Patent Publication Number: US-2023136762-A1

Title: Battery module and battery pack including the same

Description:
TECHNICAL FIELD 
     Cross Citation with Related Application(s) 
     This application claims the benefit of Korean Patent Application No. 10-2020-0146614 filed on Nov. 5, 2020 with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     The present disclosure relates to a battery module and a battery pack including the same, and more particularly, to a battery module having an expandable structure and a battery pack including the same. 
     BACKGROUND 
     A secondary battery attracts significant attention as an energy source in various products such as a mobile device and an electric vehicle. The secondary battery is a potent energy resource that can replace the use of existing products using fossil fuels, and is in the spotlight as an environment-friendly energy source because it does not generate by-products due to energy use. 
     Recently, along with a continuous rise of the necessity for a large-capacity secondary battery structure, including the utilization of the secondary battery as an energy storage source, there is a growing demand for a battery pack of a multi-module structure which is an assembly of battery modules in which a plurality of secondary batteries are connected in series/parallel. 
     Meanwhile, when a plurality of battery cells are connected in series/parallel to configure a battery pack, a method of configuring a battery module composed of at least one battery cell and then adding other components to at least one battery module to configure a battery pack is common. 
     The battery module may include a battery cell stack in which a plurality of battery cells are stacked, a module frame that houses the battery cell stack, and an insulating cover and an end plate that cover both side surfaces of the battery cell stack. 
     Conventionally, a busbar frame was mounted onto the front and rear surfaces of the battery cell stack that is disposed in a direction perpendicular to the stacking direction of the battery cell stack constituting the battery module. Further, an insulating cover was attached to the outside surface of the busbar frame to cut off electric connection between the battery cell stack and the busbar frame and the outside. Further, an end plate was mounted onto the outside surface of the insulating cover to physically protect the battery cell stack and the electrical components connected thereto. However, when the battery module is produced by separately providing the insulating cover and the end plate in this way, the structure of the battery module may become complicated. 
     Meanwhile, recently, in the case of battery modules mounted on electric vehicles, various types of battery module structures have been put on the market in order to efficiently utilize the to space inside the vehicle. As the number of cell blocks increases, a demand for an expandable battery module structure capable of utilizing the space inside the vehicle is growing. 
     At this time, in the case of an expandable battery module structure including at least two or more cell blocks, an insulating cover and an end plate must be separately provided for each battery cell stack when the conventional structure of an end plate and an insulating cover is applied, whereby the weight of the battery module may increase, the production process may be lengthened, and the battery module structure itself may become complicated. In addition, the arrangement of the cooling system for the expandable battery module structure may also be complicated. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problem 
     It is an object of the present disclosure to provide a battery module capable of simplifying the structure of an expandable battery module. 
     However, the technical problem to be solved by embodiments of the present disclosure is not limited to the above-described problems, and can be variously expanded within the scope of the technical idea included in the present disclosure. 
     Technical Solution 
     In order to achieve the above object, according to one embodiment of the present disclosure, there is provided a battery module comprising: a cell block assembly including a battery cell stack in which a plurality of battery cells are stacked and a busbar frame mounted on at least one of a front surface or a rear surface of the battery cell stack, a module frame housing the cell block assembly, the module frame being in a front surface and a rear surface thereof, an upper plate covering an upper surface and the front and rear surfaces of the cell block assembly; and a cross beam disposed adjacent to a side surface part of the upper plate covering the front and rear surfaces of the cell block assembly, is the cross beam being formed in a straight line shape, wherein the cell block assembly includes a first cell block assembly and a second cell block assembly arranged side by side in a longitudinal direction of the plurality of battery cells, and wherein the first cell block assembly and the second cell block assembly are arranged separately from each other so that the busbar frames mounted on the first and second cell block assemblies face each other. 
     The upper plate may further comprise a protruding bottom part protruding from the side surface part. 
     The cross beam may be disposed on the protruding bottom part. 
     The battery module may further comprise a sealing member formed between the protruding bottom part and the cross beam. 
     A refrigerant flow path may be formed inside the cross beam to allow refrigerant to flow therethrough. 
     The first and second cell block assemblies may be disposed along a direction perpendicular to a stacking direction of the battery cell stack. 
     A cooling plate may be located below a bottom part of the module frame. 
