Abstract:
A busbar module connects a first cell and a second cell adjacent to the first cell, arranged in a first direction and each having first and second electrode terminals spaced apart in a second direction normal to the first direction. The busbar module includes a busbar that electrically connects a first electrode terminal of the first cell and a second electrode terminal of the second cell to each other, and an insulating portion that accommodates the busbar. The busbar includes a first recessed mounting portion, the first recessed mounting portion and a protruding shape of the first electrode terminal having interfitting shapes and a second recessed mounting portion, the second recessed mounting portion and a protruding shape of the second electrode terminal having interfitting shapes, the first and second mounting portions, being slideably coupleable with the first and second electrode terminals.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2014-0012438, filed on Feb. 4, 2014, in the Korean Intellectual Property Office, and entitled: “Busbar Module,” which is incorporated by reference herein in its entirety. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    An aspect relates to a busbar module. 
         [0004]    2. Description of the Related Art 
         [0005]    A power supply device includes a battery cell assembly configured with a plurality of battery cells each having a positive electrode at one end thereof and a negative electrode at the other end thereof. The plurality of battery cells are connected in series to one another so as to obtain a required voltage. 
       SUMMARY 
       [0006]    Embodiments are directed to a busbar module that connects a first cell and a second cell adjacent to the first cell, arranged in a first direction and each having first and second electrode terminals spaced apart in a second direction normal to the first direction. The busbar module includes a busbar that electrically connects a first electrode terminal of the first cell and a second electrode terminal of the second cell to each other, and an insulating portion that accommodates the busbar. The busbar includes a first recessed mounting portion, the first recessed mounting portion and a protruding shape of the first electrode terminal having interfitting shapes and a second recessed mounting portion, the second recessed mounting portion and a protruding shape of the second electrode terminal having interfitting shapes, the first and second mounting portions, being slideably coupleable with the first and second electrode terminals. 
         [0007]    The first and second mounting portions may be slideably coupleable with the first and second electrode terminals in a direction parallel to the second direction. 
         [0008]    The insulating portion may include a spacer that extends between the first cell and the second cell. 
         [0009]    The insulating portion may further include a horizontal member that contacts a top surface of the first cell and a top surface of the second cell between the first electrode terminal of the first cell and the second electrode terminal of the second cell. 
         [0010]    The spacer may extend from the horizontal member to maintain a predetermined interval between the first cell and the second cell. 
         [0011]    The spacer may include at least one through-hole that extends through the spacer from an outside of the first cell and the second cell to a space between the first cell and the second cell defined by the predetermined interval. 
         [0012]    The spacer may include at least one through-groove that extends on an outer surface of the spacer from an outside of the first cell and the second cell to an space between the first cell and the second cell defined by the predetermined interval. 
         [0013]    The spacer may be positioned between the first mounting portion and the second mounting portion. 
         [0014]    The first mounting portion may be slideably coupleable with a side of the first electrode terminal that is farthest from the second electrode terminal. The second mounting portion may be slideably coupleable with a side of the second electrode terminal that is farthest from the first electrode terminal. 
         [0015]    The first mounting portion may include a first guide portion that slidingly engages a first guide groove at the side of the first electrode terminal. The second mounting portion may include a second guide portion that slideably engages a second guide groove at the side of the second electrode terminal. 
         [0016]    The busbar may further include a stopping portion at an end of at least one of the first mounting portion and the second mounting portion to limit sliding of the first guide portion relative to the first guide groove and sliding of the second guide portion relative to the second guide groove. 
         [0017]    At least one surface of the first guide portion or the second guide portion may include a plurality of fixing projections. 
         [0018]    The insulating portion may include a covering portion that covers an outer surface of the busbar. 
         [0019]    The busbar may be in an accommodating groove between the covering portion and the horizontal member. 
         [0020]    Embodiments are also directed to a battery module including at least a first cell and a second cell arranged in a first direction, the first cell and the second cell each having first and second electrode terminals, spaced apart in a second direction, and a busbar module connecting a first electrode terminal of the first cell and a second electrode terminal of the second cell. The busbar module includes a busbar that electrically connects a first electrode terminal of the first cell and a second electrode terminal of the second cell to each other and an insulating portion coupled with the busbar, the insulating portion including a spacer that extends between the first cell and the second cell. 
