Abstract:
A battery module includes a plurality of battery cells arranged in a same direction and a same orientation; and a housing portion disposed on the outer surfaces of the plurality of battery cells. In the battery module, the housing portion includes a reinforcing plate positioned between at least two of the battery cells. The reinforcing plate is part of the housing portion, and strengthens the housing portion, thereby enabling a lighter weight battery module and improving the safety of the battery module.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Application No. 61/813,134, filed on Apr. 17, 2013 in the U.S. Patent and Trademark Office, the entire content of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    An aspect of the present invention relates to a battery module. 
         [0004]    2. Description of the Related Art 
         [0005]    A high-power battery module with high energy density that uses a non-aqueous electrolyte has recently been developed. A large-capacity battery module may be manufactured by connecting a plurality of battery cells in series, and is intended for use in driving devices that require high power output, e.g., the motors of electric vehicles and the like. 
         [0006]    Since the number of devices employing high-power battery modules is increasing, studies have been conducted to improve the productivity of the battery module. Also, as the external appearance of these devices is diversified, the shape of the battery module needs to be variable. However, the basic safety of the battery module should also be secured. Therefore, studies on the structure of a battery module capable of satisfying all these requirements have been conducted in various fields. 
       SUMMARY 
       [0007]    In some embodiments of the present invention, a battery module is light in weight and has improved safety, and these characteristics are achieved by substantially preventing deformation of the housing portion, which is generally caused by external impact. 
         [0008]    According to an aspect of the present invention, a battery module includes: a plurality of battery cells arranged in a same direction and a same orientation; and a housing portion disposed on outer surfaces of the plurality of battery cells. The housing portion includes a reinforcing plate positioned between at least two of the battery cells. 
         [0009]    The housing portion may include side plates respectively covering both side surfaces of the plurality of battery cells, and the reinforcing plate has both of its side surfaces respectively coupled to the side plates. 
         [0010]    The reinforcing plate may be welded to the side plates. 
         [0011]    A protrusion may be provided on any one of the reinforcing plate and the side plates, and a groove may be provided in the other of the reinforcing plate and the side plates. The protrusion may be inserted into the groove to couple or fix the reinforcing plate and the side plates to each other. 
         [0012]    The reinforcing plate and the side plates may be coupled or fixed to each other by screws. 
         [0013]    The housing portion may further include end plates adjacent to the outermost battery cells, and both side surfaces of each end plate are connected to the respective side plates. 
         [0014]    The thicknesses of the side plates and the reinforcing plate may be identical to or thinner than the thickness of the end plate. 
         [0015]    The housing portion may further include a bottom plate, and both side surfaces of the bottom plate may be connected to the respective side plates, thereby covering the surface of the housing portion opposite to the surface from which the electrode tabs of the plurality of battery cells are extracted. 
         [0016]    The reinforcing plate may be welded to the bottom plate. 
         [0017]    A protrusion may be provided on one of the reinforcing plate and the bottom plate, and a groove may be provided in the other of the reinforcing plate and the bottom plate. The protrusion may be inserted into the groove to thereby couple or fix the reinforcing plate and the side plates to each other. 
         [0018]    The reinforcing plate and the bottom plate may be coupled or fixed to each other with screws. 
         [0019]    The housing portion may include iron. 
         [0020]    The housing portion may include stainless steel. 
         [0021]    The reinforcing plate may be coupled to the side plates near a center of the plurality of battery cells. 
         [0022]    An insulative coating layer may be formed on at least one surface of the reinforcing plate. 
         [0023]    Other features and advantages of the present invention will become more apparent from the following detailed description, when taken in conjunction with the accompanying drawings. 
         [0024]    Terms or words used in the present specification and claims should not be interpreted as restricted to their ordinary meanings or dictionary-based meanings, but rather should be interpreted as having the meanings defined herein, in keeping with the ability of an inventor to define terms in the way he sees fit to describe and explain his or her invention. 
         [0025]    According to embodiments of the present invention, in the battery module, the reinforcing plate is included in the housing portion, thereby strengthening the housing portion while also improving the safety of the battery module and enabling the battery module to be light in weight. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    These and other features and advantages of the present invention will be better understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, in which. 
           [0027]      FIG. 1  is a perspective view of a battery module according to an embodiment of the present invention. 
           [0028]      FIG. 2  is an exploded perspective view of the battery module shown in  FIG. 1 . 
           [0029]      FIG. 3  is a sectional view of the housing portion of the battery module  100   a  of  FIG. 2  taken along line A-A′. 
           [0030]      FIG. 4  is an exploded perspective view of a battery module according to another embodiment of the present invention. 
