Patent Publication Number: US-2019198952-A1

Title: Battery module and manufacturing method thereof

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the present invention relate to a battery module and a manufacturing method thereof. 
     2. Description of the Related Art 
     Research into a rechargeable secondary battery capable of being charged and discharged has been actively conducted in accordance with the development of state-of-the-art fields such as a digital camera, a cellular phone, a laptop computer, a hybrid automobile and the like. An example of the secondary battery includes a nickel-cadmium battery, a nickel-metal hydride battery, a nickel-hydrogen battery, and a lithium secondary battery. Among them, the lithium secondary battery, which has operating voltage of 3.6 V or more, is used as a power supply of a portable electronic device, or is used for a high output hybrid automobile by connecting a plurality of lithium secondary batteries are connected in series with each other to thereby be used for a high output hybrid automobile. Since the lithium secondary battery has operating voltage three times higher than that of the nickel-cadmium battery or the nickel-metal hydride battery and is more excellent in view of energy density characteristics per unit weight than the nickel-cadmium battery or the nickel-metal hydride battery, the use of the lithium secondary battery has been rapidly increased. 
     Meanwhile, a conventional battery module further requires a separate fixing member for stacking and fixing a plurality of battery cells, and separate cooling members such as cooling tins and a cooling plate for cooling the battery cells, therefore, a volume of the battery module is increased. Furthermore, since respective sides of the battery module case are separately prepared as a separate component, and then are coupled with each other, a process of manufacturing the battery module is complicated, as well as time and costs are increased. 
     For example, Korean Patent Registration No. 10-1560217 discloses a battery module with improved cooling efficiency, which includes cooling members mounted on at least one surface of a stack of battery cells, and an electric insulation thermal conductive member provided between the stack of battery cells and the cooling member, however, it did not solve the above-described problems. 
     SUMMARY OF THE INVENTION 
     It is an object of embodiments of the present invention to provide a battery module capable of maximizing a volume thereof by largely increasing space utilization and maximizing energy density, and a manufacturing method thereof. 
     In addition, another object of embodiments of the present invention is to provide a battery module in which strength and rigidity thereof are reinforced to improve assemblability, and a manufacturing method thereof 
     Further, another object of embodiments of the present invention is to provide a battery module in which one side of a cooling housing is opened to easily apply a fixing/heat transfer resin and insert a battery group during manufacturing, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module capable of minimizing an application amount of a fixing/heat transfer resin, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module in which a surface contact between a battery group and a cooling housing is maximized by an elastic pad provided on an upper side of the battery group, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module in which a fixing/heat transfer resin is thinly spread between a battery group and a cooling housing to increase a contact area therebetween, and thus maximize heat transfer efficiency of the battery group and the cooling housing, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module which includes an adhesion part in which a battery cell is not sealed, such that cooling efficiency of the battery module is enhanced through adhesion between the adhesion part and a cooling plate, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module in which a cooling plate includes protrusions having a shape corresponding to adhesion parts of battery cells, such that contact areas between the cooling plate and the battery cells are increased, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module capable of preventing a problem in which battery cells and a cooling plate do not come into surface contact with each other due to a tolerance in a width between the battery cells in a stacking direction thereof and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module capable of easily placing and assembling bus bar assemblies, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module in which extension parts protruding outward from the battery cell are received in recesses formed in a cooling plate, such that a plurality of battery cells may be maintained in a state of being stacked with each other, and a method for producing the same. 
     Further, another object of embodiments of the present invention is to provide a battery module in which a cooling plate may include accommodating grooves to increase workability during manufacturing compared to the recesses, and a manufacturing method thereof. 
     Further, another object of embodiments of the present invention is to provide a battery module that may prevent a laser beam from penetrating battery cells in a process of coupling a cooling housing with front and rear cover parts or a cover plate, and a manufacturing method thereof. 
     Furthermore, another object of embodiments of the present invention is to provide a battery module in Which a cooling housing is formed as a single piece through an extrusion process, such that a manufacturing time and costs may be greatly reduced, and a manufacturing method thereof. 
     To accomplish the above objects, according to an aspect of the present invention, there is provided a battery module including: a battery group formed by stacking a plurality of battery cells, each of which includes electrode tabs; a cooling housing including a cooling plate located corresponding to one side of sides of the battery group, in which the electrode tabs are not extended, and side plates located on both sides of the battery group perpendicular to the one side of the sides, thus to house the battery group; a cover plate located on the other side of the battery group; and a front cover part and a rear cover part, which are located at outermost front and rear of the battery group on both sides in a direction in which the electrode tabs are extended. 
     The battery module may further include a heat transfer member, wherein the heat transfer member is located in a thin film form between the cooling plate and the battery group. 
     The heat transfer member is filled in an empty space between the cooling plate and the plurality of battery cells. 
     Each of the plurality of battery cells may include a sealing part and an adhesion part, which are formed at outer peripheries thereof by a sheath, wherein the sealing part is formed on three sides among four sides of circumferences of the battery cell, and the adhesion part is formed on the other side of the battery cell, and the cooling plate closely comes into contact with the adhesion part of the plurality of stacked battery cells through the heat transfer member. 
     The cooling plate may have a plurality of protrusions formed thereon, and each of the protrusions is disposed across the adhesion parts of adjacent battery cells. 
     Each of the protrusions may have a curved surface corresponding to a shape of a portion of the adhesion part. 
     A portion of the sealing part adjacent to the adhesion part may have an extension part extending in a direction perpendicular to the adhesion part. 
     The cooling plate may have a plurality of recesses formed therein to receive the extension part. 
     The plurality of recesses may be formed in the cooling plate at positions corresponding to the extension parts. 
     The cooling plate may have a plurality of accommodating grooves formed therein to receive the extension parts of one or more battery cells adjacent to each other of the plurality of stacked battery cells, respectively. 
     The cooling housing may be formed in as a single piece. 
     The electrode tabs may be extended from both sides of the battery group, and the battery module may further include: bus bar assemblies which are connected to the electrode tabs on both sides thereof, respectively, to electrically connect the plurality of battery cells to each other, and a sensing module assembly which is located on the other side of the battery group. 
     The battery module may further include: a sensing board located at one side of the bus bar assemblies on both sides thereof to detect a voltage of the plurality of battery cells, wherein the sensing module assembly electrically connects the remaining one of the bus bar assemblies to the sensing board. 
