficial effects of this application are as follows: 
     The main body and the frame of the fireproof component are parts independent of each other, and therefore, can be made of different materials and formed separately in different molding processes. In this way, both the main body and the frame can be formed by using an appropriate molding process based on their respective materials, thereby helping to shorten a total molding time of the fireproof component, improving production efficiency, and ensuring high structural strength of the frame of the fireproof component. Therefore, when the frame is fixedly connected to the battery module, the main body does not need to be fixed to the battery module, thereby avoiding the problems such as crushing and cracking of the main body in a case of fixing the main body to the battery module. This improves safety of the fireproof component, and thereby improves safety and reliability of the battery pack in which the fireproof component is mounted. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       To describe the technical solutions in the embodiments of this application more clearly, the following outlines the drawings used in the embodiments of this application. Evidently, the drawings outlined below are merely a part of embodiments of this application. A person of ordinary skill in the art may derive other drawings from the outlined drawings without making any creative efforts. 
         FIG. 1  is an exploded view of a battery pack according to this application; 
         FIG. 2  is a schematic diagram of a location relationship between a fireproof component and a battery module shown in  FIG. 1 ; 
         FIG. 3  is a three-dimensional view of the fireproof component shown in  FIG. 2 ; 
         FIG. 4  is an exploded view of a fireproof component according to an embodiment; 
         FIG. 5  is an exploded view of a fireproof component according to another embodiment; 
         FIG. 6  is an assembly diagram of a frame shown in  FIG. 5 . 
     
    
    
     REFERENCE NUMERALS 
     
         
         
           
               1 . Fireproof component; 
               11 . Main body; 
               12 . Frame; 
               12 A. Body portion; 
               12 B. Extension portion; 
               12 C. Opening; 
               121 . Connecting piece; 
               1211 . First plate portion; 
               1212 . Second plate portion; 
               1213 . Positioning slot; 
               121 A. First connecting piece; 
               121 B. Second connecting piece; T 1 . First connecting hole; 
             T 2 . Second connecting hole; 
             T 3 . Third connecting hole; 
             T 4 . Avoidance notch; 
               2 . Battery module; 
               3 . Upper box; 
               4 . Lower box; 
             M. Module cell; 
             X. First direction; 
             Y. Second direction; 
             Z. Third direction. 
           
         
       
