Abstract:
A polymer battery pack assembly comprising a mounting frame having a first cavity defining a first mounting location and a second cavity defining a second mounting location, the first and second cavities being separated from each other; a top case mounted on the second mounting location, the top case having a third cavity defining a third mounting location; a lithium polymer battery cell mounted within the first mounting location, the battery cell having a positive tap and a negative tap extending beyond the first cavity towards the second mounting location; and a protection circuit module mounted in the third mounting location, the protection circuit module being electrically connected to the positive tap and the negative tap when the top case is mounted to the mounting frame such that the protection circuit module fits into said second cavity.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Provisional Patent Application No. 61/362,973 filed in the U.S. Patent and Trademark Office on Jul. 9, 2010, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    One or more embodiments of the present invention relate to a polymer battery pack in which a top case is coupled to a lithium polymer battery cell molded by a mounting frame. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, secondary batteries may be charged or discharged, unlike a primary battery, which may not be charged. Secondary batteries are used as energy sources of small-sized devices, such as a cellular phone, a laptop computer, and a camcorder, and medium-large sized devices such as an electric car, a hybrid electric car, an electric bicycle, and a uninterruptible power supply (UPS). 
         [0006]    A lithium secondary batteries is an example of a secondary battery. The lithium secondary battery may be classified into a can-type secondary battery, which has a cylindrical or square shape according to the shape of a case accommodating an electrode assembly, and a pouch-type secondary battery having flexibility. 
         [0007]    Secondary batteries may be classified into a liquid electrolyte battery and a polymer electrolyte battery according to the type of electrolyte. In general, a battery using a liquid electrolyte is referred to as a lithium ion battery, and a battery using a polymer electrolyte is referred to as a polymer battery. Lithium-ion polymer batteries, polymer lithium ion, or more commonly lithium polymer batteries (abbreviated Li-poly, Li-Pol, LiPo, LIP, PLI or LiP) are rechargeable batteries (secondary cell batteries). 
         [0008]    Many cells sold today as polymer batteries are pouch cells. Unlike lithium-ion cylindrical cells, which have a rigid metal case, pouch cells have a flexible, foil-type (polymer laminate) case. In cylindrical cells, the rigid case presses the electrodes and the separator onto each other; whereas in polymer cells this external pressure is not required because the electrode sheets and the separator sheets are laminated onto each other. 
         [0009]    Since individual pouch cells have no strong metal casing, by themselves they are over 20% lighter than equivalent cylindrical cells. However, all Li-Ion cells expand at high levels of SOC (State of Charge); if uncontained, this may result in delamination, and reduction of reliability and cycle life; the case of cylindrical cells provides that containment, while pouch cells, by themselves, are not contained. Therefore, to achieve the rated performance, a battery composed of pouch cells must include an overall, strong, external casing to retain its shape. 
         [0010]    Conventionally, a battery cell accommodating an electrode assembly is coupled to a protection circuit module (PCM). A top case is installed on the battery cell coupled to the PCM. In addition, the battery cell is inserted into a film-type outer case by using a double-sided tape, and a label is attached on an outer surface of the outer case. A battery pack is manufactured through the above-described processes. 
         [0011]    However, a conventional battery pack requires a large number of processes and causes a severe poor distribution due to a worker. Insert injection process performed during a manufacturing process of a battery pack may affect the PCM and a positive temperature coefficient (PTC) element. 
       SUMMARY OF THE INVENTION 
       [0012]    According to one or more embodiments of the present invention, there is provided a polymer battery pack capable of easily coupling a top case to a lithium polymer battery cell molded by a mounting frame. 
         [0013]    An exemplary embodiment of the present invention provides a polymer type battery having a polymer cell a top case, a frame having a first area for accommodating the polymer cell and a second area for locating the top case wherein the second area is separate from the first area, and first and second engaging elements coupling the top case to the frame. 
         [0014]    The polymer type battery having a protection circuit module located in the top case, and an electrode tap extends from the polymer cell beyond the frame to the protection circuit module. 
