Patent Publication Number: US-2023155226-A1

Title: Battery pack with increased lifespan of battery cell and device including the same

Description:
TECHNICAL FIELD 
     This application claims the benefit of priority to Korean Patent Application No. 2020-0121927 filed on Sep. 22, 2020, the disclosure of which is incorporated herein by reference in its entirety. 
     The present invention relates to a battery pack and a device including the same, and more particularly to a battery pack with increased lifespan of a battery cell configured to have a structure in which pressure applied to the battery cell is maintained at an appropriate level, whereby lifespan of the battery cell is extended, and the battery cell is in surface contact with a heat sink, whereby rapid heat dissipation is achieved, and a device including the same. 
     BACKGROUND ART 
     With recent development of alternative energies due to air pollution and energy depletion caused as the result of use of fossil fuels, demand for secondary batteries capable of storing electrical energy that is produced has increased. The secondary batteries, which are being capable of being charged and discharged, are intimately used in daily life. For example, the secondary batteries are used in mobile devices, electric vehicles, and hybrid electric vehicles. 
     Required capacities of secondary batteries used as energy sources of various kinds of electronic devices inevitably used in modern society have been increased due to an increase in usage of mobile devices, increasing complexity of the mobile devices, and development of electric vehicles. In order to satisfy demand of users, a plurality of battery cells is disposed in a small-sized device, whereas a battery module including a plurality of battery cells electrically connected to each other or a battery pack including a plurality of battery modules is used in a vehicle. 
     Meanwhile, a battery cell swells during repeated charging and discharging thereof, whereby the overall volume of the battery cell is increased. In order to increase lifespan of the battery cell, however, electrical contact between an electrode and an active material must be improved. To this end, it is necessary to constantly apply a predetermined level of pressing force to the battery cell. 
       FIG.  1    is a perspective view showing the structure of a conventional battery module. As shown in  FIG.  1   , the conventional battery module includes a plurality of single cells  10  disposed perpendicular to a heat sink  20 , a case  30  configured to wrap the plurality of single cells  10  in order to protect the plurality of single cells, pressing plates  40  located at opposite sides of the plurality of single cells  10  vertically disposed, and pressure adjustment members  50  located between the pressing plates  40  and the case  30 . 
     The conventional battery module is configured to have a structure in which the pressure adjustment members  50 , which are elastic members, are located between the case  30  and the pressing plates  40  in order to press the opposite sides of the single cells  10 , whereby an increase in volume of the single cells at the time of swelling is inhibited. 
     In the conventional battery module, however, only pressing is performed and no pressure adjustment function is provided. As a result, it is not possible to increase lifespan of the battery cells. 
     PRIOR ART DOCUMENT 
     (Patent Document 1) Japanese Patent Application Publication No. 2019-125455 
     DISCLOSURE 
     Technical Problem 
     The present invention has been made in view of the above problems, and it is an object of the present invention to provide a battery pack having a structure capable of constantly pressing a battery cell within a predetermined range irrespective of swelling of the battery cell and a device including the same. 
     It is another object of the present invention to provide a battery pack capable of inhibiting occurrence of a secondary problem due to heat generation by efficiently removing heat generated from a battery cell and a device including the same. 
     It is a further object of the present invention to provide a battery pack capable of reducing battery cell cooling deviation by increasing adhesion force and a device including the same. 
     Technical Solution 
     In order to accomplish the above objects, a battery pack according to the present invention includes a plurality of battery modules ( 1000 ) stacked in a vertical direction in a horizontal state; a pressing plate ( 2100 ) including an upper pressing plate ( 2110 ) and a lower pressing plate ( 2120 ) located outside the battery modules ( 1000 ); a second elastic member ( 2220 ) configured to connect the upper pressing plate ( 2110 ) and the lower pressing plate ( 2120 ) to each other; and a pack case ( 2300 ) configured to wrap the pressing plate ( 2100 ), wherein the pack case ( 2300 ) includes an upper pack cover ( 2310 ) and a lower pack cover ( 2320 ), and a third elastic member ( 2230 ) is provided between the upper pack cover ( 2310 ) and the upper pressing plate ( 2110 ). 