     The sensing module assembly may further include an elastic pad to press the battery group toward the cooling plate. 
     The battery group may include elastic members disposed between at least two bundles of the plurality of battery cells. 
     According to another aspect of the present invention, there is provided a method of manufacturing a battery module, including: stacking a plurality of battery cells, each of which includes electrode tabs; mounting the stacked plurality of battery cells in a cooling housing including a cooling plate located corresponding to one side of sides of the plurality of battery cells in which the electrode tabs are not extended, disposing a front cover part and a rear cover part at outermost both sides of the plurality of battery cells, in which the electrode tabs are extended; and disposing a cover plate on the other side of the plurality of battery cells. 
     The plurality of battery cells may be placed after a heat transfer member is applied to the cooling plate. 
     When the plurality artery cells are placed on the cooling plate, the heat transfer member may be thinly spread. 
     The method may further include: when the plurality of battery cells are placed, connecting bus bar assemblies to the electrode tabs to electrically connect the plurality of battery cells with each other. 
     The bus bar assemblies may be connected to both sides of the battery group, in which the electrode tabs are extended, and after connecting the bus bar assemblies, a sensing board to detect a voltage of the plurality of battery cells may be connected to one of the bus bar assemblies on both sides thereof. 
     The method may further include: after connecting the sensing board, placing a sensing module assembly, which electrically connects the remaining one of the bus bar assemblies on both sides thereof and the sensing board, on the other side of the plurality of battery cells. 
     The method may further include: after the sensing module assembly is placed, disposing the front cover part, the rear cover part and the cover plate; and coupling the front and rear cover parts and the cover plate with the cooling housing. 
     According to embodiments of the present invention, a volume of the battery module may be maximized by largely increasing space utilization and energy density may be maximized. 
     In addition, according to the embodiments of the present invention, strength and rigidity of the battery module may be reinforced, and assemblability may be improved. 
     Further, according to the embodiments of the present invention, one side of the cooling housing is opened, such that it is easy to apply a fixing/heat transfer resin and insert the battery group during manufacturing. 
     Further, according to the embodiments of the present invention, an application amount of the fixing/heat transfer resin may be minimized. 
     Further, according to the embodiments of the present invention, a surface contact between the battery group and the cooling housing may be maximized by the elastic pad provided on an upper side of the battery group. 
     Further, according to the embodiments of the present invention, the fixing/heat transfer resin is thinly spread between the battery group and the cooling housing to increase a contact area therebetween, and thus maximize heat transfer efficiency of the battery group and the cooling housing. 
     Further, according to embodiments of the present invention, battery module includes the adhesion part in which the battery cell is not sealed, such that cooling efficiency of the battery module may be enhanced through adhesion between the adhesion part and the cooling plate. 
     Further, according to embodiments of the present invention, the cooling plate includes the protrusions having a shape corresponding to the adhesion parts of the battery cell, such that a contact area between the cooling plate and the battery cell may be increased, and cooling efficiency of the battery module may be enhanced. 
     Further, according to the embodiments of the present invention, it is possible to prevent a problem in which the battery cells and the cooling plate are not come into surface contact with each other due to a tolerance in a width between the battery cells in a stacking direction thereof. 
     Further, according to the embodiments of the present invention, the bus bar assemblies may be easily placed and assembled. 
     Further, according to the embodiments of the present invention, the extension parts protruding outward from the battery cell are received in the recesses formed in the cooling plate, such that a plurality of battery cells may be maintained in a state of being stacked with each other. 
     Further, according to the embodiments of the present invention, since the cooling plate includes the accommodating grooves, it is possible to increase workability during manufacturing compared to the recesses. 
     Further, according to the embodiments of the present invention, it is possible to prevent a laser beam from penetrating the battery cell in a process of coupling the cooling housing with the front and rear cover parts or the cover plate. 
     Furthermore, according to the embodiments of the present invention, since the cooling housing is formed as a single piece through an extrusion process, the manufacturing time and costs may be greatly reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present invention n will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is an exploded perspective view illustrating a battery module according to an embodiment of the present invention; 
         FIG. 2  is a perspective view illustrating the battery module according to the embodiment of the present invention; 
         FIG. 3  is a perspective view schematically illustrating a battery cell according to the embodiment of the present invention; 
         FIG. 4  is a front view and a partially enlarged view thereof illustrating a state in which a battery group is mounted in a cooling housing according to the embodiment of the present invention; 
         FIG. 5  is a cross-sectional view and a partially enlarged view thereof illustrating an internal structure of the battery module and the state in which the battery group is mounted in the cooling housing according to the embodiment of the present invention; 
         FIG. 6A  is a cross-sectional view and a partially enlarged view thereof illustrating a shape of a cooling plate having protrusions formed thereon according to the embodiment of the present invention, and  FIG. 6B  is a cross-sectional view and a partially enlarged view thereof illustrating a shape of a cooling housing in which the protrusion is not formed; 
         FIG. 7A  is an exploded perspective view illustrating a sensing module assembly according to the embodiment of the present invention, and  FIG. 7B  is a perspective view illustrating the assembled sensing module assembly according to the embodiment of the present invention; 
         FIG. 8  is a cross-sectional view and a partially enlarged view thereof illustrating the internal structure and an upper portion of the battery module according to the embodiment of the present invention; 
         FIG. 9  is a perspective view illustrating a connection relationship between a sensing board, the sensing module assembly,d the bus bar assemblies of the battery module according to the embodiment of the present invention, and partially enlarged front and rear perspective views of sections A and B; 
         FIG. 10  is a perspective view illustrating a coupling structure between the cooling housing and the cover plate according to the embodiment of the present invention, and a coupling structure between the cooling housing and a front cover part, and partially enlarged cross-sectional views of sections C and D; 
         FIG. 11  is a perspective view and a partially enlarged view thereof illustrating a second example of a cooling housing of the battery module according to the embodiment of the present invention; 
         FIG. 12  is a partial cross-sectional view illustrating a state in which the battery group is placed on a first region of the cooling housing illustrated in  FIG. 11 ; 
         FIG. 13  is a perspective view and a partially enlarged view thereof illustrating a third example of a cooling housing of the battery module according to the embodiment of the present invention; 
         FIG. 14  is a partial cross-sectional view illustrating a state in which the battery group is placed on a first region of the cooling housing illustrated in  FIG. 13 ; 
         FIG. 15  is a perspective view and a partially enlarged view thereof illustrating a fourth example of a cooling housing of the battery module according to the embodiment of the present invention; 
