Patent Publication Number: US-2022231354-A1

Title: Battery Module and Manufacturing Method Thereof

Description:
TECHNICAL FIELD 
     Cross Citation with Related Application(s) 
     This application claims the benefit of Korean Patent Application No. 10-2020-0044877 filed on Apr. 13, 2020 in 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 method for manufacturing the same, and more particularly to a battery module having a cooling structure, and a method for manufacturing the same. 
     BACKGROUND ART 
     A secondary battery has attracted much 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, it is common to configure a battery module composed of at least one battery cell first, and then configure a battery pack by using at least one of the battery modules and adding other components. 
     Such a battery module may include a battery cell stack in which a plurality of battery cells are stacked, a module frame for housing the battery cell stack, and a heat sink for cooling the plurality of battery cells. 
       FIG. 1  is a view illustrating a battery module coupled to a heat sink according to the related art. 
     Referring to  FIG. 1 , a conventional battery module includes a battery cell stack in which a plurality of battery cells  10  are stacked, a module frame for housing the battery cell stack, and a thermally conductive resin layer  15  located between the bottom part  20  of the module frame and the battery cell stack. Such a battery module can be formed under the bottom part  20  of the module frame and coupled with a heat sink  30  that provides a cooling function to a plurality of battery cells  10 , thereby forming a battery pack. At this time, the heat sink  30  includes an inlet through which refrigerant flows in, an outlet through which refrigerant flows out, a lower plate  31  having a cooling flow path for connecting the inlet and the outlet, and an upper plate  29  for covering the lower plate  31 . Here, a heat conductive layer  18  may be further formed between the bottom part  20  of the battery module and the heat sink  30 . 
     Conventionally, in order to improve the cooling performance of the battery module and/or the battery pack, a separate cooling structure, for example, a heat sink  30 , is required for each battery pack unit. Therefore, the cooling structure tended to be complicated, and the space between the refrigerant and the battery cell laminate  10  was formed by a multi-layered structure consisting of an upper plate  29 , a module frame bottom part  20 , and the like, whereby there was a limit that it has no choice but to cool the battery cells indirectly. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problem 
     It is an object of the present disclosure to provide a battery module having improved assembling property of the cooling structure to improve cooling performance, and a method for manufacturing the same. 
     The objects of the present disclosure are not limited to the aforementioned objects, and other objects which are not described herein should be clearly understood by those skilled in the art from the following detailed description. 
     Technical Solution 
     According to one embodiment of the present disclosure, there is provided a battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; a module frame for housing the battery cell stack; end plates for covering front and rear surfaces of the battery cell stack; and a cooling port configured to supply a refrigerant to a heat sink formed on a bottom part of the module frame, wherein the module frame comprises a module frame protrusion, which is extended and formed so as to pass through the end plates on the bottom part of the module frame, wherein the cooling port is formed at an upper surface part of the module frame protrusion, and wherein the end plate comprises an end plate opening formed at a portion thereof corresponding to the cooling port, and an insulator formed so as to cover the end plate opening. 
     A height of the end plate opening may be identical to or larger than a height of the cooling port. 
     The cooling port may be formed so as to be protruded on the upper surface of the module frame protrusion. 
     The module frame protrusion may be formed so as to extend in a vertical direction to a plate surface of the end plate, and the end plate opening may be formed at a portion that meets the module frame protrusion. 
     Terminal busbars may be formed on upper sides of both ends of the end plates, and the end plate opening may be formed at a portion at which the end plates meet the terminal busbars. 
     The insulator may be formed of an insulation tape, and a periphery of the insulation tape may be attached to a circumferential surface of the end plate opening to cover the end plate opening. 
     The battery module may further include a heat sink protrusion part, which is formed so as to correspond to the module frame protrusion. 
     According to another embodiment of the present disclosure, there is provided a battery pack comprising the battery module. 
