Abstract:
A battery module is provided that includes a plurality of battery cells. Each battery cell can include a vent. A cover encloses the vents, and an insulation member is located between the plurality of battery cells and the cover. The insulation member can include a bent part that sealably engages the cover. The plurality of battery cells can be arranged in a first direction such that the vent of each battery cell is aligned with the vent of an adjacent battery cell. The cover and the insulating member can extend in the first direction to enclose the vents.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/500,304, filed on Jun. 23, 2011, and entitled: “Battery Module,” which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     Exemplary embodiments relate to a battery module including a plurality of battery cells. 
     2. Description of the Related Art 
     In a high-output battery module using a non-aqueous electrolyte with a high energy density, a plurality of battery cells are connected in series to constitute a high-capacity battery module for apparatuses requiring high power, e.g., for a motor of an electric car. 
     A battery cell includes an electrolyte and an electrode assembly formed of a positive plate and a negative plate and generates energy by electrochemical reaction between the plates and the electrolyte. Gas may be generated in the battery cells due to side reactions of the electrochemical reaction. 
     SUMMARY 
     According to an embodiment, there is provided a battery module, including a plurality of battery cells, each battery cell including a vent, a cover enclosing the vent, and an insulation member between the battery cell and the cover, wherein the insulation member includes a bent part that sealably engages the cover. 
     The may cover sealably engage the insulation member to form a gas-tight space between the cover and the battery cell. 
     The cover may include a body part and an accommodating part, the accommodating part accommodating the bent part. 
     The bent part may be accommodated by press-fit engagement between the accommodating part and a sidewall of the body part. 
     The cover may include at least one rib extending from an inward-facing side of the body part. 
     The rib may include a contact part that presses the insulation member and a non-contact part that does not contact the insulation member. 
     The insulation member may be a heat resistant, elastic material. 
     According to an embodiment, there is provided a battery module, including a plurality of battery cells, each battery cell including a vent, a cover enclosing the vent, and an insulation member between the battery cell and the cover, wherein the battery cells are arranged in a first direction such that the vent of each battery cell is aligned with the vent of an adjacent battery cell to provide a plurality of vents aligned in the first direction, the cover and the insulating member extend in the first direction to enclose the vents, and the insulation member includes a bent part sealably engaging the cover. 
     The insulation member may be a single body extending between adjacent ones of the battery cells. 
     The insulation member may include openings, each of the openings corresponding to one of the vents. 
     The vents may be disposed in cap plates of the battery cells. The insulation member may contact the cap plates in sealing engagement therewith. 
     The bent part may extend in a second direction away from the cap plates, the second direction being perpendicular to the first direction. 
     The cover may include a gas outlet at one end thereof. 
     The bent part may extend in the first direction. The cover may include a body part and an accommodating part, the body part and the accommodating part extending in the first direction, the accommodating part accommodating the bent part by press-fit engagement with the accommodating part. 
     The accommodating part may be on an inside or an outside of the cover along the first direction. 
     The cover and the insulation member may be a pre-assembled unit. 
     The cover may include at least one rib extending inwardly toward the battery cells from an inward-facing side of the body part and extending in the first direction. 
     The rib may include a contact part that presses the insulation member and a non-contact part that does not contact the insulation member. 
     The non-contact part may correspond to the openings of the insulation member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  illustrates a perspective view of a battery module according to one exemplary embodiment; 
         FIG. 2  illustrates an exploded perspective view of the battery module of  FIG. 1 ; 
         FIG. 3A  illustrates an enlarged perspective view of a cover of  FIG. 1 ; 
         FIG. 3B  illustrates a perspective view of the cover of  FIG. 1  which is turned; 
         FIG. 4A  illustrates a cross-sectional view taken along line A-A′ of  FIG. 1 ; and 
         FIG. 4B  illustrates an enlarged view of a portion B of  FIG. 4A . 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     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. 
       FIG. 1  is a perspective view of a battery module according to one exemplary embodiment,  FIG. 2  is an exploded perspective view of the battery module of  FIG. 1 ,  FIG. 3A  is an enlarged perspective view of a cover of  FIG. 1 ,  FIG. 3B  is a perspective view of the cover of  FIG. 1  which is turned,  FIG. 4A  is a cross-sectional view taken along line A-A′ of  FIG. 1 , and  FIG. 4B  is an enlarged view of a portion B of  FIG. 4A . 
     Referring to  FIGS. 1 to 3A , the battery module  100  according to the present embodiment includes a plurality of battery cells  10 , each battery cell  10  including a vent  13 . The battery cells  10  may be arranged in one direction. A cover  120  encloses the vent  13 . The cover may include a body part  121 , and an accommodating part  125  formed on at least a portion of the body part  121 . An insulation member  130  is disposed between the battery cell  10  and the cover  120 . The insulating member  130  may correspond to the vent  13  and may include a bent part  135  accommodated in the accommodating part  125 . 