         [0021]    The first electrode terminal may include a first guide groove at a side of the first electrode terminal facing away from the second electrode terminal, the first guide groove extending in a second direction, the second direction being perpendicular to the first direction and parallel to a top surface of the first cell. The second electrode terminal may include a second guide groove at a side of the second electrode terminal facing away from the first electrode terminal, the second guide groove extending in the second direction. The busbar may include a first mounting portion including a first concave portion having a first guide portion that slidingly engages first guide groove, and a second mounting portion including a second concave portion having a second guide portion that slidingly engages second guide groove, such that the busbar module is slidingly coupleable with the first cell and the second cell by sliding the busbar in the second direction. 
         [0022]    The insulating portion may further include a horizontal member that extends in the first direction between the first electrode terminal of the first cell and the second electrode terminal of the second cell and contacts the top surface of the first cell and the top surface of the second cell. 
         [0023]    The spacer may extend from the horizontal member in a third direction perpendicular to the first direction and the second direction to maintain a predetermined interval between the first cell and the second cell. 
         [0024]    Embodiments are also directed to a busbar module including a busbar including a first recessed mounting portion and a second recessed mounting portion spaced apart at bottom thereof, and an insulating portion coupled with the busbar, the insulating portion including a spacer that extends downwardly in a direction away from the bottom of the busbar, the spacer being made of an insulating material. 
         [0025]    The busbar may be made of a conductive material and may include guide portions at ends of the bottom of the busbar and a middle portion between the first and second recessed mounting portions, the middle portion being stepped from the first and second recessed mounting portions. The insulating portion may include an upper insulating portion that covers a top surface of the busbar and a lower insulating portion that covers the middle portion of the bottom of the busbar, the spacer extending from the lower insulating portion. The spacer may include at least one through-hole that extends through the spacer or at least one through-groove that extends on an outer surface of the spacer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    Features will become apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which: 
           [0027]      FIGS. 1A and 1B  illustrate perspective views showing states before and after a busbar module is mounted to battery cells according to an embodiment. 
           [0028]      FIG. 2  illustrates a perspective view of the busbar module according to the embodiment. 
           [0029]      FIG. 3  illustrates an exploded perspective view of the busbar module according to the embodiment. 
           [0030]      FIG. 4  illustrates a perspective view of the busbar module viewed from the bottom according to the embodiment. 
           [0031]      FIG. 5  illustrates an exploded perspective view of the busbar module viewed from the bottom according to the embodiment. 
           [0032]      FIG. 6  illustrates a partial enlarged view showing the state in which the busbar module is mounted to the cells according to the embodiment. 
           [0033]      FIG. 7  illustrates a left side view showing the state in which the busbar module is mounted to the cells according to the embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    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. 
         [0035]    In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout. 
         [0036]    Generally, a secondary battery has a structure in which an electrode assembly formed by winding a positive electrode, a negative electrode and a separator in a jelly-roll shape is inserted inside a case through an opening of the case, and the opening is covered with a cap assembly. 
         [0037]    A collector plate is mounted at an end portion of the electrode assembly. The collector plate is electrically connected to a terminal unit provided to the cap assembly. 
         [0038]    If an external terminal is connected to the terminal unit of the cap assembly, current generated in the electrode assembly is supplied to the external terminal via the collector plate and the terminal unit of the cap assembly. 
         [0039]      FIGS. 1A and 1B  illustrate perspective views showing states before and after a busbar module  100  is mounted to battery cells  10  and  20  according to an embodiment. 
         [0040]      FIG. 2  illustrates a perspective view of the busbar module  100  according to the embodiment.  FIG. 3  illustrates an exploded perspective view of the busbar module  100  according to the embodiment.  FIG. 4  illustrates a perspective view of the busbar module  100  viewed from the bottom according to the embodiment.  FIG. 5  illustrates an exploded perspective view of the busbar module  100  viewed from the bottom according to the embodiment. 
         [0041]    As shown in  FIGS. 1 to 5 , the busbar module  100  according to this embodiment includes electrically connects first and second cells  10  and  20  to each other, and includes a busbar  110  and an insulating portion  120 . 
         [0042]    The cell  10  or  20  may include various types of battery cells, e.g., a primary battery, a secondary battery, or the like. Herein, it is assumed that, for convenience of illustration, the cell  10  or  20  is a secondary battery. The cell  10  or  20  may include various secondary batteries including a lithium secondary battery. 
         [0043]    The first cell  10  may include an electrode assembly and electrode terminals  11  and  12 , and the second cell  20  may include an electrode assembly and electrode terminals  21  and  22 . 
         [0044]    The electrode assembly may include a positive electrode, a separator, and a negative electrode. The electrode assembly may be accommodated in the cell  10  or  20  in a state in which the electrode assembly is formed as a winding type or stacking type. 
