Patent Publication Number: US-2015064541-A1

Title: Battery pack

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2013-0102005, filed on Aug. 27, 2013, in the Korean Intellectual Property Office, and entitled: “Battery Pack,” which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     Embodiments relate to a battery pack. 
     2. Description of the Related Art 
     Unlike primary batteries, secondary batteries are rechargeable. Secondary batteries may be used as energy sources of devices such as mobile devices, electric vehicles, hybrid electric vehicles, electric bicycles, and uninterruptible power supplies (UPSs). Single-cell secondary batteries or multi-cell secondary batteries (secondary battery packs) in which a plurality of cells are connected may be used according to types of external devices using the secondary batteries. 
     SUMMARY 
     Embodiments are directed to a battery pack. 
     The embodiments may be realized by providing a battery pack including a plurality of battery cells; a case frame having an opened end, the case frame receiving the plurality of battery cells; and a finishing plate coupled with the opened end of the case frame, wherein the case frame includes a pair of side plates extending in an arrangement direction of the battery cells to cover lateral sides of the battery cells; and an end plate between the side plates, the end plate closing an end of the case frame, and wherein the side plates and the end plate are a one piece structure. 
     The end plate and the side plates may be connected without joints therebetween. 
     The side plates may include catch jaws supporting bottom sides of the battery cells, the bottom sides of the battery cells adjoining the lateral sides of the battery cells. 
     The catch jaws may protrude inwardly from main bodies of the side plates toward the battery cells and form a one piece structure with the main bodies of the side plates. 
     The catch jaws may protrude from main bodies of the side plates toward one another. 
     Edge portions of the bottom sides of the battery cells that are adjacent to the side plates may be covered with the catch jaws, and center regions of the bottom sides of the battery cells may be exposed by the catch jaws. 
     The catch jaws may extend along entire lengths of the side plates in the arrangement direction of the battery cells. 
     The catch jaws may extend across all the bottom sides of the battery cells in the arrangement direction of the battery cells. 
     The finishing plate may include a base plate facing the battery cells; and a lower flange bent from the base plate in a direction away from the battery cells, and the catch jaws overlap the lower flange and support the lower flange. 
     The catch jaws may include fastening holes for coupling with the lower flange. 
     The finishing plate may include a base plate facing the battery cells; and a flange bent from the base plate in a direction away from the battery cells, and the flange may include lateral flanges on lateral sides of the base plate; and a lower flange on a lower side of the base plate. 
     The lateral flanges of the finishing plate may be coupled to the side plates at the opened end of the case frame, and the lower flange of the finishing plate may be coupled to the catch jaws of the side plates. 
     The battery pack may further include a top plate on top sides of the battery cells and opposite to the catch jaws. 
     The top plate may include a base frame between the finishing plate and the end plate, the base frame supporting the finishing plate and the end plate; and a support frame between the side plates, the support frame supporting the side plates. 
     The side plates may include a pair of first and second side plates, the support frame may include first and second support frames extending from the base frame, the first and second support frames being coupled to the first and second side plates, respectively, and the first and second support frames may be alternately arranged and staggered along a lengthwise direction of the base frame. 
     Fastening holes of the finishing plate and the side plates may be aligned at fastening positions, and fastening members in the aligned fastening holes may couple the finishing plate with the side plates. 
     The finishing plate and the side plates may include assembling guides that align the finishing plate with the side plates. 
     The assembling guides may include assembling pins protruding from the finishing plate; and assembling rails in the side plates, the assembling rails receiving the assembling pins and guide-sliding the assembling pins. 
     The finishing plate may include a base plate facing the battery cells; and lateral flanges bent from the base plate in a direction away from the battery cells, and the assembling pins may be on the lateral flanges. 
     The assembling pins on the lateral flanges may be slideably insertable into the assembling rails at ends of the side plates to fastening positions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features will be apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which: 
         FIG. 1  illustrates an exploded perspective view of a battery pack according to an embodiment; 
         FIG. 2  illustrates a perspective view of an arrangement of battery cells depicted in  FIG. 1 ; 
         FIG. 3  illustrates a perspective view showing how a finishing plate and a case frame are assembled; 
         FIG. 4  illustrates an enlarged perspective view of assembling portions of the finishing plate and the case frame; 
         FIGS. 5A and 5B  illustrate views showing how the finishing plate is aligned with an assembling position using an assembling guide; 
         FIG. 6  illustrates a perspective view of the case frame depicted in  FIG. 1 ; 
         FIG. 7  illustrates a perspective view of a top plate; and 
         FIG. 8  illustrates a view of an exemplary upper structure of the battery pack. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art. 
     In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another element, it can be directly on the other element, or intervening elements may also be present. In addition, it will also be understood that when an element is referred to as being “between” two elements, it can be the only element between the two elements, or one or more intervening elements may also be present. Like reference numerals refer to like elements throughout. 
     As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. 
     A battery pack will now be described in detail with reference to the accompanying drawings, in which exemplary embodiments are shown. 