           [0031]      FIG. 5  is a sectional view of the housing portion of the battery module of  FIG. 4  taken along line B-B′. 
           [0032]      FIG. 6  is a plan view showing a portion of the housing portion of the battery module shown in  FIG. 4 . 
           [0033]      FIG. 7  is an exploded perspective view of a battery module according to still another embodiment of the present invention. 
           [0034]      FIG. 8  is a plan view showing a portion of the housing portion of the battery module shown in  FIG. 7 . 
           [0035]      FIG. 9  is a perspective view of a battery module according to still another embodiment of the present invention. 
           [0036]      FIG. 10  is an exploded perspective view of the battery module shown in  FIG. 9 . 
           [0037]      FIG. 11  is a sectional view of the housing portion of the battery module of  FIG. 9  taken along line C-C′. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]    In the following detailed description, certain exemplary embodiments of the present invention are shown and described, and are presented for illustrative purposes. As those skilled in the art would realize, the described embodiments may be modified in various different ways 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 other element or indirectly on the other element with one or more intervening elements therebetween. Also, when an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element with one or more intervening elements therebetween. Also, throughout the description, like reference numerals refer to like elements. 
         [0039]      FIG. 1  is a perspective view of a battery module  100   a  according to an embodiment of the present invention.  FIG. 2  is an exploded perspective view of the battery module  100   a  shown in  FIG. 1 . As shown in  FIGS. 1 and 2 , the battery module  100   a  according to this embodiment includes a plurality of battery cells  100  arranged in the same direction and in the same orientation. The battery module  100   a  also includes a housing portion  120   a  disposed on the outer surfaces of the plurality of battery cells  110 . The housing portion  120   a  may include a reinforcing plate  122   a  positioned between at least two of the battery cells  110 . 
         [0040]    The battery cell  110  is an energy generating element, and a plurality of battery cells are aligned in the same direction and in the same orientation. 
         [0041]    Here, each battery cell  110  may include a battery case having an opened surface. Each battery cell  110  also includes an electrode assembly and an electrolyte which are housed in the battery case. The battery cell  110  generates energy by an electrochemical reaction between the electrode assembly and the electrolyte. The battery case may be sealed, for example, by including a cap assembly on a first surface  111  of the battery cell  110 . Terminals  114  having different polarities, i.e., positive and negative electrode terminals  115  and  116 , may protrude from the first surface  111  of the battery cell  110 . A vent  117  may also be provided as a safety means in the first surface  111  of the battery cell  110 . The vent  117  serves as a passage for gas generated inside the battery cell  110  to be exhausted to the outside of the battery cell  110 . The terminals  114  of adjacent battery cells  110  in the plurality of battery cells  10  may be electrically connected to each other by a bus-bar  118 , and the bus-bar  118  may be fixed to the terminal portions  114 , for example, by a fixing means  119 , such as a nut. The battery cell  110  may include the first surface  111  from which the terminal portions  114  extend, a second surface  112  opposite the first surface  111 , and side surfaces  113  that connect the first and second surfaces  111  and  112  to each other. 
         [0042]    The housing portion  120   a , as shown in  FIGS. 1 and 2 , is disposed on the outer surfaces of the plurality of battery cells  110  to house the plurality of battery cells  110  in the same direction and same orientation and to protect the plurality of battery cells  110  from the outside. 
         [0043]    In some embodiments, the housing portion  120   a  may include, for example, two side plates  121   a , two end plates  123  and a reinforcing plate  122   a . The side plates  121   a  respectively cover both side surfaces  113  of the plurality of battery cells  110 , and the end plates  123  are respectively adjacent to the outermost battery cells  110 , i.e., to respectively cover the wide surfaces of the outermost battery cells  110 . Thus, the housing portion  120   a  forms a box having opened upper and lower surfaces, and the battery cells  110  are accommodated within the box. The side plates  121   a  and the end plate  123  may be connected to each other by screws, welding or mechanical groove-protrusion coupling. The outer surfaces of the reinforcing plate  122   a  may be respectively coupled to the two side plates  121   a , for example, through welding. The reinforcing plate  122   a  may be positioned between at least two of the battery cells  110  in the plurality of battery cells  110 . The reinforcing plate  122   a  may be positioned between two of the battery cells  110  near the center or at the center of the plurality of battery cells  110 , or may be positioned between any other two battery cells  110 . Alternatively, a plurality of reinforcing plates  122   a  may be provided and positioned between different sets of two battery cells in the plurality of battery cells  110 . 
