Abstract:
A bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including a bus bar holder plate having an opening in a lengthwise direction thereof and configured such that at least some electrode terminals of the plurality of batteries are extendable through the opening and slidable along the opening; and a bus bar for electrically connecting at least two electrode terminals of adjacent batteries, wherein the bus bar holder plate includes a settling groove in which the bus bar is settled, and the bus bar attached to the electrode terminals is slidable when the electrode terminal slides along the opening.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This is a divisional application based on pending application Ser. No. 12/801,765, filed Jun. 24, 2010, the entire contents of which is hereby incorporated by reference. 
         [0002]    Korean Patent Application No. 10-2009-0104311, filed on Oct. 30, 2009, in the Korean Intellectual Property Office, and entitled: “Bus Bar Holder,” is incorporated by reference herein in its entirety. 
     
    
     BACKGROUND 
       [0003]    1. Field 
         [0004]    Embodiments relate to a bus bar holder. 
         [0005]    2. Description of the Related Art 
         [0006]    Due to the increased use of gasoline vehicles, vehicle exhaust gases, which include various harmful substances e.g., nitrogen oxides, carbon monoxide due to incomplete combustion, hydrocarbon, etc., have created a very serious pollution problem. Furthermore, due to the steady depletion of fossil fuels, much research has been conducted on the development of next-generation energy sources and electric-powered vehicles. In this regard, traveling distances of an electric-powered vehicle depend on the performance of its battery. A battery may not be able to supply enough electric energy to guarantee that an electric-powered vehicle travels a sufficient distance. In the case of a vehicle that uses a fossil fuel, e.g., gasoline, light oil, or gas, the vehicle may be quickly resupplied with fuel at a gas station. However, in the case of an electric-powered vehicle, a significant amount of time may be required to recharge a battery, even if recharge stations are established. The time elapsed for charging a battery is a problem that has to be solved for commercialization of electric-powered vehicles. Therefore, improvement of battery performance is considered as the most important issue in relation to the development of electric-powered vehicles. 
       SUMMARY 
       [0007]    Embodiments are directed to a bus bar holder, which represents advances over the related art. 
         [0008]    It is a feature of an embodiment to provide a bus bar holder having improved connectivity with respect to electrodes of a battery having predetermined tolerances. 
         [0009]    At least one of the above and other features and advantages may be realized by providing a bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including a bus bar holder plate having an opening in a lengthwise direction thereof and configured such that at least some electrode terminals of the plurality of batteries are extendable through the opening and slidable along the opening; and a bus bar for electrically connecting at least two electrode terminals of adjacent batteries, wherein the bus bar holder plate includes a settling groove in which the bus bar is settled, and the bus bar attached to the electrode terminals is slidable when the electrode terminal slides along the opening. 
         [0010]    The opening may be a single opening through which the electrode terminals are extendable through and slidable along the opening. 
         [0011]    The opening may be configured to correspond to the electrode terminals, the opening having a predetermined length, for slidability of an electrode terminal, and the length of the opening being proportional to a distance from a reference point to the opening. 
         [0012]    The opening may have a length proportional to a summed value of tolerances t of the batteries. 
         [0013]    The settling groove may extend in the lengthwise direction of the bus bar holder plate and may correspond to the opening. 
         [0014]    The bus bar holder plate may include an insulator, and the bus bar may include holes through which the electrode terminals extend. 
         [0015]    At least one of the above and other features and advantages may also be realized by providing a bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including bus bars for electrically connecting at least two electrode terminals of the plurality of batteries; a plurality of unit bus bar holders, the unit bus bar holders being between the bus bars and the batteries, having holes through which the electrode terminals are extendable to be attached to the bus bars, and having settling grooves in which the bus bars are settled; and a bus bar holder plate including an opening in which the plurality of unit bus bar holders are slidable in a lengthwise direction along sliding grooves, the sliding grooves being disposed in inner surfaces of the bus bar holder plate. 
         [0016]    The opening of the bus bar holder plate may have a length sufficient for the plurality of unit bus bar holders to slide. 
         [0017]    The bus bar holder may further include elastic members interposed between adjacent unit bus bar holders. 