     Thermal conductive resin layers may be formed between the first and second cell block assemblies and a bottom part of the module frame, and the thermal conductive resin layers may be formed at a lower end on front and rear sides of the first cell block assembly and a lower end on front and rear sides of the second cell block assembly, respectively. 
     The battery module may further comprise a mounting member located between the first cell block assembly and the second cell block assembly. 
     The upper plate comprises a connection part that connects spaced apart portions of the first cell block assembly and the second cell block assembly, and the mounting member may couple the connection part and a bottom part of the module frame. 
     According to another embodiment of the present disclosure, there is provided a battery pack comprising: the battery module described above, and a lower pack housing to which the battery module is mounted, wherein the upper plate further comprises a protruding bottom part protruding from the side surface part, and wherein the protruding bottom part is adjacent to a first side wall part of the lower pack housing. 
     The battery pack further comprises a first coupling member located between the first side wall part of the lower pack housing and the first cell block assembly, and a second coupling member located between a second side wall part of the lower pack housing and the second cell block assembly, wherein the first coupling member and the second coupling member couple the upper plate and a bottom part of the module frame or the lower pack housing. 
     Advantageous Effects 
     According to embodiments of the present disclosure, by eliminating the end plate and insulating cover structure that were conventionally used in an expandable battery module structure, the battery module can be made lightweight, the assembling property can be improved, the unit production cost of the battery module can be reduced, and parts management cost can be reduced by reducing the number of parts. 
     In addition, by straightening the cooling pipe and eliminating the connection part, it is possible to simplify the structure and reduce in weight. 
     The effects of the present disclosure are not limited to the effects mentioned above and additional other effects not described above will be clearly understood from the description of the appended claims by those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an exploded perspective view showing a battery module according to an embodiment of the present disclosure; 
         FIG.  2    is a perspective view illustrating a state in which the battery module of  FIG.  1    is assembled; 
         FIG.  3    is a top view of  FIG.  2    as viewed from above; 
         FIG.  4    is a perspective view showing an upper plate according to an embodiment of the present disclosure; 
         FIG.  5    shows a section A-A of  FIG.  2   , which is a cross-sectional view of a battery module according to an embodiment of the present disclosure; 
         FIG.  6    is an enlarged view of region P of  FIG.  5   ; 
         FIG.  7    is a perspective view showing a battery pack according to another embodiment of the present disclosure; and 
         FIG.  8    is a comparative example, which is a view showing a structure including an end plate in a conventional battery module. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     It should be appreciated that the exemplary embodiments, which will be described below, are illustratively described to assist in the understand the present disclosure, and the present disclosure can be variously modified to be carried out differently from the exemplary embodiments described herein. However, in the description of the present disclosure, the specific descriptions and illustrations of publicly known functions or constituent elements will be omitted when it is determined that the specific descriptions and illustrations may unnecessarily obscure the subject matter of the present disclosure. In addition, in order to help understand the present disclosure, the accompanying drawings are not illustrated based on actual scales, but parts of the constituent elements may be exaggerated in size. 
     As used herein, terms such as first, second, and the like may be used to describe various components, and the components are not limited by the terms. The terms are used only to discriminate one component from another component. 
     Further, the terms used herein are used only to describe specific exemplary embodiments, and are not intended to limit the scope of the present disclosure. A singular expression includes a plural expression unless they have definitely opposite meanings in the context. It should be understood that the terms “comprise”, “include”, and “have” as used herein are intended to designate the presence of stated features, numbers, steps, movements, constitutional elements, parts or combinations thereof, but it should be understood that they do not preclude a possibility of existence or addition of one or more other features, numbers, steps, movements, constitutional elements, parts or combinations thereof. 
     Now, a structure of a battery module according to an embodiment of the present disclosure will be described with reference to  FIGS.  1  to  6   . 
       FIG.  1    is an exploded perspective view showing a battery module according to an embodiment of the present disclosure.  FIG.  2    is a perspective view illustrating a state in which the battery module of  FIG.  1    is assembled.  FIG.  3    is a top view of  FIG.  2    as viewed from above.  FIG.  4    is a perspective view showing an upper plate according to an embodiment of the present disclosure.  FIG.  5    shows a section A-A of  FIG.  2   , which is a cross-sectional view of a battery module according to an embodiment of the present disclosure.  FIG.  6    is an enlarged view of region P of  FIG.  5   . 