         [0015]    The first engaging element having one of a fixing slot or a fixing tab on the top case, and the second engaging element having a correspond one of fixing tab or a fixing slot on the frame, the fixing slot receiving the fixing tab when the top case is coupled to the frame. 
         [0016]    The polymer type battery having a pair of channels formed in opposite end sidewalls of the top case and a corresponding pair of runners disposed in the second area and formed in opposite end sidewalls thereof, the runners slidably engaging the channels when the top case is mounted on frame. 
         [0017]    The first engaging element having a plurality of fixing tabs on the top case, and the second engaging element having a corresponding plurality fixing slots on the frame, the fixing slot receives the fixing tab when the top case is coupled to the frame, the fixing tabs and fixing slots being asymmetrically disposed with respect to a central axis of the top case and frame. 
         [0018]    An exemplary embodiment of the present invention provides a polymer battery pack assembly having a mounting frame having a first cavity defining a first mounting location and a second cavity defining a second mounting location, the first and second cavities being separated from each other; a top case mounted on the second mounting location, the top case having a third cavity defining a third mounting location; a polymer battery cell mounted within the first mounting location, the battery cell having a positive tap and a negative tap extending beyond the first cavity towards the second mounting location; a first engaging member formed in the mounting frame, and a second engaging member formed in the top case; and a protection circuit module mounted in the third mounting location, the protection circuit module being electrically connected to the positive tap and the negative tap when the top case is mounted to the mounting frame such that the protection circuit module fits into said second cavity. 
         [0019]    The polymer battery pack assembly having at least two fixing tabs and at least two corresponding fixing slots, the fixing slots receiving the fixing tabs when the top case is mounted on the second mounting location. The fixing tabs protrude from a sidewall of the second mounting location and the fixing slots are formed in a sidewall of the top case, or alternatively the fixing tabs protrude from a sidewall of the top case and the fixing slots are formed in a sidewall of the second mounting location. 
         [0020]    The polymer battery pack assembly having a pair of channels formed at opposite ends of the second cavity and a corresponding pair of runners slidably engaging said channels when the top case is mounted on the second mounting location. 
         [0021]    The polymer battery pack assembly having first and second reinforcement members formed in a sidewall of the second mounting location, the first and second reinforcement members defining mounting slots for receiving corresponding ones of the positive and a negative taps when the battery cell is mounted within the first mounting location. 
         [0022]    The polymer battery pack assembly having an outer case having a pouch shape to receive the mounting frame, the outer case providing added protection and strength to the batter pack assembly, and a protection film cover for covering and molding the outer case. 
         [0023]    An exemplary embodiment of the present invention provides a mounting frame for a polymer battery pack assembly, the mounting frame having a first mounting location having a first cavity for receiving a battery cell, the battery cell having a positive tap and a negative tap extending beyond the first cavity; a second mounting location having a second cavity, the first and second cavities being separated from each other; a top case for covering the second mounting location, the top case having a third cavity defining a third mounting location for receiving a protection circuit module, when the top case is fixed to the second mounting location the protection circuit module fitting into said second cavity and being electrically connected to the positive tap and the negative tap, and first engaging elements of the top case being coupled to second engaging elements of the frame. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    A more complete appreciation of the present invention, and many of the attendant advantages thereof, will become readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
           [0025]      FIG. 1  is an exploded perspective view illustrating a polymer battery cell, according to an embodiment of the present invention; 
           [0026]      FIG. 2  is an exploded perspective view illustrating a battery pack, according to an embodiment of the present invention; 
           [0027]      FIG. 3  is an exploded perspective view illustrating a part of the battery pack of  FIG. 2 ; 
           [0028]      FIG. 4  is an exploded perspective view illustrating a part of a battery pack, according to another embodiment of the present invention; 
           [0029]      FIG. 5  is an exploded perspective view illustrating a part of a battery pack, according to another embodiment of the present invention; 
           [0030]      FIG. 6  is a plane view illustrating a top case of  FIG. 4 , according to another embodiment of the present invention; and 
           [0031]      FIG. 7  is a plane view illustrating a top case of  FIG. 4 , according to another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0032]    Hereinafter, the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
         [0033]      FIG. 1  is an exploded perspective view illustrating a polymer battery cell  100 , according to an embodiment of the present invention. 
