Abstract:
A battery module includes a battery array having a plurality of battery cells each including a terminal surface exposing an electrode terminal and a vent, and a bottom surface generally opposite to the terminal surface, wherein the battery cells are stacked together; end plates adjacent outer ends of the battery array and having electrode openings exposing the electrode terminals; vertical fixing plates having side holders extending along a portion of a side of the battery array; and horizontal insulating members located between adjacent ones of the stacked battery cells.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0109181, filed on Nov. 4, 2010, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The present invention relates to a battery module. 
         [0004]    2. Description of Related Art 
         [0005]    In general, secondary batteries can be reused by discharging and recharging, unlike primary batteries that can not be recharged. The secondary batteries are used as energy sources for mobile devices, electric vehicles, hybrid vehicles, electric bicycles, and uninterrruptible power supplies, and may be used in a single battery type or a battery module type composed of a plurality of batteries connected in one unit, in accordance with various available external devices. 
         [0006]    Although small mobile devices, such as mobile phones, can operate for some time with the output and capacity of a single battery, electric modules having larger output and capacity are often more suitable to operate electric vehicles and hybrid vehicles with high power for a long time because such vehicles consume a large amount of electricity. The battery modules are used by connecting a required number of batteries in parallel or series in accordance with output and capacity. 
       SUMMARY 
       [0007]    In one embodiment, a battery module is provided that does not need specific side fixing members. Further, in another embodiment, a battery module is provided having a structure that can effectively discharge heat generated from battery cells while maintaining sufficient strength for fixing a battery array. 
         [0008]    In one embodiment, a battery module is provided including a battery array having a plurality of battery cells each including a terminal surface exposing an electrode terminal and a vent, and a bottom surface generally opposite to the terminal surface, wherein the battery cells are stacked together; end plates adjacent outer ends of the battery array and having electrode openings exposing the electrode terminals; vertical fixing plates having side holders extending along a portion of a side of the battery array; and horizontal insulating members located between adjacent ones of the stacked battery cells. 
         [0009]    In one embodiment, the battery array includes a pair of battery cells stacked together such that each of the bottom surfaces face each other, wherein a plurality of the pair of battery cells are stacked together such that side surfaces of the battery cells face each other, wherein one of the end plates contacts the terminal surface of at least one of the battery cells, and wherein the vertical fixing plates extend between and are coupled to each of the end plates. 
         [0010]    Further, a vertical insulating member may located between the bottom surface of adjacent ones of the battery cells. In one embodiment, the vertical insulating member is a plastic H-beam and is fixed to the vertical fixing plates. In one embodiment, the vertical fixing plates have ridges, wherein the ridges are recessed from the vertical fixing plate in a longitudinal direction of the vertical fixing plate. 
         [0011]    Additionally, in one embodiment, the vertical fixing plates have a notch on a edge thereof and wherein the end plate has a body and an extending portion extending at an angle from an edge of the body and fastening through-holes on the extending portion, the fastening through holes being adjacent to the notch. Further, the vertical fixing plate may include a reinforcing wall extending between the side holders. 
         [0012]    The battery module according to embodiments of the present invention can fix the battery arrays without specific side fixing members. Further, according to embodiments of the present invention, it is possible to fix the battery array with sufficient strength and effectively discharge the heat produced from the battery cells. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The accompanying drawings, together with the specification, illustrate exemplary embodiments of the present invention, and, together with the description, serve to explain the principles of the present invention. 
           [0014]      FIG. 1  is a perspective view showing an example of a transverse type of battery module. 
           [0015]      FIG. 2  is a schematic exploded perspective view of the battery module shown in  FIG. 1 . 
           [0016]      FIG. 3A  is a perspective view showing a vertical fixing plate according to an embodiment. 
           [0017]      FIG. 3B  is a front view showing the vertical fixing plate shown in  FIG. 3A . 
           [0018]      FIG. 4A  is a perspective view showing a vertical fixing plate according to another embodiment. 
           [0019]      FIG. 4B  is a front view showing the vertical fixing plate shown in  FIG. 4A . 
           [0020]      FIG. 5  is a perspective view showing a vertical fixing plate with heat dissipation holes. 
           [0021]      FIG. 6  is a perspective view showing an upper fixing plate with cut-off portions. 
           [0022]      FIG. 7  is a bottom perspective view showing a vertical fixing plate with reinforcing portions. 
           [0023]      FIG. 8A  is a perspective view showing a vertical insulating member according to an embodiment. 
           [0024]      FIG. 8B  is a transverse cross-sectional view showing the vertical insulating member of  FIG. 8A . 
