Patent Publication Number: US-2023145945-A1

Title: Battery box and battery module

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 17/359,878, filed on Jun. 28, 2021, which is a continuation of International Application No. PCT/CN2019/075822, filed on Feb. 22, 2019, which claims priority to Chinese Patent Application No. 201822254225.6, filed with the Chinese Patent Office on Dec. 29, 2018. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present application relates to the field of battery technologies, and in particular, relates to a battery box and a battery module. 
     BACKGROUND 
     In recent years, the emergence of new energy vehicles has played an enormous role in promoting social development and environmental protection. A power battery pack is a rechargeable battery that is the power source for the new energy vehicles and is widely used in the field of new energy vehicles. Where, in order to ensure the overall structural strength of a battery pack and realize the safe driving of the vehicle, the structural strength of a box of a battery module located inside the battery pack is also particularly important. At present, end plates and side plates of the box of the battery module are usually welded together by butt-welding to enclose and form an accommodating cavity of the box of the battery module, to ensure that battery cells are stably installed in the box of the battery module. Or the structural strength of the box of the battery module is improved by increasing the thickness of a board. 
     Though the box of the battery module in the prior art can increase the strength of the connection between the end plates and the side plates to a certain extent, it has the following problems respectively. (1) The strength of the butt-welding is low, where the vibration occurred during the driving of the vehicle can easily cause the connection between the end plate and the side plate to be disconnected; and the method of butt-welding is easy to leak a laser, and the laser passes through the box will cause damage to the battery cell. (2) The overall structural strength of the box of the battery module may be ensure by increasing the thickness of the board, but the weight of the entire battery pack is greatly increased, thereby increasing the energy consumption of the vehicle. 
     SUMMARY 
     The purpose of the present application is to provide a battery box and a battery module, to alleviate the technical problem of low connection strength between an end plate and a side plate of the battery box in the prior art. 
     The present application is provided with a battery box, including:
         at least two end plates;   at least two side plates, where one of the at least two end plates is provided between two adjacent side plates of the at least two side plates, and where the at least two end plates and the at least two side plates are connected to one another to enclose a cavity of the battery box;   a plurality of welding members, where the plurality of welding members are formed by bending an end portion of a side plate of the at least two side plates or an end portion of an end plate of the at least two end plates multiple times, where the end portion of the side plate or the end portion of the end plate is configured to implement the connection of at least two side plates and the at least two end plates to one another to enclose the cavity of the battery box;   where the plurality of the welding members are configured to be welded to a corresponding end plate or a corresponding side plate.       

     Further, the end portion of the side plate or the end portion of the end plate for enclosure is configured to bend twice to form two welding members. 
     Further, the two welding members are attached to each other. 
     Further, the end portion of the end plate for enclosure is configured to bend in a direction away from the cavity of the battery box to form a first welding member, and the end portion of the end plate for enclosure is configured to bend in the direction deviating from the adjacent side plate to form a second welding member. 
     Further, the plurality of welding members are located outside of the cavity of the battery box. 
     Further, a bottom portion of the end plate is configured to bend for at least once to form a first stiffening arm, and the first stiffening arm is perpendicular to one of the at least two side plates. 
     Further, a connecting member of the battery box is configured to connect to a case of a battery pack though the first stiffening arm. 
     Further, the first stiffening arm is located outside of the cavity of the battery box. 
     Further, a top portion of the end plates is configured to bend for at least once to form a second stiffening arm, the second stiffening arm is perpendicular to one of the at least two side plates, and the second stiffening arm is located outside of the cavity of the battery box. 
     Further, the side plate is configured to bend for multiple times to form a connecting arm, the connecting arm is perpendicular to one of the at least two end plates;
         and a connecting member of the battery box is configured to connect to a case of a battery pack though the connecting arm.       

     Further, the connecting arm is located outside of the cavity of the battery box. 
     Further, the connecting arm is located in the middle portion of the side plate. 
     Further, the connecting arm includes:
         two oppositely provided bending portions, where the two bending portions are provided with a plurality of connecting holes corresponding to each other;   and the connecting member of the battery box is configured to connect to the case of the battery pack though the plurality of connecting holes.       