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     To make the objectives, technical solutions, and advantages of this application clearer, the following describes this application in further detail with reference to accompanying drawings and embodiments. Understandably, the specific embodiments described herein are merely intended to explain this application, but are not intended to limit this application. 
     In the context of this application, unless otherwise expressly specified, the terms “first”, “second”, and “third” are for the sole purpose of description rather than indicating or implying any order of preference; the term “a plurality of” means two or more (including two); unless otherwise expressly specified, the term “connect” needs to be understood in a broad sense. For example, a “connection” may be a fixed connection, or a detachable connection, or an integrated connection, or an electrical connection or signal connection; or may be a direct connection or an indirect connection implemented through an intermediate medium. A person of ordinary skill in the art understands the specific meanings of the terms in this application according to the context. 
     Understandably, in the context of this application, directional terms such as “on”, “above”, “under”, and “below” described in the embodiments of this application are described from a perspective shown in the drawings, and are not to be understood as a limitation on the embodiments of this application. The following describes this application in further detail with reference to specific embodiments and accompanying drawings. 
     A device using a battery as a power supply according to this application includes a battery pack and a power source. The power source is configured to provide a driving force for the device, and the battery pack is configured to provide electrical energy to the power source. The device may be a mobile device such as a vehicle, a ship, or a small aircraft. The power source may be a battery pack and an engine, and the driving force provided by the power source may be solely electrical energy, or may include electrical energy and other types of energy (such as mechanical energy). Therefore, all devices that use a battery as a power supply fall within the protection scope of this application. 
     Using a vehicle as an example, a vehicle according to an embodiment of this application may be a new energy vehicle. The new energy vehicle may be a battery electric vehicle, or may be a hybrid electric vehicle, a range-extended electric vehicle, or the like. Specifically, the vehicle may include a vehicle body, a drive motor, a battery pack, a transmission mechanism, and wheels. The battery pack and the drive motor are disposed in the vehicle body. The battery pack is electrically connected to the drive motor to provide electrical energy for the drive motor. The drive motor is connected to the wheels on the vehicle body through the transmission mechanism, so as to drive the vehicle to move. Specifically, the battery pack may be horizontally disposed at a bottom of the vehicle body. 
     Referring to  FIG. 1  and  FIG. 2 , the battery pack includes a fireproof component  1 , a battery module  2 , an upper box  3 , and a lower box  4 . The fireproof component  1  may be fixedly connected to the battery module  2  by a bolt. The lower box  4  fits with the upper box  3 , and works together with the upper box  3  to accommodate the battery module  2  and the fireproof component  1 . The battery module  2  includes a plurality of batteries. When a battery in the battery module  2  is thermally runaway, the fireproof component  1  can effectively slow down the spread of the thermal runaway of the battery, thereby avoiding occurrence of accidents such as a fire or explosion and improving safety and reliability of the battery pack. 
     Specifically, the battery module  2  may be one or plural in number. When the battery module  2  is plural in number, a plurality of battery modules  2  may be arranged in at least one row of module cells M. In this case, the fireproof component  1  may be disposed on each row of module cells M, as shown in  FIG. 2 . 
     Referring to  FIG. 2  to  FIG. 6 , the fireproof component  1  may include a main body  11  (made of a fire-retardant material) and a frame  12 . The frame  12  includes a body portion  12 A, an extension portion  12 B, and an opening  12 C. The body portion  12 A is a concentric square-shaped structure. An inner peripheral face of the body portion  12 A defines the opening  12 C. The extension portion  12 B is located circumferentially outside the body portion  12 A and connected to an outer peripheral face of the body portion  12 A. The extension portion  12 B extends along a third direction Z and protrudes beyond the body portion  12 A. The main body  11  covers the opening  12 C of the frame  12  and is connected to the body portion  12 A. Specifically, the main body  11  may be connected to the body portion  12 A of the frame  12  by riveting, welding, or bolting. 
     When the fireproof component  1  is applied in a battery pack, the main body  11  of the fireproof component  1  and the body portion  12 A of the frame  12  are located above the battery module  2 , the extension portion  12 B is located circumferentially outside the battery module  2 , and the body portion  12 A of the frame  12  may be fixedly connected to the battery module  2  by a bolt. When the battery in the battery module  2  is thermally runaway, because the main body  11  of the fireproof component  1  is fire-retardant, the fireproof component  1  can effectively slow down the spread of the thermal runaway of the battery. In addition, because the body portion  12 A and the extension portion  12 B of the frame  12  together form an L-shaped structure, the frame  12  can lead a flame to spray downward, thereby preventing the flame from burning the upper box  3  (made of a composite material) of the battery pack, and improving safety and reliability of the battery pack. 