         FIG. 16  is a partial cross-sectional view illustrating a state in which the battery group is placed on a first region of the cooling housing illustrated in  FIG. 15 ; 
         FIGS. 17A to 17C  are views illustrating a state in which the battery group is mounted in the cooling housing according to another embodiment; 
         FIG. 18  is a perspective view illustrating a process in which a sensing module assembly is fastened to an upper portion of the battery group to which a bus bar assembly connected, according to another embodiment of the present invention; 
         FIG. 19  is a perspective view and a front view illustrating a state in which the bus bar assembly and the cooling housing are fastened, according to another embodiment of the present invention; and 
         FIG. 20  is a perspective view illustrating a process of fastening the sensing board to the bus bar assembly according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, these are merely illustrative examples and the present invention is not limited thereto. 
     In descriptions of the embodiments of the present invention, publicly known techniques that are judged to be able to make the purport of the present invention unnecessarily obscure will not be described in detail. Referring to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views. In addition, the terms as used herein are defined by taking functions of the present disclosure into account and can be changed according to the custom or intention of users or operators. Therefore, definition of the terms should be made according to the overall disclosure set forth herein. 
     It should be understood that the technical spirit and scope of the present invention are defined by the appended claims, and the following embodiments are only made to efficiently describe the present invention to persons having common knowledge in the technical field to which the present invention pertains. 
       FIG. 1  is an exploded perspective view illustrating a battery module  1  according to an embodiment of the present invention, and  FIG. 2  is a perspective view illustrating the battery module  1  according to the embodiment of the present invention. 
     Referring to  FIGS. 1 and 2 , the battery module  1  according to the embodiment of the present invention includes: a battery group  10  formed by stacking a plurality of battery cells  11 ; a cooling housing  20  which is configured to house the battery group  10 , and is made of a material having a high thermal conductivity to cool the battery group  10 ; a sensing module assembly  50  located on an upper side of the battery group  10  to connect bus bar assemblies  60   a  and  60   b  located on both sides (front and rear of the battery module  1 ) of the battery group  10  in a longitudinal direction thereof and a sensing board  70  located at one side (front or rear of the battery module  1 ) with each other; a cover plate  40  disposed on an upper side of the sensing module assembly  50 ; the bus bar assemblies  60   a  and  60   b  which are located on the front and rear of the battery group  10  (both sides of the battery group  10  in a direction in which electrode tabs  12  are extended), and are connected to a plurality of electrode tabs  12  so as to electrically connect the plurality of battery cells  11  with each other; the sensing board  70  connected to an outside of any one bus bar assembly  60   a  of the bus bar assemblies  60   a  and  60   b  to detect voltages of the plurality of battery cells  11 ; and front and rear cover parts  30   a  and  30   b  which are located at outermost front and rear of the battery group  10  to protect and fix the battery group  10  when coupling the cooling housing  20  and the cover plate  40  with each other. 
     As described above, in the battery module  1  according to the embodiment of the present invention, all six outer surfaces of the battery group  10  are sealed by the cooling housing  20 , the front and rear cover parts  30   a  and  30   b,  and the cover plate  40 . Therefore, the battery module may be protected from an external impact or foreign matters, and strength and rigidity thereof may be reinforced, such that assemblability may be improved. 
     Meanwhile, the cooling housing  20  may be formed so as to surround three sides of sides from which the electrode tab  12  of the battery group  10  is not drawn. Specifically, the cooling housing  20  includes: a cooling plate  20   a  which surrounds a lower side of the battery group  10  (i.e., one side of both sides of the battery group  10  in a direction perpendicular to a direction in which the plurality of battery cells  11  are stacked); and side plates  20   b  which surround the both sides (i.e. outsides of the respective battery cells  11  located on both ends) of the battery group  10  in the direction in which the plurality of battery cells  11  are stacked. More specifically, the above-described cooling plate  20   a  may be located on one side (preferably, on a lower side in the drawing) of the remaining sides of the circumferential surfaces of the battery group  10  on planes perpendicular to the direction in which the battery cells  11  are stacked except for the sides in which the electrode tabs  12  are located, and the above-described pair of side plates  20   b  may be located on both sides of the battery group  10  in the direction in which the battery cells  11  are stacked. 
     Hereinafter, the above-described cooling housing  20  will be described as surrounding the lower side and both sides of the battery group  10 , but it is not limited thereto, and the cooling housing  20  may surround the upper side and both sides of the battery group  10 . As described above, the cooling housing  20  is formed in a structure that surrounds three surfaces of the battery group  10 , thus to support and protect the battery group  10  housed therein. 
     In addition, since the cooling housing  20  is made of a material having a high thermal conductivity, it may perform the same function as a conventional cooling member. As described above, the battery group  10  may be cooled through the cooling housing  20  surrounding the three surfaces of the battery group  10 . Further, since an additional member such as a cooling member or cooling fins is not required, a volume of the battery module  1  may be minimized to improve energy density of the battery module  1 . 
     Meanwhile, the side plates  20   b  may vertically extend from both sides of the cooling plate  20   a  to the battery group  10  side, and the side plates  20   b  and the cooling plate  20   a  may be formed as a single piece through an extrusion process or the like. That is, the cooling housing  20  may be formed in an integral U-shape. 
     Further, the side plates  20   b  and the cooling plate  20   a  may be made of the same material, and preferably made of aluminum (AL), for example. However, these plates are not limited to being made of the same material, and may be made of materials different from each other. For example, the cooling plate  20   a  may be made of a material having a high thermal conductivity to dissipate heat generated in the battery group  10 , while the side plates  20   b  may be made of a material having insulation properties to minimize a temperature deviation between the plurality of battery cells  11 . 
       FIG. 3  is a perspective view schematically illustrating the battery cell  11  according to the embodiment of the present invention. 
     Referring to  FIG. 3 , the battery cell  11  includes a sheath  15  that houses an electrode assembly (not illustrated) from which the electrode tabs  12   a  and  12   b  are drawn. The sheath  15  includes an adhesion part  153  which is adhered to at least one side of the sides of the electrode assembly, and a sealing part  151  formed by adhering the sheath  15  on sides other than the side of the adhesion part  153 . The sealing part  151  may include extension parts  152  extending with a predetermined length L 1  in a direction perpendicular to the adhesion part  153  at portions adjacent to the adhesion part  153 . 
     Specifically, the sealing part  151  may be formed by adhering the sheath  15  along outer peripheries of the electrode assembly. The sealing part  151  is formed by adhering the sheath  15 , and may be formed along four surfaces of circumferences of the electrode assembly in a thickness direction thereof. At this time, the electrode tabs  12   a  and  12   b  may be drawn to an outside of the sealing part  151  at both ends of the electrode assembly. 