       FIG. 1  illustrates an exploded perspective view of a battery pack according to an embodiment. Referring to  FIG. 1 , the battery pack may include a plurality of battery cells  10  arranged in an arrangement direction (directions ±Z1), and plates  120 ,  130 ,  140 , and  150  surrounding the battery cells  10 . 
       FIG. 2  illustrates a perspective view of the battery cells  10  depicted in  FIG. 1 . Referring to  FIGS. 1 and 2 , the battery cells  10  may be secondary battery cells, e.g., lithium ion battery cells. The battery cells  10  may have a suitable shape, e.g., a cylindrical shape or a prismatic shape. In an implementation, the battery cells  10  may be a suitable type of battery cell, e.g., a polymer battery cell. 
     For example, each of the battery cells  10  may include a case  10   b , an electrode assembly (not shown) in the case  10   b , and electrode terminals  10   a  electrically connected to the electrode assembly and exposed to the outside of the case  10   b . For example, the electrode terminals  10   a  may be exposed to the outside of the case  10   b  and may form portions of the top side of the case  10   b . Although not shown, the electrode assembly may include a positive electrode, a separator, and a negative electrode. The electrode assembly may be a jelly-roll or stack type electrode assembly. The case  10   b  accommodates the electrode assembly, and the electrode terminals  10   a  may be exposed to the outside of the case  10   b  for electric connection with an external circuit. 
     For example, neighboring battery cells  10  may be electrically connected to each other by connecting electrode terminals  10   a  of the battery cells  10 . For example, neighboring battery cells  10  may be electrically connected in series or parallel to each other by connecting electrode terminals  10   a  of the battery cells  10  using bus bars  15 . 
     A safety vent  10 ′ may be formed in the case  10   b . The safety vent  10 ′ may be relatively weak so that if the inside pressure of the case  10   b  becomes equal to or higher than a predetermined value, the safety vent  10 ′ may be fractured to release gas from the inside of the case  10   b.    
     Spacers  50  may be disposed between neighboring battery cells  10 . The spacers  50  may insulate the neighboring battery cells  10  from each other. For example, the cases  10   b  of the battery cells  10  may have electric polarities. The spacers  50  may be formed of an insulation material and disposed between the cases  10   b  to help prevent electric interference or connection between neighboring pairs of the battery cells  10 . 
     In addition, the spacers  50  may function as heat-dissipating paths between the battery cells  10 . For example, heat-dissipating holes  50 ′ may be formed in the spacers  50 . Heat-dissipating holes  140 ′ (refer to  FIG. 1 ) may be formed in a pair of side plates  140  (described below). The heat-dissipating holes  140 ′ of the side plates  140  may be aligned with the heat-dissipating holes  50 ′ of the spacers  50  to form heat-dissipating paths between the battery cells  10 . 
     The spacers  50  may be disposed between the battery cells  10  and may help reduce and/or prevent thermal expansion (swelling) of the battery cells  10 . The cases  10   b  of the battery cells  10  may be formed of a deformable material such as metal. Thus, the spacers  50  may be formed of a less deformable material such as polymer to help suppress swelling the battery cells  10 . 
     The spacers  50  may be disposed on outermost sides of the battery cells  10  in the arrangement direction (directions ±Z1) as well as being disposed between the battery cells  10 . For example, referring to  FIG. 1 , an end plate  150  and a finishing plate  130  may be disposed on ends of the battery cells  10  in the arrangement direction (directions +Z1). One of the spacers  50  may be disposed between the end plate  150  and the corresponding outermost battery cell  10 , and another spacer  50  may be disposed between the finishing plate  130  and the corresponding outermost battery cell  10 , so as to electrically insulate the end plate  150  and the finishing plate  130  from the outermost battery cells  10 . 
     Referring to  FIG. 1 , the battery pack may include a binding structure ( 130  and  160 ) in which the battery cells  10  are arranged and bound in the arrangement direction (directions ±Z1). 
     The binding structure ( 130  and  160 ) may include: a case frame  160  having an opened end to receive the battery cells  10 ; and the finishing plate  130  configured to be coupled to the opened end of the case frame  160  for closing the opened end. 
     The case frame  160  may cover three sides of a battery cell array (including a plurality of the arranged battery cells  10  and spacers  50 ) disposed in the arrangement direction (directions ±Z1). For example, the battery cell array may include the battery cells  10  and the spacers  50  arranged in the arrangement direction (directions ±Z1). For example, the case frame  160  may include: the pair of side plates  140  extending in the arrangement direction (directions ±Z1) to cover sides of the battery cell array, and the end plate  150  between ends of the side plates  140  to cover an end of the battery cell array. The pair of side plates  140  and the end plate  150  may be formed in one piece, e.g., monolithically as one continuous piece. Thus, the side plates  140  may be smoothly connected to the end plate  150  without any joints therebetween. For example, the case frame  160  may be formed by bending a raw material sheet without using any fastening members. For example, additional fastening members such as bolts and nuts may not be used to couple the side plates  140  and the end plate  150 . 
