Patent Publication Number: US-2023155210-A1

Title: Battery module

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of U.S. patent application Ser. No. 15/931,366 filed on May 13, 2020, which claims the benefit under 35 USC 119(a) of Korean Patent Application No. 10-2019-0056206 filed on May 14, 2019 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
    
    
     BACKGROUND 
     1. Field 
     This application relates to a battery module. 
     2. Description of Related Art 
     Unlike primary batteries, secondary batteries may charge and discharge electrical energy. Thus, secondary batteries may be applied to various fields, for example, in the areas of digital cameras, mobile phones, notebook computers, hybrid vehicles, and the like. Examples of secondary batteries may include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-hydrogen batteries, lithium secondary batteries, and the like. 
     Among such secondary batteries, a large amount of research into lithium secondary batteries having a relatively high energy density and a relatively high discharge voltage is in progress. Recently, lithium secondary batteries have been manufactured as pouched battery cells having flexibility. In this case, the pouched battery cells are provided as a plurality of pouched battery cell modules, The plurality of pouched battery cell modules may be configured to be connected and used as battery modules. 
     Meanwhile, when the battery module is used for a lengthy period of time, heat may be generated by the battery module. In particular, an internal temperature of the battery module may rise rapidly, during a charging operation thereof In this case, such an increase in temperature of the battery module may shorten a lifespan of the battery module, may decrease efficiency of the battery module, and, in the worst case, ignition or explosion may occur therein. 
     Therefore, the battery module requires a cooling system for cooling the battery cells accommodated therein. However, in the related art an issue in which cooling efficiency may be significantly low because heat generated by the battery cells is not effectively dissipated has been encountered. 
     SUMMARY 
     Example embodiments of the present disclosure provide a battery module, capable of efficiently dissipating heat generated in a battery cell. 
     A battery module according to example embodiments includes a cell unit, including a plurality of battery cells disposed on both surfaces of a unit plate, and a case accommodating the cell unit and provided with a cooling device on at least one surface of the case. The unit plate includes a plurality of receiving spaces formed by a plate portion, having a flat surface, and a side portion protruding upwardly and downwardly of the plate portion from both sides of the plate portion. The plurality of battery cells are received in each of the receiving spaces. 
     In example embodiments, the case may include a first plate disposed below the cell unit, a second plate disposed above the cell unit, and a third plate disposed on a side portion of the cell unit and including the cooling device. 
     In example embodiments, the side portion may have an external surface disposed to oppose the third plate. 
     In example embodiments, the battery module may further include a heat transfer member disposed between the side portion and the third plate. 
     In example embodiments, the heat transfer member may be formed of one of thermal grease, a thermally conductive adhesive, and a pad. 
     In example embodiments, the third plate may include an internal side plate disposed to oppose the cell unit, an external side plate disposed outside of the internal side plate to be in contact with the internal side plate, and a cooling flow path provided between the internal side plate and the external side plate. 
     In example embodiments, the third plate may further include a reinforcing plate coupled to the external side plate while covering an external surface of the external side plate and formed of a material having greater rig ty than that of the external side plate. 
     In example embodiments, the third plate may be formed of aluminum, and the reinforcing plate may be formed of an ultrahigh-strength steel sheet. 
     In example embodiments, in the plate portion of the unit plate, a portion connected to the side portion may be formed to have a large thickness. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings. 
         FIG.  1    is a schematic perspective view of a battery module according to example embodiments of the present disclosure. 
         FIG.  2    is an exploded perspective view of the battery module illustrated in  FIG.  1   . 
         FIG.  3    is an exploded perspective view of a cell unit illustrated in  FIG.  2   . 
         FIG.  4    is a partially enlarged plan view of a connection. member of  FIG.  3   . 
         FIG.  5    is a cross-sectional view taken along line I-I′ in  FIG.  4   . 
         FIG.  6    is an exploded perspective view of a unit plate and a circuit board illustrated in  FIG.  3   . 
         FIG.  7    is an exploded perspective view of a cell unit and a coupling unit illustrated in  FIG.  2   . 
         FIG.  8    is a cross-sectional view taken along line II-II′ in  FIG.  1     
     
    
    
     DETAILED DESCRIPTION 
     Prior to the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, the configurations described in the following description with reference the accompanying drawings do not represent all technical concepts or ideas of the present disclosure but should be considered to be exemplary embodiments of the present disclosure. It should be understood that various modifications and equivalents of the embodiments may be devised within the scope of the present invention at the time of the filing of the application. 