         [0034]    Referring to  FIG. 1 , the polymer battery cell  100  includes an electrode assembly  110  and a pouch  120  for accommodating the electrode assembly  110 . The electrode assembly  110  includes a positive electrode plate  111 , a negative electrode plate  112 , and a separator  113  interposed between the positive electrode plate  111  and the negative electrode plate  112 . 
         [0035]    A positive electrode tap  114  is electrically connected to the positive electrode plate  111  and a positive electrode insulating tape  116  is wound on the positive electrode tap  114 . A negative electrode tap  115  is electrically connected to the negative electrode plate  112  and a negative electrode insulating tape  117  is wound on the negative electrode tap  115 . 
         [0036]    The pouch  120  is a flexible pouch type case. The pouch  120  includes an upper case  121  and a lower case  122  coupled to the upper case  121 . At least one surface of the upper case  121  and at least one surface of the lower case  122  are coupled to each other as one body. The pouch  120  is formed of a triple-layered structure including a metal foil  120   a  and insulating films  120   b  and  120   c  that are attached on opposite sides of the metal foil  120   a , but the present invention is not limited thereto. 
         [0037]    The electrode assembly  110  is disposed in a space portion  123  formed inside the pouch  120 . The positive electrode insulating tape  116  and the negative electrode insulating tape  117  are thermally adhered to a sealing surface  124 . Ends of the positive electrode tap  114  and the negative electrode tap  115  are exposed outside of the pouch  120 . 
         [0038]      FIG. 2  is an exploded perspective view illustrating a battery pack  200 , according to an embodiment of the present invention.  FIG. 3  is an exploded perspective view illustrating a part of the battery pack  200  of  FIG. 2 . 
         [0039]    Like reference numerals in the following description denote like elements in the previous description. 
         [0040]    Referring to  FIGS. 2 and 3 , the battery pack  200  includes the battery cell  100 , an mounting frame  210 , and a top case  220 . 
         [0041]    The battery cell  100  includes the pouch  120  accommodating the electrode assembly  110  (see  FIG. 1 ). The ends of the positive electrode tap  114  and the negative electrode tap  115  are exposed outside of the pouch  120 . The ends of the positive electrode tap  114  and the negative electrode tap  115  are disposed at a side of the top case  220 . Since the pouch  120  is a flexible pouch-type case, after the electrode assembly  110  is accommodated in the pouch  120 , the pouch  120  may be freely folded. 
         [0042]    The battery cell  100  is partially molded by the mounting frame  210 . The mounting frame  210  comprises a first portion  211  covering side walls of the battery cell  100 , a second portion  212  covering an upper end portion of the battery cell  100  corresponding to the exposed ends of the positive electrode tap  114  and the negative electrode tap  115 , and a third portion  213  opposite to the second portion  212  and covering a lower portion of the battery cell  100 . 
         [0043]    The first portion  211 , the second portion  212 , and the third portion  213  are formed as one body forming includes a cavity  10  for receiving the body of the battery cell  100 . The mounting frame  210  including the first portion  211 , the second portion  212 , and the third portion  213  is formed to mold at least a part of an outer surface of the battery cell  100  and is formed by injection-molding using a polymer resin. 
         [0044]    Alternatively, the mounting frame  210  may be formed to entirely mold the battery cell  100 , except for the exposed ends of the positive electrode tap  114  and the negative electrode tap  115 , but the present invention is not limited to any one injection-molded structure. 
         [0045]    At this time, for coupling between the mounting frame  210  and the top case  220 , at least a part of the upper end portion of the battery cell  100  corresponding to the exposed ends of the positive electrode tap  114  and the negative electrode tap  115  may be injection molded. 