     In an implementation, the side plates  140  and the end plate  150  may be coupled by a method such as welding without using any fastening members. In the current embodiment, the side plates  140  and the end plate  150  may be formed of a raw material sheet. For example, the side plates  140  and the end plate  150  may be smoothly connected without any welding points or joints therebetween. 
     The finishing plate  130  may be coupled to the opened end of the case frame  160 . For example, the battery cell array may be pushed into the case frame  160  in a direction from the opened end to the end plate  150  of the case frame  160 . Then, the opened end of the case frame  160  may be closed by coupling the finishing plate  130  to the opened end. For example, the case frame  160  and the finishing plate  130  may be coupled by a mechanical coupling method. For example, the finishing plate  130  may be inserted (e.g., slid) into the opened end of the case frame  160  in an assembling direction to overlap the finishing plate  130  and the case frame  160  and align fastening holes at an end portion of the case frame  160  and lateral flanges  135  of the finishing plate  130 . Then, fastening members  171  may be inserted in the fastening holes. 
     In an implementation (not shown), the finishing plate  130  and the case frame  160  may be coupled by using other mechanical coupling methods, e.g., by using a hook structure, instead of using screws or bolts as fastening members  171 . For example, the finishing plate  130  may be slid into the opened end of the case frame  160  in an assembling direction and may be locked by a hook structure so that the finishing plate  130  may not be separated from the case frame  160  if a releasing action is not taken. The hook structure may include hook jaws (not shown) and fastening holes (not shown) formed on mutually-facing sides of the finishing plate  130  and the case frame  160 . For example, when the finishing plate  130  is inserted in the opened end of the case frame  160  in the assembling direction, hook jaws (not shown) on the finishing plate  130  may be slid into fastening holes (not shown) formed in the case frame  160 . Once the hook jaws are slid into the fastening holes, the hook jaws may be stably held in the fastening holes. 
     The finishing plate  130  and the end plate  150  may be disposed at ends of the battery cell array. The finishing plate  130  and the end plate  150  may include flanges  132 ,  133 ,  135 ,  152 , and  153  bent in directions opposite to or away from the battery cell array. For example, the flanges  132 ,  133 ,  135 ,  152 , and  153  may be bent from edge portions of the finishing plate  130  and the end plate  150  in directions opposite to or away from the battery cell array. The flanges  132 ,  133 ,  135 ,  152 , and  153  may include upper flanges  132  and  152  and lower flanges  133  and  153  on upper and lower sides of the finishing plate  130  and the end plate  150 , respectively. The flanges  132 ,  133 ,  135 ,  152 , and  153  may function as coupling positions at which neighboring elements may be coupled to the finishing plate  130  and the end plate  150 . Fastening holes may be formed in the flanges  132 ,  133 ,  135 ,  152 , and  153 , and screws may be inserted into the fastening holes. For example, a top plate  120  may be disposed on top of the battery cell array and coupled to the finishing plate  130  and the end plate  150  through the fastening holes formed in the upper flanges  132  and  152 . The flanges  132 ,  133 ,  135 ,  152 , and  153  may help enhance mechanical stiffness of the finishing plate  130  and the end plate  150 . 
     The finishing plate  130  may include a base plate  131  facing the battery cells  10 , and upper, lower, and lateral flanges  132 ,  133 , and  135  bent from the base plate  131  in a direction opposite to or away from the battery cells  10 . The upper flange  132  may be coupled to the top plate  120 , and the lateral and lower flanges  135  and  133  may be coupled to the side plates  140 . 
     The lateral flanges  135  of the finishing plate  130  may be coupled to ends of the side plates  140  (e.g., at the opened end of the case frame  160 ), and the lower flange  133  of the finishing plate  130  may be coupled to catch jaws  140   a  of the side plates  140 , which will described below in more detail. The finishing plate  130  may be coupled to the side plates  140  by aligning the lateral flanges  135  and the lower flange  133  thereof with ends of the side plates  140  (e.g., at the opened end of the case frame  160 ) and fastening holes  140   a ′ of the catch jaws  140   a  of the side plates  140 , and inserting fastening members  171  into the fastening holes  140   a′.    
     The side plates  140  may be disposed on sides of the battery cells  10 . For example, the side plates  140  may cover sides of the battery cells  10  arranged in the arrangement direction (directions ±Z1). For example, the side plates  140  provided as a pair may be disposed on opposite lateral sides of the battery cells  10 . The side plates  140  may extend in the arrangement direction (directions ±Z1) of the battery cells  10  and may be coupled to the finishing plate  130  at an end of the battery cells  10 . 
     The catch jaws  140   a  may be bent from the side plates  140  toward the battery cells  10  to support portions of the bottom sides of the battery cells  10 . For example, the pair of side plates  140  may be on the opposite lateral sides of the battery cells  10 , and the catch jaws  140   a  that are bent from the side plates  140  to face each other may support bottom sides of the battery cells  10 . 