     Also, in the battery pack according to the present invention, a distance retention portion ( 2500 ) may be further provided between the upper pack cover ( 2310 ) and the upper pressing plate ( 2110 ). 
     Also, in the battery pack according to the present invention, the distance retention portion ( 2500 ) may be a quadrangular pillar. 
     Also, in the battery pack according to the present invention, the distance retention portion ( 2500 ) may be made of a metal material. 
     Also, in the battery pack according to the present invention, each of the battery modules ( 1000 ) may include a heat sink ( 100 ) having a predetermined area, the heat sink being horizontally located; a support plate ( 200 ) including an upper support plate ( 210 ) and a lower support plate ( 220 ) located respectively at the upper surface and the lower surface of the heat sink ( 100 ); a battery cell ( 500 ) including a first battery cell ( 510 ) disposed in tight contact with the upper support plate ( 210 ) and a second battery cell ( 520 ) disposed in tight contact with the lower support plate ( 220 ); and a cover plate ( 600 ) including an upper cover plate ( 610 ) located above the first battery cell ( 510 ) and a lower cover plate ( 620 ) located under the second battery cell ( 520 ). 
     Also, in the battery pack according to the present invention, the heat sink ( 100 ) may be provided on the upper surface thereof with a protuberance ( 110 ) protruding by a predetermined height, and the upper support plate ( 210 ) may be provided with a first opening ( 211 ) configured to receive the protuberance ( 110 ). 
     Also, in the battery pack according to the present invention, the first battery cell ( 510 ) may be located at the upper surface of the protuberance ( 110 ). 
     Also, in the battery pack according to the present invention, the heat sink ( 100 ) may be provided on the lower surface thereof with a protuberance ( 110 ) protruding by a predetermined height, and the lower support plate ( 220 ) may be provided with a second opening ( 221 ) configured to receive the protuberance ( 110 ). 
     Also, in the battery pack according to the present invention, the second battery cell ( 520 ) may be located at the lower surface of the protuberance ( 110 ). 
     Also, in the battery pack according to the present invention, first support frames ( 410 ) may be located between the upper support plate ( 210 ) and the upper cover plate ( 610 ) so as to extend along opposite edges and the middle thereof while having a predetermined height and width. 
     Also, in the battery pack according to the present invention, second support frames ( 420 ) may be located between the lower support plate ( 220 ) and the lower cover plate ( 620 ) so as to extend along opposite edges and the middle thereof while having a predetermined height and width. 
     Also, in the battery pack according to the present invention, the first support frame ( 410 ) and the second support frame ( 420 ) extending along the middle of each of the upper support plate and the upper cover plate or the middle of each of the lower support plate and the lower cover plate may be provided respectively with a first through-hole ( 411 ) and a second through-hole ( 421 ) configured to allow a first elastic member ( 2210 ) to be inserted therethrough. 
     Also, in the battery pack according to the present invention, a first busbar assembly ( 310 ) may be located between the upper support plate ( 210 ) and the upper cover plate ( 610 ), and the first busbar assembly ( 310 ) may include a first busbar frame ( 311 ) having a first receiving recess ( 311 ( a )) formed therein and a busbar ( 312 ) seated in the first receiving recess ( 311 ( a )), the busbar being configured to have a concave-convex structure that is bent at a predetermined angle a plurality of times. 
     Also, in the battery pack according to the present invention, a second busbar assembly ( 320 ) may be located between the lower support plate ( 220 ) and the lower cover plate ( 620 ). 
     In addition, the present invention provides a device including the battery pack. 
     Advantageous Effects 
     As is apparent from the above description, a battery pack with increased lifespan of a battery cell according to the present invention and a device including the same have an advantage in that an elastic member is provided between an upper pressing plate and a lower pressing plate, whereby it is possible to constantly press battery cells interposed between the upper and lower pressing plates within a predetermined range, and therefore it is possible to increase lifespan of the battery cells. 
     In addition, the battery pack with increased lifespan of the battery cell according to the present invention and the device including the same have a merit in that relatively wide side surfaces of the battery cells and a heat sink are in tight contact with each other in a state of being located in a horizontal direction, whereby cooling performance of the battery cells is improved due to an increase in heat transfer area. 