         [0046]    A label  230  may be disposed between the outer surface of the battery cell  100  and the mounting frame  210 . The label  230  is adhered to a front surface or a rear surface of the battery cell  100  by using a double-sided tape or an adhesive solvent. The label  230  may preferably be adhered to the outer surface of the battery cell  100  before the mounting frame  210  is disposed on the battery cell  100 . The label  230  is adhered to the outer surface of the battery cell  100  in order to display information about the battery cell  100 . 
         [0047]    A protection circuit module  240  is disposed in a cavity  12  formed in second portion  212  and a cavity  14  formed in the top case  220 , when the top case  220  is mounted on the mounting frame  210 . 
         [0048]    The protection circuit module  240  includes a circuit board  241 , a plurality of electronic elements  242  mounted on the circuit board  241 , and a positive temperature coefficient (PTC) element  243  functioning as a safety element. 
         [0049]    The circuit board  241  includes a printed circuit board (PCB) in which at least one circuit pattern layer is stacked. The electronic elements  242  include an integrated circuit (IC) chip, a field effect transistor (FET), a resistor, a capacitor, etc. 
         [0050]    The positive temperature coefficient (PTC) element  243  includes conductive particles and a polymer. A first metal thin plate  244  is disposed on the positive temperature coefficient (PTC) element  243 , and a second metal thin plate  245  is disposed under the positive temperature coefficient (PTC) element  243 . The first metal thin plate  244  is electrically connected to a first electrode terminal  246  disposed in the circuit board  241 , and the second metal thin plate  245  is electrically connected to the negative electrode tap  115 . Meanwhile, the positive electrode tap  114  is electrically connected to a second electrode terminal  247  disposed in the circuit board  241 . 
         [0051]    In the present invention, the first electrode terminal  246  has a negative electrode, similar to the negative electrode tap  115 , and the second electrode terminal  247  has a positive electrode, similar to the positive electrode tap  114 . However, electrical connections between the electrode taps  114  and  115  and the electrode terminals  246  and  247  may be modified into any of various structures. 
         [0052]    A plurality of external terminals  248  electrically connected to the first electrode terminal  246  and the second electrode terminal  247  are formed on the circuit board  241 . 
         [0053]    The protection circuit module  240  is accommodated in the cavity  14  in the top case  220 . When the protection circuit module  240  is accommodated in the top case  220 , the top case  220  may be coupled to the upper end portion of the second portion  212  of mounting frame  210 . A plurality of external terminal holes  221  through which the external terminals  248  may be exposed are formed in the top case  220 . 
         [0054]    The top case  220  protects the protection circuit module  240  against an external impact and prevents the protection circuit module  240  from being circuit-shorted. As such, the protection circuit module  240  and the top case  220  are coupled to each other so as to be formed as one body. The top case  220  may be formed as a shaped body including a polymer resin such as polycarbonate. 
         [0055]    Meanwhile, the battery cell  100  partially molded by the mounting frame  210  may be installed in an outer case  250  that may protect the battery cell  100  and may reinforce the strength of the battery cell  100 . The outer case  250  may be a pouch to which an adhesive is adhered. In addition, the outer case  250  may be molded by a protection film cover  260 . 
         [0056]      FIG. 3  illustrates the battery pack  200  of  FIG. 1  wherein the mounting frame  210  and the top case  220  in an uncoupled state. 
         [0057]    Referring to  FIG. 3 , the mounting frame  210  is formed on a part of the outer surface of the battery cell  100  and is formed by injection-molding using a polymer resin. The label  230  is interposed between the battery cell  100  and the mounting frame  210 . 
         [0058]    The mounting frame  210  includes the second portion  212 , which is coupled to the top case  220 . The second portion  212  of mounting frame  210  is formed so as to cover the upper end portion of the battery cell  100 , in which ends of the positive electrode tap  114  and the negative electrode tap  115  are exposed. The second portion  212  of mounting frame  210  may be injection-molded together with the first portion  211  covering the side walls of the battery cell  100 . 