     Hereinafter, example embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the sane elements are denoted by the same reference numerals as much as possible. Furthermore, detailed descriptions related to well-known functions or configurations may be omitted in order not to unnecessarily obscure subject matters of the present disclosure. For the same reason, some of the elements in the accompanying drawings are exaggerated, omitted, or Shown schematically, and the size of each element may not entirely reflect the actual size. 
       FIG.  1    is a schematic perspective view of a battery module according to example embodiments, and  FIG.  2    is an exploded perspective view of the battery module illustrated in  FIG.  1   . 
       FIG.  3    is an exploded perspective view of a cell unit illustrated in  FIG.  2   ,  FIG.  4    is a partially enlarged plan view of a connection member of  FIG.  3   , and  FIG.  5    is a cross-sectional view taken along line I-I′ in  FIG.  4   . 
       FIG.  6    is an exploded perspective view of a unit plate and a circuit board illustrated in  FIG.  3   ,  FIG.  7    is an exploded perspective view of a cell unit and a coupling unit illustrated in  FIG.  2   , and  FIG.  8    is a cross-sectional view taken along line II-Ii′ in  FIG.  1   . 
     Referring to  FIGS.  1  to  3   , a battery module  100  according to this embodiment may have a substantially hexahedral shape and may include a cell assembly  60 , in which a plurality battery cells  10  are coupled to each other, and a case  40  protecting the cell assembly  60  from the outside. 
     The cell assembly  60  includes a plurality of cells units  20  coupled to each other. 
     Referring to  FIG.  3   , the cell unit  20  includes a unit plate  21 , a plurality of battery cells  10  stacked on the unit plate  21 , and a circuit board  28 . 
     The battery cell  10  may be provided as a plurality of battery cells stacked side by side, and may have a structure in which electrode leads  15  protrude outwardly of a body. The battery cell  10  may be, for example, a pouched secondary battery. 
     The battery cell  10  may have a configuration in which. an electrode assembly, not illustrated, is accommodated in a pouch  11 . 
     The electrode assembly may include a plurality of electrode plates and a plurality of electrode tabs, and may be accommodated in the pouch  11 . Each of the electrode plates may include a positive electrode plate and a negative electrode plate, and the electrode assembly may have a configuration which the positive electrode plate and the negative electrode plate are stacked such that relatively large surfaces oppose each other with a separator interposed therebetween. 
     The positive electrode plate and the negative electrode plate may be formed to have structure in which an active material slurry is coated on a current collector. The slurry may be formed by stirring a granular active material, an auxiliary conductor, a binder, a plasticizer, and the like, in a state in which a solvent is added. 
     In the electrode assembly, a plurality of positive electrode plates and a plurality of negative electrode plates may be vertically stacked. In this case, the plurality of positive electrode plates and the plurality of negative electrode plates may be provided with electrode tabs, respectively, and may be in contact with each other with the same polarity to be in connected to the same electrode lead  15 . 
     In this embodiment, two electrode leads  15  are disposed to face in opposing directions. 
     The pouch  11  may be formed to have a container shape to provide an internal space in which the electrode assembly and electrolyte, not illustrated, are accommodated. In this case, a portion of the electrode lead  15  of the electrode assembly may be exposed outwardly of the pouch  11 . 
     The pouch  11  may be divided into a sealing portion  202  and an accommodation portion  204 . 
     The accommodation portion  204  may be formed to have a container shape to provide an internal space having a rectangular shape. The electrode assembly and the electrolyte 
     Maybe accommodated in the internal space of the accommodation portion  204 . 
     The sealing portion  202  may be formed to have a flange shape extending outwardly of the accommodation portion  204  formed to have the container shape. Therefore, the sealing portion  202  may be disposed to have an edge shape along an external surface of the accommodation portion  204 . 
     A method of bonding sealing portions  202  to each other may be thermal fusion bonding, but the present disclosure is riot limited thereto. 
     In this embodiment, the sealing portion  202  may be divided into a first sealing portion  2021 , in which the electrode leads  15  are disposed, and a second sealing portion  2022  in which the electrode leads  15  are not disposed. 
     In this embodiment, since the electrode leads  15  are disposed to face in opposing directions, the two electrode leads  15  are disposed on the sealing portions  202  formed on different sides. Accordingly, the sealing portion  202  provided on four sides of the accommodation portion  204  includes two first sealing portions  2021 , on which the electrode leads  15  are disposed, and two sealing portions  2022  on which the electrode leads  15  are not disposed. 