         [0018]    At least one of the above and other features and advantages may also be realized by providing a bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including bus bars for electrically connecting at least two adjacent electrode terminals of the plurality of batteries; a plurality of unit bus bar holders, the unit bus bar holders being between the bus bars and the batteries, including holes through which the electrode terminals are extendable for attaching to the bus bars, and including settling grooves in which the bus bars are settled; and a length adjuster interposed between adjacent the unit bus bar holders. 
         [0019]    The length adjuster may have an elastic bellows structure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    The above and other features and advantages will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which: 
           [0021]      FIG. 1  illustrates a perspective view of a bus bar holder attached to a battery module according to an embodiment; 
           [0022]      FIG. 2  illustrates an exploded perspective view of the structure shown in  FIG. 1 ; 
           [0023]      FIG. 3  illustrates a sectional view taken along a line of  FIG. 2 ; 
           [0024]      FIG. 4  illustrates an exploded perspective view of a bus bar holder attached to a battery module according to another embodiment; 
           [0025]      FIG. 5  illustrates a sectional view taken along a line V-V′ of  FIG. 4 ; 
           [0026]      FIG. 6  illustrates an exploded perspective view showing a bus bar holder attached to a battery module according to yet another embodiment; 
           [0027]      FIG. 7  illustrates a sectional view taken along a line VII-VII′ of  FIG. 6 ; 
           [0028]      FIG. 8  illustrates a sectional view taken along a line VIII-VIII′ of  FIG. 6 ; 
           [0029]      FIG. 9  illustrates a modification of the embodiment shown in  FIG. 6 ; 
           [0030]      FIG. 10  illustrates a plan view of  FIG. 9 ; 
           [0031]      FIG. 11  illustrates an exploded perspective view of a bus bar holder attached to a battery module according to still another embodiment; and 
           [0032]      FIG. 12  illustrates a plan view of the bus bar holder shown in  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Korean Patent Application No. 10-2009-0104311, filed on Oct. 30, 2009, in the Korean Intellectual Property Office, and entitled: “Bus bar Holder,” is incorporated by reference herein in its entirety. 
         [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 the scope of the invention to those skilled in the art. 
         [0035]    In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another element, it can be directly on the other element, or intervening elements may also be present. In addition, it will also be understood that when an element is referred to as being “between” two elements, it can be the only element between the two elements, or one or more intervening elements may also be present. Like reference numerals refer to like elements throughout. 
         [0036]    Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. 
         [0037]    Referring to  FIGS. 1 through 3 , a bus bar holder  101  according to an embodiment will be described below.  FIG. 1  illustrates a perspective view of the bus bar holder  101  attached to a battery module  1  according to an embodiment.  FIG. 2  illustrates an exploded perspective view of the structure shown in  FIG. 1 .  FIG. 3  illustrates a sectional view taken along a line of  FIG. 2 . The bus bar holder  101  may be interposed between bus bars  110  and the battery module  1 . 
         [0038]    The battery module  1  may include a plurality of batteries  10 , a top plate  20 , a bottom plate  30 , side plates  40 , and end plates  50 . The batteries  10  may be various types of batteries, e.g., primary batteries or secondary batteries. For convenience of explanation, it is assumed below that the batteries  10  are secondary batteries, e.g., lithium secondary batteries. However, the batteries  10  may be other types of secondary batteries. 
         [0039]    The secondary battery  10  may include an electrode assembly (not shown) and an electrode terminal  12 . The electrode assembly may include a negative electrode (not shown), a separator (not shown), and a positive electrode (not shown), and may have a wound structure or stacked structure. The electrode assembly may be housed in the secondary battery  10  and the electrode terminal  12  may be used for electrical connection to an external device. The secondary batteries  10  may be arranged next to each other in a predetermined direction and may be electrically connected to each other in parallel or in series. When connected in series, the secondary batteries  10  may be arranged so that the negative electrode of one secondary battery  10  contacts the positive electrode of an adjacent secondary battery  10 . The electrode terminals  12  of the secondary batteries  10  may be connected to each other via the bus bars  110 . 