         [0059]    The second portion  212  of the mounting frame  210  includes the cavity  12  defined by a bottom portion  214  covering the upper end portion of the battery cell  100 , first side walls  215  extending in a direction perpendicularly to the bottom portion  214  from long side edges of the bottom portion  214 , and second side walls  216  extending in the direction perpendicularly to the bottom portion  214  from short side edges of the bottom portion  214 . 
         [0060]    The first side walls  215  are respectively formed to a predetermined height from the long side edges of the bottom portion  214 , and the height and shape thereof are not limited thereto. The second side walls  216  are respectively formed to a predetermined height from the short side edges of the bottom portion  214 , and the height and shape thereof are not limited thereto. 
         [0061]    A reinforcement portion  217  is formed to protrude in the first side wall  215  that correspond to the positive and negative electrode taps  114  and  115  so that movement of the positive electrode tap  114  and the negative electrode tap  115  is reduced when the ends of the positive electrode tap  114  and the negative electrode tap  115 , which are electrically connected to the electrode assembly  110  (see  FIG. 1 ) of the battery cell  100 , are exposed. 
         [0062]    A plurality of fixing tabs  310  are formed in the first side walls  215 . The fixing tabs  310  are formed to protrude from outer surfaces of the first side walls  215  in a direction (x-axis direction) perpendicular to that in which the battery cell  100  is vertically positioned (y-axis direction). The plurality of fixing tabs  310  are formed in a lengthwise direction (z-axis direction) of the first side walls  215 . The fixing tabs  310  may be formed in both first side walls  215 . 
         [0063]    Although the fixing tabs  310  are formed in the first side walls  215  in the present embodiment, the present invention is not limited thereto. That is, the fixing tabs  310  may be formed in the second side walls  216  or in both the first side walls  215  and the second side walls  216 . 
         [0064]    The fixing tabs  310  formed in one first side wall  215  may be formed symmetrically with those formed in the other first side wall  215 . Alternatively, the fixing tabs  310  may be formed asymmetrically in order to easily determine a coupling orientation when coupling the top case  220  to the fixing tabs  310 . However, the present invention is not limited thereto. That is, the fixing tabs  310  may be alternately formed in vertical and horizontal directions in both the first side walls  215 . 
         [0065]    The top case  220  includes a top portion  222  in which the plurality of external terminal holes  221  are formed, first side walls  223  formed from long side edges of the top portion  222  at right angles toward the battery cell  100 , and second side walls  224  formed from short side edges of the top portion  222  at right angles toward the battery cell  100 . The first side wall  223  and the second side wall  224  extend from edges of the top portion  222  and are formed as one body, but the height and size thereof are not limited thereto. 
         [0066]    A plurality of fixing slots  320  are formed in the first side walls  223  of the top case  220 , wherein the fixing slots  320  may be coupled to the fixing tabs  310 . The fixing slots  320  are formed to correspond to the fixing tabs  310  formed in the first side walls  215  of the mounting frame  210  when the battery cell  100  molded by the mounting frame  210  and the top case  220  are coupled to each other. Thus, in the present invention, the plurality of fixing slots  320  are formed in the first side walls  223  of the top case  220  in a lengthwise direction (z-axis direction) of the first side walls  223 . 
         [0067]    Thus, when the fixing tabs  310  formed in the second side walls  215  of the mounting frame  210  are inserted in a vertical direction (y-axis direction) into the fixing slots  320  formed in the first side walls  223  of the top case  220 , coupling between the battery cell  100  molded by the mounting frame  210  and the top case  220  may be improved. 
         [0068]    Meanwhile, the fixing tabs  310  may be formed by injection-molding using a guide groove when the mounting frame  210  is formed. Similarly, the fixing slots  320  may also be formed using a guide pin. 
         [0069]      FIG. 4  is an exploded perspective view illustrating a part of a battery pack  400 , according to another embodiment of the present invention. 
         [0070]    Hereinafter, only parts related to the main characteristics of the embodiments of the present invention will be mainly described. 