           [0025]      FIG. 9  is a perspective view showing an example of a battery module with an exemplary vertical fixing plate. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0026]    In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. 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. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. In addition, when an element is referred to as being “on” another element, it can be directly on the another element or be indirectly on the another element with one or more intervening elements interposed therebetween. Also, when an element is referred to as being “connected to” another element, it can be directly connected to the another element or be indirectly connected to the another element with one or more intervening elements interposed therebetween. Hereinafter, like reference numerals refer to like elements. 
         [0027]    Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. The terms representing directions, such as “up, down, left, right” used herein are considered to be based on the status shown in the drawings, if not specifically defined or stated. Further, the same reference numerals represent the same parts throughout the embodiments. 
         [0028]    Meanwhile, the arrangement of battery cells and the stacked structure are defined as a battery array hereafter. 
         [0029]    The type of a battery module  100   a  where the present invention is applied is described with reference to  FIGS. 1 and 2 .  FIG. 1  is a perspective view showing an example of a transverse type of battery module and  FIG. 2  is an exploded perspective view of the battery module shown in  FIG. 1 . 
         [0030]    The present invention can be applied to the transverse type of battery module  100   a  shown in  FIG. 1 . The transverse type of battery module  100   a  may include a plurality of battery cells  10  forming a battery array, a configuration for insulating, and a configuration for fixing. 
         [0031]    In one embodiment, the battery cells  10  are generally formed in hexahedral shapes. A terminal surface  11  is provided to support both electrode terminals (an anode terminal  11   b  and a cathode terminal  11   a ) and a vent  17 . The vent  17  is formed at the center of the terminal surface  16 . The vent  17  allows a gas produced in the battery cell  10  to be discharged. The electrode terminals  11  are formed on either side of the vent  17 . Both electrode terminals  11  function as a path allowing the current produced in the battery cell  10  to flow to the outside. Further, the opposite side to the terminal surface  11  is referred to as a bottom surface  15  hereafter. 
         [0032]    The battery cells  10  are transversely oriented such that the bottom surfaces  15  of two battery cells  10  face each other. The electrode terminals  11  are oriented to face the outside of the battery array. The pair of battery cells  10  oriented as described above are stacked in two or more layers, as shown in  FIG. 2 . The electrode terminals  11  of the upper and lower stacked battery cells  10  may have the same polarity or opposite polarities. As shown in  FIG. 2 , two opposite battery cells may be provided in one layer, but single cells  10  may be stacked. Further, embodiments of the present invention may be applied when the number of stacked battery cells  10  is two or more, but is not limited thereto. 
         [0033]    Fixing members are provided, which may include upper and lower fixing members  300 , side fixing members  400 , and end plates  200 . The end plates  200  are fastened to the terminal surfaces  16  at both ends of the battery array  10  such that the electrode terminals  11  and the vent hole  17  are exposed to the outside. In one embodiment, the upper and lower fixing members  300  are located on and under the battery array  10 . Specifically, the upper and lower fixing members  300  may be fixed to the top and the bottom of the end plates  200  as shown for example in  FIG. 2  to restrict vertical movement of the battery array  10 . The side fixing members  400  are located on the sides of the battery array  10 . In one embodiment, the side fixing members  400  are fixed to both sides of the end plates  200  to restrict side movement of the battery array  10 . 
         [0034]    A vertical insulating member  500   a  and a horizontal insulating member  600   a  may be provided as insulating members. The vertical insulating member  500   a  is located between the bottom surfaces  15  of two opposite battery cells  10  for insulation and the horizontal insulating member  600   a  is located between two stacked battery cells  10  for insulation. 
         [0035]    Embodiments of the present invention relate to a configuration corresponding to the vertical fixing plate  300  as described in detail below. 
         [0036]    A vertical fixing plate  300  with holders is described with reference to  FIGS. 3A and 3B .  FIG. 3A  is a perspective view showing a vertical fixing plate according to an embodiment.  FIG. 3B  is a front view showing the vertical fixing plate shown in  FIG. 3A . 
         [0037]    The vertical fixing plate  300   a  has holders  360  vertically extending from the outsides of both sides of a body  350 . Although it is possible to reduce weight by cutting off a portion of the holders  360 , when the holders  360  replace the side fixing members, it is advantageous in strength not to cut off the holders  360 . The holders  360 , as described above, contact with and hold the sides of the battery cell fixed by the upper and lower plates  300   a.    
         [0038]    Further, through-holes  310  are formed at both ends of the body  350  and through-holes  311  for fastening to the vertical insulating member  500  (see  FIG. 8A ), which is described below, are formed at the center of the body  350 . 