     The catch jaws  140   a  may extend along an entire length of the side plates  140  in the arrangement direction (directions ±Z1) of the battery cells  10 . Ends of the catch jaws  140   a  (e.g., at the opened end of the case frame  160 ) may be coupled to the lower flange  133  of the finishing plate  130  using screws. Fastening holes  140   a ′ may be formed in the catch jaws  140   a  and the lower flange  133 . Then, the side plates  140  and the finishing plate  130  may be coupled by aligning the fastening holes  140   a ′ of the catch jaws  140   a  and the lower flange  133 , and inserting fastening members into the fastening holes  140   a ′ and tightening the fastening members. 
     As described above, heat-dissipating holes  140 ′ may be formed in the side plates  140 . For example, the heat-dissipating holes  140 ′ of the side plates  140  may form patterns. Air may flow to the battery cells  10  through the heat-dissipating holes  140 ′, and thus heat generated during operation of the battery cells  10  may be rapidly dissipated. 
       FIG. 3  illustrates a perspective view showing how the finishing plate  130  and the case frame  160  are assembled.  FIG. 4  illustrates an enlarged perspective view of assembling portions of the finishing plate  130  and the case frame  160 . 
     Referring to  FIGS. 3 and 4 , assembling guides  195  may be formed on mutually-facing sides of the finishing plate  130  and the case frame  160 . For example, the assembling guides  195  may include assembling pins  191  formed on the lateral flanges  135  of the finishing plate  130 . The assembling pins  191  may be used to guide assembling of the finishing plate  130  and the case frame  160 . The finishing plate  130  and the case frame  160  may be assembled by sliding the finishing plate  130  inwardly along inner surfaces of the case frame  160  until the finishing plate  130  and the case frame  160  overlap each other and fastening holes  130 ″ and  140 ″ in the lateral flanges  135  of the finishing plate  130  and an end portion of the case frame  160  are aligned with each other, and inserting fastening members in the fastening holes  130 ″ and  140 ″. For example, relative positions of the finishing plate  130  and the case frame  160  may be guided using the assembling pins  191  until the fastening holes  130 ″ and  140 ″ are aligned with each other. 
     An exemplary method of assembling the battery pack will now be described with reference to  FIGS. 3 and 4 . The battery cells  10  may be inserted into the case frame  160  through the opened end of the case frame  160 . For example, the battery cell array may be pushed into the case frame  160  in a direction from the opened end of the case frame  160  to the other end of the case frame  160  that is closed by the end plate  150 . Then, for example, the battery cells  10  and the spacers  50  may be alternately arranged in the case frame  160 . After the battery cell array ( 10 ,  50 ) is inserted in the case frame  160 , the finishing plate  130  may be coupled to the opened end of the case frame  160  to close the opened end. 
     The finishing plate  130  may be inserted into the opened end of the case frame  160  using the assembling guides  195 . The assembling guides  195  may include the assembling pins  191  on the lateral flanges  135  of the finishing plate  130 , and assembling rails  192  in the side plates  140 . 
       FIGS. 5A and 5B  illustrate views showing how the finishing plate  130  is aligned with an assembling position using the assembling guides  195 . 
     Referring to  FIGS. 5A and 5B , the finishing plate  130  and the side plates  140  may be aligned by inserting the assembling pins  191  formed on the finishing plate  130  into the assembling rails  192  of the side plates  140 . The finishing plate  130  may be pushed toward the battery cell array ( 10 ,  50 ) in a sliding direction (direction −Z1). For example, the finishing plate  130  may be pushed toward the battery cell array ( 10 ,  50 ) in the sliding direction (direction −Z1) by a pressing tool (not shown) such as a press machine. The finishing plate  130  may be slid along inner surfaces of the side plates  140  and overlapped with opened ends of the side plates  140 . Then, if the fastening holes  130 ″ and  140 ″ of the finishing plate  130  and the side plates  140  are aligned with each other, fastening members may be inserted therein and tightened. In this way, a battery pack may be roughly assembled. 
     According to the above-described assembling method, the assembling pins  191  of the finishing plate  130  may be guided along the assembling rails  192  of the side plates  140 , and, when the finishing plate  130  is slid in the arrangement direction of the battery cells  10 , the relative positions of the finishing plate  130  and the side plates  140  may be properly maintained. In this state, the finishing plate  130  may reach fastening positions P of the side plates  140 . 
     For example, the assembling pins  191  of the finishing plate  130  may be inserted into the assembling rails  192  of the side plates  140  to align the finishing plate  130  and the side plates  140 . The assembling rails  192  may be formed in lateral sides of the side plates  140  and may have opened sides. The assembling pins  191  of the finishing plate  130  may be inserted into the assembling rails  192  through the opened sides of the assembling rails  192 . 