     According to yet another embodiment of the present disclosure, there is provided a method for manufacturing a battery module, the method comprising the steps of: manufacturing an end plate in which an end plate opening is formed; moving the end plate such that the end plate opening passes through a cooling port located on a module frame protrusion, which is extended and formed from a bottom part of a module frame; coupling the end plate to the module frame; and assembling an insulator so as to cover the end plate opening. 
     In the step of coupling the end plate to the module frame, the end plate moves in a direction that is perpendicular to a surface formed by edges of front and rear surfaces of the module frame, and thus can be coupled to the module frame. 
     Advantageous Effects 
     According to the embodiments of the present disclosure, since there is no assembly feature interference between the cooling port and the end plate, the assembling process of the end plate can be simplified and the difficulty of assembly can be improved. 
     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 a view illustrating a battery module coupled to a heat sink according to the related art; 
         FIG. 2  is a view illustrating a battery module illustrated as a comparative example; 
         FIG. 3  is a view illustrating an interference due to a cooling port when assembling an end plate formed in  FIG. 2 ; 
         FIG. 4  is a view illustrating a state in which the end plate of  FIG. 3  is assembled away from the cooling port; 
         FIG. 5  is an exploded perspective view illustrating a battery module according to an embodiment of the present disclosure; 
         FIG. 6  is an enlarged view of part A of  FIG. 5 , which is a view illustrating a state in which an insulator is attached to an end plate opening of  FIG. 5 ; 
         FIG. 7  is a view illustrating a state in which the end plate is assembled according to the embodiment of the present disclosure; and 
         FIG. 8  is a view illustrating a state in which the insulator is assembled according to the embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     It should be appreciated that the exemplary embodiments, which will be described below, are illustratively described to help understand the present disclosure, and the present disclosure may 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. 
     Hereinafter, a battery module to which a cooling port is coupled according to an embodiment of the present disclosure will be described with reference to  FIGS. 5 to 6 . 
       FIG. 5  is an exploded perspective view illustrating the battery module according to the embodiment of the present disclosure.  FIG. 6  is an enlarged view of part A of  FIG. 5 , which is a view illustrating a state in which an insulator is attached to an end plate opening of  FIG. 5 . 
     Referring to  FIGS. 5 and 6 , a battery module according to an embodiment of the present disclosure includes a battery cell stack  100  in which a plurality of battery cells are stacked, a module frame  200  for housing the battery cell stack  100 , end plates  400  for covering front and rear surfaces of the battery cell stack  100 , and a cooling port  500  for supplying a refrigerant to a heat sink  300  formed on a bottom part of the module frame  200 . The module frame  200  includes a module frame protrusion  211 , which is extended and formed so as to pass through the end plates  400  on the bottom part of the module frame. The cooling port  500  is formed at an upper surface part of the module frame protrusion  211 . The end plate  400  includes an end plate opening  410  formed at a portion corresponding to the cooling port  500  and an insulator  600  formed so as to cover the end plate opening  410 . 
     A battery cell according to the embodiment of the disclosure is a secondary battery, which may be configured of a pouch type secondary battery. The battery cell may be formed of a plurality of cells, and the plurality of battery cells may be stacked so as to be electrically connected to each other, thereby forming the battery cell stack  100 . Each of the plurality of the battery cells may include an electrode assembly, a cell case, and an electrode lead protruding from the electrode assembly. 
     The module frame  200  houses the battery cell stack  100 . According to an embodiment of the present disclosure, the module frame  200  may include a lower frame  210  for covering a lower surface and both side surfaces of the battery cell stack  100 , and an upper plate  220  for covering an upper surface of the battery cell stack 100 . The module frame  200  includes a module frame protrusion  211 , which is extended and formed so as to passe through the end plates on the bottom part of the module frame. The cooling port  500  which will be described below may be seated on an upper side of the module frame protrusion part  211 . 
     However, a structure of the module frame  200  is not limited thereto, and may be a mono frame shape surrounding four surfaces excluding the front and rear surfaces of the battery cell stack  100 . 