     Referring to  FIGS.  1  to  6   , a battery module according to an embodiment of the present disclosure includes first and second cell block assemblies  100  and  200  including a battery cell stack  110  and a busbar frame  120  mounted on the front and rear surfaces of the battery cell stack  110 , a module frame  300  that houses the first and second cell block assemblies  100  and  200  and is opened in a front and rear direction, and an upper plate  400  that covers the upper surface and front and rear surfaces of the first cell block assembly  100  and the upper surface and front and rear surfaces of the second cell block assembly  200 . The first cell block assembly  100  and the second cell block assembly  200  included in the battery module may be arranged side by side along the longitudinal direction of the battery cell. The longitudinal direction of the battery cells may be a direction that defines a battery cell spacing between the front and rear surfaces of the first cell block assembly  200  in which the busbar frame  120  is disposed. 
     The module frame  300  may include a bottom part and at least two side surface parts connected to the bottom part. In particular, at least two side surface parts may be bent at both ends of the bottom part. The module frame  300  may be U-shaped. 
     At this time, the busbar frame  120  may be mounted on the front and rear surfaces of the first cell block assembly  100 , respectively, and a busbar frame  120  may be mounted on the front and rear surfaces of the second cell block assembly  200 , respectively. In a state where the busbar frame  120  mounted on one side of the first cell block assembly  100  and the busbar frame mounted on one side of the second cell block assembly  200  are adjacent to each other and face each other, the first cell block assembly  100  and the second cell block assembly  200  may be arranged separately from each other. The upper plate  400  may be coupled to the bottom part of the module frame  300  between the first cell block assembly  100  and the second cell block assembly  200  and on the entire front and rear surfaces of the first and second cell block assemblies  100  and  200 . 
     The battery cell according to the present embodiment is a secondary battery and can be configured into a pouch type secondary battery. The battery cells can be configured by a plurality of numbers, and the plurality of battery cells can be stacked so as to be electrically connected to each other, thereby forming a battery cell stack  110 . The plurality of battery cells may include an electrode assembly, a battery case, and an electrode lead protruding from the electrode assembly, respectively. 
     According to embodiments of the present disclosure, it may be formed as a large-area cell block in which the number of stacked battery cells is greatly increased as compared with the conventional case. The large-area cell block may include a case where about 32 to 48 battery cells are stacked in one cell block to constitute the battery cell stack  110 , as compared with the conventional case where about 12 to 24 battery cells are stacked in one cell block. 
     The module frame  300  can house the first and second cell block assemblies  100  and  200 . The module frame  300  is formed of a bottom part  310  and both side surface parts  320 , and can cover the lower surface and both side surfaces of the entire first and second cell block assemblies  100  and  200 . More specifically, the first and second cell block assemblies  100  and  200  are arranged apart from each other in a direction in which the busbar frames face each other, and the module frame  300  is formed in a size that houses up to the first and second cell block assemblies  100  and  200  and a separation space between the first cell block assembly  100  and the second cell block assembly  200 , thereby being able to house the first and second cell block assemblies  100  and  200 . 
     At this time, the first and second cell block assemblies  100  and  200  can be disposed along a direction perpendicular to the stacking direction of the battery cell stack  110 . 
     According to the present embodiment, the upper plate  400  may have a shape in which a plurality of concavo-convex parts are formed so as to integrally cover the upper surface and front and rear surfaces of the first cell block assembly  100  and the upper side surface and front and rear surfaces of the second cell block assembly  200 . The upper plate  400  may be formed so as to cover all portions where the busbar frames  120  are located, and at the same time, may be formed so as to cover the upper surfaces of the first and second cell block assemblies  100  and  200 . The busbar frame  120  may be formed on the front and rear surfaces of the first cell block assembly  100 , and may be formed on the front and rear surfaces of the second cell block assembly  200 , respectively. 
       FIG.  8    is a comparative example, which is a view showing a structure including an end plate in a conventional battery module. 
     The conventional battery module includes a battery cell stack  10  formed in a large area, a module frame  20  for housing the battery cell stack  10 , an upper plate  30  for covering the upper surface of the battery cell stack  10 , an end plate  40  for covering the front and rear surfaces of the battery cell stack  10 , and a heat sink  50  formed below the bottom surface of the module frame  20 . 