     Furthermore, the battery pack with increased lifespan of the battery cell according to the present invention and the device including the same have an advantage in that the battery cells, the heat sink, a support plate, etc. are fastened to each other via a plurality of support frames and fastening members, whereby it is possible to maintain uniform adhesion force between the battery cells and the heat sink while maximizing space utilization. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view of a conventional battery module. 
         FIG.  2    is a perspective view of a battery pack according to a preferred embodiment of the present invention. 
         FIG.  3    is an exploded perspective view of the battery pack shown in  FIG.  2   . 
         FIG.  4    is a sectional view taken along line A-A′ of  FIG.  2   . 
         FIG.  5    is an exploded perspective view of a battery module according to a preferred embodiment of the present invention. 
         FIG.  6    is a perspective view illustrating a coupling structure between a heat sink and a support plate in the battery module according to the preferred embodiment of the present invention. 
         FIG.  7    is a perspective view illustrating a battery cell mounting structure in the battery module according to the preferred embodiment of the present invention. 
         FIG.  8    is a perspective view illustrating a support frame disposition structure in the battery module according to the preferred embodiment of the present invention. 
         FIG.  9    is a perspective view illustrating a coupling structure between battery cells and busbars in the battery module according to the preferred embodiment of the present invention. 
     
    
    
     BEST MODE 
     Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that the preferred embodiments of the present invention can be easily implemented by a person having ordinary skill in the art to which the present invention pertains. In describing the principle of operation of the preferred embodiments of the present invention in detail, however, a detailed description of known functions and configurations incorporated herein will be omitted when the same may obscure the subject matter of the present invention. 
     In addition, the same reference numbers will be used throughout the drawings to refer to parts that perform similar functions or operations. In the case in which one part is said to be connected to another part in the entire specification, not only may the one part be directly connected to the other part, but also, the one part may be indirectly connected to the other part via a further part. In addition, that a certain element is included does not mean that other elements are excluded, but means that such elements may be further included unless mentioned otherwise. 
     Hereinafter, a battery pack with increased lifespan of a battery cell according to the present invention will be described with reference to the accompanying drawings. 
       FIG.  2    is a perspective view of a battery pack according to a preferred embodiment of the present invention,  FIG.  3    is an exploded perspective view of the battery pack shown in  FIG.  2   , and  FIG.  4    is a sectional view taken along line A-A′ of  FIG.  2   . 
     As shown in  FIGS.  2  to  4   , the battery pack  2000  according to the present invention includes a plurality of horizontally stacked battery modules  1000 , a pressing plate  2100  located at the upper surface and the lower surface of the plurality of stacked battery modules  1000 , an elastic member  2200 , a pack case  2300 , a plurality of fastening members  2400  configured to fix the battery modules  1000 , and a distance retention portion  2500 . 
     First, the pressing plate  2100  includes an upper pressing plate  2110  located on the upper surface of the stacked battery modules  1000  in tight contact therewith, a lower pressing plate  2120  located on the lower surface of the stacked battery modules  1000  in tight contact therewith, and a plurality of side plates  2130  located at opposite side surfaces of the battery modules  1000  in a state of being spaced apart therefrom by a predetermined distance. 
     The elastic member  2200  includes a first elastic member  2210 , a second elastic member  2220 , and a third elastic member  2230 . One side of each of a plurality of first elastic members  2210 , which are inserted perpendicularly through middle parts of the battery modules  1000 , is connected to the upper pressing plate  2110 , and the other side of each of the first elastic members is connected to the lower pressing plate  2120 . Since middle parts of the upper pressing plate  2110  and the lower pressing plate  2120  are pulled, therefore, it is possible to constantly press battery cells  500  located at the middle parts of the battery modules  1000  within a predetermined range irrespective of swelling. 
     The second elastic member  2220 , which connects the upper pressing plate  2110  and the lower pressing plate  2120 , specifically the edge of the upper pressing plate  2110  and the edge of the lower pressing plate  2120 , to each other, constantly presses battery cells  500  located at edges of the battery modules  1000  within a predetermined range. 