         [0040]    In the secondary battery  10 , the electrode assembly may expand or contract during charging and discharging. The expansion and contraction of the electrode assembly may act as a physical force on the secondary battery  10 . Thus, a sealing assembly accommodating the electrode assembly may physically expand or contract according to the physical deformations of the electrode assembly. Due to repeated expansions and contractions, the secondary battery  10  may be permanently deformed; and an increase in volume of the secondary battery  10  may increase the electrical resistance thereof. Thus, the efficiency of the secondary battery  10  may be deteriorated. Therefore, the end plates  50  may be arranged at both ends of the plurality of second batteries  10 ; and the side plates  40  may be connected to the side ends of the end plates  50  to firmly fix the plurality of secondary batteries  10 , to prevent the plurality of secondary batteries  10  from expanding/contracting in the lengthwise direction. 
         [0041]    The top plate  20  may be disposed on top of the plurality of secondary batteries  10  and may be connected to the top ends of the end plates  50 . The bottom plate  30  may be disposed below the plurality of secondary batteries  10  to support the secondary batteries  10  and may be connected to the bottom end of the end plates  50 . 
         [0042]    The bus bar  110  may electrically connect at least two electrode terminals  12  of neighboring batteries  10 . The bus bar  110  may contain a metal. Holes  110   a  through which the electrode terminals  12  are to be inserted may be formed in the bus bar  110 ; and attaching units  120  may correspond to the holes  110   a . In other words, the electrode terminals  12  inserted through the holes  110   a  in the bus bar  110  may be attached to the attaching units  120 . Thus, the bus bar  110  and the electrode terminals  12  may be attached to each other. The attaching units  120  may be screws or nuts attached to the electrode terminals  12 . 
         [0043]    The bus bar holder  101  may be interposed between the bus bar  110  and the electrode terminals  12 . The bus bar holder  101  may include an insulation material to prevent a short circuit and may guide attachment of the bus bar  110  so that the bus bar  110  is easily attached to the electrode terminals  12 . When the bus bar holder  101  is attached to the electrode terminals  12 , if holes were to be disposed evenly apart from each other in the bus bar holder  101 , attachment problems may occur due to manufacturing tolerances of the secondary batteries  10 . When the secondary batteries  10  are manufactured, if the manufacturing tolerances are high, the manufacturing costs may increase. Furthermore, since the secondary batteries  10  are lithium secondary batteries and the volumes thereof may change during charging and discharging, if the bus bar holder  101  is attached to the electrode terminals  12  through holes disposed evenly apart from each other, a connection problem may occur between the bus bar holder  101  and the electrode terminals  12  when the secondary batteries  10  are charged or discharged. 
         [0044]    The bus bar holder  101  of an embodiment may include a bus bar holder plate  100 . The bus bar holder plate  100  may include an opening  100   a  formed in its lengthwise direction so that the electrode terminals  12  of the plurality of batteries  10  may be inserted through the opening  100   a . The electrode terminals  12  may slide, i.e., is slidable, along the opening  100   a . The opening  100   a  may be a single opening through which all of the electrode terminals  12  may be inserted. The bus bar holder plate  100  may have a settling groove  100   b  in which the bus bar  110  may be settled. The bus bar  110  attached to the electrode terminals  12  may slide in the settling groove when the bus bar  110  is fixed to the battery module  1 . The electrode terminals  12  may slide along the opening  100   a . A first bus bar  110  may be easily attached to the electrode terminals  12  regardless of the volumes of the secondary batteries  10  or manufacturing tolerance of the electrode terminals  12 . Furthermore, even if the volumes of the secondary batteries  10  change, other bus bars  110  attached to the electrode terminals  12  may slide along the settling groove  100   b . Thus, the bus bar holder  101  may have a structure easily adaptable to volume changes of the secondary batteries  10 . 