     Further, the end plate and the side plate are connected by penetration welding, and a penetration welding area is configured to connect to the plurality of welding members and the end plate or the side plate;
         where a welding seam is located at one side of the side plate away from the welding member.       

     Further, the plurality of welding members are provided in the connecting positions between an end plate and a side plate adjacent to each other. 
     Further, the battery box is made of a steel material or aluminum material. 
     The beneficial effects of the present application are:
         the present application is provided with a battery box, and the battery box includes at least two end plates and at least two side plates; where one of the end plates is provided between the adjacent side plates, and the end plates and the side plates enclose and form a cavity of the battery box. Specifically, a plurality of welding members are formed by bending an end portion of the side plate and/or the end plate for enclosure for multiple times, and each of the welding members is welded to a corresponding end plate or side plate. When the end plate and the side plate are welded, a plurality of end plates and a plurality of side plates enclose and form the cavity of the battery box sequentially, where a plurality of welding members are provided in the connecting positions between the end plates and the side plates adjacent to each other. By the method of welding, each welding member is welded to a corresponding end plate or the side plate to improve the connection strength between the end plate and the side plate adjacent to each other. At the same time, since each welding member is formed by bending the end portion of the side plate and/or the end plate for enclosure for multiple times. That is, the end plate and/or the side plate and the welding member are integrally formed.       

     Therefore, the robustness of the connecting position between the end plate and the side plate are further improved, and the occurrence of open welding at the connecting positions of the end plate and the side plate is reduced or even avoided. 
     The present application is provided with a battery module, which includes a plurality of battery cells stacked together and the foregoing battery box. 
     The beneficial effect of the present application is: the battery module provided by the present application having the same advantages as the foregoing battery box, and it will not be repeated here. 
     Another aspect of the present disclosure provides an apparatus including the battery module according to any of the above embodiments, wherein the battery module is adapted to provide power for the apparatus. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to illustrate the implementations of the present application or the technical solutions in the prior art more clearly, a brief description will be made below to the drawings required in the implementation of the present application or the prior art, and apparently, the drawings described below are some implementations of the present application, and other drawings could be obtained based on these drawings by those ordinary skilled in the art without creative efforts. 
         FIG.  1    is a structural schematic diagram of a battery box before assembly provided by an embodiment of the present application; 
         FIG.  2    is a structural schematic diagram of a battery box after assembly provided by an embodiment of the present application; 
         FIG.  3    is another structural schematic diagram of a battery box after assembly provided by an embodiment of the present application; 
         FIG.  4    is an enlarged view of A in  FIG.  2   ; 
         FIG.  5    is an enlarged view of B in  FIG.  2   ; and 
         FIG.  6    is yet another structural schematic diagram of a battery box after assembly provided by an embodiment of the present application. 
     
    
    
