Abstract:
A rechargeable battery includes an electrode assembly; a case housing the electrode assembly; a cap plate sealing an opening of the case; an electrode terminal that is electrically connected to the electrode assembly and extends through a terminal hole of the cap plate and is oriented outside of the cap plate; and an insulating member that electrically insulates the cap plate and the electrode terminal while supporting the electrode terminal at an outer surface of the cap plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0026027 filed in the Korean Intellectual Property Office on Feb. 24, 2015, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The present invention relates to a rechargeable battery and a rechargeable battery module including the rechargeable battery. 
         [0004]    2. Description of the Related Art 
         [0005]    A rechargeable battery can repeatedly perform charge and discharge, unlike a primary battery. A rechargeable battery of a small capacity is used for a small portable electronic device like a mobile phone or a laptop computer and a camcorder, and a rechargeable battery of a large capacity is used as a power source for driving a motor of a hybrid vehicle and an electric vehicle. 
         [0006]    A rechargeable battery may be used as a single battery cell, as in for a small electronic device, or may be used in a module state in which a plurality of battery cells are electrically connected, as when used for driving a motor. A rechargeable battery module is typically formed by connecting electrode terminals of unit battery cells with a busbar. 
         [0007]    The rechargeable battery has a negative electrode terminal that is connected to a negative electrode of the electrode assembly and a positive electrode terminal that is connected to a positive electrode thereof. When forming a rechargeable battery module, negative and positive electrode terminals of adjacent rechargeable batteries are connected with a busbar. 
         [0008]    In this case, an insulating member that supports negative and positive electrode terminals at an outer surface of a cap plate may be melted or may generate smoke due to a welding heat occurring upon laser welding. Therefore, strength deterioration and an external appearance failure of an insulating member may occur. 
         [0009]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY 
       [0010]    Embodiments of the present invention provide a rechargeable battery being able stably support an electrode terminal that is installed in a cap plate with an insulating member. Further, embodiments of the present invention provide a rechargeable battery module being able to prevent or reduce the likelihood that an insulating member will melt when welding a busbar to an electrode terminal of unit battery cells. 
         [0011]    An exemplary embodiment of the present invention provides a rechargeable battery including: an electrode assembly that charges and discharges a current; a case that houses the electrode assembly; a cap plate that closes and seals an opening of the case; an electrode terminal that is electrically connected to the electrode assembly and that is drawn out to a terminal hole of the cap plate to be disposed outside of the cap plate; and an insulating member that electrically insulates the cap plate and the electrode terminal while partially supporting the electrode terminal at an outer surface of the cap plate. 
         [0012]    The insulating member may be insert injection molded to be integrally provided between the electrode terminal and an outer surface of the cap plate, between the electrode terminal and the terminal hole, and between the electrode terminal and an inner surface of the cap plate. 
         [0013]    The electrode terminal may include: a current collecting portion that is connected to the electrode assembly; a pillar portion that is connected to the current collecting portion to be located at the terminal hole; and a plane portion that is connected to the pillar portion to be extended in a direction receding from the terminal hole. 
         [0014]    The plane portion may face and be separated from an outer surface of the cap plate at both sides of a width direction of the cap plate. 
         [0015]    The insulating member may include: a first insulating portion that encloses the pillar portion at a periphery of the terminal hole and that supports one side of the plane portion; and a second insulating portion that is located at a separated location in a length direction of the cap plate in the first insulating portion to support another side of the plane portion, wherein at both sides of a width direction of the cap plate, a heat avoidance space that avoids welding heat occurring when welding a busbar to the plane portion may be set. 
         [0016]    The insulating member may further include a third insulating portion that is oriented in a length direction of the cap plate to connect the first insulating portion and the second insulating portion and that supports the plane portion. 
         [0017]    The heat avoidance space may be set at both sides of the width direction of the third insulating portion. 
         [0018]    In the width direction, the first insulating portion may be formed in a first width at the adjacent side of the cap plate and may be formed in a second width that is larger than the first width at the adjacent side of the plane portion. 
         [0019]    In the width direction, the second insulating portion may be formed with the same width as the first width. 
         [0020]    In the width direction, the plane portion may be formed in the second width to be supported in the second width in the first insulating portion and be supported in the first width in the second insulating portion to not have support at an outer edge of the second insulating portion. 