     Herein, the volume of the battery module  1  may be increased by a length in which the sealing part  151  is formed. Therefore, in the battery cell  11  according to the embodiment of the present invention, the sealing part  151  is formed along three circumferences of the electrode assembly in the thickness direction thereof not along all four circumferences, and the sheath  15  is formed so as to be adhered to the electrode assembly on at least one surface, such that the volume of the battery module  1  may be reduced. 
     The sheath  15  may be adhered to at least one side of the electrode assembly. Herein, a portion in which the sheath  15  is adhered to the electrode assembly will be described while referring to the adhesion part  153 . The adhesion part  153  may be formed by adhering the sheath to the electrode assembly. 
     Meanwhile, the adhesion part is not limited to the above-described adhesion part  153  in which the sheath  15  is completely adhered to the electrode assembly, and may mean a side of sides in which the electrode tabs  12   a  and  12   b  of the battery cell  11  are not extended except for the sealing part  151  formed by adhering the sheath  15 . At this time, an electrolyte or the like contained in the sheath  15  may be present between the adhesion part  153  and the electrode assembly. 
     In addition, the sealing part  151  may include at least one extension part  152  extending adjacent to the electrode tabs  12   a  and  12   b.  Herein, the extension part  152  may be extended at a portion adjacent to the adhesion part  153  with a predetermined length L 1  in the direction perpendicular to the adhesion part  153 . Accordingly, a space may be formed between the extension part  152  and the adhesion part  153  by the extended length of the extension part  152 . Herein, the extension part  152  may have a length L of several millimeters. The two extension parts  152  may be extended in the same direction and may be extended in a direction perpendicular to the direction in which the electrode tabs  12  are extended. Further, the extension part  152  may be extended from one side (adhesion part  153 ) in which the electrode tabs  12   a  and  12   b  of the electrode assembly (not illustrated) are not formed. 
     Furthermore, since the adhesion part  153  is formed on one side of the battery cell  11 , cooling efficiency of the battery cell  11  may be improved. The adhesion part  153  may come into contact with the cooling plate  20   a  of the cooling housing  20  capable of cooling the battery cells  11 . For example, the plurality of battery cells  11  are stacked side by side so that the adhesion part  153  is located on a down side, and the cooling plate  20   a  capable of cooling the battery group  10  is disposed on the lower side of the battery group  10  so as to come into contact with the adhesion part  153  of the plurality of battery cells  11 . 
     Further, the cooling plate  20   a  of the cooling housing  20  is adhered to the adhesion part  153 , and extension parts  152  are extended from both ends of the adhesion part  153  in the direction perpendicular to the adhesion part  153 . Thereby, the extension parts  152  may serve to maintain an arrangement of the battery group  10  with respect to the cooling housing  20 . 
       FIG. 4  is a front view and a partially enlarged view thereof illustrating a state in which the battery group  10  is mounted in the cooling housing  20  according to the embodiment of the present invention,  FIG. 5  is a cross-sectional view and a partially enlarged view thereof illustrating an internal structure of the battery module  1  and the state in which the battery group  10  is mounted in the cooling housing according to the embodiment of the present invention,  FIG. 6A  is a cross-sectional view and a partially enlarged view thereof illustrating a shape of the cooling plate  20   a  having protrusions  22  formed thereon according to the embodiment of the present invention, and  FIG. 6B  is a cross-sectional view and a partially enlarged view thereof illustrating a shape of a cooling housing  20 ′ in which the protrusion  22  is not formed. 
     Referring to  FIGS. 4 to 6 , the plurality of battery cells  11  are stacked side by side, and the plurality of stacked battery cells  11  are placed on the cooling plate  20   a,  such that the plurality of battery cells  11  may be cooled by the cooling housing  20 . 
     Meanwhile, the cooling plate  20   a  may have curved surfaces formed according to a shape of the adhesion parts  153  of the plurality of battery cells  11 . 
     Specifically, the cooling plate  20   a  of the cooling housing  20  may have a plurality of protrusions  22  formed to have a curved surface corresponding to the shape of a portion of the adhesion part  153 , so as to come into contact with the adhesion part  153  of the battery cell  11  across the widest surface thereof. At this time, each of the above-described plurality of protrusions  22  may be disposed between the adhesion parts  153  formed in two adjacent battery cells  11 , and is formed corresponding to the partially curved shape of the two adhesion parts  153 , thereby a contact area between the adhesion parts  153  and the cooling plate  20   a  may be maximized. 
     In addition, the cooling plate  20   a  may have a plurality of recesses  25  formed in a groove shape to receive the extension parts  152  of the battery cell  11 . The recess  25  may be an empty space formed in the cooling plate  20   a  at a predetermined interval. The recesses  25  may be formed in the cooling plate  20   a  in a direction parallel to a direction in which the battery cells  11  are arranged. The extension parts  152  protruding outward from the battery cells  11  are received in the recesses  25 , such that the stacked state of the battery cells  11  may be maintained (the first embodiment of the cooling housing  20 ). 
     In addition, the battery group  10  may include the plurality of battery cells  11  formed by stacking, and may further include elastic members  13  disposed between bundles of the predetermined number of the battery cells  11  among the plurality of battery cells  11 . At this time, the elastic member  13  may buffer the battery cells  11  from swelling, and may prevent an external shock and a vibration from being transmitted to the battery cells  11 . However, it is not limited to the configuration in which the elastic member  13  is disposed between the bundles of the predetermined number of the battery cells  11 , for example, the elastic members  13  are disposed between two bundles of the battery cells  11  and between four bundles of the battery cells  11 , as illustrated in  FIG. 5 . 
     Furthermore, a heat transfer member  21  such as a gap filler or a thermally conductive adhesive may be applied between the battery group  10  and the cooling plate  20   a  to increase a contact strength between the battery group  10  and the cooling plate  20   a.  Specifically, the heat transfer member  21 , such as a thermally conductive adhesive having thermal conductive applied between the battery group  10  and the cooling plate  20   a  in a thinly spread state, they maximizing the contact surface between the battery group  10  and the cooling plate  20   a.  In addition, since the space between the battery group  10  and the cooling plate  20   a  is minimized, the heat transfer efficiency in cooling the battery group  10  of the cooling housing  20  may be increased. 
     Meanwhile, after applying the heat transfer member  21  to the cooling plate  20   a  according to the structure of the U-shaped cooling housing  20 , the battery group  10  is placed on the heat transfer member  21 . In this case, the heat transfer member  21  may be applied in a minimum amount, then the heat transfer member  21  may be thinly spread, which will be described in detail below. 
     Meanwhile, Table 1 below shows data on simulation results related to temperatures such as a maximum temperature (° C.) in the battery cell, a minimum temperature (° C.) in the battery cell, a difference between the maximum temperature (° C.) and the minimum temperature (° C.), and a maximum thermal resistance (K/M) in the battery module in a case in which the protrusions  22  are formed on the cooling plate  20   a  of the cooling housing  20  as illustrated in  FIG. 6A  (left side), and a case in which the protrusion  22  is not formed on the cooling housing  20 ′ as illustrated in  FIG. 6B  (tight side). 
     At this time, the above-described simulation may be executed under conditions of an initial flow rate of 1 LPM of cooling water flowing into a heat sink, etc. outside the battery module  1 , an initial temperature of 15° C., and a current of 80 A of the battery cell  11 . 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Cooling housing 
               