         [0039]    A vertical fixing plate  300   b  with ridges is described with reference to  FIGS. 4A and 4B .  FIG. 4A  is a perspective view showing a vertical fixing plate according to another embodiment.  FIG. 4B  is a front view showing the vertical fixing plate shown in  FIG. 4A . 
         [0040]    The vertical fixing plate  300   b  may have ridges  335  recessed from the body  350  and extending in the longitudinal direction. As shown in  FIG. 4B , a plurality of ridges  355  depressed on the body  350  are formed, such that the strength against bending of the body  350  is increased. 
         [0041]    A vertical fixing plate with heat dissipation holes is described with reference to  FIG. 5  which is a perspective view showing a vertical fixing plate with heat dissipation holes. 
         [0042]    In one embodiment, heat dissipation holes  356  may be formed in a vertical plate  300   c . The heat dissipation holes  356  function as paths for discharging internal heat produced in the battery cells to the outside. Further, because the internal heat is usually produced around the battery cells, the heat dissipation holes  356  may be located to generally correspond to the battery cells when a battery module is formed. The heat dissipation holes  356  may be formed on the body  350  or on the ridges  355  and the appropriate number is determined with respect to the desired strength of the vertical plate  300   c.    
         [0043]    A vertical fixing plate  300   d  with cut-off portions or notches is described with reference to  FIG. 6 , which illustrates a perspective view showing an upper fixing plate with cut-off portions. 
         [0044]    Cut-off portions  370  are formed at generally the center portions of both ends of the upper fixing plate  300   d . As shown in the figure, the cut-off portions are portions which are recessed from the fixing plate  300   d . In one embodiment, a tool is used in the cut-off portions  370  in order to assemble one battery module by combining the components described above or to fix the combined battery modules to an object, such as an electric vehicle. In particular, it may be difficult to fix the battery module in an electric vehicle requiring large capacity and/or high output because the space for the battery module is small. The fixing work can be more easily performed with the inclusion of the cut-off portions  370 . 
         [0045]    A vertical fixing plate  300   e  with reinforcing portions is described with reference to  FIG. 7  which illustrates a bottom perspective view showing a vertical fixing plate with reinforcing portions. 
         [0046]    As shown in  FIG. 7 , reinforcing portions  380  may be located on the inner side of the vertical fixing plate  300   e  and extend across the plate. The reinforcing portions  380  are connected to holders  380  at both sides, thereby increasing the structural strength of the fixing plate  300   e . The reinforcing portions  380  may be formed anywhere on the vertical fixing plate  300   e , and in one embodiment are formed on both sides of a fastening through-hole  311  at the center of the vertical fixing plate  300   e  to avoid interfering with the battery cells during assembly of a battery module. 
         [0047]    A vertical insulating member is described with reference to  FIGS. 8A and 8B .  FIG. 8A  is a perspective view showing a vertical insulating member according to an embodiment and  FIG. 8B  is a horizontal cross-sectional view of the vertical insulating member of  FIG. 8A . 
         [0048]    As shown in  FIG. 2 , the vertical insulating member is located between the bottom surfaces  15  of the battery array for insulation. 
         [0049]    The vertical insulating member  500  may be used to insulate the bottom surfaces  15  of the battery cells  10 , for example in a plate shape as described above, regardless of the shape of the battery cells. Often, the battery cells  10  expand slightly when being repeatedly charged and discharged. According to an embodiment of a battery module, since the distance between both terminal surfaces  16  of battery cells  10  in one array is relatively large, the vertical fixing member  300   a  may not sufficiently compress the battery cells  10  together. The vertical insulating member  500  may be an H-beam (i.e., a cross-section of the insulating member  500  is generally H-shaped) shown in  FIGS. 11A and 11B . Thread-fastening portions  510  may be formed at the upper and lower ends of the H-beam to be connected with the vertical fixing plate  300   a . A metal layer  511  may be further formed by double injection molding to reinforce the strength of the thread-fastening portions  510 . The thread-fastening portion  510  and the second through-hole  311  described above are coupled by a bolt in assembling this embodiment. 
         [0050]    An example of a battery module with a vertical plate is described with reference to  FIG. 9  which illustrates a perspective view of an exemplary battery module with a vertical fixing plate. 
         [0051]    As described above, the vertical fixing plate  300   d  is located on the battery module  100  and fixed to the end plates  200  at both ends. Further, the lower fixing plate  300   e  is located under the battery module  100  and fixed to the end plates  200  at both ends. The upper and lower fixing plates  300   d ,  300   e  restrict side movement in addition to vertical movement of the battery array  10 . Further, the heat produced from the battery cells  10  can be easily discharged through the heat dissipation holes  356 , even after the battery cells  10  stop operating. 
         [0052]    While the present invention has been described in connection with certain 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, and equivalents thereof.