     The first elastic member  2210  and the second elastic member  2220  provide tensile force between the upper pressing plate  2110  and the lower pressing plate  2120 , whereas the third elastic member  2230  is located between the upper pressing plate  2110  and an upper pack cover  2310  to provide pressing force. In particular, it is preferable for the third elastic member  2230  to be provided in plural in a state of being spaced apart from each other by a predetermined distance. The third elastic member inhibits bending of the pressing plate that may be caused by a swelling deviation between the battery cells, whereby it is possible to minimize a deviation in pressing force. 
     Here, each of the first elastic member  2210 , the second elastic member  2220 , and the third elastic member  2230  may be a coil. However, the present invention is not limited thereto. 
     The pack case  2300  includes an upper pack cover  2310  located at the upper surface of the upper pressing plate  2110 , a lower pack cover  2320  located at the lower surface of the lower pressing plate  2120 , and side pack covers  2330  located parallel to the side plates  2130 . 
     The fastening members  2400  are configured to fix the plurality of battery modules  1000 , which are stacked in a vertical direction, using predetermined force. As an example, each of the fastening members may be a bolt having a screw thread formed at one end thereof, and a nut may be fastened to the other side of the fastening member in order to fix the battery modules  1000 . 
     Of course, it is preferable for the nuts to be somewhat loosely fastened to the fastening members in consideration of expansion of the battery modules upon swelling. 
     Meanwhile, the distance retention portion  2500  may be further provided between the upper pressing plate  2110  and the upper pack cover  2310  at the middle thereof in order to supplement tensile force by the first elastic member  2210  and pressing force by the third elastic member  2230 . The distance retention portion may be a quadrangular pillar made of metal. 
       FIG.  5    is an exploded perspective view of a battery module according to a preferred embodiment of the present invention. As shown in  FIG.  5   , the battery module  1000  includes a heat sink  100 , a support plate  200 , a busbar assembly  300 , a support frame  400 , battery cells  500 , and a cover plate  600 . 
     First, the heat sink  100  is a flat plate that is provided with a flow channel defined therein and has a predetermined area. A plurality of protuberances  110  is formed on the upper surface and the lower surface of the heat sink  100  so as to protrude therefrom in a state of being spaced apart from each other by a predetermined distance. The protuberances  110  will be described below in detail. 
     The support plate  200  includes an upper support plate  210  and a lower support plate  220  located at opposite surfaces of the heat sink  100 , more specifically the upper surface of the support plate  200  and the lower surface of the heat sink  100 , respectively. 
     The busbar assembly  300  configured to electrically connect the battery cells  500  to each other includes a first busbar assembly  310  and a second busbar assembly  320 . The first busbar assembly  310  is located at the upper surface of the upper support plate  210 , and the second busbar assembly  320  is disposed at the lower surface of the lower support plate  220 . 
     A total of six first busbar assemblies  310 , one of which is located in the vicinity of each of opposite edges of the upper support plate  210  and four of which are located between the two first busbar assemblies located in the vicinity of the opposite edges of the upper support plate in a state of being spaced apart from each other by a predetermined distance in a longitudinal direction (an X-axis direction), are shown in the figure, which, however, is merely an example. The number or position of first busbar assemblies may be changed as long as the first busbar assemblies can be brought into tight contact with the upper support plate  210 . 
     The second busbar assemblies  320  are symmetrical with the first busbar assemblies  310 , and therefore an additional description thereof will be omitted. 
     Next, the support frame  400  includes first support frames  410  and second support frames  420 . The first support frames  410  are located between the upper support plate  210  and an upper cover plate  610 , and the second support frames  420  are located between the lower support plate  220  and the lower cover plate  620 . The first support frames and the second support frames will be described below in more detail. 
     The battery cells  500  include a plurality of first battery cells  510  and a plurality of second battery cells  520  located parallel to the heat sink  100 . Specifically, the first battery cells  510  are located between the upper support plate  210  and the upper cover plate  610 , and the second battery cells  520  are located between the lower support plate  220  and the lower cover plate  620 . 
