Patent Publication Number: US-2023148313-A1

Title: Battery Module and Battery Pack Including the Same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2020/014959 filed on Oct. 29, 2020, which claims priority to and the benefit of Korean Patent Application No. 10-2019-0151596 filed in the Korean Intellectual Property Office on Nov. 22, 2019, and Korean Patent Application No. 10-2020-0082054 filed in the Korean Intellectual Property Office on Jul. 3, 2020, the entire disclosures of all of which are hereby incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module in which a structure for heat dissipation is improved more simply and efficiently, and a battery pack including the same. 
     BACKGROUND ART 
     Rechargeable batteries having high application characteristics and electrical characteristics such as high energy density according to their products are widely applied to battery vehicles, hybrid vehicles, and electric power storage devices driving electric driving sources as well as portable devices. These rechargeable batteries are attracting attention as new energy sources for improving environmental-friendliness and energy efficiency in that they do not generate any by-products of energy use as well as their primary merit, in which they can drastically reduce the use of fossil fuels. 
     In small mobile devices, one, two, or three battery cells are used per device, while medium and large devices such as automobiles require high power/large capacity. Therefore, a medium-to-large battery module in which a plurality of battery cells are electrically connected is used. 
     Since it is preferable for medium and large battery modules to be manufactured with as small a size and weight as possible, a prismatic battery and a pouch-type battery, which may have a high integration degree and have a small weight with respect to capacity, are mainly used as a battery cell of the medium and large battery modules. 
     On the other hand, when a battery pack is configured by coupling a plurality of battery cells in series or in parallel, a general method is to first configure a battery module composed of at least one battery cell, and then add other constituent elements by using at least one battery module to configure a battery pack. 
     In the case of such a battery module, as the required battery capacity increases, importance of a technology capable of efficiently cooling heat generated from the battery cell is gradually increasing. In particular, although a configuration for heat dissipation is included in the battery module itself, since the heat dissipation is not sufficient by this configuration alone, an additional heat dissipation means is sometimes provided in the battery pack unit. However, in this case, since the configuration for the heat dissipation is overlapped and included, there are problems in that the structure is complicated, and the efficiency of the heat dissipation is also deteriorated. 
     DISCLOSURE 
     Technical Problem 
     The problem to be solved by the present invention is to provide a battery module and a battery pack capable of simplifying and increasing efficiency of the entire structure by simplifying the structure for the heat dissipation. 
     However, tasks to be solved by embodiments of the present invention may not be limited to the above-described task, and may be extended in various ways within a range of technical scopes included in the present invention. 
     Technical Solution 
     A battery module according to an embodiment of the present invention includes: a battery cell laminated body in which a plurality of battery cells are stacked; a lower plate to which the battery cell laminated body is disposed; and a module frame coupled to the lower plate and including two side parts facing each other and an upper part connecting two side parts to cover three surfaces of the battery cell laminated body, and in which a cooling path is formed on the lower plate. 
     The battery module may further include a thermally conductive resin layer formed between the lower plate and the battery cell laminated body. 
     The cooling path may include an inlet connected to the outside at one side of the lower plate, and an outlet connected to the outside at the other side facing the one side. 
     The cooling path may be connected throughout the entire lower plate between the inlet and the outlet. 
     The thermally conductive resin layer may be in direct contact with the lower plate and the battery cell laminated body. 
     The lower plate may be of a flat plate type. 
     The cooling path may be formed by extrusion when forming the lower plate of a flat type. 
     A battery pack according to another embodiment of the present invention may include at least one battery module as described above, and a pack case for packing at least one battery module. 
     The lower plate of the at least one battery module may be fixed to the pack case, and the pack case may be in a form of a flat plate. 
     The battery pack may further include a connection part that connects the cooling paths formed in each of the battery modules to communicate with each other. 
     The connection part may be formed of a flexible material. 
     A device according to another embodiment of the present invention may include at least one battery pack as described above. 
     Advantageous Effects 
     According to embodiments, it is possible to increase the efficiency thereof in the battery module while simplifying the heat dissipation structure. In addition, even in the battery pack including such a battery module, heat may be sufficiently discharged without an additional heat dissipation means of the battery pack unit, thereby simplifying the structure of the battery pack. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an exploded perspective view showing a battery module according to an embodiment of the present invention. 
         FIG.  2    is a schematic view showing an internal structure of a lower plate of the battery module of  FIG.  1   . 
         FIG.  3    is a cross-section view taken along a z-axis direction of the battery module of  FIG.  1   . 
         FIG.  4    is a perspective view showing a battery pack according to another embodiment of the present invention. 
         FIG.  5    is a top view of the battery pack of  FIG.  4   . 
     
    
    
     MODE FOR INVENTION 
     The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. 
     Descriptions of parts not related to the present invention are omitted, and like reference numerals designate like elements throughout the specification. 