     The main body  11  and the frame  12  of the fireproof component  1  are parts independent of each other, and therefore, can be made of different materials and formed separately in different molding processes (in other words, the molding process of the frame  12  is not limited by the molding process of the main body  11 ). In this way, both the main body  11  and the frame  12  can be formed by using an appropriate molding process based on their respective materials, thereby helping to shorten a total molding time of the fireproof component  1 , improving production efficiency, and ensuring high structural strength of the frame  12  of the fireproof component  1 . Therefore, when the frame  12  is fixedly connected to the battery module  2 , the problems such as crushing and cracking of the frame  12  under a locking force of the bolt are avoided, thereby improving safety and reliability of the battery pack. 
     A mica board is resistant to a high temperature. Therefore, in some embodiments, the main body  11  may be a mica board. The mica board includes a plurality of mica sheets (made of a mica material) and an adhesive disposed between every two adjacent mica sheets. The plurality of mica sheets and the adhesive may integrally form a flat slab structure by compression molding. Because the compression molding method works without a need to develop a mold, the main body  11  of the fireproof component  1  can be mass-produced rapidly. 
     Specifically, the main body  11  may be a mica board of uniform thickness. In order to improve an anti-ablation capability of the main body  11 , the main body  11  may be a partially thick mica board. That is, a thickness of a part that is of the main body  11  and that corresponds to the explosion-proof valve of the battery is greater than a thickness of a part that is of the main body  11  and that is located outside the explosion-proof valve. 
     The frame  12  may be a sheet metal part and formed by stamping, and the sheet metal part is made of a metal material. The technique of forming by stamping is mature, thereby improving the production efficiency of the frame  12 . In addition, due to high strength of the sheet metal part, when the frame  12  is fixedly connected to the battery module  2 , the problems such as crushing and cracking of the frame  12  under a locking force of the bolt are avoided, thereby improving safety and reliability of the battery pack. 
     In an embodiment, referring to  FIG. 3  to  FIG. 5 , in the third direction Z, the main body  11  may be located on one side of the body portion  12 A of the frame  12  and fixedly connected to the body portion  12 A. That is, a part of the main body  11  overlaps the body portion  12 A. Specifically, a first connecting hole T 1  may be disposed on the body portion  12 A of the frame  12 , and a second connecting hole T 2  may be disposed on the main body  11 . The main body  11  is riveted or bolted to the body portion  12 A through the second connecting hole T 2  and the first connecting hole T 1 . 
     Referring to  FIG. 3  to  FIG. 6 , a third connecting hole T 3  may be further disposed on the body portion  12 A of the frame  12 , and the third connecting hole T 3  is disposed close to the extension portion  12 B in contrast with the first connecting hole T 1 . An avoidance notch T 4  may be further disposed on the main body  11 , and the avoidance notch T 4  is configured to expose the third connecting hole T 3  out of the main body  11 . In this case, the body portion  12 A of the frame  12  is fixedly connected to the battery module  2  through the third connecting hole T 3 . Because the main body  11  is not fixedly connected to the battery module  2  directly, the main body  11  is prevented from being damaged in a connecting process, thereby ensuring reliability of the connection between the fireproof component  1  and the battery module  2 . 
     In another embodiment not shown, the main body  11  may be integrally accommodated in the opening  12 C and fixedly connected to the inner peripheral face of the body portion  12 A. 
     In an embodiment, referring to  FIG. 4 , the body portion  12 A and the extension portion  12 B of the frame  12  may be integrally formed. 
     In another embodiment, referring to  FIG. 5  and  FIG. 6 , the frame  12  may include a plurality of connecting pieces  121 , and the plurality of connecting pieces  121  are spliced in tandem together circumferentially to form a hollow frame  12 . Specifically, the splicing may be implemented by welding (such as spot welding), riveting or bolting. Each connecting piece  121  may be a sheet metal part and may be formed by stamping. A single connecting piece  121  is structurally simple and fast moldable, thereby improving the overall molding efficiency of the frame  12 . 
     Each connecting piece  121  may include a first plate portion  1211  and a second plate portion  1212 . The second plate portion  1212  extends along the third direction Z and protrudes beyond the first plate portion  1211 . The first plate portions  1211  of all the connecting pieces  121  constitute the body portion  12 A of the frame  12 , and the second plate portions  1212  of all the connecting pieces  121  constitute the extension portion  12 B of the frame  12 . 
     To facilitate positioning and mounting of the plurality of connecting pieces  121 , in a circumferential direction, a positioning slot  1213  is disposed at an end of one of two adjacent connecting pieces  121 , and the positioning slot  1213  accommodates an end of the other of the two adjacent connecting pieces  121 . 
     In an embodiment not shown, all the connecting pieces  121  may be the same in structure and in size. That is, the plurality of connecting pieces  121  are the same type of parts. In this case, the connecting pieces  121  are mass-producible, so that the production efficiency is improved. 
     In another embodiment, referring to  FIG. 5  and  FIG. 6 , the plurality of connecting pieces  121  of the frame  12  may include two first connecting pieces  121 A and two second connecting pieces  121 B. The two first connecting pieces  121 A are spaced apart in a first direction X. The two second connecting pieces  121 B are spaced apart in a second direction Y. Each of the second connecting pieces  121 B is connected to the two first connecting pieces  121 A. In this case, the frame  12  includes just two types of parts (that is, the first connecting piece  121 A and the second connecting piece  121 B). Therefore, both the first connecting piece  121 A and the second connecting piece  121 B are mass-producible, so that the production efficiency is improved.