         [0045]    Referring to  FIGS. 4 and 5 , a bus bar holder  201  according to another embodiment will be described below.  FIG. 4  illustrates an exploded perspective view of the bus bar holder  201  attached to the battery module  1  according to another embodiment.  FIG. 5  illustrates a sectional view taken along a line V-V′ of  FIG. 4 . According to the present embodiment, the bus bar holder  201  may include a bus bar holder plate  200 . Openings  200   a  may be formed in the bus bar holder plate  200  in the lengthwise direction. First electrode terminals  12  of the plurality of secondary batteries  10  may be inserted through the openings  200   a , and the electrode terminals  12  may slide along the openings  200   a . The openings  200   a  may be formed at locations corresponding to the electrode terminals  12 . Furthermore, the openings  200   a  may have predetermined lengths so that the electrode terminals  12  may slide therein. In particular, the predetermined lengths may be proportional to a distance from a reference point S to the openings  200   a . The length of the openings  200   a  may extend in correspondence to a sum of manufacturing tolerances t of the bus bar holder  201  as a distance A from the reference point S to the openings  200   a  increases. The sum of the manufacturing tolerances t of the bus bar holder  201  indicates a value of a portion of the lengths of the openings  200   a  of the bus bar holder plate  200  that extends in correspondence to the sum of manufacturing tolerances of the sizes of the secondary batteries  10  and the locations of the electrode terminals  12 . The sum of the manufacturing tolerances t may include dimensional tolerances or geometric tolerances of the secondary batteries  10 , the electrode terminals  12 , and the bus bar holder plate  200 . The manufacturing tolerances t may accumulate as the distance from the reference point S to the openings  200   a  increases. Therefore, the openings  200   a  may have lengths extending as much as sums of the diameter d and the accumulated manufacturing tolerances t, which is sufficient for inserting the electrode terminals  12  through the openings  200   a . Furthermore, the lengths of the openings  200   a  may be determined in consideration of not only the manufacturing tolerances t, but also movements of the electrode terminals  12  due to contraction and/or expansion of the secondary batteries  10 . Distances between the secondary batteries  10  adjacent to each other may be fixed by the bus bars  110 . Thus, the length of openings  200   a  corresponding to adjacent secondary batteries  10  may be equal. In other words, referring to  FIG. 5 , the length of the opening  200   a , which is two distance units  2 A apart from a reference point, and the length of the opening  200   a , which is three distance units  3 A apart from the reference point, may be d+3t (d indicates the diameter sufficient for inserting the electrode terminals  12  through the openings  200   a , and 3t indicates the manufacturing tolerances t summed three times). The lengths of the opening  200   a , which is two distance units  2 A apart from the reference point, and the opening  200   a , which is three distance units  3 A apart from the reference point, may both be d+3t, since intervals among the electrode terminals  12  may be evenly maintained by the bus bar  110 , the bus bar  110  may move with respect to the greater value between d+2t, which is required at the point with respect to two distance units away from the reference point, and d+3t, which is required at the point with respect to three distance units away from the reference point. 
         [0046]    Accordingly, the bus bar holder plate  200  with the openings  200   a , which may be formed in consideration of the manufacturing tolerances t, may be easily attached to the electrode terminals  12  of the battery module  1 . Furthermore, the bus bar holder  201  may be effectively adapted to compensate for contraction and expansion of the secondary batteries  10 . 
         [0047]    Settling grooves  200   b  may be formed in the bus bar holder plate  200  to correspond to the length of the openings  200   a Therefore, when the electrode terminals  12  and the bus bars  110  are attached to each other and slide on the bus bar holder plate  200 , the electrode terminals  12  and the bus bars  110  may slide along the settling grooves  200   b.    
         [0048]    Referring to  FIGS. 6 through 8 , a bus bar holder  301  according to yet another embodiment will be described below.  FIG. 6  illustrates an exploded perspective view of the bus bar holder  301  attached to the battery module  1  according to yet another embodiment.  FIG. 7  illustrates a sectional view taken along a line VII-VII′ of  FIG. 6 .  FIG. 8  illustrates a sectional view taken along a line VIII-VIII′ of  FIG. 6 . 
         [0049]    According to the present embodiment, the bus bar holder  301  may include a bus bar holder plate  300  and a plurality of unit bus bar holders  310 . 