     The first battery cells  510  and the second battery cells  520  may be battery cells having the same construction. For example, each battery cell may include a cell case, in which an electrode assembly (not shown) is received, and a pair of electrode leads. 
     Here, the electrode assembly may be a jelly-roll type assembly, which is configured to have a structure in which a long sheet type positive electrode and a long sheet type negative electrode are wound in the state in which a separator is interposed therebetween, a stacked type assembly which is configured to have a structure in which a rectangular positive electrode and a rectangular negative electrode are stacked in the state in which a separator is interposed therebetween, a stacked and folded type assembly, which is configured to have a structure in which unit cells are wound using a long separation film, or a laminated and stacked type assembly, which is configured to have a structure in which battery cells are stacked in the state in which a separator is interposed therebetween and are then attached to each other. However, the present invention is not limited thereto. It is preferable for the electrode assembly according to the present invention to be a stacked and folded type assembly or a laminated and stacked type assembly, which has lowest physical stress when a curved module is formed. 
     The electrode assembly is received in the cell case. The cell case is generally configured to have a laminate sheet structure including an inner layer, a metal layer, and an outer layer. The inner layer is disposed in direct contact with the electrode assembly, and therefore the inner layer must exhibit high insulation properties and high resistance to an electrolytic solution. In addition, the inner layer must exhibit high sealability in order to hermetically seal the cell case from the outside, i.e. a thermally-bonded sealed portion between inner layers must exhibit excellent thermal bonding strength. The inner layer may be made of a material selected from among a polyolefin-based resin, such as polypropylene, polyethylene, polyethylene acrylate, or polybutylene, a polyurethane resin, and a polyimide resin, which exhibit excellent chemical resistance and high sealability. However, the present invention is not limited thereto, and polypropylene, which exhibits excellent mechanical-physical properties, such as tensile strength, rigidity, surface hardness, and impact strength resistance, and excellent chemical resistance, is the most preferably used. 
     The metal layer, which is disposed so as to abut the inner layer, corresponds to a barrier layer configured to prevent moisture or various kinds of gas from permeating into the battery from the outside. An aluminum thin film, which is light and easily shapeable, may be used as a preferred material for the metal layer. 
     The outer layer is provided on the other surface of the metal layer. The outer layer may be made of a heat-resistant polymer that exhibits excellent tensile strength, resistance to moisture permeation, and resistance to air transmission such that the outer layer exhibits high heat resistance and chemical resistance while protecting the electrode assembly. As an example, the outer layer may be made of nylon or polyethylene terephthalate. However, the present invention is not limited thereto. 
     Meanwhile, the pair of electrode leads is constituted by a positive electrode lead and a negative electrode lead, which may be exposed from the cell case in a state of being electrically connected respectively to positive electrode tabs and negative electrode tabs of the cell assembly or may be directly connected to the cell assembly in the state in which tabs are omitted. 
     Next, the cover plate  600  serves to protect the battery cells  500  from the outside, and includes an upper cover plate  610  and a lower cover plate  620 . 
     Specifically, the upper cover plate  610  is located above the first battery cells  510  to protect the upper surfaces of the first battery cells  510 , and the lower cover plate  620  is located above the second battery cells  520  to protect the lower surfaces of the second battery cells  520 . 
     Each of the upper cover plate  610  and the lower cover plate  620  is provided with a plurality of through-holes formed so as to be spaced apart from each other by a predetermined distance such that the first elastic members  2210  and the fastening members  2400  are inserted therethrough. 
       FIG.  6    is a perspective view illustrating a coupling structure between the heat sink and the support plate in the battery module according to the preferred embodiment of the present invention. 
     Referring to  FIG.  6   , the upper support plate  210  is located at the upper surface of the heat sink  100  according to the present invention, and the lower support plate  220  is located at the lower surface of the heat sink  100 . 
     Meanwhile, it is preferable for the protuberances  110  to be formed on the opposite surfaces of the heat sink  100 , i.e. the upper surface and the lower surface of the heat sink, so as to protrude therefrom by a predetermined height while having a predetermined shape. It is more preferable for the upper support plate  210  to have first openings  211  configured to receive the protuberances  110  formed on the upper surface of the heat sink  100  and for the lower support plate  220  to have second openings  221  configured to receive the protuberances  110  formed on the lower surface of the heat sink  100 . 