         [0071]    Referring to  FIG. 4 , the battery cell  100  (see  FIG. 1 ) is molded by an outer frame  410  formed by injection-molding using a polymer resin. The outer frame  410  includes a first portion  411  covering the front, rear, and side surfaces of the battery cell  100  and a second portion  412  covering the upper end portion of the battery cell  100 . The second portion  412  of the outer frame  410  is formed to cover the upper end portion of the battery cell  100  in which the ends of the positive electrode tap  114  and the negative electrode tap  115  are exposed. 
         [0072]    The second portion  412  of the outer frame  410  includes a cavity  12  defined by a bottom portion  413  covering the upper end portion of the battery cell  100 , first side walls  414  formed in a direction (y-axis direction) perpendicular to the bottom portion  413  and formed from long side edges of the bottom portion  413 , and second side walls  415  formed in the direction (y-axis direction) perpendicular to the bottom portion  413  and formed from short side portions of the bottom portion  413 . 
         [0073]    A reinforcement portion  417  is formed to protrude in the first side wall  414  that correspond to the positive and negative electrode taps  114  and  115  so that movement of the positive electrode tap  114  and the negative electrode tap  115  is reduced when the ends of the positive electrode tap  114  and the negative electrode tap  115 , which are electrically connected to the electrode assembly  110  (see  FIG. 1 ) of the battery cell  100 , are exposed. 
         [0074]    A plurality of fixing slots  430  may be formed in both first side walls  414  in a lengthwise direction (z-axis direction) of the first side walls  414 . 
         [0075]    The fixing slots  430  formed in one first side wall  414  may be formed symmetrically with those formed in the other first side wall  414 . Alternatively, the fixing slots  430  may be formed asymmetrically in order to easily determine a coupling orientation when coupling the top case  420  to the fixing slots  430 . However, the present invention is not limited thereto. That is, the fixing slots  430  may be alternately formed vertically and horizontally in both the first side walls  414 . 
         [0076]    The top case  420  includes a top portion  422  in which a plurality of external terminal holes  421  are formed, first side walls  423  formed from long side edges of the top portion  422  at right angles toward the battery cell  100 , and second side walls  424  formed from short side edges of the top portion  422  at right angles toward the battery cell  100 . 
         [0077]    A plurality of fixing tabs  440  are formed in the top case  420 , wherein the fixing tabs  440  may be coupled to the fixing slots  430 . The fixing tabs  440  are formed to correspond to the fixing slots  430  formed in the first side walls  414  of the outer frame  410 . The plurality of fixing tabs  440  are formed to extend in a y-axis direction from the first side walls  423  of the top case  420 . 
         [0078]    As described above, the plurality of fixing tabs  440  may be formed asymmetrically with each other so as to corresponding to the fixing slots  430  when the fixing slots  430  are alternately formed in vertical and horizontal directions with respect to the outer frame  410 . For example, as illustrated in  FIG. 6 , a plurality of fixing tabs  640  may be formed asymmetrically with each other in a horizontal direction (central axis line V-V) with respect to a top case  620 . Alternatively, as illustrated in  FIG. 7 , a plurality of fixing tabs  740  may be formed asymmetrically with each other in a vertical direction (central axis line VI-VI) with respect to a top case  720 . 
         [0079]    Referring back to  FIG. 4 , when the fixing tabs  440  are inserted in a vertical direction into the fixing slots  430 , coupling between the battery cell  100  molded by the outer frame  410  and the top case  420  may be improved. 
         [0080]    Meanwhile, the fixing slots  430  may be formed by injection-molding using a guide pin when the outer frame  410  is formed. Similarly, the fixing tabs  440  may also be formed using a mold structure such as a guide groove. 
         [0081]      FIG. 5  is an exploded perspective view illustrating a part of a battery pack  500 , according to another embodiment of the present invention. 
         [0082]    Hereinafter, only parts related to the main characteristics of the embodiments of the present invention will be mainly described. 