               
                   
                 Cooling housing 20 having 
                 20 without 
               
               
                   
                 protrusions formed therein 
                 protrusion 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Maximum temperature in 
                 35.7° 
                 C. 
                 38.5° 
                 C. 
               
               
                 battery cell 
               
               
                 Minimum temperature in 
                 27.2° 
                 C. 
                 29.1° 
                 C. 
               
               
                 battery cell 
               
               
                 Difference between 
                 8.5° 
                 C. 
                 9.4° 
                 C. 
               
               
                 maximum and minimum 
               
               
                 temperature 
               
               
                 Maximum heat resistance 
                 1.8 
                 K/W 
                 2.2 
                 K/W 
               
               
                   
               
            
           
         
       
     
     In the case of the battery module  1  having the protrusions  22  formed on the cooling housing  20  as described above, the temperature in the battery module  1  is lower due to higher cooling efficiency than the case in which the protrusion  22  is not formed, thereby the thermal resistance therein may be lowered. 
       FIG. 7A  is an exploded perspective view illustrating the sensing module assembly  50  according to the embodiment of the present invention, and  FIG. 7B  is a perspective view illustrating the assembled sensing module assembly  50  according to the embodiment of the present invention,  FIG. 8  is a cross-sectional view and a partially enlarged view thereof illustrating the internal structure and an upper portion of the battery module  1  according to the embodiment of the present invention, and  FIG. 9  is a perspective view illustrating a connection relationship between the sensing board  70 , the sensing module assembly  50 , and the bus bar assemblies  60   a  and  60   b  of the battery module  1  according to the embodiment of the present invention, and partially enlarged front and rear perspective views of sections A and B. 
     Referring to  FIGS. 7 to 9 , the sensing module assembly  50  may include a plate-shaped sensing module member  51  and an elastic pad  52  having a size corresponding to the sensing module member  51 . At this time, the elastic pad  52  has a compressive reaction force, so as to press the battery group  10  downward from the upper side of the battery group  10  to make the battery group  10  more closely come into contact with the cooling plate, and the surface contact between the battery group  10  and the cooling plate  20   a  is maximized, such that the efficiency of heat transfer in cooling the battery group  10  of the cooling housing  20  may be increased. 
     The sensing module member  51  may include at least one voltage sensing connection member  511  which is connected to the bus bar assembly  60   b  on one side thereof, that is, on the side in which the sensing board  70  is not disposed (the rear of the battery module  1  in the drawing), and is connected to the sensing board  70  on the other side thereof. Specifically, the voltage sensing connection member  511  may include a first connection member  511   a  connected to the rear bus bar assembly  60   b , a second connection member  511   b  connected to the sensing board  70  on the front of the battery group  10 , and a connection wire  511   c  for connecting the first connection member  511   a  with the second connection member  511   b.    
     In addition, at least a portion of the sensing board  70  may be in electrical contact with at least a portion of the front bus bar assembly  60   a  to be electrically connected thereto, and may be electrically connected to the rear bus bar assembly  60   b  through the first connection member  511   a.  Thereby, a voltage signal of the battery group  10  detected by the rear bus bar assembly  60   b  may be transmitted to the sensing board  70  through the voltage sensing connection member  511  (Section B in  FIG. 9 ), and the sensing board  70  connected to the front bus bar assembly  60   a  may measure a voltage of the battery group  10  to confirm the voltage state thereof (Section A in  FIG. 9 ). 
     Meanwhile, the sensing board  70  illustrated in  FIG. 9  may include a printed circuit board (PCB), for example. Herein, the shape of the sensing board  70  and a connection position with the bus bar assembly  60   a  are illustrated as an example, but it is not limited thereto, and it will be apparent to those skilled in the art that they may be changed depending on the circuit design and the shape of the bus bar assembly  60   a.    
     Further, the voltage sensing connection member  511  may be located and fixed between the sensing module member  51  and the elastic pad  52 . The sensing module member  51  and the elastic pad  52  are made of an insulation material, such that the possibility of electrical communication between the connection wire  511   c  and the battery group  10  may be blocked. 
     Meanwhile, the first connection member  511   a,  the second connection member  511   b,  and the connection wire  511   c  of the sensing module member  51  are merely illustrated as an example, and it is not limited thereto. Any method may be used so long as it can sufficiently transmit a voltage signal on one side of the battery group  10  to the sensing board  70  on the other side, for example, transmit a voltage signal of the battery group  10  detected by the rear bus bar assembly  60   b  to the front sensing board  70  through a flexible print circuit. 
     Furthermore, the sensing module assembly  50  and the cover plate  40  are described herein as a separate component, respectively, but it is not limited thereto. The sensing module assembly  50  and the cover plate  40  may be configured as one component to perform both the connection function between the sensing board  70  and the bus bar assembly  60   b  and the protection function of the battery module  1 . 
       FIG. 10  is a perspective view illustrating a coupling structure between the cooling housing  20  and the cover plate  40  according to the embodiment of the present invention, and a coupling structure between the cooling housing  20  and a front cover part  30   a,  and partially enlarged cross-sectional views of sections C and D. 
     Referring to  FIG. 10 , the side plate  20   b  of the cooling housing  20  may include stepped parts  23  formed at each edge thereof coupled with the front and rear cover parts  30   a  and  30   b,  and the cover plate  40 , respectively. Further, each of the front and rear cover parts  30   a  and  30   b,  and the cover plate  40  may include vertical parts  31  and  41  formed at each edge thereof by extending at right angles therefrom. Specifically, the side plate  20   b  of the cooling housing  20  may include the stepped parts  23  formed in a step shape at each edge thereof coupled with the front and rear cover parts  30   a  and  30   b,  and at the edge thereof coupled with the cover plate  40 . Further, each of the front and rear cover parts  30   a  and  30   b,  and the cover plate  40  may include the vertical parts  31  and  41  formed at each edge thereof coupled with the side plate  20   b  of the cooling housing  20  by extending at right angles so as to correspond to the stepped parts  23 . 