     When the upper support plate  210  and the lower support plate  220  are brought respectively into tight contact with the upper surface and the lower surface of the heat sink  100  having the protuberances  110  formed on the opposite surfaces thereof, the protuberances  110  formed on the upper surface of the heat sink  100  are inserted into the first openings  211 , and the protuberances  110  formed on the lower surface of the heat sink  100  are inserted into the second openings  221 , whereby rolling of the heat sink from side to side may be prevented. 
     Here, each of the upper support plate  210  and the lower support plate  220  may be made of a thermally conductive resin. 
     Meanwhile, a coolant inlet port  120  configured to supply a coolant is provided at one side of the heat sink  100 , and a coolant outlet port  130  configured to discharge the coolant that has performed heat exchange is provided in the vicinity of the coolant inlet port. It is obvious that the coolant inlet port  120  and the coolant outlet port  130  are not necessarily located so as to be adjacent to each other as long as it is possible to supply and discharge the coolant. 
     Meanwhile, the heat sink  100 , the upper support plate  210 , and the lower support plate  220  are provided with through-holes, through which the first elastic members  2210  and the fastening members  2400  are inserted. 
       FIG.  7    is a perspective view illustrating a battery cell mounting structure in the battery module according to the preferred embodiment of the present invention, and  FIG.  8    is a perspective view illustrating a support frame disposition structure in the battery module according to the preferred embodiment of the present invention. 
     The plurality of first battery cells  510  according to the present invention is horizontally seated on the protuberances  110  of the heat sink  100 , exposed to the outside in a state of being inserted through the first openings  211  of the upper support plate  210 , and the upper support plate  210 . 
     A conventional battery module is configured to have a structure in which battery cells are located perpendicular to a heat sink, whereby contact area between the battery cells and the heat sink is small, and therefore cooling performance of the battery module is limited. 
     In contrast, the battery module  1000  according to the present invention is configured to have a structure in which the first battery cells  510  are located parallel to the heat sink  100  and in which the horizontal side surfaces of the first battery cells  510  contact the protuberances  110  of the heat sink  100 , whereby rapid heat transfer is achieved, and therefore heat transfer efficiency is improved. 
     Of course, it is obvious that the remaining portions of the first battery cells  510 , which are not in tight contact with the protuberances  110  of the heat sink  100 , are in tight contact with the upper support plate  210 . 
     Meanwhile, a known thermally conductive resin layer may be interposed between each of the protuberances  110  and a corresponding one of the first battery cells  510  in order to fix the protuberance and the first battery cell to each other. 
     The structure in which the second battery cells  520  and the lower support plate  220  are mounted is identical to the structure in which the first battery cells  510  and the upper support plate  210  are coupled to each other except for only difference in direction, and therefore a detailed description thereof will be omitted. 
     As previously described, the support frame  400  includes the first support frames  410  and the second support frames  420 . 
     The first support frames  410  are located between the upper support plate  210  and the upper cover plate  610 , more specifically at opposite edges and the middle of the upper support plate  210  in the longitudinal direction of the battery module (the X-axis direction). Each of the first support frames is a bar that has a predetermined width, height, and length and that has an approximately quadrangular section. Each of the first support frames  410  is provided with a plurality of first through-holes  411  formed so as to be spaced apart from each other by a predetermined distance such that the first elastic members  2210  and the fastening members  2400  can be inserted therethrough. 
     The second support frames  420  are identical in construction to the first support frames  410  except that the second support frames are located between the lower support plate  220  and the lower cover plate  620 . That is, each of the second support frames  420  is provided with a plurality of second through-holes  421  formed so as to be spaced apart from each other by a predetermined distance such that the fastening members B can be inserted therethrough. 
     Even though the plurality of battery modules  1000  is fastened to each other in a state of being stacked, the support plate  200  and the cover plate  600  may be maintained spaced apart from each other by a predetermined distance by the first support frames  410  and the second support frames  420 , whereby it is possible to prevent the battery cells from being pressed more than necessary and to inhibit local expansion at the time of swelling. 