         [0021]    The insulating member may include: a first insulating portion that encloses the pillar portion at a periphery of the terminal hole and that supports one side of the plane portion; a second insulating portion that is located at a separated location in a length direction of the cap plate in the first insulating portion to support another side of the plane portion; and a bottom portion that connects the first insulating portion and the second insulating portion at an outer surface of the cap plate, wherein the plane portion may face and be separated from the bottom portion of the insulating member at both sides of a width direction of the cap plate. 
         [0022]    The insulating member may set a heat avoidance space that avoids welding heat occurring when welding a busbar to the plane portion on the bottom portion at both sides of a width direction of the cap plate. 
         [0023]    The insulating member may further include a third insulating portion that is oriented in a length direction of the cap plate on the bottom portion to connect the first insulating portion and the second insulating portion and that supports the plane portion. 
         [0024]    The insulating member may further include a fourth insulating portion that is oriented in the width direction between the first insulating portion and the second insulating portion on the bottom portion to support the plane portion. 
         [0025]    The heat avoidance space may be set at both sides of the width direction of the third insulating portion and may be partitioned by the fourth insulating portion in the length direction. 
         [0026]    In the width direction, the first insulating portion may be formed with a first width at the adjacent side of the cap plate and may be formed with a second width that is larger than the first width at the adjacent side of the plane portion. 
         [0027]    In the width direction, the second insulating portion and the fourth insulating portion may be formed with the same width as the first width. 
         [0028]    In the width direction, the plane portion may be formed with a second width to be supported in a second width in the first insulating portion and be supported with a first width in the second insulating portion and the fourth insulating portion to not have support at an outer edge of the second insulating portion. 
         [0029]    Another embodiment of the present invention provides a rechargeable battery module including: a plurality of unit battery cells that insulate a negative electrode terminal and a positive electrode terminal made of different metals by partially supporting with an insulating member at an outer surface of a cap plate; and a busbar that is made of a clad metal having a negative electrode portion and a positive electrode portion made of the same material as that of the negative electrode terminal and the positive electrode terminal to be connected by welding to the negative electrode terminal and the positive electrode terminal of adjacent unit battery cells, wherein the insulating member sets a heat avoidance space that avoids welding heat occurring when welding the busbar to the negative electrode terminal and the positive electrode terminal at both sides of a width direction of the cap plate. 
         [0030]    The negative electrode terminal and the negative electrode portion may be made of copper to be connected, and the positive electrode terminal and the positive electrode portion may be made of aluminum to be connected. 
         [0031]    According to an exemplary embodiment of the present invention, at an outer surface of a cap plate, when welding a busbar to an electrode terminal of a unit battery cell, an insulating member supporting the electrode terminal can prevent battery components from melting, even if subjected to welding heat. Therefore the insulating member can stably support the electrode terminal with respect to the cap plate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a perspective view illustrating a rechargeable battery according to a first exemplary embodiment of the present invention. 
           [0033]      FIG. 2  is a cross-sectional view illustrating the rechargeable battery taken along line II-II of  FIG. 1 . 
           [0034]      FIG. 3  is a perspective view illustrating an insulating member that is formed at an outer surface of a cap plate in the rechargeable battery of  FIG. 1 . 
           [0035]      FIG. 4  is a cross-sectional view illustrating the insulating member taken along line IV-IV of  FIG. 3 . 
           [0036]      FIG. 5  is a cross-sectional view illustrating the insulating member taken along line V-V of  FIG. 3 . 
           [0037]      FIG. 6  is a partial perspective view illustrating a portion of a rechargeable battery according to a second exemplary embodiment of the present invention. 
           [0038]      FIG. 7  is a cross-sectional view illustrating the rechargeable battery taken along line VII-VII of  FIG. 6 . 
           [0039]      FIG. 8  is a top plan view illustrating a rechargeable battery module to which the rechargeable battery of  FIG. 1  is applied. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    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. 
         [0041]      FIG. 1  is a perspective view illustrating a rechargeable battery according to a first exemplary embodiment of the present invention, and  FIG. 2  is a cross-sectional view illustrating the rechargeable battery taken along line II-II of  FIG. 1 . 
         [0042]    Referring to  FIGS. 1 and 2 , a rechargeable battery  1  according to the first exemplary embodiment includes an electrode assembly  10  that charges and discharges a current, a case  15  that houses the electrode assembly  10 , a cap plate  20  that closes and seals an opening of the case  15 , electrode terminals (hereinafter, for convenience, referred to as “negative and positive electrode terminals  21  and  22 ) that are electrically connected to the electrode assembly  10  and located outside of the cap plate  20 , and insulating members  36  and  37  that electrically insulate the cap plate  20  and the negative and positive electrode terminals  21  and  22 , respectively. 