     At this time, the vertical parts  31  and  41  may be located with being in contact with the outsides of the stepped parts  23 , and the cooling housing  20  (i.e., the side plate  20   b ) and each of the front and rear cover parts  30   a  and  30   b,  and the cooling housing  20  (i.e., the side plate  20   b ) and the cover plate  40  may be bonded and coupled with each other by welding or the like. As described above, the vertical parts  31  and  41  may be located outside the stepped parts  23 . Therefore, even when the battery cells  11  are expanded with use of the battery module  1 , it is possible to prevent the battery module  1  from being broken by a tensile force applied in a direction in which the plurality of battery cells  11  are stacked. Specifically, the stepped parts  23  are located inside the vertical parts  31  and  41 , thus to closely come into contact with the vertical parts  31  and  41  in a direction perpendicular to a direction in which the above-described tensile force is applied. Therefore, even when the battery cells  11  are expanded, the stepped parts  23  may be supported by the vertical parts  31  and  41 , and the possibility of breakage of the battery module  1  may be reduced. 
     Furthermore, the above-described parts may be bonded to each other by laser beam welding. At this time, a beam emitted from a laser L irradiated on a bonding portion may be prevented from being irradiated to the battery group  10  inside the cooling housing  20  by the stepped parts  23 . Specifically, the cooling housing  20  and each of the front and rear cover parts  30   a  and  30   b,  and the cooling housing  20  and the cover plate  40  may be bonded to each other at the ends of the vertical parts  31  and  41 , respectively. As described above, since the stepped parts  23  are located inside the vertical parts  31  and  41 , the stepped parts  23  may prevent the laser beam emitted from the laser L from penetrating the cooling housing  20  and reaching the battery group  10  inside the cooling housing  20 , thereby improving the stability during manufacturing the battery module  1 . 
       FIG. 11  is a perspective view and a partially enlarged view thereof illustrating a second example of a cooling housing  20   x  of the battery module  1  according to the embodiment of the present invention, and  FIG. 12  is a partial cross-sectional view illustrating a state in which the battery group  10  is placed on a first region of the cooling housing  20   x  illustrated in  FIG. 11 . 
     Referring to  FIGS. 11 and 12 , a cooling plate  20   ax  on which the battery group  10  is placed may include a first region  20   ax   1  formed therein, on which the adhesion parts  153  of the plurality of battery cells  11  are placed, and second regions  20   ax   2  formed on both sides thereof, on which the extension parts  152  formed in the sealing part  151  on sides from which the electrode tabs  12  are extended are placed. That is, the second region  20   ax   2 , the first region  20   ax   1 , and the second region  20   ax   2  may be sequentially arranged on the cooling plate  20   ax  based on the direction from which the electrode tabs  12  are drawn. Moreover, the front and rear bus bar assemblies  60   a  and  60   b  may be placed on the second region  20   ax   2 . 
     Specifically, in a case of the second example of the cooling housing  20   x,  the cooling housing  20   x  may include the cooling plate  20   ax  and side plates  20   by  formed at both ends of the cooling plate  20   ax  in the direction in which the battery cells  11  are stacked in this case, the cooling plate  20   ax  may have a plurality of protrusions  22   x  formed thereon, which are the same as the protrusions  22  of the first embodiment of the above-described cooling housing  20 . That is, the plurality of protrusions  22   x  may be formed on the cooling plate  20   ax  over the first region  20   ax   1  and the second regions  20   ax   2 . 
     Meanwhile, each of the second regions  20   ax   2  on which the plurality of extension parts  152  of the battery group  10  are placed may have a plurality of recesses  25   x  formed in a groove shape so as to receive the extension parts  152 , respectively. That is, the extension parts  152  protruding outward from the battery cells  11  are received in the recesses  25   x,  such that the plurality of battery cells  11  may be maintained in a mutually stacked state. 
     As described above, when removing portions of the first region  20   ax   1  for forming the recesses  25 , the contact area between the cooling plate  20   ax  and the adhesion parts  153  may be increased, and the overall contact surface between the lower side of the battery group  10  and the cooling plate  20   ax  is increased, and the cooling efficiency of the battery module  1  may be further increased. 
       FIG. 13  is a perspective view and a partially enlarged view thereof illustrating a third example of a cooling housing  20   y  of the battery module  1  according to the embodiment of the present invention, and  FIG. 14  is a partial cross-sectional view illustrating a state in which the battery group  10  is placed on a first region of the cooling housing  20   y  illustrated in  FIG. 13 . 
     Referring to  FIGS. 13 and 14 , in a case of the third example of the cooling housing  2 o y,  the cooling housing  20   y  may include a cooling plate  20   ay  and side plates  20   by.  At this time, the above-described cooling plate  20   ay  may have a first region  20   ay   1  formed thereon to be flat without a portion partially protruding or being cut, on which the adhesion parts  153  of the battery group  10  are placed. 
     Thereby, it is possible to prevent such a problem that the battery cells  11  are mounted on the protrusions  22  of the cooling plate  20   a,  and the battery cells  11  and the cooling plate  20   a  do not come into surface contact with each other, due to a tolerance in a width of the stacking direction of the battery cells  11 , which may occur during a process of manufacturing the battery cells  11 . 
     In addition, the same structure as the above-described protrusions  22  may not be formed in the second region  20   ay   2  on which the extension parts  152  and the front and rear bus bar assemblies  60   a  and  60   b  are placed. Thereby, the placing surfaces for the above-described bus bar assemblies  60   a  and  60   b  are increased, such that the bus bar assemblies  60   a  and  60   b  may be easily placed and assembled. 
     Meanwhile, each of the second regions  20   ay   2  in which the plurality of extension parts  152  of the battery group  10  are placed may have a plurality of recesses  25   y  formed in a groove shape to receive each of the plurality of extension parts  152 . That is, the extension parts  152  protruding outward from the battery cell  11  are received in the recesses  25   y,  such that the plurality of battery cells  11  may be stably maintained in the stacked state. 
       FIG. 15  is a perspective view and a partially enlarged view thereof illustrating a fourth example of a cooling housing  20   z  of the battery module  1  according to the embodiment of the present invention, and  FIG. 16  is a partial cross-sectional view illustrating a state in which the battery group  10  is placed on a first region of the cooling housing  20   z  illustrated in  FIG. 15 . 
     Referring to  FIGS. 15 and 16 , in a case of the fourth example of the cooling housing  20   z,  the cooling housing  20   z  may include a cooling plate  20   az  and side plates  20   bz.  At this time, the above-described cooling plate  20   az  may have a first region  20   az   1  formed thereon to be flat without a portion partially protruding or being cut, on which the battery group  10  is placed. 
     Further, the cooling plate  20   az  may include a second region  20   az   2  having a plurality of accommodating grooves  25   z  cut therein to receive one or more extension parts  152 , respectively, on which the plurality of extension parts  152  of the battery group  10  are placed. 