     The battery cell  10  according to this embodiment may constitute the seal j ng portion.  202  while being folded at least once to improve bonding reliability of the sealing portion  202  and to significantly reduce an area of the sealing portion  202 . 
     The battery cell  10  refers to a chargeable and dischargeable nickel metal hydride (Ni-MH) cell or lithium ion (Li-ion) cell, and generates current. A plurality of battery cells  10  are disposed in a line on both surfaces of the unit plate  21  to be described later. 
     The unit plate  21  includes a plate portion, with which the accommodation portion  204  of the battery cell  10  is in surface-contact, and side portions  23  disposed on both side surfaces of the plate portion  22  to protect the second sealing portion  2022  of the battery cell  10 . 
     The plate portion  22  is formed as a flat surface, and the side portion  23  is formed to protrude upwardly and downwardly of the plate portion  22  from both edge portions or the plate portion  22 . Accordingly, the unit plate  21  may be formed such that a cross section, obtained by cutting the plate portion  22  and the side portion  23 , has an H-beam shape. 
     As illustrated in  FIG.  8   , a connection portion  23   a  of the plate portion  22 , connected to the side portion  23 , may be formed to have a thickness greater than a thickness of the other portion to secure rigidity. in this case, heat of the plate portion  22  may be more effectively transferred to the side portion  23 . In addition, the entire external surface of the side portion  23  is disposed to face the third plate  50  provided with a cooling device, and is disposed to be significantly close to the third plate  50 . Therefore, the heat transferred to the side portion  23  may be rapidly discharged to an external entity through the third plate  50 . 
     A shape of the above-described connection portion  23   a  is not limited to a shape illustrated in the drawing, and may be variously modified as necessary, for example, forming an empty space in the connection portion  23   a,  or the like. 
     The unit plate  21  according to this embodiment has one surface, on which three battery cells  10  arranged in a line, and the other surface on which three battery cells  10  arranged in a line. Therefore, a total of six battery cells  10  are coupled to each other in a single unit plate  21 . However, the present disclosure is not limited thereto, and one or two battery cells  10  may be disposed on each of both surfaces of the unit plate  21 . As necessary, four or more battery cells  10  may be disposed on each of both surfaces of the unit plate  21 . 
     As three battery cells  10  are disposed on each of both surfaces of the unit plate  21 , the unit plate  21  has three battery cell receiving spaces R 1 , R 2 , and R 3  on one surface thereof. 
     Each of the receiving spaces R 1 , R 2 , and R 3  is defined by the plate portion  22  and the side portions  23 . A connection member  26 , to which the electrode lead  15  of the battery cell  10  is connected, is disposed between the receiving spaces R 1 , R 2 , and R 3 . 
     Referring to  FIGS.  4  and  5   , the connection member  26  may include a busbar  26   a,  formed of a conductive material, and a bracket  26   b  formed of an insulating material. 
     The bracket  26   b  is disposed along the circumference of a busbar  26   a,  and is in contact with the unit, plate  21  when the connection member  26  is coupled to the unit plate  21 . Therefore, when the connection member  26  is coupled to the unit plate  21 , the busbar  26   a  is spaced apart from the unit plate  21 , and thus, is not in direct contact with or not electrically connected to the unit plate  21 . 
     The busbar  26   a  is formed of a flat metal plate, and has both surfaces exposed outwardly of the bracket  26   b.  Therefore, the battery cells  10  are bonded to both surfaces of the busbar  26   a  to be electrically connected to each other. 
     In this embodiment, two battery cells  10  are connected to one surface of the busbar  26   a,  and thus, a total of four battery cells  10  are connected to one busbar  26   a.    
     The electrode lead  15  of the battery cell  10  is bent to be bonded to the busbar  26   a  by welding, or the like. However, a method of bonding the electrode lead  15  of the battery cell  10  is not limited thereto. 
     The busbar  26   a  and the bracket  26   b  may be manufactured through insert injection. However, a method of manufacturing the busbar  26   a  and the bracket  26   b  is not limited thereto, and the busbar  26   a  and the bracket  26   b  may be coupled to each other after being individually manufactured. 
     The unit plate  21  is provided with a coupling hole  22   a  in which the connection member  26  is coupled between the receiving spaces R 1 , R 2 , and R 3 . When the connection member  26  is coupled to the coupling hole  22   a,  the busbar  26   a  of the connection member  26  and the plate portion  22  may be disposed on the same plane, as illustrated in  FIG.  5   . 
     In this embodiment, the connection member  26  is coupled to the unit plate  21  in such a manner that the bracket  26   b  is fitted into the coupling hole  22   a  formed in the unit plate  21 . 