     The battery module  200  according to the embodiment of the disclosure may further include end plates  400  for covering the front and rear surfaces of the battery cell stack  100 . Through the above-mentioned module frame  200 , the battery cell stack  100  housed inside the frame may be physically protected. 
     Referring to  FIG. 5 , a heat sink  300  may be formed at a lower part of the module frame  200 . The heat sink  300  may include a lower plate  310  that forms a skeleton of the heat sink  300  and makes contact with the bottom part of the module frame  200 , an inlet  320  that is formed on one side of the heat sink  300  to supply a refrigerant from the outside to the interior of the heat sink  300 , an outlet  330  that is formed on one side of the heat sink and allows a refrigerant flowed inside the heat sink to be discharged to the outside of the heat sink, and a flow passage part  340  that connects the inlet  320  and the outlet  330  and allows the refrigerant to flow. 
     In detail, the flow passage part  340  may indicate a structure in which the lower plate  310  making contact with a lower surface of a lower frame  210  corresponding to the bottom part of the module frame  200  is formed to be recessed on a lower side. An upper side of the flow passage part  340  is opened, whereby a flow path is formed between the flow passage part  340  and the bottom part of the module frame  200 , and thus the refrigerant can flow through the flow path. That is, the battery module  200  according to the embodiment of the disclosure may have an integrated type cooling structure, in which the bottom part of the module frame  200  functions to correspond to the upper plate of the heat sink  300 . 
     Conventionally, a structure in which the refrigerant flows is separately formed on a lower side of the module frame, so that it has no choice but to cool the module frame indirectly and thus, the cooling efficiency is deteriorated. In addition, there was a problem that a separate refrigerant flow structure is formed, which reduces the space utilization of the battery module and the battery pack on which the battery module is mounted. However, according to the embodiment of the present disclosure, the structure in which the heat sink  300  is integrated at a lower part of the module frame  200  can be employed so as to allow the refrigerant to directly flow between the flow passage part  340  and the bottom part of the module frame  200 , thereby increasing the cooling efficiency due to direct cooling. Moreover, through the structure in which the heat sink  300  is integrated with the bottom part of the module frame  200 , the space utilization of the battery module and the battery pack on which the battery module is mounted can be further increased. 
     The lower plate  310  may be formed so as to correspond to the bottom part of the module frame  200 . The bottom part of the module frame  200  may correspond to the bottom part of the lower frame  210 , the lower plate  310  and the bottom part of the lower frame  210  can be coupled to each other through welding, and a rigidity of the entire battery module can be reinforced through the lower plate  310 . The lower plate  310  and the bottom part of the lower frame  210  are sealed through welding, whereby the refrigerant can flow without leakage in the flow passage part  340  formed inside the lower plate  310 . 
     Both the inlet  320  and the outlet  330  may be formed on one side of the heat sink  300 . In more detail, both the inlet  320  and the outlet  330  may be formed on one side of the heat sink  300  that is formed at a portion at which the end plate  400  is located. The inlet  320  and the outlet  330  may be located at both ends of one side of the heat sink  300 , respectively. The inlet  320  and the outlet  330  may be formed at locations corresponding to the module frame protrusion parts  211  so as to be connected to lower surface parts of the module frame protrusion parts  211 . The heat sink  300  includes heat sink protrusion parts  300   p  formed so as to correspond to the module frame protrusion parts  211 , and the inlet  320  and the outlet  330  may be located on the heat sink protrusion parts  300   p , which is formed to protrude from one side of the heat sink  300 . 
     The flow passage part  340  may be formed so as to cover the bottom part of the module frame  200  while being bent. The flow passage part  340  is formed in most of areas of the bottom part of the module frame  200  excluding a portion in which the lower plate  310  makes contact with the bottom part of the module frame  200 , whereby all the parts of the battery cell stack  100 , which are disposed so as to occupy most of areas of the bottom part of the module frame  200 , can be uniformly cooled. 