         [0045]    The electrode terminals  11  and  12  or  21  and  22  may be connected to the electrode assembly inside the cell, to provide a path through which the cell is electrically connected to an outside. 
         [0046]    Hereinafter, it is assumed that, for convenience of illustration, the first cell  10  includes a (1-1)-th electrode terminal  11  and a (1-2)-th electrode terminal  12 , and the (1-1)-th and (1-2)-th electrode terminals  11  and  12  are respectively positive and negative electrodes. Similarly, it is assumed that the second cell  20  includes a (2-1)-th electrode terminal  21  and a (2-2)-th electrode terminal  22 , and the (2-1)-th and (2-2)-th electrode terminals are respectively positive and negative electrodes. 
         [0047]    As shown in  FIG. 1 , the plurality of battery cells  10  and  20  may be arranged in a predetermined direction while facing each other. The cells  10  and  20  may be electrically connected to each other. 
         [0048]    The plurality of battery cells  10  and  20  may be connected in series or parallel to each other. In order to perform a serial connection, as shown in  FIG. 1 , the electrode terminals  11 ,  12 ,  21  and  22  of the cells  10  and  20  may be arranged so that the positive and negative electrodes alternately cross each other. 
         [0049]    For example, in order to perform the serial connection of the first and second cells  10  and  20 , the (1-1)-th electrode terminal  11  of the first cell  10  and the (2-2)-th electrode terminal  22  of the second cell  20  may be connected to each other through the busbar module  100 . 
         [0050]    Hereinafter, the case where the first and second cells  10  and  20  are arranged while facing each other and connected in series by the busbar module  100  will be mainly described. 
         [0051]    As described above, in order to perform the serial connection of the first and second cells  10  and  20 , the (1-1)-th electrode terminal  11  of the first cell  10  and the (2-2)-th electrode terminal  22  of the second cell  20  may be electrically connected to each other. 
         [0052]    To this end, the busbar  110  according to this embodiment is formed in the shape of a plate made of a conductive material. The busbar  110  may include a first mounting portion  111  mounted on the (1-1)-th electrode terminal  11 , and a second mounting portion  112  mounted on the (2-2)-th electrode terminal  22 . 
         [0053]    The mounting portion  111  or  112  may have a shape corresponding to that of the electrode terminal  11  or  22  so as to be stably mounted on the electrode terminal  11  or  22 . For example, the mounting portion  111  or  112  may have a concave shape that can be engaged with the convex electrode terminal  11  or  22 . 
         [0054]    As shown in  FIGS. 1 to 5 , a (1-1)-th guide groove  11 - 1  that extends in the width direction of the cell  10  may be formed in one surface of the (1-1)-th electrode terminal  11  of the first cell  10 . The busbar  110  may include a first guide portion  113  that protrudes inside the first mounting portion  111  to be slidingly fastened to the (1-1)-th guide groove  11 - 1 . 
         [0055]    Symmetrically, a (2-2)-th guide groove  22 - 1  that extends in the width direction of the cell  20  may be formed in one surface of the (2-2)-th electrode terminal  22  of the second cell  20 . The busbar  110  may include a second guide portion  114  that protrudes inside the second mounting portion  112  to be slidingly fastened to the (2-2)-th guide groove  22 - 1 . 
         [0056]    For example, the busbar module  100  according to this embodiment connects the (1-1)-th electrode terminal  11 , which is the positive electrode of the first cell  10 , and the (2-2)-th electrode terminal  22 , which is the negative electrode of the second cell  20 , to each other in order to achieve the serial connection of the plurality of cells  10  and  20 . The cells  10  and  20  may be connected in series to each other in such a manner that the mounting portions  111  and  112  are mounted on the electrode terminals  11  and  22  through the guide portions  113  and  114  slidingly fastened to the guide grooves  11 - 1  and  22 - 1  formed in the electrode terminals  11  and  22 , respectively. 
         [0057]    As shown in  FIGS. 1 to 5 , the busbar module  100  may be preferably inserted in the direction (arrow direction) in which the guide portions  113  and  114  are slidingly fastened to the guide grooves  11 - 1  and  22 - 1 , respectively. If the busbar module  100  were to be inserted in the opposite direction, the fastening may not be relatively easy due to interference with the other electrode terminals  12  and  21 . 
         [0058]    The busbar  110  may further include a stopping portion  115  or  116  formed at an end of the mounting portion  111  or  112  such that the sliding fastening of the guide portion  113  or  114  to the guide groove  11 - 1  or  22 - 1  is halted. For example, the stopping portion  115  or  116  may be formed in a step shape at the end of the mounting portion  111  or  112 . 