     An adhesive may be interposed between the connection member  26  and the unit plate  21  to stably couple the connection member  26  to the unit plate  21 . As necessary, an additional fixing member such as a bolt or a screw may be used. 
     In the unit plate  21 , two battery cells  10 , disposed on both surfaces of the plate portion  22  to oppose each other with the plate portion  22  interposed therebetween, are connected in parallel —  through the connection member  26 . In addition, three battery cells  10 , disposed in a line on one of the surfaces of the unit plate  21 , are connected in series through the connection member  26 . Accordingly, in a single cell unit  20 , a plurality of battery cells  10  are connected in parallel while two battery cells  10  constitute a pair, and the three battery cells  10  connected in parallel are connected in series. 
     As illustrated in  FIG.  3   , the unit plate  21  according to this embodiment is provided with fastening grooves  22   b  formed between the receiving spaces R 1 , R 2 , and R 3  and the receiving space R 1 , R 2 , and R 3 , for example, in a portion in which the connection member  26  is disposed. 
     More specifically, the coupling groove  22   b  is formed in an external side of the connection member  26  as a groove formed in such a manner that the plate portion  22  and the side portion  23  are removed. Therefore, the fastening groove  22   b  is formed in such a manner that a width of the plate portion  22  or the cell unit is reduced, and the side portion  23  is discontinuously disposed by the fastening groove  22   b.    
     The fastening groove  22   b  is a region. in which a fastening portion  55  of the case  40 , to be described later, is disposed. Therefore, the fastening groove  22   b  is formed to have a size at which the fastening portion  55  may be easily disposed. 
     An external connection member  27  is disposed on both end portions of the unit plate  21 . Similarly to the above-described connection member  26 , the external connection member  27  may include a bracket and a busbar 
     Only two battery cells  10 , disposed to oppose each other with the plate portion  22  interposed therebetween, are connected to a busbar  27   a  of the external connection member  27 . The other portion of the busbar  27   a  is used as a terminal  271  electrically connecting the cell units  20  to each other (hereinafter referred to as a coupling terminal  271 ) 
     In the busbar  27   a  of the external connection member  27 , a portion used as the coupling terminal  271  is disposed to protrude outwardly of the unit plate  21  and to be bent upwardly or downwardly of the plate portion  22 . 
     The coupling terminal  271  is coupled to the coupling terminal  271  of another cell unit  20 . Accordingly, the plurality of cell units  20  may be connected to each other in series or parallel through the coupling terminal  271 . Welding or a fixing member such as a bolt or a screw may be used to connect the coupling terminals  271  to each other, but the present disclosure is not limited thereto. 
     The above-configured unit plate  21  serves as a cooling plate while supporting the battery cell  10 . Heat, generated in the battery cell  10 , is transferred to a third plate  50  to be described later through the plate portion  22  and the side portion  23  of the unit plate  21 . In this embodiment, the third plate  50  serves as a cooling member. Accordingly, the heat of the battery cells  10  disposed on both sides of the plate portion  22  may be rapidly dissipated. 
     he circuit board  28  is connected to the busbar  26   a  of each of the connection members  26  to measure a voltage of the battery cell  10 . The circuit board  28  may be provided with at least one temperature sensor  28   a  to measure a temperature of a battery and may further include a fuse, as necessary. 
     The temperature sensor  28   a  may be disposed to be in contact with the accommodation portion  204  or the sealing portion  202  of the battery cell  10 , but the present disclosure is not limited thereto. In this embodiment, a negative temperature coefficient-thermal resistor (an NTC thermistor) is used as the temperature sensor  28   a,  but the present disclosure is not limited thereto. 
     The circuit board  28  should be electrically connected to an outside of the battery module to detect a voltage or a temperature of the battery cell from the outside of the battery module  100 . Thus, the circuit board  28  should connect the temperature sensor  28   a  and the busbar  26   a  to the outside of the battery module. 
     To this end, the circuit board  28  according to this embodiment is formed as a flexible circuit board (FPCB) As illustrated in  FIG.  8   , the circuit board  28 , disposed in the receiving spaces R 1 , R 2 , and R 3 , is disposed between the battery cell  10  and the side portion  23 . More specifically, the circuit board  28  is attached to an internal side surface of the side portion  23  to be led outwardly of The unit plate  21  along the side portion  23 . The circuit board  28 , attached to the internal side surface of the side portion  23 , may be firmly bonded to the side portion  23  through an adhesive or an adhesive tape. 