         [0043]    For example, the electrode assembly  10  is formed by placing a negative electrode  11  and a positive electrode  12  on respective surfaces of a separator  13 , which is an insulator, and by spirally-winding the negative electrode  11 , the separator  13 , and the positive electrode  12  in a jelly roll state. 
         [0044]    The negative electrode  11  and the positive electrode  12  respectively include coated regions  11   a  and  12   a  in which an active material is applied to a current collector made of a metal foil, and uncoated regions  11   b  and  12   b , respectively, that are formed with an exposed current collector because an active material is not applied thereto. 
         [0045]    The uncoated region  11   b  of the negative electrode  11  is formed in an end portion of one side of the negative electrode  11  along the spiral-wound negative electrode  11 . The uncoated region  12   b  of the positive electrode  12  is formed in an end portion of one side of the positive electrode  12  along the spiral-wound positive electrode  12 . The uncoated regions  11   b  and  12   b  are located at opposite end portions of the electrode assembly  10 . 
         [0046]    For example, the case  15  may be formed as an approximate cuboid to provide a space that houses the electrode assembly  10  and an electrolyte solution therein, and may form an opening that connects the outside and an internal space thereof at one surface of the cuboid. The opening enables the electrode assembly  10  to be inserted into the case  15 . 
         [0047]    The cap plate  20  is installed in an opening of the case  15  to close and seal the case  15 . For example, the case  15  and the cap plate  20  may be made of the same material, such as aluminum, and are welded to each other. 
         [0048]    Further, the cap plate  20  has an electrolyte injection opening  29 , a vent hole  24 , and terminal holes H 1  and H 2 . The electrolyte injection opening  29  enables injection of an electrolyte solution into the case  15 . After the electrolyte solution is injected, the electrolyte injection opening  29  is sealed by a seal stopper  27 . 
         [0049]    In order to discharge an internal gas and an internal pressure of the rechargeable battery  1 , the vent hole  24  is closed and sealed with a welded vent plate  25 . When an internal pressure of the rechargeable battery  1  reaches a predetermined pressure, the vent plate  25  is fractured to open the vent hole  24 . The vent plate  25  has a notch  25   a  that induces fracture. 
         [0050]    The negative and positive electrode terminals  21  and  22  are connected to the electrode assembly  10  at one side with the respective insulating members  36  and  37 , penetrate the terminal holes H 1  and H 2  of the cap plate  20 , and are located at the outside of the cap plate  20  at the other side. 
         [0051]    The insulating members  36  and  37  electrically insulate the negative and positive electrode terminals  21  and  22  from the cap plate  20  while partially supporting the negative and positive electrode terminals  21  and  22 , respectively, at an outer surface of the cap plate  20 . 
         [0052]    For example, the insulating members  36  and  37  may be insert injection molded to be integrally formed and connected between the negative and positive electrode terminals  21  and  22  and an outer surface of the cap plate  20 , between the negative and positive electrode terminals  21  and  22  and the terminal holes H 1  and H 2 , and between the negative and positive electrode terminals  21  and  22  and an inner surface of the cap plate  20 . 
         [0053]    Further, the negative and positive electrode terminals  21  and  22  include integrally formed current collecting portions  211  and  221 , pillar portions  212  and  222 , and plane portions  213  and  223  while being insulated from the cap plate  20  to correspond to the insulating members  36  and  37 , respectively. 
         [0054]    For example, because the negative electrode terminal  21  is connected to the negative electrode  11 , the negative electrode terminal  21  may be made of copper forming a current collector of the negative electrode  11 , and because the positive electrode terminal  22  is connected to the positive electrode  12 , the positive electrode terminal  22  may be made of aluminum forming a current collector of the positive electrode  12 . 
         [0055]    The current collecting portions  211  and  221  are welded to the uncoated regions  11   b  and  12   b  of the negative electrode  11  and the positive electrode  12 , respectively, of the electrode assembly  10  within the case  15  to be electrically connected. The pillar portions  212  and  222  are connected to bend to the current collecting portions  211  and  221  and are located at the terminal holes H 1  and H 2  with the insulating members  36  and  37 , respectively, between the pillar portions and the cap plate. The plane portions  213  and  223  are connected to bend to the pillar portions  212  and  222  and are extended and oriented in a direction receding from the terminal holes H 1  and H 2  by interposing the insulating members  36  and  37 , respectively, at the outside of the case  15 . 
         [0056]      FIG. 3  is a perspective view illustrating an insulating member that is formed at an outer surface of a cap plate in the rechargeable battery of  FIG. 1 . For convenience, the negative electrode terminal  21  and the insulating member  36  will be described with reference to  FIG. 3 . 
         [0057]    The plane portion  213  is separated from (i.e., spaced from) an outer surface of the cap plate  20  at both sides of a width direction (y-axis direction) of the cap plate  20  to face an outer surface of the cap plate  20 . In other words, the plane portion  213  is insulated from the insulating member  36  in a portion thereof and is separated in another portion to be insulated from the atmosphere. 