         [0044]    When the housing portion  120   a  includes iron, e.g., stainless steel, the weight of the battery module  100   a  may be decreased. However, deformation of a battery module  100   a  that is longer in length may be caused by impact. Accordingly, a battery module  100   a  according to an embodiment of the present invention includes the reinforcing plate  122   a  coupled to or fixed to a central portion of the side plates  121   a  in order to strengthen the housing portion  120   a , thereby substantially solving this problem. The reinforcing plate  122   a  may be coupled to or fixed to the side plates  121   a , for example, through welding, such as laser welding. However, welding produces high temperatures as a result of heat generated during the welding. Hence, in some embodiments, the battery cells  110  are positioned in the housing portion after the reinforcing plate  122   a  is coupled to or fixed to the side plates  121   a , and the end plates  123  are connected to the side plates  121   a . When the reinforcing plate  122   a  is coupled to or fixed to the side plates  121   a  through welding, the welding is difficult to perform when the reinforcing plate  122   a  and the side plates  121   a  are too thick. Therefore, the thickness of each of the reinforcing plate  122   a  and the side plates  121   a  may be identical to or thinner than the thicknesses of the end plates  123 . For example, the reinforcing plate  122   a  and the side plates  121   a  may each have a thickness of 0.8 to 1 mm, and the end plate  123  may have a thickness of 1.5 mm or more. 
         [0045]    In some embodiments, an insulative coating layer may be formed by coating an insulative material on at least one surface of the reinforcing plate  122   a . For example, the surfaces of the reinforcing plate  122   a  that contact the battery cells  110  may be coated with an insulative coating so that the reinforcing plate  122   a  and the battery cell  110  are not unintentionally short-circuited with each other. 
         [0046]      FIG. 3  is a sectional view of the housing portion  120   a  of the battery module  110  shown in  FIG. 2  taken along line A-A′. Hereinafter, a housing portion  120   a  according to an embodiment of the present invention will be described with reference to  FIG. 3 . 
         [0047]    When the side plates  121   a  and the reinforcing plate  122   a  are simply connected to each other through welding, the coupling between the side plates  121   a  and the reinforcing plate  122   a  is relatively weak. Therefore, the side plates  121   a  and the reinforcing plate  122   a  may separate from each other as a result of an external force. However, in a battery module  100   a  according to an embodiment of the present invention, the coupling between the side plates  121   a  and the reinforcing plate  122   a  includes a protrusion  124   a  and a groove  125   a , as shown in  FIG. 3 . This coupling enables firm attachment of the side plates  121   a  to the reinforcing plate  122   a.    
         [0048]    For example, the protrusion  124   a  may be formed on the reinforcing plate  122   a , and the groove  125   a  may be formed in the side plates  121   a . The protrusion  124   a  of the reinforcing plate  122   a  is inserted into the groove  125   a  of the side plates  121   a . The area of attachment where the protrusion  124   a  of the reinforcing plate  122   a  engages the groove  125   a  of the side plates  121   a  may then be welded in order to more firmly couple or fix the reinforcing plate  122   a  to the side plates  121   a . The protrusion  124   a  is first inserted into the groove  125   a , and then the welding is performed. Hence, the attachment of the reinforcing plate  122   a  to the side plates  121   a  is firm. Further, by first engaging the protrusion  124   a  with the groove  125   a  before the welding the position of the reinforcing plate  122   a  is aligned and stabilized for the welding process. 
         [0049]    There may be the same number of grooves  125   a  as there are protrusions  124   a , and the shapes and positions of the grooves  125   a  may correspond to the shapes and positions of the protrusions  124   a . As used herein, the term ‘groove’ is not limited to grooves, but also encompasses holes that extend completely through the side plates  121   a . Although it has been described that the protrusion  124   a  is formed on the reinforcing plate  122   a , and the groove  125   a  is formed in the side plates  121   a , in some embodiments, the protrusion  124   a  may be formed on the side plates  121   a , and the groove  125   a  may be formed in the reinforcing plate  122   a.    
         [0050]      FIG. 4  is an exploded perspective view of a battery module  100   b  according to another embodiment of the present invention.  FIG. 5  is a sectional view of a housing portion  120   b  of the battery module  100   b  shown in  FIG. 4  taken along line B-B′.  FIG. 6  is a plan view showing a portion of the housing portion  120   b  of the battery module  100   b  shown in  FIG. 4 . Hereinafter, the battery module  100   b  according to an embodiment of the present invention will be described with reference to  FIGS. 4 to 6 . In this description, components that are identical to or correspond to those described above with respect to other embodiments are designated by like reference numerals, and their detailed descriptions will be omitted to avoid redundancy. 