     The assembling rails  192  may not be completely surrounded by walls of the side plates  140  but rather may have opened sides. For example, the assembling rails  192  may be opened to the outside through the opened sides. Therefore, the assembling pins  191  may be pushed into the assembling rails  192  from the opened sides of the assembling rails  192 . The assembling rails  192  may be opened in consideration of assembling of the finishing plate  130  and the side plates  140 . For example, when the finishing plate  130  and the side plates  140  are assembled by sliding the finishing plate  130  along the inner surfaces of the side plates  140  until the finishing plate  130  overlaps end portions (fastening holes  140 ″) of the side plates  140  and reaches the fastening positions P, the assembling pins  191  of the finishing plate  130  may be pushed into the opened sides of the assembling rails  192  and slid in the assembling rails  192 . The assembling rails  192  may have a long, narrow shape in the assembling direction (direction −Z1) of the finishing plate  130 . For example, the assembling rails  192  may be elongated in the arrangement direction (directions ±Z1) of the battery cells  10 . 
       FIG. 6  illustrates a perspective view of the case frame  160  depicted in  FIG. 1 . Referring to  FIGS. 1 and 6 , the case frame  160  may include the side plates  140 , and the side plates  140  may extend in a direction to cover lateral sides of the battery cell array ( 10 ,  50 ). The side plates  140  may be disposed on opposite lateral sides of the battery cells  10 . The side plates  140  may extend in the arrangement direction (directions ±Z1) of the battery cells  10 . Ends of the side plates  140  may be coupled to the finishing plate  130 , and other ends of the side plates  140  may be coupled to the end plate  150 . The side plates  140  may be coupled to the lateral flanges  135  on lateral edges of the finishing plate  130  by superposing the lateral flanges  135  on the side plates  140 , aligning the fastening holes of the lateral flanges  135  and the side plates  140 , and fastening the lateral flanges  135  and the side plates  140  using fastening members, e.g., bolts and nuts. In an implementation, at least portions of the side plates  140  and the lateral flanges  135  may be in contact with each other. 
     The assembling rails  192  may be formed in the side plates  140 . The assembling guides  195  may include the assembling rails  192  and the assembling pins  191 , and the assembling pins  191  may be inserted into the assembling rails  192  for aligning the finishing plate  130  and the side plates  140 . 
     For example, the assembling rails  192  may have opened sides. The assembling pins  191  of the finishing plate  130  may be inserted into the assembling rails  192  through the opened sides of the assembling rails  192  and slid in the assembling rails  192  in an extending direction (direction −Z1) of the assembling rails  192 . For example, the finishing plate  130  may be slid on the inner surfaces of the side plates  140  until fastening holes of the finishing plate  130  and the side plates  140  are aligned. Then, the finishing plate  130  and the side plates  140  may be coupled to each other. The sliding of the finishing plate  130  may be guided because the assembling pins  191  of the finishing plate  130  are slid along the assembling rails  192  of the side plates  140 . Therefore, the sliding of the finishing plate  130  may be restricted by the assembling pins  191  of the finishing plate  130  and the assembling rails  192  of the side plates  140 , and an additional aligning structure or procedure may not be required. For example, the coupling positions of the finishing plate  130  and the side plates  140  may be aligned by simply sliding the finishing plate  130  in the sliding direction (direction −Z1). 
     The assembling rails  192  may have a long, narrow shape in the sliding direction (direction −Z1) of the finishing plate  130 . Therefore, movement of the finishing plate  130  may be restricted in the sliding direction (direction −Z1) by the assembling rails  192 . For example, the assembling rails  192  may be elongated in the arrangement direction (directions ±Z1) of the battery cells  10 . 
     The assembling rails  192  may be formed in the opened ends of the side plates  140 , respectively. For example, one assembling rail  192  may be formed in one opened end of the side plates  140 . In an implementation, a number of the assembling rails  192  may be determined in consideration of the decrease of the stiffness of the side plates  140 . If two or more assembling rails  192  are formed in one opened end of the side plates  140 , the side plates  140  may be easily torn or damaged in the extending direction (direction Z1) of the assembling rails  192 . For example, when the assembling rails  192  of the side plates  140  make contact with the assembling pins  191  of the finishing plate  130 , the side plates  140  may be torn or damaged by vibration caused by assembling tolerances of the finishing plate  130  and the side plates  140 . 
     In addition, as the numbers of the assembling rails  192  and the assembling pins  191  increase, it may be difficult to assemble the assembling rails  192  and the assembling pins  191 , and thus the numbers of the assembling rails  192  and the assembling pins  191  may be limited. 
     The side plates  140  may have a plate shape, and the catch jaws  140   a  may be bent from the side plates  140  to support the bottom sides of the battery cells  10 . The side plates  140  may be disposed on the opposite lateral sides of the battery cells  10 , and the catch jaws  140   a  bent from the side plates  140  to face each other may support the bottom sides of the battery cells  10 . Herein, the bottom sides of the battery cells  10  may mean sides of the battery cells  10  adjoining the lateral sides of the battery cells  10 . 
