Patent Publication Number: US-2015079428-A1

Title: Battery module

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Korean Patent Application No. 10-2013-0111638, filed on Sep. 17, 2013, in the Korean Intellectual Property Office, and entitled: “Battery Module,” is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     Embodiments relate to a battery module. 
     2. Description of the Related Art 
     A high-power battery module using a non-aqueous electrolyte with high energy density has recently been developed. The high-power battery module may be configured as a large-capacity battery module manufactured by connecting a plurality of battery cells in series so as to be used in driving motors of devices requiring high power, e.g., electric vehicles or the like. Further, a battery pack may be configured by electrically connecting such a plurality of battery modules to one another. 
     SUMMARY 
     Embodiments are directed to a battery module. 
     The embodiments may be realized by providing a battery module including a plurality of battery cells aligned in one direction, the plurality of battery cells each having a vent on a top surface thereof; and at least one vent cover covering the vent and covering side surfaces of the plurality of battery cells, wherein one vent cover covers outer side surfaces of outermost battery cells among the aligned plurality of battery cells, or a plurality of vent covers cover side surfaces of a battery cell of the plurality of battery cells. 
     The vent cover may include a first cover covering the vent; and second covers extending at sides of the first cover, the second covers each covering a side surface of a battery cell of the plurality of battery cells. 
     The first cover may be spaced apart from the vent. 
     The battery module may further include an absorbing member on one surface of the first cover, the one surface being opposite to the vent. 
     The absorbing member may absorb at least one of an internal gas or electrolyte exhausted or discharged through the vent when the vent is fractured. 
     The second covers may press inwardly on side surfaces of the battery cell of the plurality of battery cells. 
     The battery module may further include a heat insulating member between one of the second covers and a corresponding side surface of the battery cell of the plurality of battery cells. 
     The heat insulating member may include at least one of elastic rubber, a urethane, or silicon. 
     An inner surface of each second cover may include at least one protruding portion thereon. 
     The second covers may extend from only portions of respective sides of the first cover, and one second cover extending from one portion of one side of the first cover may be offset with respect to another second cover extending from another portion of another side of the first cover. 
     The battery module may further include a shielding member between adjacent battery cells of the plurality of battery cells, wherein the second covers cover the outer side surfaces of the outermost battery cells among the aligned plurality of battery cells, and wherein the first cover includes at least one insertion hole therein, the shielding member being inserted into the insertion hole. 
     The battery module may further include a barrier between adjacent battery cells of the plurality of battery cells, wherein the second covers cover the outer side surfaces of the outermost battery cells among the aligned plurality of battery cells. 
     The battery module may further include a shielding portion extending upwardly from a partial area of a top surface of the barrier, wherein the shielding portion contacts a bottom surface of the first cover. 
     The barrier may further include one or more protruding portions thereon. 
     The barrier may be a heat insulating member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features will be apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which: 
         FIG. 1  illustrates a perspective view showing a battery module according to an embodiment. 
         FIG. 2  illustrates a side view of a coupling relationship between a battery cell and a vent cover according to an embodiment. 
         FIG. 3  illustrates a side view of a coupling relationship between the battery cell and the vent cover according to another embodiment. 
         FIG. 4  illustrates a side view of a coupling relationship between the battery cell and the vent cover portion according to still another embodiment. 
         FIG. 5  illustrates a perspective view of a vent cover according to an embodiment. 
         FIG. 6  illustrates a perspective view showing the battery module to which the vent cover of  FIG. 5  is coupled. 
         FIG. 7  illustrates a perspective view showing a battery module according to another embodiment. 
         FIG. 8  illustrates a perspective view showing a battery module according to still another embodiment. 
     
    
    
     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 exemplary implementations 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. 
     In addition, when an element is referred to as being “on” another element, it can be directly on the other element or be indirectly on the other 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 other element or be indirectly connected to the other element with one or more intervening elements interposed therebetween. It will 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. 
       FIG. 1  illustrates a perspective view showing a battery module according to an embodiment. 
     Referring to  FIG. 1 , the battery module  100  according to this embodiment may be used by forming, as a set, a plurality of battery modules  100  connected to one another, in order to use high power. Each battery module  100  may be formed by aligning a plurality of battery cells  10  in one direction. The battery cells  10  may be electrically connected to each other, and each battery cell  10  may include a battery case of which one surface or side is opened, and an electrode assembly and an electrolyte, which are accommodated in the battery case. 