     A section, disposed in the receiving spaces R 1 , R 2 , and R 3  of the circuit board  28 , has a width less than a width of The side portion  23 . Therefore, even when the circuit board  28  is disposed on the internal side surface of the side portion  23 , the circuit board  28  is not exposed outwardly of the side portion  23 . 
     Accordingly, the circuit board  28  may be led outwardly of the unit plate  21  without interference with the battery cell  10 . 
     In the circuit board  28 , a portion led outwardly of the unit plate  21  may be connected to an external entity through a connector, not illustrated, provided in a cover plate  70  to be described later. 
     The cell assembly  60  according to this embodiment is configured by stacking a plurality of cell units  20 . 
     To this end, the cell assembly  60  includes a coupling unit  30  disposed between the cell units  20 . 
     As illustrated in  FIG.  7   , the coupling unit  30  is disposed between two cell units  20 , stacked in a vertical direction, to be fixedly coupled to the two cell units  20 . 
     The coupling unit  30  may include a frame  31 , disposed between the side portions  23  of the unit plate  21 , and support. portions  32  and  33  disposed on the end portions of the frame  31 . 
     The support portions  32  and  33  may include a first support  32  and a second support  33 . 
     The first support portion  32  supports both end portions of the cell unit  20 . When the first support portion  32  is disposed between the coupling terminals  271  of the cell unit  20  to electrically connect the coupling terminals  271  to each other, the first support portion  32  may serve to fix the coupling terminals  271 . To this end, the first support  32  may be provided with a fastening hole  36  in which a coupling member such as a bolt or screw, used when the coupling terminals  271  are coupled, is fastened. Accordingly, the fixing member penetrates through both of the two coupling terminals  271  and the fastening hole  36  to fixedly couple the coupling terminals  271  to the first support portion  32 . 
     The first support  32  is provided with a first protrusion  34  protruding upwardly of the first support  32 . The first protrusion  34  is provided for easy coupling to the external connection member  27  of the cell unit  20  stacked on the first protrusion  34 . The first protrusion  34  may be inserted into a hole provided in the unit plate  21  or the external connection member  27 . 
     The second support portion  33  is disposed between the connection members  26  of the cell unit  20  to support the connection member  26 . Accordingly, when both end potions of the frame  31  are disposed between the connection members  26 , second supports  33  may be disposed on both end portions of the frame  31 , respectively. 
     The second support portion  33  may be configured to be coupled to and separated from a second support portion  33  of another frame  31 . For example, the second support portion  33  may be configured to be fitted in and coupled to the second support  33  of another frame  31 . However, the configuration of the second support portion  33  is not limited thereto, and the second supports  33  may be coupled to each other using an additional fixing member. 
     In addition, the second support. portion  33  may be provided with a second protrusion  35  for easy coupling to the connection member  26 . Similarly, the second protrusion  35  may also be configured to be inserted into a hole provided in the unit plate  21  or the connection member  26 . 
     As described above, the first protrusion  34  and the second protrusion  35  define a coupled location of the cell unit.  20 . Accordingly, the cell unit  20  and the coupling unit  30  may be easily aligned and coupled to each other while assembling the cell assembly  60 . 
     The frame  31  is formed to have a rectangular ring shape along a contour of the battery cell  10 , and is disposed between the side portions  23  of the cell units  20  stacked in a vertical direction. 
     An inside of the frame  31  is formed as an empty space. Therefore, as illustrated in  FIG.  8   , when the cell units  20  are coupled. to the coupling unit  30 , a portion of the battery cell  10  coupled to the cell unit  20  is accommodated in the internal space of the frame  31 . For example, when the battery cell  10  is coupled to the unit plate  21 , a portion of the accommodation portion  204  of the battery cell  10  protrudes outwardly of the receiving spaces R 1 , R 2 , and R 3  of the unit plate  21 . The protruding portion is disposed in the internal space of the frame  31  of the coupling unit  30 . 
     The coupling unit  30  according to this embodiment is provided with a plurality of frames  31 . More specifically, the frames  31  are provided as many as the number of battery cells  10  arranged in a line in the cell unit  20  to be coupled to the coupling unit  30 . Accordingly, in this embodiment, each of the coupling units  30  is provided with three frame. However, the number thereof is not limited thereto. An insulating pad  18  may be disposed between the battery cells  10 , opposing each other, in the internal space of the frame  31 . 
     The insulating pad  18  is formed of a compressed pad or a foam material to prevent direct contact between battery cells and to increase insulation. In addition, an assembly tolerance may be absorbed during a manufacturing process to enhance ease of assembling. 