     Further, since sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, the present invention is not limited to the illustrated sizes and thicknesses. In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, for better understanding and ease of description, the thicknesses of some layers and areas are exaggerated. 
     It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. Further, in the specification, the word “on” or “above” means positioned on or below the object portion, and does not necessarily mean positioned on the upper side of the object portion based on a gravitational direction. 
     In addition, unless explicitly described to the contrary, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. 
     Further, in the specification, the phrase “on a plane” means viewing the object portion from the top, and the phrase “on a cross-section” means viewing a cross-section of which the object portion is vertically cut from the side. 
       FIG.  1    is an exploded perspective view showing a battery module according to an embodiment of the present invention,  FIG.  2    is a view schematically showing an internal structure of a lower plate of a battery module according to an embodiment of the present invention, and  FIG.  3    is a view showing a cross-section taken along a z-axis direction in a state where constituent elements of the battery module of  FIG.  1    are combined. 
     Referring to  FIG.  1    to  FIG.  3   , the battery module  100  according to the present embodiment includes a battery cell laminated body  120  including a plurality of battery cells  110 , a lower plate  300  in which the battery cell laminated body  120  is disposed, a module frame  400  combined with the lower plate  300  and formed to cover three surfaces of the battery cell laminated body  120  by opening the bottom surface, the front surface, and the rear surface, and an end plate  150  positioned on the front and rear surfaces of the battery cell laminated body  120 , respectively. 
     The module frame  400 , as shown in  FIG.  1   , includes two side parts facing each other and an upper part connecting them to cover three surfaces of the battery cell laminated body. That is, when the opened sides of the module frame  400  are called the first side and the second side, respectively, the module frame  400  is formed of a plate-shaped structure that is bent so as to continuously cover the front, upper, and rear surfaces adjacent to each other among the remaining outer surfaces except for the surfaces of the battery cell laminated body  120  corresponding to the first side and the second side. Here, the portion covering the front and rear surfaces of the battery cell laminated body  120  forms two side parts of the module frame  400  facing each other, and the portion covering the upper surface between them forms the upper part of the module frame  400 . The lower surface corresponding to the upper part of the module frame  400  is opened. 
     The lower plate  300  has a plate-shaped structure corresponding to the lower surface except for the front, upper, and rear surfaces of the battery cell laminated body  120  covered by the module frame  400 . The module frame  400  and the lower plate  300  may form a structure surrounding the battery cell laminated body  120  by bonding by welding, etc., while the corresponding corners are in contact with each other. That is, the module frame  400  and the lower plate  300  may be bonded at the corners corresponding to each other by a bonding method such as welding. 
     The battery cell laminated body  120  includes a plurality of battery cells  110  stacked in one direction, and a plurality of battery cells  110 , as shown in  FIG.  1   , may be stacked in the y- axis direction. The battery cell  110  is preferably a pouch-type battery cell. The electrode lead included in each battery cell  110  is a positive electrode lead or a negative electrode lead, and the end of the electrode lead of each battery cell  110  may be bent in one direction, thereby coming into contact with the end of the electrode lead of another adjacent battery cell  110 . 
     Two electrode leads in contact with each other may be fixed to each other through welding or the like, and through this, an electrical connection between the battery cells  110  inside the battery cell laminated body  120  may be made. In addition, the electrode leads aligned at both ends of the battery cell laminated body  120  may be coupled to the bus bar frame  130  to be electrically connected to the bus bar mounted on the bus bar frame  130 . 
     Inside the lower plate  300 , a cooling path  320  through which a fluid for cooling may be passed is formed. The cooling path  320 , as shown in  FIG.  2   , includes an inlet  321  connected to the outside at one side of the lower plate  300  and an outlet  322  connected to the outside at the other side facing the one side, and is formed to connect between the inlet  321  and the outlet  322  inside the lower plate  300 . As shown in  FIG.  2   , the cooling path  320  may be formed to reciprocate between one side and the other side to be disposed over the entire lower plate  300 , but it is not limited thereto, and if the cooling path  320  has a configuration that may be uniformly disposed on the lower plate  300 , it may be appropriately selected. 
     A thermally conductive resin layer  310  is positioned between the lower plate  300  and the battery cell laminated body  120 . The thermally conductive resin layer  310  is made of a material having thermal conductivity that may dissipate heat generated from the battery cell laminated body  120  to the outside, and may be composed of, for example, a thermal resin. Examples of such thermal resins include silicone, urethane, and epoxy. 
     The thermally conductive resin layer  310  may be formed by coating a thermally conductive resin on the lower plate  300  and then curing it. Particularly, in the present embodiment, since the thermally conductive resin layer  310  is formed by coating a thermally conductive resin on the lower plate  300  of the opened state, compared to a battery module composed of a mono-frame in a form of a square tube, it is possible to easily form the thermally conductive resin layer  310 , and particularly, because it is easy to control the amount and position of the thermally conductive resin to be coated, it is possible to prevent excessive injection of the thermal conductive resin during the manufacturing process, which increases manufacturing cost and increases the weight of the battery module. In addition, since the module frame  400  is assembled after confirming that the thermal conductive resin is sufficiently hardened, the occurrence of defects due to non-curing may be minimized. 