     At this time, in addition to the module frame  20  for housing the battery cell stack  10 , an upper plate  30  covering the upper surface and an end plate  40  covering the front and rear surfaces are separately provided to form a frame structure of the battery cell stack  10 . However, in the case of the structure of the end plate  40 , it contains an accessory structure that requires a certain level of strength, for example, it is formed in a size that covers all one side surface of the battery cell stack  10  formed in a large area, and a module mounting part  41  for mounting onto a battery pack is formed on one side, as shown in  FIG.  8   . Therefore, the weight of the end plate  40  can occupy a significant portion of the total weight of the battery module. In addition, since the upper plate  30  and the end plate  40  must be separately installed in addition to the module frame  20 , there is a problem that the assembly process is complicated. 
     Further, in the case of an expandable battery module structure in which two cell blocks are arranged as in embodiments of the present disclosure, the weight of the battery module becomes considerable and the structure of the battery module may become relatively complicated, as compared with the battery module including the single cell block assembly shown in  FIG.  8   . Therefore, a compact structure for reducing the weight of the battery module and simplifying the structure is essentially required. 
     Thus, according to the embodiment of the present disclosure, the portions provided with the busbar frame  120  at the first and second cell block assemblies  100  and  200  can be covered by using the integrally formed upper plate  400 . Thereby, the end plate provided in the conventional battery module can be eliminated, and both the upper surface and front and rear surfaces of the two cell block assemblies can be covered with one upper plate  400 , thereby reducing the weight occupied by the conventional end plate and simplifying the structure of the expandable large area battery module. 
     According to the present embodiment, an insulating film  500  can be formed on the inside surface of the upper plate  400  as shown in  FIG.  5   . Conventionally, it was necessary to form a structure in which an insulating cover was additionally disposed between the end plate and the busbar frame, so that a separate process for assembling the insulating cover between the busbar frame and the end plate was required. On the other hand, according to the present embodiment, the insulating film  500  is attached to the inside surface of the upper plate  400  and thus, at the time of assembling the upper plate  400 , the insulating film  500  can also be mounted onto the battery module at the same time, so that insulation of the battery module can be ensured only through a simple assembly process. 
     According to the present embodiment, a thermal conductive resin layer  700  may be formed between the cell block assembly including the first and second cell block assemblies  100  and  200  and the bottom part  310  of the module frame  300 , as shown in  FIG.  1   . The thermal conductive resin layer  700  may be formed on the lower ends of the front and rear sides of the first cell block assembly  100  and the lower ends of the front and rear sides of the second cell block assembly  200 , respectively. The thermal conductive resin layer  700  can perform the function of transferring the heat generated from the first and second cell block assemblies  100  and  200  to the outside. The thermal conductive resin layer may include a thermal resin. 
     According to the present embodiment, the cooling plate  600  may be disposed below the bottom part  310  of the module frame  300 , as shown in  FIG.  1   . The battery module can be cooled by flowing the refrigerant in the inside of the cooling plate  600 . The refrigerant flow path may be formed between the cooling plate  600  and the bottom part  310 . Thereby, unlike the conventional cooling structure in which a separate heat sink is provided, a structure is adopted in which the coolant flows so that the bottom part  310  becomes a part of the coolant flow path, so that the cooling performance of the battery module can be improved and the battery module can be made lightweight. 
     Referring to  FIGS.  5  and  6   , the battery module according to the present embodiment further includes a cross beam that is disposed adjacent to the side surface part of the upper plate  400  covering the front and rear surfaces of the cell block assemblies  100  and  200 , and is formed in a straight line shape  800 . The upper plate  400  further includes a protruding bottom part  400 P protruding from the side surface part. At this time, the cross beam  800  may be disposed on the protruding bottom part  400 P. 
     A refrigerant flow path  800 P is formed inside the cross beam  800  according to the present embodiment, and the refrigerant may flow through the refrigerant flow path. A sealing member  450  may be formed between the protruding bottom part  400 P and the cross beam  800 . The sealing member  450  may have a gasket structure. The sealing member  450  can prevent the refrigerant from leaking between the cross beam  800  and the protruding bottom part  400 P of the upper plate  400  when the cross beam  800  functions as a cooling pipe through which the refrigerant flows. 