     However, an example of the insulating pad  18  is not limited thereto, and various modifications, such as an insulating pad  18  formed of a double-sided adhesive tape or adhesive resin, may be made. 
     The insulating pad  16   a,  disposed. between the cell assembly  60  and the first and second plates  40   a  and  40   b,  serves to prevent the overall volume of the battery cells from expanding when a specific battery cell expands. Can perform the function. Thus, the insulating pad  18   a,  disposed between the cell assembly  60  and the first and second plates  40   a  and  40   b , may be formed of polyurethane foam. However, a material of the insulating pad  18   a  is not limited thereto. 
     The case  40  may include a first plate  40   a  coupled to a lower portion of the assembly  60 , a second plate  40   b  coupled to an upper portion of the cell assembly  60 , a third plate  50  coupled to a side surface of the cell assembly  60 , and a cover plate  70 , as illustrated in  FIG.  2   . 
     At least one of the first, second, and third plates  40   a,    40   b,    50  may serve as a cooling member of the battery module  100 . In this embodiment, the third plate  50  serves as a cooling member. However, the configuration of the present disclosure is not limited thereto, and the first plate  40   a  or the second plate  40   b  may also be configured to serve as a cooling member having the same shape as the third plate  50 , depending on a size of the battery cell  10 . 
     To this end, the first, second, and third plates  40   a,    40   b,    50  may be formed of a material having high thermal conductivity such as metal. For example, the first, second, and third plates  40   a,    40   b,  and  50  may be formed of aluminum. However, a material thereof is not limited thereto, and various materials may be used as long as the material has similar strength and thermal conductivity even if the material is not a metal. 
     The first plate  40   a  is disposed below the cell assembly  60  to support lower surfaces of the battery cells  10 , and the second plate  40   b  is disposed above The cell assembly  60  to cover upper surfaces of battery cells  10 . The third plate  50  is disposed on each of both side surfaces of the cell assembly  60  to be coupled to the first plate  40   a  and the second plate  40   b.  Thus, the first, second, and third plates  40   a,    40   b,  and  50  constitute a tubular case. 
     The third plate  50  protects a side surface of the cell assembly  60 , and cools the battery cell  10 . To this end, the third plate  50  includes an internal plate  50   a  and an external plate  50   b,  as illustrated in  FIG.  8   . 
     The internal plate  50   a  is disposed on a side of the cell assembly  60 , and the external plate  50   b  is disposed on an external side of the internal plate  50   a  and coupled to the external surface of the internal plate  50   a.    
     The inner plate  50   a  is coupled to the above-described first and second plates  40   a  and  40   b.  The external plate  50   b  is bonded to an external surface of the internal plate  50   a.  In this case, the entirety of the external plate  50   b  may not be bonded and at least a portion thereof may be bonded. At least a portion of the unbonded portion may be spaced apart from the internal plate  50   a.  Thus, a space is formed between the internal plate  50   a  and the external plate  50   b  to be used as a cooling flow path (S in  FIG.  8   ) 
     The external plate  50   b  may be bonded to the internal plate  50   a  through welding or brazing. As necessary, the external plate  50   b  may be bonded to internal plate  50   a.  using an adhesive. 
     The cooling flow path S is disposed in the entire external plate  50   b.  A shape of the cooling passage S may be variously modified, as necessary. 
     The above-configured external plate  50   b  may be manufactured by pressing a metal plate. In this embodiment, the internal plate  50   a  and the external plate  50   b  are formed of the same material (for example, aluminum). However, the material thereof is not limited thereto, and the internal plate  50   a  and the external plate  50   b  may be formed of different materials to each other. 
     In this embodiment, one side of the internal plate  50   a  is provided with an inlet  52  and an outlet  54  of a cooling flow path S. Accordingly, cooling water is introduced into the above-described cooling flow path S through the inlet  52  and passes through the cooling flow path  5 , and is then discharged outwardly of the cooling flow path S through the outlet  54 . However, the configuration of the present disclosure is not limited thereto. As necessary, locations of the outlet  54  and the inlet  52  may be variously modified. For example, the outlet.  54  and the inlet  52  may be disposed on the external plate  50   b  or the external plate  50   b,  or may be disposed the external plate  50   b  and the external plate  50   b,  respectively. 
     The third plate  50  according to this embodiment is used as a water-cooled cooling device having a cooling flow path S therein. However, the configuration of the present disclosure is not limited thereto, and an air-cooled cooling device may be applied. 