     Before forming the thermally conductive resin layer  310 , that is, before the coated thermal conductive resin is cured, as the battery cell laminated body  120  is disposed on the lower plate  300  and then the thermal conductive resin is cured, the battery cell laminated body  120  may be fixed to the lower plate  300 . That is, the thermally conductive resin layer  310  may serve to transfer the heat generated from the battery cell  110  to the lower plate  300  and to fix the battery cell laminated body  120 . 
     In the battery module  100  according to the present embodiment, since the cooling path  320  is formed inside the lower plate  300  that is in direct contact with the thermally conductive resin layer  310 , the lower plate  300 , which has received heat from the thermally conductive resin layer  310 , acts as a heat sink by itself, thereby effectively dissipating heat from the resultant battery module  100 . Particularly, for such an effect, the sufficient heat dissipation effect may be obtained without a separate heat dissipation pad mounted on the battery module  100  or an additional heat dissipation means provided for a battery pack to be described later. 
     In addition, since the portion where the cooling path  320  is formed is the lower plate  300  in the form of a flat plate, the forming process of the cooling path  320  may also be simplified. That is, the cooling path  320  may be formed by extruding a metal material such as aluminum constituting the lower plate  300 , and when the structure in which the cooling path  320  is integrally formed is a U-shaped or square tubular frame, the forming process of the cooling path  320  may also be complicated. However, in the present embodiment, it is possible to manufacture more easily because the cooling path  320  is formed on the lower plate  300  having a simple shape in the form of a flat plate. That is, when forming the lower plate  300  of the flat shape including the cooling path  320 , the size of the mold for realizing this may be reduced, and the structure may be simplified. On the other hand, when trying to form a cooling path in a rectangular tubular monoframe or the part of a U-shaped lower frame, since the structure to be extruded is complicated and large, the mold for implementing this is also designed to be large and complex, and there is a problem in that the manufacturing cost increases and the process becomes complicated. 
     As described above, according to the battery module  100  according to the present embodiment, heat generated from the battery cell  110  may be efficiently dissipated by a simple structure. In addition, the process of forming the lower plate  300  on which the cooling path  320  is formed and the process of forming the thermally conductive resin layer  310  on the lower plate  300  may be simplified to obtain such a structure, thereby reducing the manufacturing process and cost. 
       FIG.  4    is a perspective view showing a battery pack according to another embodiment of the present invention, and  FIG.  5    is a view showing the battery pack of  FIG.  4    from above. 
     Referring to  FIG.  4    and  FIG.  5   , one or more battery modules according to an embodiment of the present invention may be packaged in the pack case  1001  to form a battery pack  1000 . 
     In the battery pack  1000  according to an embodiment of the present invention, since it is not necessary to further include a separate heat dissipation means, the structure of the pack case  1001 , as shown in  FIG.  4   , may be simplified in the form of a simple flat plate. That is, in the prior art, it was necessary to form an additional cooling path in the pack case  1001  itself in which the battery module  100  is accommodated, or to provide a separate thermal pad under the battery module  100  when the battery module  100  is mounted. However, in the present embodiment, since the cooling path  320  is provided on the lower plate  300  itself on which the battery cell laminated body  120  is mounted in the battery module  100 , heat may be sufficiently dissipated without a separate heat dissipation means in the battery pack  1000 . Therefore, the structure of the battery pack  1000  may be simplified. 
     The battery pack  1000  according to the present embodiment includes a connection part  1002  connecting the cooling paths  320  formed in each of a plurality of battery modules  100  included in the battery pack  1000  to communicate with each other. That is, by connecting the outlet  322  of one battery module  100  and the inlet  321  of the adjacent battery module  100  by the connection part  1002 , the cooling paths  320  are configured to communicate throughout the battery pack  1000 . Accordingly, since the cooling path  320  in the battery module  100  may be connected into one in the battery pack  1000 , the heat dissipation effect of the battery pack  1000  may be easily obtained by injecting the cooling fluid into this one cooling path  320 . 
     In this case, the connection part  1002  may be formed of a flexible material, for example, a resin. In this way, a handling may be improved in the process of forming the battery pack  1000  by combining the battery modules  100 . 
     The aforementioned battery module and battery pack including the same may be applied to various devices. The device may be applied to a vehicle such as an electric bicycle, an electric vehicle, or a hybrid vehicle, but the present invention is not limited thereto, and may be applied to various devices that can use a battery module, and this is also included in the scope of the present invention. 
     While this invention has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
     DESCRIPTION OF SYMBOLS 
       100 : battery module 
       150 : end plate 
       300 : lower plate 
       400 : module frame 
       320 : cooling path 
       1000 : battery pack