     The portion at which the flow passage part  340  is bent may be formed of a curved surface. Accordingly, the portion at which a partition wall  350  is bent may also be formed of a curved surface. When angled edge portions are formed in the flow passage part  340 , it is likely that a flow of the refrigerant will stagnate at the angled edge portions, thus increasing a temperature deviation and a pressure drop. In this regard, if the bending part is treated with curved surfaces as in the embodiment of the present disclosure, the flow of the refrigerant can be made naturally. 
     The cooling port  500  is connected to the upper surface of the module frame protrusion part  211  so that the refrigerant is supplied to the heat sink  300  through the module frame protrusion part  211 . The cooling port  500  may be formed so as to be protruded on the upper surface of the module frame protrusion part  211 . In more detail, a connection hole is formed on the module frame protrusion part  211  connected to the cooling port  500 , and the connection hole may be connected to the inlet  320  and the outlet  330  of the heat sink  300 . Accordingly, the refrigerant supplied through the cooling port  500  may sequentially pass through the connection hole formed on the module frame protrusion part  211  and the inlet  320  formed in the heat sink protrusion part  300   p  to be flowed into the interior of the heat sink  300 . Further, the refrigerant that circulates in the interior of the heat sink  300  may sequentially pass through the outlet  330  formed in the heat sink protrusion part  300   p  and the connection hole formed in the module frame protrusion part  211  to be discharged to the outside through the cooling port  500 . 
     The end plate opening  410  formed at the portion corresponding to the cooling port  500  is included on the end plate  400 . The end plate opening  410  may be formed in a size by which the cooling port  500  can pass through. For example, a height of the end plate opening  410  may be identical to or larger than a height of the cooling port  500 . Therefore, when the end plate  400  is assembled in the module frame  200 , the end plate  400  can be assembled in a direction in which the cooling port  500  passes through. During the assembling, the end plate  400  is moved such that the cooling port  500  passes through the end plate opening  410 , and thus, the end plate opening  410  may be formed so as to completely pass through the end plate body, without being partially blocked. 
     The module frame protrusion part  211  may be formed so as to extend in a vertical direction to a plate surface of the end plate  400 , and the end plate opening  410  may be formed in the portion that meets the module frame protrusion part  211 . Because the cooling port  500  is connected to the module frame protrusion part  211 , the end plate opening  410  may be also formed such that a lower end of the end plate body is opened, and thus the lower end of the opening  410  may be formed so as to meet the module frame protrusion part  211 . Further, the module frame protrusion part  211  is extended in a vertical direction to the plate surface of the end plate  400 , thereby being assembled, without interference of the module frame protrusion part  211 , in a direction that is perpendicular to the surface formed by edges of the module frame  200  to which the end plate  400  is coupled. 
     Terminal busbars  420  may be formed on upper sides of both ends of the end plates, and openings  410  of the end plates may be formed at portions corresponding to the terminal busbars  420 . 
     The insulator  600  is formed so as to cover the end plate opening  410  formed at the portion corresponding to the cooling port  500 . Because there is a danger that the busbar located in the interior of the end plate is exposed to the outside through the end plate opening  410 , the insulator  600  can be assembled in the end plate opening  410  to interrupt the electrical connection of the inside and the outside of the battery module. 
     The insulator  600  according to an embodiment of the present disclosure may be formed of an insulation tape. A periphery of the insulation tape may be attached to the circumferential surface of the end plate opening  410  to cover the end plate opening  410 . However, the type of the insulator  600  is not limited to the insulation tape, and it may be variously applied as materials or components which are capable of insulation. 
     Hereinafter, referring to  FIGS. 5 to 8 , a method for manufacturing a battery module to which ae cooling port is coupled according to an embodiment of the present disclosure will be described in comparison with a comparative example illustrated in  FIGS. 2 to 4 . 
       FIG. 2  is a view illustrating the battery module illustrated as a comparative example.  FIG. 3  is a view illustrating an interference due to the cooling port when assembling the end plate formed in  FIG. 2 .  FIG. 4  is a view illustrating a state in which the end plate of  FIG. 3  is assembled away from the cooling port.  FIG. 7  is a view illustrating a state in which the end plate is assembled according to an embodiment of the present disclosure.  FIG. 8  is a view illustrating a state in which the insulator is assembled according to an embodiment of the present disclosure. 