       FIG.  9    is a perspective view illustrating a coupling structure between the battery cells and busbars in the battery module according to the preferred embodiment of the present invention. 
     When describing with further reference to  FIG.  7   , the busbar assembly  300  includes a first busbar assembly  310  and a second busbar assembly  320 , which are identical in construction to each other except for only difference in disposition. Hereinafter, therefore, a description will be given based on the first busbar assembly  310 . 
     The first busbar assembly  310  includes a first busbar frame  311  and busbars  312 . The first busbar frame  311  is configured to electrically connect adjacent ones of the busbars  312  to each other while supporting the busbars  312 . The first busbar frame  311  is provided with first receiving recesses  311 ( a ) configured to receive the busbars  312  in a seated state and second receiving recesses  311 ( b ) depressed deeper than the first receiving recesses  311 ( a ). 
     Each of the busbars  312 , which is configured to have a concave-convex structure that is bent at a predetermined angle a plurality of times, includes a first horizontal portion  312 ( a ), a second horizontal portion  312 ( b ) located lower than the first horizontal portion  312 ( a ), and a connection portion  312 ( c ) configured to connect the first horizontal portion  312 ( a ) and the second horizontal portion  312 ( b ) to each other, the connection portion being bent at a predetermined angle. 
     When the busbar  312  having the above construction is seated in the receiving recesses of the first busbar frame  311 , the first horizontal portion  312 ( a ) is inserted into the first receiving recess  311 ( a ), and the second horizontal portion  312 ( b ) is inserted into the second receiving recess  311 ( b ), whereby the busbar  312  is securely fastened to the first busbar frame  311 . 
     Meanwhile, an electrode lead  511  of each of the first battery cells  510  is seated on the first horizontal portion  312 ( a ). 
     The conventional battery module has no function of cooling the busbar assembly  300  or further needs to have such a cooling function. In the present invention, however, the busbar assembly  300  is located in surface contact on the upper support plate  210  and the lower support plate  220  located respectively at the upper surface and the lower surface of the heat sink  100 , whereby it is possible to cool the busbar assembly  300  using only the heat sink  100 , which is configured to cool the battery cells, and therefore it is possible to minimize an increase in volume of the battery module. 
     The present invention may provide a device including a battery pack having at least one of the above-mentioned features, and the device may be an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. 
     Those skilled in the art to which the present invention pertains will appreciate that various applications and modifications are possible within the category of the present invention based on the above description. 
     DESCRIPTION OF REFERENCE SYMBOLS 
     
         
         
           
               1000 : Battery module 
               100 : Heat sink 
               110 : Protuberance 
               120 : Coolant inlet port 
               130 : Coolant outlet port 
               200 : Support plate 
               210 : Upper support plate 
               211 : First opening 
               220 : Lower support plate 
               221 : Second opening 
               300 : Busbar assembly 
               310 : First busbar assembly 
               311 : First busbar frame 
               311 ( a ): First receiving recess  311 ( b ): Second receiving recess 
               312 : Busbar 
               312 ( a ): First horizontal portion  312 ( b ): Second horizontal portion 
               312 ( c ): Connection portion 
               320 : Second busbar assembly 
               400 : Support frame 
               410 : First support frame  411 : First through-hole 
               420 : Second support frame  421 : Second through-hole 
               500 : Battery cell 
               510 : First battery cell 
               511 : Electrode lead 
               520 : Second battery cell 
               600 : Cover plate 
               610 : Upper cover plate 
               620 : Lower cover plate 
               2000 : Battery pack 
               2100 : Pressing plate 
               2110 : Upper pressing plate 
               2120 : Lower pressing plate 
               2130 : Side plate 
               2200 : Elastic member 
               2210 : First elastic member 
               2220 : Second elastic member 
               2230 : Third elastic member 
               2300 : Pack case 
               2310 : Upper pack cover 
               2320 : Lower pack cover 
               2330 : Side pack cover 
               2400 : Fastening member 
               2500 : Distance retention portion