     Specifically, in a case of the above-described recesses  25 ,  25   x  and  25   v,  each of the extension parts  152  of the battery cell  11  is received therein, on the other hand, in a case of the accommodating grooves  25   z  formed in the cooling plate  20   az  of the cooling housing  20   z,  one or more extension parts  152  formed in the battery cells  11  may be simultaneously received therein. 
     More specifically, the above-described accommodating groove  25   z  may have a width, corresponding to the direction in which the battery cells  11  are stacked, which is formed in a size capable of receiving at least one extension part  152  formed in at least one adjacent battery cell  11  of the stacked plurality of battery cells  11 . In addition, the above-described accommodating grooves  25   z  may be formed between positions in which the elastic members  13  of the battery group  10  are disposed on the cooling plate  20   az,  and the extension part  152  of at least one battery cell  11  disposed between two adjacent elastic members  13  may be received in one accommodating groove  25   z.  Thereby, compared to the recesses  25 ,  25   x,  and  25   y  that should be formed in correspondence with each of the plurality of battery cells  11 , workability of the accommodating groove  25   z  may be increased during manufacturing. 
     Meanwhile, although the accommodating grooves  25   z  shown in  FIG. 15  are illustrated as capable of receiving two or four extension parts  152  of the adjacent battery  11 , but it is merely illustrated as an example, and the present invention is not limited thereto. 
     Meanwhile, details of the above-described side plates  20   bx,    20   by  and  20   bz  are the same as those of the side plates  20   b  of the cooling housing  20 , and details of the above-described protrusions  22   x  and the recesses  25   x  and  25   y  are the same as those of the protrusions  22  and the recesses  25  of the cooling housing  20 , and therefore will not be described in detail. 
     In addition, definitions of the above-described first and second regions  20   av   1  and  20   ay   2 , and the first and second regions  20   az   1  and  20   az   2  are the same as those of the first and second regions  20   ax   1  and  20   ax   2  of the second example of the cooling housing  20   x,  and therefore will not be described in detail. 
     Moreover, the heat transfer member  21  may be applied to the first region  20   ax   1 ,  20   ay   1  and  20   az   1  of the cooling plate  20   ax,    20   ay  and  20   az  uniformly. Further, as the battery group  10  is placed on the cooling plate  20   ax,    20   ay  and  20   az,  an empty space between the n cooling plate  20   ax,    20   ay  and  20   az  and the plurality of battery cells  11  may be filled with the heat transfer member  21 . 
       FIG. 17  is views illustrating a state in which the battery group  10  is mounted in the cooling housing  20  according to another embodiment of the present invention. Specifically,  FIG. 17A  is a perspective view illustrating a state in which a cooling plate  20   a  is applied with a heat transfer member  21 , and  FIG. 17B  is an exploded perspective view illustrating a state in which the battery group  10  having a plurality of battery cells  11  stacked therein is mounted in the cooling housing  20  applied with the heat transfer member  21 , and  FIG. 17C  is a front view illustrating a state in which the battery group  10  is placed on the cooling plate  20   a  applied with the heat transfer member  21  as viewed from a side in which the electrode tabs  12  of the battery group  10  are extended. 
     Referring to  FIG. 17  and  FIG. 5  again, the battery group  10  may be formed by stacking a plurality of battery cells  11 , and the elastic members  13  may be disposed between bundles of the predetermined number of the battery cells  11  among the plurality of battery cells  11 . At this time, the plurality of battery cells  11  may be adhered to each other by an adhesive (not illustrated) such as a double-sided tape or the like, and the elastic members  13  may also be adhered to the battery cells  11  on both sides thereof with its own adhesive force. However, this configuration is merely an example for fixing the state of adhesion between the plurality of battery cells  11 , but it is not limited thereto, and any method may be used so long as it can adhere a plurality of battery cells  11  to each other, thus to sufficiently maintain the shape of the stacked battery group  10 . 
     Further, the heat transfer member  21  such as a gap filler or a thermally conductive adhesive may be applied to at least a portion of the cooling housing  20  whose one side is opened. In particular, the heat transfer member  21  may be applied to the cooling plate  20   a  of the cooling housing  20 , and may be applied through nozzles  21 ′ or the like that can apply in a specific section, and control an applying amount of adhesive. Since the upper side of the cooling housing  20  is opened, the applying state may be visually confirmed in the applying process, such that it is possible to easily control the applying amount of the heat transfer member  21  and an applying section to which the heat transfer member  21  is applied. Thereby, since the heat transfer member  21  may be applied only to a required section, the amount of use of the heat transfer member  21  may be minimized. 
     Meanwhile, when applying the heat transfer member  21 , an adhesive such as a bond may be further applied to the cooling housing  20  so as to increase an adhesive strength with the battery group  10 , but it is not limited thereto. 
     As described above, after the heat transfer member  21  is completely applied, the battery group  10  is placed on the cooling plate  20   a  of the cooling housing  20 , and the battery group  10  and the cooling plate  20   a  closely come into contact with each other. Therefore, the heat transfer member  21  may be adhered in a thinly spread state between the battery group  10  and the cooling plate  20   a,  and the heat transfer member  21  having a sufficient adhesion force and thermal conductivity may be applied by using a minimum amount of the heat transfer member  21 . 
     Meanwhile, the heat transfer member  21  may be adhered and located in a thinly spread state with a reduced thickness as described above. Preferably, the heat transfer member  21  may be formed in a thickness of 0 to 1 mm or less. Specifically, the heat transfer member  21  may have different thicknesses depending on a tolerance in the size of the battery cells  11  between the manufacturing processes of the battery cells  11 , and may be formed to have different thicknesses for each position of the battery cells  11  to be adhered. Furthermore, the heat transfer member  21  may be formed to have a thickness very close to zero (0), and at least a portion of the cooling plate  20   a  may come into directly contact with the battery cell  11  according to circumstances. 
     Meanwhile, after the battery group  10  is placed on the cooling plate  20   a,  the bus bar assemblies  60   a  and  60   b  may be connected to the plurality of electrode tabs  12  of the battery group  10 . Specifically, each of the plurality of electrode tabs  12  of the battery group  10  may be inserted into and fixed to each of the plurality of slits  61  formed in the bus bar assemblies  60   a  and  60   b,  and the electrode tabs  12  and bus bar assemblies  60   a  and  60   b  may be electrically connected to each other by laser beam welding. That is, the front electrode tab  12  of the battery group  10  illustrated in  FIG. 1  may be inserted into the slit  61  of the front bus bar assembly  60   a  to be connected thereto, and the rear electrode tab  12  of the battery group  10  may be inserted into the slit  61  of the rear bus bar assembly  60   b  to be connected thereto. 