     The electrode assembly and the electrolyte may generate energy through an electrochemical reaction therebetween, and the battery case may be hermetically sealed with a cap plate. A terminal portion  11  and  12  and a vent  13  may be provided to a top surface  14  of the battery cell  10 . The terminal portion  11  and  12  may include positive and negative electrode terminals  11  and  12  having different polarities from each other. The vent  13  may be a safety means or mechanism of the battery cell  10 , and may act as a passage through which gas generated inside the battery cell is exhausted to the outside of the battery cell  10 . The positive and negative electrode terminals  11  and  12  of adjacent battery cells  10  may be electrically connected through a bus-bar  15 . The bus-bar  15  may be fixed to the positive and negative electrode terminals  11  and  12 , using a member, e.g., a nut  16 . A vent cover  30  may cover the vent  13  and at least one side surface, e.g., side surfaces, of the battery cell  10 . 
       FIG. 2  illustrates a side view of a coupling relationship between a battery cell and a vent cover according to an embodiment. 
     Referring to  FIG. 2 , the vent cover  30  may include a first cover that covers the vent  13 , and second covers  33  respectively extending from sides, e.g., both sides, of the first cover  31 . The second covers  33  may each cover a respective side surface of a corresponding one of the battery cells  10 . 
     The first cover  31  may be spaced apart from the vent  13 . The second covers  33  may be coupled to, contact, or be adhered closely to the side surfaces of the corresponding one of the battery cells  10 . 
     A swelling phenomenon (in which gas or the like is generated and filled inside a battery cell at a high temperature/high voltage) may occur in the battery cell  10 . In a case where the internal pressure of the battery cell  10  is increased due to the generation of the gas, the vent  13  in the top surface of the battery cell  10  may be fractured, so that the internal gas may be exhausted to the outside of the battery cell  10 . When the vent  13  is fractured, a spark could be temporarily generated, and the electrolyte may be discharged, together with the internal gas, to the outside of the battery cell  10 . 
     In this case, the first cover  31  (covering the vent  13 ) and the second covers  33  may help reduce the likelihood of and/or prevent the spark (that may be generated when the vent  13  is fractured) from, e.g., adversely, influencing an adjacent battery cell  10 . In addition, the first and second covers  31  and  33  may help prevent the electrolyte (discharged from the inside of the battery cell  10 ) from being transferred or exposed to the adjacent battery cell  10 , so that the performance of the adjacent battery cell  10  may be constantly maintained, thereby improving stability. 
     In an implementation, an absorbing member  40  may be disposed on one surface of the first cover  31  that is opposite to the vent  13 , e.g., the one surface of the first cover  31  may be opposite to and/or face the vent  13 . The absorbing member  40  may absorb the gas or electrolyte that is exhausted or discharged from the inside of the battery cell  10 , and may help prevent the electrolyte from being moved or exposed to another battery cell  10 . 
     In a case where the swelling phenomenon occurs in the battery cell  10 , the side surfaces of the battery cell  10  may be generally swelled by the pressure increased inside the battery cell  10 . In this case, performance of the battery cell  10  may be decreased. According to an embodiment, the second covers  33  may be respectively coupled to or adhered closely to the side surfaces, e.g., both side surfaces, of the battery cell  10 , and may help maintain performance of the battery cell  10  before the vent  13  is fractured by helping to prevent swelling of the battery cell  10 . For example, the second covers  33  may press inwardly on the sides of the battery cell  10  in order to help suppress the swelling of the battery cell. In an implementation, the second covers  33  may be formed of a material having high strength in order to help reduce and/or prevent the swelling phenomenon (caused by an increase in the internal pressure of the battery cell  10 ). 
       FIG. 3  illustrates a side view of a coupling relationship between the battery cell and the vent cover according to another embodiment. 
     Referring to  FIG. 3 , components of the battery module except for a heat insulating member  50  may be substantially identical to those of the embodiment shown in  FIG. 2 . Therefore, the substantially identical components are designated by like reference numerals, and repeated detailed descriptions thereof may be omitted. 
     As shown in  FIG. 3 , the heat insulating member  50  may be between at least one of the second covers  33  and a corresponding side surface of the battery cell  10 . 