         [0050]    The unit bus bar holder  310  may be interposed between the bus bar  110  and the secondary battery  10 . A holder hole  310   a  may be formed in the unit bus bar holder  310 ; and the electrode terminal  12  may be inserted, i.e., may extend, through the holder hole  310   a  so that the electrode terminals  12  and the bus bars  110  may be attached to each other. A settling groove  310   b  for receiving the bus bar  110  may be formed in a surface of the unit bus bar holder  310 . 
         [0051]    Sliding grooves  300   c  may be formed in inner surfaces of the bus bar holder plate  300  so that the plurality of unit bus bar holders  310  may slide along the sliding grooves  300   c . Grooves  310   c  corresponding to the sliding groove  300   c  may be formed in the side surfaces of the bus bar holders  310 . Although the sliding grooves  300   c  may be concave grooves and the corresponding grooves  310   c  may be convex grooves, as illustrated in  FIG. 8 , the embodiments are not limited thereto, and various modifications may be made. For example, the unit bus bar holders  310  may include casters, so that the unit bus bar holders  310  may slide on the inner surfaces of the bus bar holder plate  300 . Also, openings  300   a  of the bus bar holder plate  300  may have sizes sufficient for the plurality of unit bus bar holders  310  to slide therein. Therefore, the bus bar holder  301  may be easily adapted to changes in locations of the electrode terminals  12  due to tolerances or deformation of secondary batteries  12  by sliding of the unit bus bar holders  310 .  FIGS. 9 and 10  illustrate another modification of the embodiment shown in  FIG. 6 . In particular,  FIG. 9  illustrates a modification of the embodiment shown in  FIG. 6  and  FIG. 10  illustrates a plan view of  FIG. 9 . According to the modified embodiment illustrated in  FIGS. 9 and 10 , an elastic member  420  may be further disposed among a plurality of unit bus bar holders  410 . Accordingly, the unit bus bar holders  410  may elastically maintain intervals therebetween via the elastic members  420 . 
         [0052]    Referring to  FIGS. 11 and 12 , a bus bar holder  501  according to still another embodiment will be described below.  FIG. 11  illustrates an exploded perspective view of the bus bar holder  501  attached to the battery module  1  according to still another embodiment.  FIG. 12  illustrates a plan view of the bus bar holder  501  shown in  FIG. 11 . 
         [0053]    The bus bar holder  501  may include a plurality of unit bus bar holders  510  and length adjusters  520 . 
         [0054]    The unit bus bar holder  510  may be interposed between the bus bar  110  and the secondary battery  10 . A holder hole  500   a  may be formed in the unit bus bar holder  510 ; and the electrode terminal  12  may be inserted through holder hole  500   a  so that the electrode terminals  12  and the bus bars  110  may be attached to each other. A settling groove  500   b  for accommodating the bus bar  110  may be formed in a surface of the unit bus bar holder  510 . 
         [0055]    The length adjuster  520  may elastically connect the unit bus bar holders  510  to the adjacent unit bus bar holder  510 . For example, as illustrated in  FIGS. 11 and 12 , the length adjuster  520  may be an elastic object with a bellows structure. Accordingly, the bus bar holder  501  may be easily adapted to changes in length due to manufacturing tolerances as the length adjuster  520  elastically adjusts its length. 
         [0056]    In comparison to the bus bar holder  501  illustrated in  FIG. 11 , the bus bar holder  401  illustrated in  FIG. 9  may restrict a sliding range of the electrode terminals  12  along the length of the bus bar holder plate  400  and may also be advantageous due to the bus bar holder plate  400  that guides the unit bus bar holders  410  during sliding. 
         [0057]    The bus bar holders  101 ,  201 ,  301 ,  401 , and  501  illustrated in  FIGS. 1 through 12  may be applied to the battery module  1 . In an implementation, the battery module  1  may include twelve secondary batteries  10 ; and eight battery modules  1  may be stacked to form a battery pack. Such a battery module  1  or a battery pack may be applied to electric-powered vehicles, and it is clear that the bus bar holders  101 ,  201 ,  301 ,  401 , and  501  may be applied to the battery module  1  and the battery pack. 
         [0058]    Exemplary 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. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.