     The battery module according to the present embodiment may further include a mounting member  410  located between the first cell block assembly  100  and the second cell block assembly  200 . The mounting member  410  can couple the upper plate  400  and the bottom part  310  of the module frame  300 . More specifically, the upper plate  400  includes a connection part  401  that connects the separated portion of the first cell block assembly  100  and the second cell block assembly  200 , and the mounting member  410  can couple the connection part  401  and the bottom part  310  of the module frame  300 . 
     A mounting member  410  is located between the first cell block assembly  100  and the second cell block assembly  200 , the first and second coupling members  420  and  430  are located in front and rear sides of the entire first and second cell block assemblies  100  and  200 , and the coupling members  420  and  430  can couple the upper plate  400  and the module frame  300 . 
     Looking closely at the coupling structure of the upper plate  400  and the module frame  300 , the upper plate  400  includes an intermediate connection part  401  formed between the first and second cell block assemblies  100  and  200  and front and rear bottom parts formed in front and rear parts  402  and  403  of the entire first and second cell block assemblies  100  and  200 . At this time, referring to  FIG.  5   , the intermediate connection part  401  is spaced apart from the bottom part  310  of the module frame  300 , and the mounting member  410  can connect and couple the bottom part  401  between the connection part  401  and the bottom part  310  of the module frame  300 . 
     The insulating film  500  may be separated from the connection part  401  between the first cell block assembly  100  and the second cell block assembly  200 , and may be formed to contact the bottom part  310  of the module frame  300 . The front and rear end bottom parts  402  and  403  are in contact with the bottom part  310  of the module frame  300 , and can be coupled to each other by the first and second coupling members  420  and  430 . 
     The connection part and bottom parts that can be coupled with the module frame  300  are formed at both ends and the middle portion of the upper plate  400 , and the portion where the connection part, the bottom parts and the bottom part of the module frame  300  meet is coupled through the coupling members, so that the upper plate  400  and the module frame  300  can be firmly coupled. At the same time, it is possible to physically protect the two cell block assemblies located between the upper plate  400  and the module frame  300 . 
       FIG.  7    is a perspective view showing a battery pack according to another embodiment of the present disclosure. 
     Referring to  FIG.  7   , the battery pack according to the present embodiment includes the above-mentioned battery module and the lower pack housing  1000  to which the battery module is mounted. As described above, the upper plate  400  further includes a protruding bottom part  400 P that is protruded from the side surface part, wherein the protruding bottom part  400 P may be adjacent to the side wall part  1100  of the lower pack housing  1000 . The cross beam  800  disposed adjacent to the side surface part of the upper plate  400  and formed in a straight line shape is disposed between the side surface part of the upper plate  400  and the side wall part  1100  of the lower pack housing  1000 , whereby the rigidity is complemented, the module space utilization is increased, and the cross beam  800  functions as a cooling flow path, which realizes structural simplification and weight reduction by straightening the flow path. 
     The first coupling member  420  described in  FIGS.  5  and  6    is located between one side wall part  1100  of the lower pack housing  1000  and the first cell block assembly  100 , and the second coupling member  430  may be located between the other side wall part  1100  of the lower pack housing  1000  and the second cell block assembly  200 . At this time, the first coupling member  420  and the second coupling member  430  can couple the upper plate  400  to the bottom part  310  of the module frame  300  and/or the lower pack housing  1000 . 
     Such a battery pack may have a structure in which one or more of the battery modules according to the embodiment of the present disclosure are gathered, and packed together with a battery management system (BMS) and a cooling device that control and manage battery&#39;s temperature, voltage, etc. 
     The battery pack can be applied to various devices. Such a device may be applied to a vehicle means such as an electric bicycle, an electric vehicle, or a hybrid vehicle, but the present disclosure is not limited thereto, and is applicable to various devices that can use a battery module, which also belongs to the scope of the present disclosure. 
     Although preferred embodiments of the present disclosure have been shown and described above, the scope of the present disclosure is not limited thereto, and numerous other modifications can be carried out by those skilled in the art, without deviating from the spirit and scope of the principles of the invention described in the appended claims. Further, these modified embodiments should not be understood individually from the technical spirit or perspective of the present disclosure. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
         
           
               100 : first cell block assembly 
               110 : battery cell stack 
               120 : busbar frame 
               200 : second cell block assembly 
               210 : battery cell stack 
               300 : module frame 
               400 : upper plate 
               401 : connection part 
               410 : mounting member 
               420 : first coupling member 
               430 : second coupling member