     The catch jaws  140   a  may support the bottom sides of the battery cells  10 . The battery cell array ( 10 ,  50 ) may be vertically confined by the catch jaws  140   a  and the top plate  120  fastened to the top side of the battery cell array ( 10 ,  50 ). Thus, vertical wobbling or movement of the battery cell array ( 10 ,  50 ) may be reduced and/or prevented. The catch jaws  140   a  may be continuous from the side plates  140 . The catch jaws  140   a  may be bent inwardly from main bodies  140   b  of the side plates  140  toward the battery cells  10 . The catch jaws  140   a  may have a strip shape. For example, the catch jaws  140   a  may extend in mutually-facing directions from the side plates  140  that cover the lateral sides of the battery cells  10 . 
     The catch jaws  140   a  may extend along the entire length of the battery cells  10  in the arrangement direction (directions ±Z1). The catch jaws  140   a  may extend across all the bottom sides of the battery cells  10  in the arrangement direction (directions ±Z1). 
     The case frame  160  may cover three sides of the battery cell array ( 10 ,  50 ), and the catch jaws  140   a  (formed in one piece with the case frame  160  (e.g., the side plates  140 )) may support the bottom side of the battery cell array ( 10 ,  50 ). For example, the case frame  160  may cover four sides of the battery cell array ( 10 ,  50 ). The case frame  160  may be continuously or monolithically formed without any joints. For example, the case frame  160  may be manufactured by bending a single sheet of a raw material to continuously form the end plate  150  and the side plates  140 . In addition, the catch jaws  140   a  may also be continuously bent from the side plates  140 . For example, the case frame  160  (capable of supporting four sides of the battery cell array ( 10 ,  50 )) may be simply formed of a single sheet of a raw material through a continuous bending process. 
     If the case frame  160  were to be formed of a plurality of members by coupling or fastening the members, a plurality of processes may be performed to form the case frame  160 . This may increase the total number of manufacturing processes and manufacturing errors, which may make it difficult to control the quality of products. In addition, if the case frame  160  were to be formed of a plurality of members through coupling or fastening processes instead of forming the case frame  160  using a sheet of a raw material, durability and mechanical stiffness of the case frame  160  may be lowered. 
     After the battery cell array ( 10 ,  50 ) is inserted in the case frame  160 , the finishing plate  130  may be fastened to the opened end of the case frame  160 , and the top plate  120  may be fastened to the top side of the battery cell array ( 10 ,  50 ). In this way, all six sides of the battery cell array ( 10 ,  50 ) may be covered to form the battery pack in which the battery cells  10  are combined or accommodated. 
     The catch jaws  140   a  may extend along the entire length of the side plates  140  in the arrangement direction (directions ±Z1) of the battery cells  10 , and opened ends of the catch jaws  140   a  may be coupled to the lower flange  133  of the finishing plate  130  using, e.g., screws. For example, the lower flange  133  may be placed and supported on the catch jaws  140   a , and fastening members may be inserted through the lower flange  133  and the catch jaws  140   a  to fasten the lower flange  133  and the catch jaws  140   a  together. 
     The fastening holes  140   a ′ may be formed in the catch jaws  140   a  and the lower flange  133 . The side plates  140  and the finishing plate  130  may be coupled by aligning the fastening holes  140   a ′ of the catch jaws  140   a  and the lower flange  133 , and inserting fastening members into the fastening holes  140   a ′ and tightening the fastening members. The catch jaws  140   a  and the lower flange  133  may make surface contact with each other at corners of the battery pack. In this way, the lower flange  133  and the lateral flanges  135  of the finishing plate  130  may be fastened to the side plates  140  to form an accommodation region for receiving an array of the battery cells  10 . 
     Leg portions  140   a   1  may be embossed on the catch jaws  140   a . The leg portions  140   a   1  may protrude downwardly from the catch jaws  140   a  to support the weight of the battery pack. 
     The heat-dissipating holes  140 ′ may be formed in the side plates  140 . For example, the heat-dissipating holes  140 ′ may be formed at regular intervals in the arrangement direction (direction Z1) of the battery cells  10 . Air may flow to the battery cells  10  through the heat-dissipating holes  140 ′, and thus heat generated during operation of the battery cells  10  may be rapidly dissipated. 
     The bottom sides of the battery cells  10  may be exposed, except for the portions supported by the catch jaws  140   a  of the side plates  140 . Thus, air may flow between the battery cells  10  through or at the bottom sides of the battery cells  10  to cool the battery cells  10 . For example, although edge portions of the bottom sides of the battery cells  10  may be covered with the catch jaws  140   a , center regions of the bottom sides of the battery cells  10  may be exposed. 
     Boss members  145  may be formed on the side plates  140  to attach a circuit board (not shown) to the boss members  145 . For example, the circuit board may be a battery management system (BMS) board. For example, inward sides of the side plates  140  may face the battery cells  10 , and the circuit boards may be attached to outward facing sides of the side plates  140 . For example, the circuit board may monitor and control charging and discharging of the battery cells  10 . 