     REFERENCE SIGNS 
       1 -End plate;
           11 -First stiffening arm;     12 -Second stiffening arm;       
       2 -Side plate;
           21 -Connecting arm;
             211 -Bending portion;     212 -Connecting hole;           
       3 -Cavity; 
       4 -Welding member; and 
       5 -Welding seam. 
     DESCRIPTION OF EMBODIMENTS 
     The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some of, rather than all of, the embodiments of the present utility model. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model. 
     In the description of the present utility model, it should be understood that orientations or positional relationships indicated by terms such as “inside” and “outside” are orientations or positional relationships shown based on the figures, and the terms are merely for convenience of describing the present utility model and for simplifying the description, but for indicating or implying that an indicated apparatus or element must have a specific orientation, and must be constructed and operated in a specific orientation, which thus may not be understood as limiting the present utility model. 
     In the description of the present utility model, it should be noted that unless otherwise explicitly specified and defined, the terms “mounting”, “connecting” and “connection” should be understood in a broad sense, for example, they may be a fixed connection, a detachable connection, an integrated connection, may be a mechanical connection, or may be an electrical connection; may be a direct connection and may also be an indirect connection via an intermediate medium, or may be communication between the interiors of two elements. A person of ordinary skill in the art can understand specific meanings of the foregoing terms in the present utility model according to a specific situation. 
     Specifically, a battery module includes a battery box and a plurality of battery cells located in the battery box. As shown in  FIG.  1   ,  FIG.  4   , and  FIG.  5   , in the present embodiment, the battery box includes at least two end plates  1  and at least two side plates  2 , where an end plate  1  is provided between the adjacent side plates  2 , and a cavity  3  of the battery box is enclosed and formed by the end plates  1  and the side plates  2 . A plurality of battery cells stacked together are provided in the cavity  3 , where a large surface of the battery cell faces the end plate  1 . Specifically, a plurality of welding members  4  are formed by bending an end portion of the side plate  2  and/or the end plate  1  for enclosure for multiple times; and each of the welding members  4  is welded to a corresponding end plate  1  or side plate  2 . When the end plate  1  and the side plate  2  are welded, a plurality of end plates  1  and a plurality of side plates  2  enclose and form the cavity  3  of the battery box sequentially. Where a plurality of welding members are provided in the connecting positions between the end plate  1  and the side plate  2  adjacent to each other. By the method of welding, each welding member  4  is welded to the corresponding end plate  1  and the side plate  2  to improve the connection strength between the end plate  1  and the side plate  2  adjacent to each other. At the same time, since each welding member  4  is formed by bending the end portion of the side plate  2  and/or the end plate  1  for enclosure for multiple times. That is, the end plate  1  and/or the side plate  2  and the welding member  4  are integrally formed. Therefore, the robustness of the connecting positions the end plate  1  and the side plate  2  are further improved, and the occurrence of open welding at the connecting positions of the end plate  1  and the side plate  2  is reduced or even avoided. 
     Among them, the battery box can be made of aluminum material, steel material, etc. In order to further improve the overall strength of the battery box, and at the same time, to ensure that the battery box has better extensibility, in some embodiments, the battery box is made of a steel material in the present embodiment. 
     As shown in  FIGS.  4  and  5   , the end portion of the side plate  2  and/or the end plate  1  for enclosure is bent twice to form two welding members  4 . In order to ensure the welding strength between the end plate  1  and the side plate  2  meets the design requirements or is beyond the design requirements, as well as simplifies the production and processing procedures, in some embodiments, the end portion of the side plate  2  and/or the end plate  1  for enclosure is bent twice to form two welding members  4  in the present embodiment. Further, a certain gap may be provided between the two welding members  4 . To further improve the robustness of the connection between the welding member  4  and the corresponding end plate  1  or side plate  2 , and reduce the occurrence of open welding, the two welding members  4  are attached to each other. 
     As shown in  FIG.  5    and  FIG.  6   , further, for the purpose of improving the structural strength of the end plate  1  and reducing the occurrence of deformation of the end plate  1  when the battery cell expands in the X-axis direction, in the present embodiment, the end portion of the end plate  1  for enclosure is bent twice to form two welding members  4 . 
     Among them, as shown in  FIG.  6   , an end surface of the end plate  1  for enclosure may be bent in the direction away from the cavity  3  of the battery box, and then continue to be bent in the direction toward its adjacent side plate  2  to form two welding members  4 . In order to increase the volumetric energy density of the module, as shown in  FIG.  5   , in the present embodiment, the end portion of the end plate  1  for enclosure is bent in the direction away from the cavity  3  of the battery box to form a first welding member  4 . The end portion of the end plate  1  for enclosure continues to be bent in the direction away from its adjacent side plate  2  to form a second welding member  4 . Where, since the second welding member  4  is located in a fixed area of the end plate  1 , no more space is occupied, such that the volume of the module used by the same specification of the battery cell is smaller. 