         [0058]      FIG. 4  is a cross-sectional view illustrating the insulating member taken along line IV-IV of  FIG. 3 . Referring to  FIGS. 3 and 4 , the insulating member  36  includes a first insulating portion  361 , a second insulating portion  362 , and a heat avoidance space S 1  according to a corresponding location of the cap plate  20  and the negative electrode terminal  21 . 
         [0059]    The first insulating portion  361  encloses the pillar portion  212  at a periphery of the terminal hole H 1  and supports one side of the plane portion  213 . The second insulating portion  362  is located at a separated location in a length direction (x-axis direction) of the cap plate  20  in the first insulating portion  361  to support the other side of the plane portion  213 . 
         [0060]    The heat avoidance space S 1  may prevent welding heat occurring when welding a busbar  71  (see  FIG. 8 ) to the plane portion  213  at both sides of a width direction (y-axis direction) of the cap plate  20  from affecting the battery structure. The heat avoidance space S 1  is set between outer surfaces of the separated plane portion  213  and cap plate  20  and between the first and second insulating portions  361  and  362 . 
         [0061]      FIG. 5  is a cross-sectional view illustrating the insulating member taken along line V-V of  FIG. 3 . The insulating member  36  further includes a third insulating portion  363 . The third insulating portion  363  is oriented in a length direction (x-axis direction) of the cap plate  20  to connect the first insulating portion  361  and the second insulating portion  362 , and supports the plane portion  213 . 
         [0062]    Therefore, the third insulating portion  363  supports an outer surface of the cap plate  20  and the separated plane portion  213  between the first and second insulating portions  361  and  362  to reinforce support strength of the negative electrode terminal  21  that is weakened due to the heat avoidance space S 1 . 
         [0063]    Due to the third insulating portion  363 , the heat avoidance space S 1  is set at both sides of a width direction (y-axis direction) of the third insulating portion  363 . Therefore, when welding the busbar  71  (see  FIG. 8 ) to the plane portion  213 , welding heat occurring at either side can be avoided at both side heat avoidance spaces S 1  of the third insulating portion  363 . In other words, even when welding heat is generated, the insulating member  36  can be prevented from melting and thus the insulating member  36  can stably support the negative electrode terminal  21  and the plane portion  213 . 
         [0064]    Further, the first insulating portion  361  has a portion that is set with a first width W 1  and a portion that is set with a second width W 2  in a width direction (y-axis direction) of the cap plate  20 . In other words, the first insulating portion  361  is formed with the first width W 1  at the adjacent side of the cap plate  20  and is formed with the second width W 2  that is larger than the first width W 1  at the adjacent side of the plane portion  213 . 
         [0065]    At the adjacent side of the cap plate  20 , the first insulating portion  361  absorbs welding heat that is radiated from an outer surface of the cap plate  20  in the plane portion  213  by a portion that is set with the narrower first width W 1  and thus an influence of welding heat may be reduced. 
         [0066]    The second insulating portion  362  is formed with the same width size as the first width W 1  of the first insulating portion  361  in a width direction (y-axis direction) of the cap plate  20 . Because the second insulating portion  362  absorbs welding heat, an influence of the welding heat may be reduced. 
         [0067]    Further, the plane portion  213  is formed with the second width W 2  in a width direction (y-axis direction) to be supported in the second width W 2  in the first insulating portion  361  and to be supported with the first width W 1  in the second insulating portion  362 . Therefore, the plane portion  213  may not be supported at an outer edge of the second insulating portion  362 . In other words, the second insulating portion  362  may further avoid welding heat of the plane portion  213 . 
         [0068]    Hereinafter, a second exemplary embodiment of the present invention will be described. In the following description, constituent elements identical to or corresponding to those of the first exemplary embodiment will be omitted, and only dissimilar constituent elements will be described. 
         [0069]      FIG. 6  is a partial perspective view illustrating a portion of a rechargeable battery according to a second exemplary embodiment of the present invention, and FIG.  7  is a cross-sectional view illustrating the rechargeable battery taken along line VII-VII of  FIG. 6 . 
         [0070]    Referring to  FIGS. 6 and 7 , in a rechargeable battery  2  according to the second exemplary embodiment, a plane portion  413  faces and is separated from a bottom portion  465  of an insulating member  46  at both sides of a width direction (y-axis direction) of a cap plate  20 . In other words, the plane portion  413  is insulated by the insulating member  46  in a portion and is separated from the bottom portion  465  in another portion to be insulated from the atmosphere. 
         [0071]    For example, the insulating member  46  may include a first insulating portion  461 , a second insulating portion  462 , the bottom portion  465 , and a heat avoidance space S 2  according to a corresponding location of the cap plate  20  and a negative electrode terminal  41 . 
         [0072]    The first insulating portion  461  encloses a pillar portion  212  at a periphery of a terminal hole H 1  and supports one side of the plane portion  413 . The second insulating portion  462  is located at a separated location in a length direction (x-axis direction) of the cap plate  20  in the first insulating portion  461  to support another side of the plane portion  413 . The bottom portion  465  connects the first insulating portion  461  and the second insulating portion  462  at an outer surface of the cap plate  20 . 