     The accommodating part  125  may be formed on an outside of the cover  120  along a lengthwise direction of the cover  120 , and the bent part  135  of the insulation member  130  may be accommodated in the accommodating part  125 . The bent part  135  of the insulation member  130  may be formed by bending part of the insulation member  130  in a z-axis direction. In the present embodiment, the accommodating part  125  is formed on the outside of the cover  120 , but embodiments are not limited thereto. For example, the accommodating part  125  may be formed inside the cover  120 . 
     The insulation member  130  may be formed of at least one material selected from rubber, silicone, and an elastic material. The bent part  135  of the insulation member  130  may be forcibly inserted and closely fit into the accommodating part  125  of the cover  120  and accommodated in the accommodating part  125 , affording no space. The bent part  135  may be accommodated by press-fit engagement between the accommodating part  125  and a sidewall of the body part  121 . Accordingly, gas tightness of the insulation member  130  and the cover  120  may be secured to prevent gas discharged from the battery cells  10  from leaking to the outside, and a gas-tight space is formed between the cover and the battery cell. Further, the insulation member  130  and the cover  120  may be assembled in advance. Accordingly, an assembly process of the battery module  100  may be simplified. In detail, alignment of the vent  13  of the battery cells  10  and the insulation member  130  may be facilitated, thereby improving assembly efficiency of the battery module  100 . 
     Referring to  FIGS. 2 to 4B , the body part  121  of the cover  120  may have a hexahedral shape, an inward side of which is open in one direction, and is seated on the battery cells  10  such that the open side of the body part  121  faces the vent  13 . The body part  121  of the cover  120  may include an outlet  127  for gas at one end and the body part  121  may be closely in contact with the insulation member  130  to form a gas passage connected to the outlet  127 . 
     At least one rib  129  may be formed on the open inward side of the body part  121  of the cover  120 . The rib  129  may be formed in a lengthwise direction of the body part  121  and may include a contact part  129   a  in contact with the insulation member  130  and the non-contact part  129   b  that provides an opening corresponding to the vent  13 . The cover  120  may have a shape nearly corresponding to the insulation member  130 . 
     When the rib  129  is formed on the open inward side of the body part  121  of the cover  120 , gas tightness of the cover  120  and the insulation member  130  is further improved. In detail, the non-contact part  129   b  of the rib  129  may be formed corresponding to an opening  131  of the insulation member  130 , and the contact part  129   a  may be in contact with the insulation member  130  between the openings  131  to press the insulation member  130 . That is, the non-contact part  129   b  of the rib  129  does not disturb gas discharge from the opening  131  of the insulation member  130  corresponding to the vent  13 , and the contact part  129   a  of the rib  129  is in contact with the insulation member  130  between the openings  131  while pressing the insulation member  130 , thereby improving gas tightness of the cover  120  and the insulation member  130 . 
     The insulation member  130  is disposed between the cover  120  and the battery cells  10 . The vents  13  of the battery cells  10  may include cap plates, and the insulation member  130  may contact he cap plates in sealing engagement therewith. The bent part  135  of the insulation member  130  may be accommodated in the accommodating part  125  of the cover  120 , and the remaining portion of the insulation member  130  other than the bent part  135  may be in contact with the contact part  129   a  of the rib  129 , being pressed thereby. The cover  120  covering the insulation member  130  may be in close contact with the insulation member  130  to maintain gas tightness of the gas passage. Further, the insulation member  130  may further include the opening  131  corresponding to the vent  13  of the battery cells  10 , and the rib  129  may include the non-contact part  129   b  that is open corresponding to the vent  13 . Accordingly, gas discharge from the battery cells  10  is not disturbed. 
     According to the present embodiment, gas tightness of the insulation member  130  and the cover  120  may be secured, thereby preventing gas discharged from the battery cells  10  from leaking to the outside. Further, the insulation member  130  and the cover  120  may be assembled in advance. The assembly process of the battery module  100  may be simplified. In detail, alignment of the vent  13  of the battery cells  10  and the insulation member  130  may be facilitated to improve the assembly efficiency of the battery module  100 . 
     The battery cells  10  may generate gas due to byproducts of electrode plates and an electrolyte with repeated charge and discharge, and such gas may be discharged through the vent  13 . The gas may be discharged to the outside through the outlet  127  formed in the cover  120 . The outlet  127  may have a T shape, left and right sides of which are open so that the gas does not affect neighboring battery modules  100 , but is not limited thereto. 