     As shown in  FIG.  4    and  FIG.  6   , in the present embodiment, the method of welding may be penetration hot-melt welding. Specifically, the end plate  1  and the side plate  2  are connected by penetration welding. A penetration welding area is connected to the welding member  4  and the end plate  1  or the side plate  2 . A welding seam  5  is located at one side of the side plate  2  away from the welding member  4 . By welding along an end surface of the side plate  2  away from the welding member  4 , it is convenient to weld a plurality of welding members  4  and the side plate  2  together. And at the same time, because there is a certain thickness formed between the side plate  2  and the welding member  4 , the welding slag may also be prevented from splashing during the welding process. 
     Further, the welding member  4  may be located inside of the cavity  3  of the battery box. 
     In the present embodiment, in order to improve the energy density, and prevent the welding member  4  from occupying the space in the battery box, the welding member  4  is located outside of the cavity  3  of the battery box. 
     As shown in  FIG.  1   ,  FIG.  2    and  FIG.  3   , in the present embodiment, in order to further improve the structural strength of the end plate  1  so that the overall structural strength of the battery box is further improved, the end plate  1  is bent to form at least one first stiffening arm  11 . Where the first stiffening arm  11  may be provided along a widthwise direction (Y-axis) of the battery box, or along a height direction (Z-axis) of the battery box. In order to improve the structural strength of the end plate  1  as well as further reduce or even avoid the occurrence of deformation of the end plate  1  when the battery cell expands along the X-axis direction, in some embodiments, the bottom portion of the end plate  1  is bent for at least once to form the first stiffening arm  11 , and the first stiffening arm  11  is perpendicular to the side plate  2 . 
     Further, in addition that the first stiffening arm  11  may improve the structural strength of the end plate  1 , the connecting member can be connected to a case of a battery pack through the first stiffening arm  11 , to fix the battery box and the case of the battery pack, and the connection fixing point of the battery box is provided, where the connecting member may be a bolt. 
     Among them, the first stiffening arm  11  may be located outside of the cavity structure of the battery box, may also be located inside of the cavity structure of the battery box. In the present embodiment, in order to improve the energy density, and prevent the first stiffening arm  11  from occupying the space in the battery box, the first stiffening arm  11  is located outside of the cavity of the battery box. 
     As shown in  FIG.  3   , in order to further improve the structural strength of the end plate  1 , in the present embodiment, along the widthwise direction (Y axis) of the battery box, the top portion of the end plate  1  is bent at for at least once to form a second stiffening arm  12 . The second stiffening arm  12  is located outside of the cavity  3  of the battery box, where the second stiffening arm  12  has the same function as the first stiffening arm  11 . The function of the first stiffening arm  11  has been clearly described above, and will not be repeated here. 
     Further, in order to improve the strength of the side plate  2  and the robustness of the connection between the battery box and the case of the battery pack, in the present embodiment, the side plate  2  is bent for multiple times to form a connecting arm  21 , and the connecting arm  21  is perpendicular to the end plate  1 . Specifically, the connecting member of the battery box is connected to the case of the battery pack through the connecting arm  21 . 
     Among them, the connecting arm  21  may be located inside of the cavity of the battery box. In the present embodiment, in order to improve the energy density and prevent the connecting arm  21  from occupying the space in the battery box, the connecting arm  21  is located outside of the cavity of the battery box bod. 
     As shown in  FIG.  1   ,  FIG.  2    and  FIG.  3   , further, the connecting arm  21  may be located at the bottom portion, middle portion or top portion of the side plate  2 , to improve the stability of the connection between the connecting arm  21  and the case of the battery pack through the connecting member. In some embodiments, the connecting arm  21  is located in the middle portion of the side plate  2 , where the connecting member may be a bolt. 
     As shown in  FIG.  4   , the side plate  2  may be bent for one or more times to form the connecting arm  21 . In order to ensure the connection between the side plate  2  and the case of the battery pack while reducing the processing steps, in the present embodiment, the connecting arm  21  is formed by bending the side plate  2  twice. Specifically, the connecting arm  21  includes two oppositely provided bending portions  211 , where the two bending portions  211  are provided with a plurality of connecting holes  212  corresponding to each other. The connecting arm  21  is connected to the case of the battery pack by the connecting members through the plurality of connecting holes  212 . 
     The embodiments of the present disclosure further provide an apparatus, which includes a battery module according to any of the embodiments as described above, wherein the battery module is adapted to provide power for the apparatus. The apparatus may be an electric vehicle, a hybrid vehicle, an electric scooter, an electric cart or any other suitable devices which can include the battery module as their own power source. 
     Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present utility model, but not for limiting the present utility model. Although the present utility model is described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they may still make modifications to the technical solutions described in the foregoing embodiments or make equivalent replacements to some or all technical features thereof, without departing from the scope of the technical solutions of the embodiments of the present utility model.