     For example, the boss members  145  may be disposed at four positions corresponding to the rectangular or square shape of the circuit board. In an implementation, the number of the boss members  145  may be multiples of four, and a plurality of circuit boards may be attached to the boss members  145 . The circuit boards may have coupling holes (not shown), and screws may be inserted in the coupling holes and the boss members  145  of the side plates  140  to fix the circuit boards to the side plates  140 . 
       FIG. 7  illustrates a perspective view of the top plate  120 . Referring to  FIGS. 1 and 7 , the top plate  120  may be disposed on a top side of the battery cells  10 . The top plate  120  may include a base frame  121  (extending along top center portions of the battery cells  10  in the arrangement direction (directions ±Z1) of the battery cells  10 ), and support frames  125  (extending from the base frame  121  toward the side plates  140 ). 
     Openings  121 ′ may be formed in the base frame  121  at positions corresponding to the positions of the safety vents  10 ′ of the battery cells  10 . The openings  121 ′ may be arranged in the length direction (directions ±Z1) of the base frame  121 . Ends of the base frame  121  may be fastened to the finishing plate  130  and the end plate  150  at opposite sides of the array of battery cells  10 . The base frame  121  may be coupled to the upper flanges  132  and  152  on upper edge portions of the finishing plate  130  and the end plate  150  using, e.g., screws or bolts. For example, the base frame  121  may be superimposed on the upper flanges  132  and  152  with fastening holes thereof being aligned, and the base frame  121  and the upper flanges  132  and  152  may be fastened to each other using fastening members, e.g., bolts and nuts. Thus, the base frame  121  may make surface contact with at least portions of the upper flanges  132  and  152 . 
     The finishing plate  130  and the end plate  150  (at ends of the array of battery cells  10  in the arrangement direction (directions ±Z1) of the battery cells  10 ) may be supported by the base frame  121 . In addition, the base frame  121  may help maintain a predetermined distance between the finishing plate  130  and the end plate  150 , and thus expansion of the battery cells  10  may be suppressed in the arrangement direction (directions ±Z1) by the finishing plate  130  and the end plate  150 . Therefore, charging and discharging characteristics of the battery cells  10  may not be deteriorated by expansion of the battery cells  10 . 
     The support frames  125  may extend above the top sides of the battery cells  10 , e.g., in directions perpendicular to the base frame  121 , and may be coupled to the side plates  140 . The support frames  125  and the base frame  121  may be monolithically formed in or as one continuous piece. 
     For example, the support frames  125  may include ends connected to the base frame  121 , and other ends extending from the ends and fastened or coupled to the side plates  140 . For example, the ends of the support frames  125  may continuously extend from the base frame  121 , and the other ends of the base frame  121  may be fastened to the side plates  140  using screws. For this, the other ends of the support frames  125  may be bent to form bent portions  125   a  capable of making surface contact with the side plates  140 . 
     The bent portions  125   a  may be brought into contact with the side plates  140  and coupled to the side plates  140 . Coupling members  125   b  may be formed or provided on the bent portions  125   a . For example, the support frames  125  and the side plates  140  may be fastened to each other by aligning the coupling members  125   b  of the bent portions  125   a  with fastening holes of the side plates  140 , inserting fastening members  171  into the fastening holes of the side plates  140 , and coupling the fastening members  171  to the coupling members  125   b . For example, the fastening members  171  may include bolts, and the coupling members  125   b  may include nuts. 
     The support frames  125  may support the side plates  140  at both lateral sides of the battery cells  10  and may maintain a predetermined distance between the side plates  140 . Therefore, lateral expansion of the battery cells  10  may be suppressed, and charging and discharging characteristics of the battery cells  10  may not be deteriorated by lateral expansion of the battery cells  10 . 
     For example, the battery cells  10  may be assembled in a state in which the battery cells  10  are compressed in the arrangement direction (directions ±Z1) by the base frame  121 , the finishing plate  130 , and the end plate  150 . In this case, the battery cells  10  may swell laterally, and as a result, the side plates  140  may be bent outwardly. 
     The support frames  125  may support a plurality of portions of the side plates  140  on lateral sides of the battery cells  10 , the lateral sides of the battery cells  10  may be pushed by the portions of the side plates  140 , and the side plates  140  may not be bent outwardly even though the battery cells  10  swell laterally. Deformation of the battery cells  10  may affect charging and discharging characteristics of the battery cells  10 , and deformation of the battery cells  10  may be reduced and/or prevented as described above to maintain the charging and discharging characteristics of the battery cells  10 . 
     The support frames  125  may provide mechanical stiffness to the battery cells  10  so that the battery cells  10  may resist twisting about their arrangement direction (directions ±Z1) axis. For example, the support frames  125  may support the side plates  140  and maintain the distance between the side plates  140 , and the side plates  140  may have sufficient stiffness to protect the battery cells  10  from twisting. 
     The support frames  125  may include: first support frames  1251  extending from a side of the base frame  121  toward one of the side plates  140  (referred to as a first side plate  141 ); and second support frames  1252  extending from the other side of the base frame  121  toward the other of the side plates  140  (referred to as a second side frame  142 ). In an implementation, the first and second support frames  1251  and  1252  may extend from opposite sides of the base frame  121  and may be alternately arranged and staggered in the length direction (directions ±Z1) of the base frame  121 . 