     The insulation member  130  may be formed in a single body. Battery cells typically generate heat with repeated charge and discharge. The plurality of battery cells  10  may emit high-temperature heat sufficient to melt an insulation member that is mounted on the battery cells  10  and that is not formed of a heat resistant material. If the insulation member  130  were to melt, sealing efficiency between the insulation member  130  and the cover  120  could be reduced, so that gas could leak. Accordingly, the insulation member  130  may be a gasket formed of a heat resistant material to prevent gas leakage. 
     An exterior case of the battery cells  10  may be formed of metal, and the cover  120  may be formed of a plastic resin. Here, if the battery cells  10  and the cover  120  were to be in direct contact with each other, contact would not be easy due to the difference in the materials of the battery cells  10  and the cover  120 , and thus gas could leak in an insecure contact part. The insulation member  130  may serve as a gasket between the battery cells  10  and the cover  120  to conveniently maintain gas tightness between the battery cells  10  and the cover  120 . 
     The insulation member  130  formed in the single body may seal a plurality of vents  13  of the battery cells  10  at the same time. The insulation member  130  may include a plurality of openings  131  corresponding to the vents  13 . 
     Each of the battery cells  10  may include a battery case having an open part and a cap plate  14  covering the open part. The battery case may accommodate an electrolyte and an electrode assembly formed of a positive plate, a negative plate, and a separator disposed between the plates. The cap plate  14  may include a positive electrode  11  connected to the positive plate and a negative electrode  12  connected to the negative plate, the electrodes being at opposite end portions and protruding to the outside. The positive plate and the negative plate constituting the electrode assembly may react with the electrolyte to generate energy, which may be transmitted to the outside through the positive electrode  11  and the negative electrode  12 . 
     Further, the vent  13  may be disposed between the positive electrode  11  and the negative electrode  12  of the cap plate  14  to serve as a passage for gas to be discharged from the battery cells  10  when pressure of gas generated in the battery cells  10  is equal to or greater than a predetermined level. Thus, the vent  13  may prevent damage of the battery cells  10  due to internal pressure. 
     In the present embodiment, the battery cells  10  may be arranged in one direction. The battery cells  10  may be arranged parallel to each other, with wider front sides facing each other. The vents  13  may be positioned in a center portion of the battery cells  10  and disposed in a nearly straight line along the arranged battery cells  10 . The positive electrodes  11  and the negative electrodes  12  of two neighboring battery cells  10  may be electrically connected to each other through a metal bus-bar (not shown). 
     A housing  110  may include a pair of end plates  111  spatially spaced from each other in one direction and a plurality of connecting members connecting the end plates  111 . The connecting members may include a side bracket  112  connecting lateral sides of the end plates  111  and a bottom bracket  113  connecting bottom sides of the end plates  111 . The plurality of battery cells  10  may be accommodated between the end plates  111 . 
     The end plates  111  may be disposed to be in surface contact with outermost battery cells  10 , respectively, and press the plurality of battery cells  10  inwardly. Further, the side bracket  112  may be connected to one end portion and the other end portion of the end plates  111  to support opposite lateral sides of the battery cells  10 . Bottom sides of the battery cells  10  may be supported by the bottom bracket  113 , and opposite end portions of the bottom bracket  113  may be connected to the end plates  111 . 
     The plurality of battery cells  10 , supported by the end plates  111 , the side bracket  112 , and the bottom bracket  113 , may be arranged therein with the positive electrodes  11  and the negative electrodes  12  being disposed alternately and connected in series using bus-bars. A connection structure and the number of battery cells  10  may be changed variously depending on a design of the battery module  100 . 
     A barrier  115  may be interposed between neighboring battery cells  10 . A spacer (not shown) may be provided to the barrier  115  so as to space apart the neighboring battery cells  10  from each other and to form a space between the battery cells  10 . 
     By way of summation and review, a battery module may have a gas passage or outlet to efficiently deal with gas generated in a plurality of battery cells. According to one exemplary embodiment, there is provided a battery module which secures tightness of gas generated in a plurality of battery cells due to a simplified working process, thereby preventing gas discharged from the battery cells from leaking to the outside. 
     Further, the battery module may have a simplified assembly process. An insulation member and a cover may be assembled in advance. 
     In addition, alignment of a vent and the insulation member may be facilitated. 
     Assembly efficiency of the battery module may be improved. 
     In the present embodiment, a polygonal lithium ion secondary battery may be illustrated as an example of the battery cell, but embodiments are not limited thereto. Various types of batteries, such as a lithium polymer battery, or various shapes, such as a cylindrical battery may be used. 
     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 of the present invention as set forth in the following claims.