     Referring to  FIG.  2   , in the third plate  50  according to this embodiment, a fastening portion  55  is formed on an internal surface opposing the cell assembly  60 . The fastening portion  55  is disposed to protrude from the internal surface of the third plate  50  to a side of the cell assembly  60 , and has a fastening hole  55   a  formed therein. 
     The fastening portion  55  is formed to have a pipe shape to be bonded to an internal surface of the third plate  50 . In this case, the fastening portion  55  is disposed to be inserted into the coupling groove ( 22   b  in  FIG.  3   ) of the above-described unit plate  21 . Accordingly, the coupling portion  55  has a size enough to be insertable into the coupling groove  22   b.  Each of the first plate  40   a  and he second plate  40   b  is provided with a through-hole into which. the fastening member  65  is inserted in a location corresponding to the fastening grooves  22   b.    
     As the cell unit  20  is stacked in a vertical direction, the fastening groove  22   b  is formed to penetrate through the cell assembly  60  in the vertical direction. Accordingly, the coupling portion  55  is also disposed in the coupling groove  22   b  to penetrate through the cell assembly  60  in the vertical direction. 
     The fastening hole  55   a  is a hole, into which the fastening member  65  such as a bolt or a screw is inserted and coupled, and is used to fix the battery module  100  to a structure or the like. 
     The fastening member  65  sequentially penetrates through the first plate  40   a,  the fastening hole  55   a  of the third plate  50 , and the second plate  40   b  to be fixedly fastened to the second plates  40   a  and  40   b.    
     in the fastening member  65 , a portion protruding downwardly of the second plate  40   b  is fastened to a structure (for example, a vehicle, or the like) in which the battery module  100  is mounted. 
     When the fastening portion  55  is not provided, it may be difficult to secure rigidity of the third plate  50  in the vertical direction. In this case, when external force is applied to the battery module  100  in the vertical direction, the second plate  40   b  is readily damaged. For example, the third plate  50  may also be deformed by a force applied to fasten the fastening member  65  to the structure. 
     However, as in this embodiment, when the fastening portion  55  is provided and the first plate  40   a  and the second plate  40   b  are respectively disposed below and above the coupling portion  55 , the fastening member  65  sequentially penetrates through the first plate  40   a,  the fastening portion  55 , and the second plate  40   b  to be fastened to the structure. 
     Accordingly, even when an external force is applied in the vertical direction, the third plate  50  is not readily deformed by the fastening portion  55  disposed between the first plate  40   a  and the second plate  40   b.    
     In addition, the fastening portion  55  is inserted into the fastening groove  22   b.  When the fastening groove  22   b  is not present, a distance between the third plates  50  should be increased or the fastening portion  55  should. be disposed on an external surface of the third plate  50 , rather than an internal surface of the third plate  50 . In this case, a volume of the battery module may be increased. 
     However, since the battery module  100  according to this embodiment is provided with a fastening groove  22   b  in the unit plate  21 , the fastening portion  55  may be disposed in a space formed in the cell assembly  60 . Thus, the above-mentioned issues may be addressed. 
     Referring to  FIG.  8   , a heat transfer member  59  may be disposed between the cell assembly  60  and the case  40 . 
     In this embodiment, the heat transfer member  59  is disposed between the cell assembly  60  and the third plate  50 . Specifically, the heat transfer member  59  is disposed between an external surface of the side portion  23  and an internal surface of an internal side plate  50   a  of the third plate  50 . However, a location of the heat transfer member  59  is not limited thereto, and the heat transfer member  59  may be disposed on sides of the first and second plate  40   a  and  40   b,  as necessary. 
     The heat transfer member  59  may be formed of a material having high heat conductivity. In addition, the heat transfer member  59  may be formed of thermal grease, a thermally conductive adhesive formed of an epoxy-based resin, a urethane-based, a silicone-based resin, or an acryl-based resin, and a pad. 
     The heat transfer member  59  may be formed by applying a liquid or gel-state material to the internal surface of the third plate  50 . Accordingly, the heat transfer member  59  is disposed to fill a space between the cell assembly  60  and the third plate. However, a location of the heat transfer member  59  is not limited thereto, and a pad-shaped heat transfer member  59  may be inserted. 
     The heat transfer member  59  absorbs an assembly tolerance between the cell assembly  60  and the third plate  50 . Thus, the cell assembly  60  may be firmly fixed to the case  40  in an internal space of the case  40  by the heat transfer member  59 , and heat dissipated from the cell assembly  60  may be rapidly transferred to the third plate  50  through the heat transfer member  59 . In addition, as the heat transfer member  59  is disposed between the cell assembly  60  and the case  40 , overall rigidity of the battery module  100  may be enhanced. 