     Referring to  FIGS. 7 and 8 , the method for manufacturing a battery module according to an embodiment of the present disclosure includes a step of manufacturing an end plate  400  in which an end plate opening  410  is formed, a step of coupling the end plate  400  to the module frame  200  by moving the end plate  400  such that the end plate opening  410  passes through a cooling port  500  ( FIG. 7 ), and a step of assembling an insulator  600  so as to cover the end plate opening  410  ( FIG. 8 ). 
     In the step of coupling the end plate  400  to the module frame  200 , the end plate  400  moves in a direction that is perpendicular to a surface formed by edges of front and rear surfaces of the module frame  200 , and thus can be coupled to the module frame. 
     Referring to  FIGS. 2 to 4 , a battery module according to a comparative example of the present disclosure may include a module frame  40  for housing the battery cell stack, end plates  50  for covering front and rear surfaces of the battery cell stack, a module frame protrusion part  60  protruded and formed from the bottom part of the module frame  40 , and a cooling port  70  formed at an upper surface part of the module frame protrusion part  60 . 
     Conventionally, the cooling port  70  is coupled to the module frame protrusion part  60  during manufacture of the module frame  40  to thereby assemble the end plate  50  in a state in which a module frame assembly is formed. Here, as illustrated in  FIG. 3 , when the end plate  50  is assembled in a direction that is perpendicular to an attached surface of the end plate, an interference may occur during assembling due to the cooling port  70  protruded upwards from the module frame protrusion part  60 . Accordingly, in order to assemble the end plate  50 , as illustrated in  FIG. 4 , the end plate  50  is moved in a lower side direction in which the module frame protrusion part  60  is located, while vertically standing towards a space between the cooling port  70  and the module frame  40 , and then is again moved in a direction which is perpendicular to the attached surface of the end plate to thereby assemble the end plate  50 . 
     As illustrated in  FIG. 4 , because the end plate  50  has to be assembled through two steps, there was problem that an assembly process becomes complicated and high transfer precision is required to couple the end plate  50  with the edge portions of the module frame  40 . 
     Thus, the method for manufacturing a battery module according to an embodiment of the present disclosure can assemble the end plate  400  and the module frame  200  by only a process of providing the end plate  400  in which the end plate opening  410  having a size by which the cooling port  500  can pass through is formed at a location corresponding to the cooling port  500 , and then moving the end plate  400  in a direction in which the end plate opening  410  the passes through the cooling port, whereby an assembly of two steps according to a comparative example can become unnecessary, the assembly process can become simple, and an assembly efficiency can be improved. 
     In addition, since a problem may occur in the insulation performance of the battery module due to reasons such as exposure of the busbar to the outside through the end plate opening  410 , the insulation performance of the battery module can be secured by assembling the insulator  600  in the end plate opening  410  after completion of the assembly of the end plate  400 . 
     The above-mentioned battery module can be included in the battery pack. The battery pack may have a structure in which one or more of the battery modules according to this embodiment 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. These devices may be applied to transportation means such as an electric bicycle, an electric vehicle, a hybrid vehicle, but the present disclosure is not limited thereto and can be applied to various devices that can use the battery module, which also falls under the scope of the present disclosure. 
     Although the preferred embodiments of the present disclosure have been illustrated and described, the present disclosure is not limited to the above-described particular embodiments, various modifications can be made by those skilled in the art without departing from the scope and spirit as disclosed in the accompanying claims, and these modifications should not be understood separately from the scope and spirit of the invention. 
     DESCRIPTION OF REFERENCE NUMERALS 
       200 : module frame 
       210 : lower frame 
       211 : module frame protrusion part 
       220 : upper plate 
       300 : heat sink 
       400 : end plate 
       410 : end plate opening 
       500 : cooling port 
       600 : insulator