     One or more reinforcing parts  128  may be formed on the top plate  120 . The reinforcing parts  128  may be formed by attaching parts to the base frame  121  and the support frames  125  for increasing mechanical stiffness of the top plate  120 . 
     The top plate  120  may support the side plates  140  and may maintain the distance between the side plates  140 , expansion of the battery cells  10  may be suppressed, and mechanical stiffness may be added to the battery cells  10  so that the battery cells  10  may resist twisting about their arrangement direction (directions ±Z1) axis. The reinforcing parts  128  may help increase the stiffness of the top plate  120  to reduce and/or prevent swelling or twisting of the battery cells  10 . 
     For example, the reinforcing parts  128  may include first reinforcing parts  128   a  on the base frame  121 , and second reinforcing parts  128   b  across boundaries of the base frame  121  and the support frames  125 . The first reinforcing parts  128   a  may be arranged on the base frame  121  between the openings  121 ′. The first reinforcing parts  128   a  may be elongated in the length direction (directions ±Z1) of the base frame  121  to help increase the lengthwise stiffness of the base frame  121 . 
     The second reinforcing parts  128   b  may extend from the base frame  121  to the support frames  125 . The second reinforcing parts  128   b  may be elongated in the length direction (directions ±Z3) of the support frames  125  to help increase lengthwise stiffness of the support frames  125 . 
     For example, the first and second reinforcing parts  128   a  and  128   b  may be elongated in the length direction (directions ±Z1) of the base frame  121  and the length direction (directions ±Z3) of the support frames  125 , respectively, so as to help increase the lengthwise stiffness of the base frame  121  and the support frames  125 . Therefore, the distances among the finishing plate  130 , the end plate  150 , and the side plates  140  may be kept constant, and swelling or twisting of the battery cells  10  may be reduced and/or prevented. 
       FIG. 8  illustrates a view of an exemplary upper structure of the battery pack. Referring to  FIG. 8 , the battery cells  10  forming the battery pack may be electrically connected to each other through bus bars  15 . For example, the battery cells  10  may be electrically connected in series. Each of the bus bars  15  may electrically connect a pair of the battery cells  10 . The electrode terminals  10   a  of the battery cells  10  may be inserted into or welded to the bus bars  15 . The bus bars  15  may be disposed on the left and right sides when viewed in the directions ±Z3, so as to sequentially connect the battery cells  10  arranged in the arrangement direction (directions ±Z1). 
     The top plate  120  may be disposed on the top sides of the battery cells  10  together with the bus bars  15 . The top plate  120  and the bus bars  15  may be properly arranged to help reduce and/or prevent mechanical/electrical interference. 
     For example, the bus bars  15  may be elongated in a predetermined direction (directions ±Z1) to connect pairs of neighboring battery cells  10 . The support frames  125  of the top plate  120  may be disposed between the bus bars  15  to help reduce and/or prevent interference between the support frames  125  and the bus bars  15 . For example, the first and second support frames  1251  and  1252  extending in opposite directions from the base frame  121  may be alternately arranged and staggered in the length direction (directions ±Z1) of the base frame  121 . The number of the first and second support frames  1251  and  1252  (support frames  125 ) may be determined according to the arrangement or number of the bus bars  15 . 
     The top plate  120  may include guide wires (not shown) extending from the connecting electrode terminals  10   a  of the battery cells  10  or the bus bars  15 . For example, a plurality of wires may extend from the connecting electrode terminals  10   a  or the bus bars  15 . The wires may extend to the outside of the battery pack to transmit information such as voltages or temperatures of the battery cells  10 . 
     For example, ends of the wires may be connected to the connecting electrode terminals  10   a  or the bus bars  15 , and other ends of the wires may be connected to a BMS (not shown) disposed on an outer side of the battery pack. Wire guides  121   a  may be formed on the top plate  120  to collect a plurality of wires and guide the wires. 
     The wire guides  121   a  may be formed on the top plate  120 , for example, on the base frame  121 . For example, the wire guides  121   a  may be formed in one piece with the base frame  121  and may have a ring shape. 
     By way of summation and review, small mobile devices such as cellular phones may be operated for a predetermined time using single-cell secondary batteries. High-output, high-capacity battery packs may be suitable for devices having long operating times and consuming large amounts of power such as electric vehicles and hybrid electric vehicles. Such battery packs may have coupling structures for structurally assembling a plurality of battery cells. 
     The embodiments may provide a battery pack having an improved coupling structure for easily assembling two or more battery cells and achieving sufficient coupling strength. 
     As described above, according to the embodiments, the battery cells may be disposed in the battery pack using the case frame (having an opened end) and the finishing plate coupled to the opened end of the case frame. 
     In addition, according to the embodiments, the finishing plate and the case frame may be easily aligned with each other by using the assembling guides when the finishing plate and the case frame are coupled to each other. 
     Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.