     The third plate  50  according to this embodiment may include a reinforcing plate  50   c  coupled to an external surface of the external side plate  50   b.    
     The reinforcing plate  50   c  is provided to reinforce the rigidity of the second plate  40   b.  Therefore, the reinforcing plate  50   c  is coupled to the external plate  50   b  to cover an entire external surface of the external plate  50   b,  and is formed of a material having rigidity greater than rigidity of the internal plate  50   a.  or the external plate  50   b.    
     For example, the reinforcing plate  50   c  may be formed of an ultrahigh-strength steel sheet having tensile strength of 1 giga Pascal (GPa) or more, but the present disclosure is not limited thereto. 
     The cover plate  70  is coupled to each of both end portions of the cell assembly  60 . 
     The cover plate  70  is coupled to the first, second, and third plates  40   a,    40   b,    50  to complete an exterior of the battery module  100 . 
     The cover plate  70  may be formed of an insulating material such as resin, and may be provided with a groove or a hole for exposing the connection terminal  272  to an external entity. The connection terminal  272  may be used to electrically connect the battery module to an external entity, and may be one of the coupling terminals  271  provided in the cell unit  20 . In addition, the cover plate  70  may e provided with a connector, not illustrated, connected to the circuit board  28 . 
     The cover plate  70  may be coupled to the first, second, third plate  40   a,    40   b,  and  50  through a fixing member such as a screw or a bolt. However, coupling of the cover plate  70  is riot limited thereto. 
     An insulating cover  80  and a flow path connection portion  90  may be disposed between the cover plate  70  and the cell assembly  60 . 
     The insulation cover  80  is formed of an insulating material and is coupled to both ends of the cell assembly  60 , to which the coupling terminals  271  are coupled, to protect the coupling terminals  271  of the cell assembly  60  and to maintain insulation. 
     At least one of the insulating cover  80  may be provided with a hole  82  through which the connection terminal  72  is disposed. The connection terminal  72  is exposed to an external entity through the hole  82  formed in the insulating cover  80 . Therefore, the through hole  82  of the insulating cover  80  is formed to have a size corresponding to a size and a shape of the connection terminal  272 . 
     Although not illustrated, a heat transfer member may fill a space between the insulating cover  80  and the cell assembly  60 , as necessary. 
     The flow path connection portion  90  is disposed between the insulating cover  80  and the cover plate  70  and has a flow path through which the cooling water passes. The flow path of the flow path connection portion  90  is connected to each of the inlet  52  and the outlet  54  provided in the third plate  50 . 
     The flow path connection portion  90  is used as a path for supplying cooling water to the battery module  100  from a device or equipment in which the battery module  100  is mounted. To this end, a flow path of the flow path connection portion.  90  includes an inlet and cutlet  92  connected to an external entity. 
     Accordingly, the cooling water supplied to the flow path connection portion  90  through the inlet and outlet  92  is supplied to the cooling flow path S of the third plate  50  through the inlet  52  of the third plate  50 . The cooling water, passing through the cooling flow path S, returns to the flow path connection portion  90  and is then discharged outwardly of the battery module  100  through the inlet and outlet  92 . 
     In the above-configured battery module  100  according to this embodiment, cooling devices are disposed on both sides of the cell assembly  60 , respectively. Since the unit plate  21  is disposed between the battery cells  10 , heat may be rapidly transferred to the cooling devices through the unit plate  21 . Thus, heat generated in the battery cell  10  may be effectively dissipated. 
     In addition, since the cell assembly  60  is completed by stacking a plurality of cell units  20 , the battery module  100  may be easily manufactured, and the battery module  100  may be manufactured to have various sizes and capacities depending on the number of cell units  20 . 
     In addition, since the third case is provided with a cooling flow path S, the cell assembly  60  and the cooling channel S are disposed as close as possible, and thus, cooling efficiency of the cell assembly  60  may be enhanced. 
     As described above, since a battery module according to an example embodiment includes a unit plate disposed between battery cells, heat may be rapidly transferred to a side of a cooling device through the unit plate. Thus, heat generated in the battery cell may be effectively dissipated. 
     In addition, since a cell assembly is completed by stacking a plurality of cell units, the battery module may be easily manufactured. 
     While this disclosure includes specific examples, it will be apparent after an understanding of the disclosure of this application that various changes in forms and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.