     In a case where the swelling phenomenon occurs in the battery cell  10 , heat may be generated inside the battery cell  10 . If the heat were to be conducted to an adjacent battery cell  10 , performance of the adjacent battery cell  10  could be decreased. Thus, the heat insulating member  50  may help prevent the heat from being conducted to the adjacent battery cell  10 , thereby maintaining the performance of the adjacent battery cell  10 . 
     In an implementation, the heat insulating member  50  may be formed of or may include at least one of, e.g., elastic rubber, a urethane, or silicon. For example, the heat insulating member may be formed of various suitable materials that are able to shield or insulate against heat. 
       FIG. 4  illustrates a side view of a coupling relationship between the battery cell and the vent cover according to still another embodiment. 
     Referring to  FIG. 4 , components of the battery module except for a protruding portion  60  may be substantially identical to those of the embodiment shown in  FIG. 2 . Therefore, the substantially identical components are designated by like reference numerals, and repeated detailed descriptions thereof may be omitted. 
     As shown in  FIG. 4 , at least one protruding portion  60  may be formed on an inner surface of at least one of the second covers  33 . The protruding portion  60  may form or provide a space between the at least one second cover  33  and the corresponding battery cell  10  by allowing the one second cover  33  and the battery cell  10  to be spaced apart from each other. Thus, the protruding portion  60  perform a barrier function, and may provide a movement path of a coolant, e.g., a coolant path, for cooling the battery cell  10 . 
       FIG. 5  illustrates a perspective view of a vent cover according to an embodiment.  FIG. 6  illustrates a perspective view showing the battery module to which the vent cover of  FIG. 5  is coupled. 
     In a case where the vent cover  30  is disposed at or on each battery cell  10  (e.g., in which each battery cell  10  is associated with one of the vent covers  30 ) as shown in  FIG. 1 , the second covers  33  may be overlapped with each other between the battery cell  10 . Therefore, an entire thickness of the battery module  100  (in the alignment direction of the battery cells  10 ) may be increased. 
     Referring to  FIG. 5 , second covers  533   a  and  533   b  of the vent cover  530  may respectively extend from only portions of sides, e.g., both sides, of a first cover  531 . For example, one second cover  533   b  may extend from a portion B of one side of the first cover  531 , and another second cover  533   a  may extend from another portion of another side of the first cover  531  that is adjacent to a portion A of the other side of the first cover  531  (e.g., portion A may overlap with or may be symmetrical with portion B of the one side of the first cover  531 ). For example, portion A (at which the second cover  533   a  is not extended from the other side of the first cover  531 ) may correspond with or overlap with portion B (from which the one second cover  533   b  extends on the one side of the first cover  531 ). For example, the second covers  533   a  and  533   b  of one vent cover  530  may be offset or asymmetrical with respect to one another. 
     Thus, in a case where a plurality of vent covers  530  are aligned in a row, as shown in  FIG. 6 , the second covers  533   a  and  533   b  may alternately extend at sides, e.g., both sides, of the first cover  531 . Hence, the second covers  533   a  and  533   b  of adjacent vent covers  530  (between the battery cells  10 ) may not be overlapped with each other (e.g., in the aligning direction of the battery cells  10 ). Thus, an entire thickness of the battery module  600  may be decreased, as compared with the thickness of the battery module of  FIG. 1 . 
     In an implementation, the vent cover  30  or  530  may be provided in plural numbers in the battery module  100  or  600  to respectively cover the vent and side surfaces of each battery cell  10  of the plurality of battery cells  10 . In an implementation, only one vent cover may be disposed in the battery module, to thus cover only outer side surfaces of outermost battery cells among the plurality of battery cells. This will be described below with reference to  FIGS. 7 and 8 . 
       FIG. 7  illustrates a perspective view showing a battery module according to another embodiment. 
     Referring to  FIG. 7 , components of the battery module except a vent cover  730  may be substantially identical to those of the embodiment shown in  FIG. 1 . Therefore, the substantially identical components are designated by like reference numerals, and repeated detailed descriptions thereof may be omitted. 
     The vent cover  730  may include a first cover  731  covering the vent  13  on top surfaces  14  of each battery cell  10  of the plurality of battery cells  10 , and second covers  733  respectively covering side surfaces of outermost battery cells  10  of the plurality of battery cells  10 . 
     The first cover  731  may be spaced apart from the vent  13 . An absorbing member ( 40 , see  FIG. 2 ) may be on one surface of the first cover  731  that is opposite to or facing the vent  13  of each of the plurality of battery cells  10 . 