         [0083]    Referring to  FIG. 5 , the battery cell  100  (see  FIG. 1 ) is molded by an outer frame  510  formed by injection-molding using a polymer resin. 
         [0084]    The outer frame  510  includes a first portion  511  covering the front, rear, and side surfaces of the battery cell  100  and a second portion  512  covering the upper end portion of the battery cell  100 . The second portion  512  of the outer frame  510  is formed to cover the upper end portion of the battery cell  100  in which the ends of the positive electrode tap  114  and the negative electrode tap  115  are exposed. 
         [0085]    The second portion  512  of the outer frame  510  includes a cavity  12  defined by a bottom portion  513  covering the upper end portion of the battery cell  100 , first side walls  514  formed from long side edges of the bottom portion  513  and formed in a direction perpendicular to the bottom portion  513 , and a second side wall  515  formed from short side edges of the bottom portion  513  and formed in the direction perpendicular to the bottom portion  513 . 
         [0086]    A plurality of channels  530  may be formed in both the second side walls  515  opposite to each other. The channels  530  are formed to a predetermined depth from inlets  515   a  of the second side walls  515  in a thickness direction of the battery cell  100 . The channels  530  may have a tapered shape in which widths thereof decrease toward ends  515   b  from the inlets  515   a  of the second side walls  515 . 
         [0087]    The top case  520  includes a top portion  522  in which a plurality of external terminal holes  521  are formed. A cavity  14  is defined by first side walls  523  formed from long side edges of the top portion  522  at right angles toward the battery cell  100 , and second side walls  524  formed from short side edges of the top portion  522  at right angles toward the battery cell  100 . 
         [0088]    A plurality of runners  540  are formed on side surfaces of the first side walls  523  of the top case  520 , wherein the runners  540  are coupled to the channels  530 . The runners  540  may be formed covered by the second side walls  524  of the top case  520 . The runners  540  may be formed to correspond to the channels  530  formed in the second side walls  515  of the outer frame  510  when the battery cell  100  entirely molded by the outer frame  510  and the top case  520  are coupled to each other. 
         [0089]    The runners  540  may have a shape corresponding to that of the tapered channels  530  when the runners  540  and the channels  530  are to be sliding-coupled to each other. 
         [0090]    Accordingly, when the runners  540  formed on the side surfaces of the first side walls  523  of the top case  520  are inserted into the channels  530  formed in the second side walls  515  of the outer frame  510  in a horizontal direction (z-axis direction), coupling between the battery cell  100  molded by the outer frame  510  and the top case  520  may be improved. 
         [0091]    The channels  530  may have a shape in which widths thereof decrease toward the ends  515   b  from the inlets  515   a  of the second side walls  515 , thereby enabling wedge coupling between the channels  530  and the runners  540 . 
         [0092]    Meanwhile, when the channels  530  and the runners  540  are coupled to each other, in order to further increase the coupling between the battery cell  100  molded by the outer frame  510  and the top case  520 , a plurality of fixing slots  550  may be formed in the first side walls  514  of the second portion  512  of the outer frame  510 , and a plurality of fixing tabs  560  that may be respectively engaged with the fixing slots  550  may be formed on outer surfaces of the first side walls  523  of the top case  520 . 
         [0093]    As such, the plurality of fixing slots  550  are formed in the first side walls  514  of the outer frame  510 , the plurality of fixing tabs  560  are formed on the outer surfaces of the first side walls  523  of the top case  520 , and the fixing slots  550  and the fixing tabs  560  are formed to correspond to each other. 
         [0094]    Thus, when the runners  540  are coupled to the channels  530  in a horizontal direction, the fixing tabs  560  are inserted into the fixing slots  550 , thereby enabling double-coupling between the battery cell  100  entirely molded by the outer frame  510  and the top case  520 . 
         [0095]    The above-described battery pack of the present invention may be simply manufactured. In addition, reliability of the coupling between the battery cell molded by an outer case and a top case may be increased. 
         [0096]    It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.