         [0073]    The heat avoidance space S 2  may avoid welding heat occurring when welding the busbar  71  (see  FIG. 8 ) to the plane portion  413  at both sides of a width direction (y-axis direction) of the cap plate  20 . The heat avoidance space S 2  is set between the separated plane portion  413  and the bottom portion  465  and between the first and second insulating portions  461  and  462 . 
         [0074]    The insulating member  46  further includes a third insulating portion  463 . The third insulating portion  463  is oriented in a length direction (x-axis direction) of the cap plate  20  on the bottom portion  465  to connect the first insulating portion  461  and the second insulating portion  462 , and further supports the plane portion  413 . 
         [0075]    The insulating member  46  further includes a fourth insulating portion  464 . The fourth insulating portion  464  is oriented in a width direction (y-axis direction) between the first insulating portion  461  and the second insulating portion  462  on the bottom portion  465  to further support the plane portion  413 . 
         [0076]    Therefore, the third and fourth insulating portions  463  and  464  support the bottom portion  465  and the separated plane portion  413  between the first and second insulating portions  461  and  462 , thereby reinforcing support strength of the negative electrode terminal  41  that is weakened due to the heat avoidance space S 2 . 
         [0077]    The heat avoidance space S 2  is set at both sides of a width direction (y-axis direction) of the third insulating portion  463  due to the third insulating portion  463 , and is set at both sides of a length direction (x-axis direction) of the fourth insulating portion  464  due to the fourth insulating portion  464 . 
         [0078]    Therefore, when welding the busbar  71  (see  FIG. 8 ) to the plane portion  413 , welding heat occurring at both sides may be avoided at the heat avoidance space S 2  of both sides of the third and fourth insulating portions  463  and  464 . In other words, even when welding heat is generated, because the insulating member  46  may be prevented from melting, the insulating member  46  can stably support the negative electrode terminal  41  and the plane portion  413 . 
         [0079]    Further, the first insulating portion  461  has a portion having a first width W 21  and a portion having a second width W 22  in a width direction (y-axis direction) of the cap plate  20 . In other words, the first insulating portion  461  is formed with a first width W 21  at the adjacent side of the cap plate  20  and is formed with a second width W 22  that is larger than the first width W 21  at the adjacent side of the plane portion  413 . 
         [0080]    At the adjacent side of the cap plate  20 , by a portion in which the first insulating portion  461  is set to the narrower first width W 21 , because the first insulating portion  461  avoids welding heat that is radiated from an outer surface of the cap plate  20  in the plane portion  413 , an influence of welding heat can be reduced. 
         [0081]    The second and fourth insulating portions  462  and  464  and the bottom portion  465  are formed with the same width size as that of the first width W 21  of the first insulating portion  461  in a width direction (y-axis direction) of the cap plate  20 . Because the second and fourth insulating portions  462  and  464  and the bottom portion  465  avoid welding heat, an influence of the welding heat can be reduced. 
         [0082]    Further, the plane portion  413  is formed with a second width W 22  in a width direction (y-axis direction) to be supported in the second width W 22  in the first insulating portion  461 , and is supported in the first width W 21  in the second and fourth insulating portions  462  and  464 . Therefore, the plane portion  413  has no support at an outer edge of the second and fourth insulating portions  462  and  464 . In other words, the second and fourth insulating portions  462  and  464  and the bottom portion  465  can further avoid welding heat of the plane portion  413 . 
         [0083]      FIG. 8  is a top plan view illustrating a rechargeable battery module to which the rechargeable battery of  FIG. 1  is applied. Referring to  FIG. 8 , a rechargeable battery module of an exemplary embodiment includes unit battery cells  100  that are formed with rechargeable batteries and a busbar  71  that couples the adjacent unit battery cells  100  in series. 
         [0084]    In one embodiment, the busbar  71  is made of a clad metal having a negative electrode portion  711  and a positive electrode portion  712  made of the same material as that of a negative electrode terminal  21  and a positive electrode terminal  22 . For example, the negative electrode portion  711  may be made of copper, and the positive electrode portion  712  may be made of aluminum. Therefore, the busbar  71  is connected to the negative and positive electrode terminals  21  and  22  of the adjacent unit battery cells  100  by laser welding with the negative and positive electrode portions  711  and  712 . 
         [0085]    As shown in the rechargeable battery  1  of the first exemplary embodiment, in the unit battery cell  100 , the heat avoidance space S 1  of the insulating member  36  may allow the insulating member  36  to avoid welding heat occurring when welding the busbar  71  to the negative and positive electrode terminals  21  and  22  at both sides of a width direction of the cap plate  20 . 
         [0086]    In other words, because the insulating member  36  is isolated from an influence of welding heat occurring upon laser welding, the insulating member  36  is not melted or does not generate smoke. Therefore, strength deterioration and an external appearance failure of the insulating member  36  can be prevented. 
         [0087]    While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
       DESCRIPTION OF SYMBOLS 
       [0088]      
         [0000]    
       