         [0051]    As shown in  FIGS. 4 to 6 , a battery module according to an embodiment of the present invention includes a housing portion  120   b , which includes a reinforcing plate  122   b  welded to two side plates  121   b . A long groove  125   b  is formed in the side plates  121   b . Specifically, the groove  125   b  may be a long vertical groove (e.g., a slit shape). A protrusion  124   b  may be inserted into the groove  125   b . Here, although two protrusions  124   b  are shown in  FIG. 5  on one side of the reinforcing plate  122   b , only one groove  125   b  is provided to engage both of two protrusions  124   b  that are on the same side of the reinforcing plate  122   b . When the groove  125   b  is a long slit, the two side plates  121   b  are spaced apart from each other, and the reinforcing plate  122   b  is inserted between the side plates  121   b  in a downward direction starting from the upper portions of the side plates  121   b , thereby making the manufacturing process of the housing portion  120   b  more convenient. 
         [0052]      FIG. 7  is an exploded perspective view of a battery module  100   c  according to still another embodiment of the present invention.  FIG. 8  is a plan view showing a portion of the housing portion  120   c  of the battery module  100   c  shown in  FIG. 7 . 
         [0053]    Hereinafter, the battery module  100   c  according to an embodiment of the present invention will be described with reference to  FIGS. 7 and 8 . Here, components that are identical to or correspond to those described above in other embodiments are designated by like reference numerals, and their detailed descriptions will be omitted to avoid redundancy. 
         [0054]    As shown in  FIGS. 7 and 8 , a battery module  100   c  according to an embodiment of the present invention includes a housing portion  120   c  that includes a reinforcing plate  122   c  coupled to or fixed to two side plates  121   c . The reinforcing plate  122   c  and the side plates  121   c  may be coupled to or fixed to each other by screws. For example, a first coupling hole  126   c  may be formed in the reinforcing plate  122   c , and a second coupling hole  127   c  may be formed in the side plates  121   c . Then, a fixing member  128  is inserted into the first and second coupling holes  126   c  and  127   c , thereby coupling or fixing the reinforcing plate  122   c  to the side plates  121   c . Each of the first and second coupling holes  126   c  and  127   c  may be threaded, and the fixing member  128  may include a bolt, so that the reinforcing plate  122   c  and the side plates  121   c  can be firmly coupled to or fixed to each other by being screwed to each other. 
         [0055]      FIG. 9  is a perspective view of a battery module  100   d  according to still another embodiment of the present invention.  FIG. 10  is an exploded perspective view of the battery module  100   c  shown in  FIG. 9 .  FIG. 11  is a sectional view of a housing portion  120   d  of the battery module  100   d  shown in  FIG. 9 . Hereinafter, a battery module  100   d  according to an embodiment of the present invention will be described with reference to  FIGS. 9 to 11 . Here, components that are identical to or correspond to those described above with respect to other embodiments are designated by like reference numerals, and their detailed descriptions will be omitted to avoid redundancy. 
         [0056]    As shown in  FIGS. 9 to 11 , a battery module  100   d  according to an embodiment of the present invention includes a plurality of battery cells  110  and a housing portion  120   d . The battery module  100   d  may further include a bottom plate  129  in addition to two side plates  121   d , a reinforcing plate  122   d  and two end plates  123 . For example, the bottom plate  129  may cover a surface  112  of the plurality of battery cells  110 . The bottom plate  129  may be connected to the end plates  123  or the side plates  121   d . For example, the reinforcing plate  122   d  may be coupled to or fixed to the bottom plate  129 , and the reinforcing plate  122   d  and the bottom plate  129  may be coupled to or fixed to each other. These couplings or connections can include, for example, simple welding, a protrusion  124   d  engaging a groove  125   d  with or without welding as shown in  FIGS. 9 to 11 , screws, etc. 
         [0057]    Although the reinforcing plate has been described here as coupled to the bottom plate, the reinforcing plate may be coupled to both the side plates and the bottom plate. In this case, protrusions may be formed on three side surfaces of the reinforcing plate to enable coupling to both the side plates and the bottom plate. Welding may also be performed at the area where the protrusions engage the grooves formed in each of the two side plates and the bottom plate. The reinforcing plate and the bottom plate may also be coupled to or fixed to each other through simple welding or by being screwed together. 
         [0058]    While certain exemplary embodiments of the present invention have been illustrated and described, those of ordinary skill in the art will understand that various modifications to the described embodiments can be made without departing from the spirit and scope of the appended claims, and equivalents thereof. Accordingly, the present invention is not limited to the specific embodiments described and illustrated herein.