         [0059]    As the front end of the mounting portion  111  or  112  approaches to the electrode terminal  11  or  22 , the guide portion  113  or  114  may be slidingly fastened to the guide groove  11 - 1  or  22 - 1 . The sliding fastening may be halted by the stopping portion  115  or  116  positioned at the end of the mounting portion  111  or  112 . 
         [0060]      FIG. 6  illustrates a partial enlarged view showing the state in which the busbar module  100  is mounted to the cells  10  and  20  according to the embodiment. As shown in  FIG. 6 , fixing projections  117  and  118  may be respectively formed on the guide portions  113  and  114  of the busbar  110 . 
         [0061]    Accordingly, after the guide portions  113  and  114  are slidingly fastened to the respective guide grooves  11 - 1  and  22 - 1 , the arbitrary separation of the busbar module  100  may be prevented. 
         [0062]    As shown in  FIG. 6 , fixing projections protruding into the guide grooves  11 - 1  and  22 - 1  may be formed on the electrode terminals, corresponding to the fixing projections  117  and  118  of the guide portions  113  and  114 , respectively. The fixing projections may enable the busbar module  100  to be more firmly fixed to the electrode terminals. 
         [0063]    An additional battery cell may be arranged in parallel to the first and second cells in order to increase power. When a third cell is additionally arranged while facing the second cell  20 , the (2-1)-th electrode terminal  21  of the second cell  20  may be connected to a (3-2)-th electrode terminal that is a negative electrode of the third cell in order to achieve the serial connection of the second and third cells. 
         [0064]    The busbar module may also be applied to the serial connection of the second and third cells. A busbar module may connect the cells in series to each other by being mounted on the electrode terminals of the second and third cells through the guide portions slidingly fastened to the guide grooves formed in the second and third cells. 
         [0065]    The busbar module for connecting the second cell  20  and the third cell to each other may be configured identically to the busbar module  100  for connecting the first and second cells  10  and  20  to each other, except the inserting direction of the busbar module (not shown) may be changed to be opposite to that of the busbar module  100 . Accordingly, a detailed description thereof will not be repeated. 
         [0066]    As described above, the busbar  110  according to this embodiment provides a sliding fastening method through the guide portions  113  and  114  respectively corresponding to the guide grooves  11 - 1  and  22 - 1  formed in the electrode terminals  11  and  22 . 
         [0067]    Accordingly, it may possible to perform a convenient serial connection between cells without any problem of deterioration of weldability between different kinds of metals. 
         [0068]    As shown in  FIGS. 1 to 5 , the insulating portion  120  according to this embodiment may have an accommodating groove  122  for accommodating the busbar  110 . 
         [0069]    The accommodating groove  122  may have a shape corresponding to the busbar  110 , and the busbar  110  may be accommodated in insulating portion  120  by being inserted into the accommodating groove  122  previously formed in the insulating portion  120 . According to another implementation, the busbar  110  may be accommodated in the insulating portion  120  by an insert injection method. 
         [0070]    The insulating portion  120  may be made of an insulative material, to prevent electricity flowing through the busbar  110  from being flowed therethrough. The busbar  110  may be coupled to the electrode terminals  11  and  22  in a state in which the busbar  110  is accommodated in the accommodating groove  122  formed in the insulating portion  120 . 
         [0071]    The insulating portion  120  may perform not only a function of insulating the busbar  110  but also a function of facilitating the coupling between the busbar  110  and the electrode terminals  11  and  22 . 
         [0072]    The insulating portion  120  according to this embodiment may include a horizontal member  124  and a spacer  126 , which align the first and second cells  10  and  20  connected in series to each other. 
         [0073]      FIG. 7  illustrates a left side view showing the state in which the busbar module  100  is mounted to the cells  10  and  20  according to the embodiment. As shown in  FIG. 7 , the horizontal member  124  may be formed to extend downward from the insulating portion  120  and may guide the horizontal alignment of the cells. The horizontal member  124  may be formed in a step shape to contact the top surfaces of the first and second cells  10  and  20 . 
         [0074]    When the busbar module  100  is mounted to the electrode terminals  11  and  22  of the cells  10  and  20 , the horizontal member  124  may contact the top surface of the first cell  10 , on which the (1-1)-th electrode terminal  11  is placed, and the top surface of the second cell  20 , on which the (2-2)-th electrode terminal  22  is placed, to allow the heights of the first and second cells  10  and  20  to be equally maintained, thereby guiding the horizontal alignment of the cells. 