         
               
               
             
           
               
                   
               
             
             
               
                 1, 2: rechargeable battery 
                 10: electrode assembly 
               
               
                 11, 12: negative electrode and 
               
               
                 positive electrode 
               
               
                 11a, 12a: coated region 
               
               
                 11b, 12b: uncoated region 
                 13: separator 
               
               
                 15: case 
                 20: cap plate 
               
               
                 21, 41: negative electrode terminal 
               
               
                 22: positive electrode terminal 
               
               
                 24: vent hole 
                 25: vent plate 
               
               
                 25a: notch 
                 27: seal stopper 
               
               
                 29: electrolyte injection opening 
               
               
                 36, 37, 46: insulating member 
               
               
                 71: busbar 
                 100: unit battery cell 
               
               
                 211, 221: current collecting portion 
               
               
                 212, 222, 212: pillar portion 
               
               
                 213, 223, 413: plane portion 
                 361, 461: first insulating portion 
               
               
                 362, 462: second insulating portion 
                 363, 463: third insulating portion 
               
               
                 465: bottom portion 
                 464: fourth insulating portion 
               
               
                 711: negative electrode portion 
               
               
                 712: positive electrode portion 
               
               
                 H1, H2: terminal hole 
                 S1, S2: heat avoidance space 
               
               
                 W1, W21: first width 
                 W2, W22: second width