       FIG. 18  is a perspective view illustrating a process in which the sensing module assembly  50  is fastened to the upper portion of the battery group  10  to which the bus bar assemblies  60   a  and  60   b  are connected, according to another embodiment of the present invention, and  FIG. 19  is a perspective view and a front view illustrating a state in which the assemblies  60   a  and  60   b  and the cooling housing  20  are fastened, according to another embodiment of the present invention, and  FIG. 20  is a perspective view illustrating a process of fastening the sensing board  70  to the bus bar assembly  60   a  according to another embodiment of the present invention. 
     Referring to  FIGS. 18 to 20 , the sensing module assembly  50  may be placed on the upper side of the battery group  10 , and then be fastened to the bus bar assemblies  60   a  and  60   b,  or to at least a portion of the cooling housing  20 . Specifically, the sensing module assembly  50  may have at least one fastening groove  512  formed in at least a portion of the front and rear ends thereof, and the bus bar assemblies  60   a  and  60   b  on both sides of the battery group  10  may have at least one fastening part  611  formed on at least a portion of the upper end thereof corresponding to the fastening grooves  512 . Thereby, when the sensing module assembly  50  is placed on the upper side of the battery group  10 , the fastening parts  611  of the bus bar assemblies  60   a  and  60   b  may be hooked and fastened to the fastening grooves  512  of the sensing module assembly  50 . At this time, as described above, the sensing module assembly  50  includes the elastic pads  52  to help the battery group  10  be adhered to the lower cooling housing  20 . Meanwhile, the forming positions of the fastening grooves  512  and the fastening parts  611  may be reversed. 
     Further, the method of hooking and fastening the fastening part  611  to the fastening groove  512  is illustrated as an example, but it is not limited thereto, and any method may be used so long as the sensing module assembly  50  can be sufficiently fastened to at least a portion of the bus bar assembly  60   a  or  60   b  or the cooling housing  20 , thus to be located on the upper side of the battery group  10 . 
     Furthermore, the front and rear bus bar assemblies  60   a  and  60   b  may be fixed and tightened to the cooling plate  20   a  of the cooling housing  20  by a first fastening member  242 . Specifically, the cooling plate  20   a  may have a first fastening hole  241  formed in at least a portion thereof on a side which comes into contact with the front and rear bus bar assemblies  60   a  and  60   b,  and the front and rear bus bar assemblies  60   a  and  60   b  may have a second fastening hole (not illustrated) corresponding to the first fastening hole  241  formed in at least a portion thereof on a side which comes into contact with the cooling plate  20   a.  Therefore, the cooling plate  20   a  and the front and rear bus bar assemblies  60   a  and  60   b  may be fixed and tightened to each other by the first fastening members  242  such as a bolt, which are inserted into the first and second fastening holes. 
     Meanwhile, the sensing board  70  may be connected to the outside of the front bus bar assembly  60   a.  In this case, the sensing board  70  is connected to the front bus bar assembly  60   a  for the convenience of description, but it is not limited thereto. As described above, the sensing board  70  may be connected to the rear bus bar assembly  60   b,  and may measure a voltage of the battery group  10  by the sensing module assembly  50  to confirm the voltage state thereof. 
     Specifically, the sensing board  70  may have at least one third fastening hole  711  formed therein, and the front bus bar assembly  60   a  may have at least one fourth fastening hole  621  formed in an outer surface thereof corresponding to the third fastening hole  711 . At this time, the third fastening hole  711  and the fourth fastening hole  621  are located corresponding to each other, and the sensing board  70  and the front bus bar assembly  60   a  may be fixed and tightened to each other by second fastening members  712  such as a bolt, which are inserted into the third and fourth fastening holes. At this time, at least one sensing contact portion  720  formed on the sensing board  70  may conic into contact with at least a portion of the outer surface of the front bus bar assembly  60   a  to be electrically connected to each other. 
     However, the coupling methods by the above-described fastening members  242  and  712 , and the coupling holes  241 ,  621  and  711  are illustrated as an example, but it is not limited thereto, and any method may be used so long as each of the front and rear bus bar assemblies  60   a  and  60   b  and the cooling housing  20 , as well as, the bus bar assembly  60   a  or  60   b  on one side of the battery group  10  and the sensing board  70  can be sufficiently tightened and coupled to be fixed to each other. 
     Thereafter, the cover plate  40  and the front and rear cover parts  30   a  and  30   b  may come into contact with the cooling housing  20  as illustrated in  FIG. 8 , and then be bonded with each other by welding to prepare the battery module  1 . At this time, details of the coupling structure of the cooling housing  20  and the cover plate  40 , and the cooling housing  20  and the front and rear cover parts  30   a  and  30   b,  respectively, are the same as those described in the above section, and therefore will not be described in detail. 
     Meanwhile, the battery group  10  of the battery module  1  and the bus bar assemblies  60   a  and  60   b  are not exposed to an outside due to the outer cooling housing  20 , the front and rear cover parts  30   a  and  30   b,  the cover plate  40  and the like. Therefore, the battery module may be protected from external foreign matters, and the fixing and supporting structure of the battery module may be maintained even when an external impact is generated through the above-described fixing structure. 
     Although the representative embodiments of the present invention have been described in detail, it will be understood by persons who have a common knowledge in the technical field to which the present invention pertains that various modifications and variations may be made therein without departing from the scope of the present invention. Accordingly, the scope of the present invention should not be limited to the above-described embodiments, but be defined by the appended claims as well as equivalents thereof. 
     DESCRIPTION OF SYMBOLS 
       1 : Battery module 
       10 : Battery group 
       11 : Battery cell 
       12 ,  12   a,    12   b:  Electrode tab 
       13 : Elastic member 
       15 : Sheath 
       151 : Sealing part 
       152 : Extension part 
       153 : Adhesion part 
       20 ,  20   x,    20   y,    20   z:  Cooling housing 
       20   a,    20   ax,    20   ay,    20   az:  Cooling plate 
       20   ax   1 ,  20   ay   1 ,  20   az   1 : First region 
       20   ax   2 ,  20   ay   2 ,  20   az   2 : Second region 
       20   b,    20   bx,    20   by,    20   bz:  Side plate 
       21 : Heat transfer member 
       21 ′: Nozzle 
       22 , Protrusion 
       23 : Stepped part 
       241 : First fastening hole 
       242 : First fastening member 
       25 ,  25   x,    25   y:  Recess 
       25   z:  Accommodating groove 
       30   a,    30   b : Cover part 
       40 : Cover plate 
       31 ,  41 : Vertical part 
       50 : Sensing module assembly 
       51 : Sensing module member 
       511 : Sensing connection member 
       511   a:  First connection member 
       511   b:  Second connection member 
       511   c:  Connection wire 
       512 : Fastening groove 
       52 : Elastic pad 
       60   a,    60   b:  Bus bar assembly 
       61 : Slit 
       611 : Fastening part 
       621 : Fourth fastening hole 
       70 : Sensing board 
       711 : Third fastening hole 
       712 : Second fastening member 
       720 : sensing contact portion 
     L: Laser 
     L 1 : Extrusion length of extension part