         [0075]    As shown in  FIGS. 1 to 7 , the horizontal member  124  may be positioned between the first and second mounting portions  111  and  112  of the busbar  110 . The horizontal member  124  may be flat. 
         [0076]    The spacer  126  may be formed to extend vertically downward from the horizontal member  124 . The spacer  126  may maintain a predetermined interval between the cells  10  and  20  connected in series to each other. 
         [0077]    The spacer  126  may be formed to extend downward from the horizontal member  124 , to be positioned between the first and second mounting portions  111  and  112  of the busbar  110 . When the busbar module  100  is mounted to the electrode terminals  11  and  22  of the cells  10  and  20 , the spacer  126  may contact one surface of the first cell  10  and one surface of the second cell  20 , to ensure a desired distance between the cells. 
         [0078]    A desired spacing distance between the cells  10  and  20  may be ensured by the spacer  126 , such that ventilation may be smoothly made between the cells. 
         [0079]    In order to allow the ventilation between the cells to be more smoothly made, as shown in  FIG. 7 , through-holes  1262  extending in the width direction of the cell may be formed inside the spacer  126 , and through-grooves  1264  extending in the width direction of the cell may also be formed on an outer surface of the spacer  126 . 
         [0080]    The horizontal member  124  and the spacer  126 , which constitute the insulating portion  120 , may be integrally formed of the same insulative material. The busbar  110 , as described above, may be accommodated in the integrally formed insulating portion  120  by the insert injection method. 
         [0081]    Although it has been described in this embodiment that, for convenience of illustration, the horizontal member  124  for guiding the horizontal alignment of the cells contacts the top surfaces of the first and second cells, and the spacer  126  for maintaining the interval between the cells contacts one surface of the first and second cells, in other implementations, the contact may be temporarily made as the busbar module  100  is slidingly fastened to the electrode terminals  11  and  22 , and at least one of the horizontal member  124  and the spacer  126  may not contact the cells at the time when the sliding fastening of the busbar module  100  is finished. 
         [0082]    By way of summation and review, serial connection of battery cells in a battery cell assembly may be performed through use of a separate connecting member. The positive electrode of any one of a pair of battery cells adjacent to each other in the battery cell assembly may be connected to the negative electrode of the another battery cell through the connecting member. However, the use of a connecting member may involve an inconvenient process for assembling the power supply device. 
         [0083]    For example, a terminal unit of a cap assembly may include positive and negative electrode terminals connected to a collector plate, a terminal plate coupled to the positive and negative electrode terminals to connect a busbar to the positive and negative electrode terminals, and the like. The coupling between the positive (or negative) electrode terminal and the terminal plate or the coupling between the terminal plate and the busbar may be performed through laser welding. 
         [0084]    However, the positive and negative electrode terminals are generally made of different metals from each other. Hence, if the terminal plate is made of any one of the two different metals, the portion at which the welding between the different kinds of metals is performed may have low weldability, and therefore, the bonding strength at the portion may be relatively weakened. 
         [0085]    For example, the positive electrode terminal may be made of aluminum, and the negative electrode terminal may be made of copper. If the terminal plate is made of any one of the aluminum and the copper, the terminal plate is made of a material different from that of any one of the positive and negative electrode terminals, and the portion at which the welding between the different kinds of metals is performed may have a different melting point. Therefore, the weldability at the portion may be deteriorated through general laser welding. 
         [0086]    Similarly, when terminal plates are respectively made of metals equal to those of the positive and negative electrode terminals, the weldability between each terminal and the corresponding terminal plate can be improved. However, when a busbar for connecting between the terminal plates is welded, the deterioration of the weldability between the different kinds of metals may occur in at least one portion. 
         [0087]    In order to prevent the deterioration of the weldability between the different kinds of metals, a nut fastening method may be considered. However, the nut fastening method causes an increase in the number of processes. 
         [0088]    In addition, when a busbar made of aluminum or copper is exposed to an outside, there exists a risk in terms of safety. 
         [0089]    In contrast, the embodiments provide a busbar module that may perform a convenient serial connection between cell terminals without any problem of deterioration of weldability between different kinds of metals and that may prevent in advance the occurrence of a safety accident due to the external exposure of the busbar. 
         [0090]    As described above, the insulating portion according to embodiments may prevent in advance the occurrence of a safety accident caused by the external exposure of the busbar, and may guide the fastening of the busbar  110  to the electrode terminals. In addition, it may be possible to increase a cooling effect through the horizontal alignment of the cells and through the smooth ventilation between the cells. 
         [0091]    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 as set forth in the following claims.