     A shielding member  735  may be disposed between battery cells  10  of the plurality of battery cells  10 . At least one insertion hole  737  (having the shielding member  735  inserted thereinto) may be provided on a top surface of the first cover  731 . 
     The shielding member  735  may partition a space between the top surfaces of the plurality of battery cells  10  and the first cover  731  for each battery cell. In a case where the vent  13  of any one battery cell  10  is fractured, the shielding portion  735  may help prevent a spark (that may be generated in the vent  13  of the battery cell  10 ) or an electrolyte (discharged from the battery cell  10 ) from being transferred to or affecting an adjacent battery cell  10 . 
       FIG. 8  illustrates a perspective view showing a battery module according to still another embodiment. 
     Referring to  FIG. 8 , components of the battery module except for a vent cover  830  and a barrier  850  may be substantially identical to those of the embodiment shown in  FIG. 1 . Therefore, the substantially identical components are designated by like reference numerals, and repeated detailed descriptions thereof may be omitted. 
     As shown in  FIG. 8 , barriers  850  may be respectively interposed between battery cells  10  of the plurality of battery cells  10 . 
     A shielding portion  851  may extend upwardly from a partial area of a top surface of the barrier  850 , and may be coupled to, contact, or be adhered closely to a bottom surface of a first cover  831 . For example, a width of the shielding portion  851  may be less than an overall width of the barrier  850  (e.g., the side of the barrier  850 ) from which the shielding portion  851  extends. Thus, the shielding portion  851  may partition a space between the top surfaces of the plurality of battery cells  10  and the first cover  831  for each battery cell. The shielding portion  851  may help prevent a spark (that may be generated in the vent  13  of any one battery cell  10 ) or an electrolyte (discharged from the battery cell  10 ) from being transferred to or affecting an adjacent battery cell  10 . 
     In an implementation, the barrier  850  may include one or more protruding portions  853 . The protruding portions  853  may be provided on at least one of first and second surfaces of the barrier  850 . The protruding portions  853  may be provided on the surface where the barrier  850  and the battery cell  10  contact each other. In an implementation, a section of the protruding portion  853  may be formed in a circular, rounded, or quadrangular shape, and a number and positions of the protruding portions  853  may be variously modified according the to design of the battery module. 
     The barrier  850  may be interposed between adjacent battery cells  10 , to allow the adjacent battery cells  10  to be spaced apart from each other. Therefore, an empty or open space may be provided between, e.g., inner parts of, the barrier  850  and the battery cell  10  by the protruding portions  853 . The space may act as a path through which heat generated in the battery cell  10  is discharged, so that the heat may not be accumulated. In an implementation, the space may become a path through which a cooling medium for cooling the battery cell  10  is moved, e.g., a coolant path. 
     In order to control swelling of the battery cell  10 , which may occur in a process of charging/discharging the battery cell  10 , the barrier  850  may perform, together with a second cover  833 , a function of compressing the battery cell  10  with a predetermined pressure or more. 
     The barrier  850  may be made of a heat insulating member that is capable of shielding or insulating against heat. The barrier  850  may help prevent heat that is generated inside the battery cell  10  from being conducted to an adjacent battery cell  10  when swelling of the battery cell  10  occurs. 
     By way of summation and review, a swelling phenomenon (in which gas or the like is generated and filled inside a battery cell at a high temperature/high voltage) may occur in a battery cell. Therefore, a vent may be provided in a top surface of the battery cell. In a case where the internal pressure of the battery cell is increased due to the gas generated inside the battery cell, the gas may be exhausted to the outside of the battery cell by fracturing the vent. 
     When the vent is fractured, a spark may be temporarily generated, or an electrolyte inside the battery cell may be discharged together with the exhausted gas. In a case where a vent of a battery cell among a plurality of battery cells is fractured, the fracture of the vent may have an influence or effect on another adjacent battery cell. 
     The embodiments provide a battery module exhibiting improved stability, even when a vent of a battery cell is fractured. 
     According to an embodiment, although the vent of any one battery cell among the plurality of battery cells may be fractured, the performance of an adjacent battery cell may be constantly maintained, thereby improving stability. 
     Further, swelling of the battery cell may be reduced and/or prevented, so that it is possible to maintain the performance of the battery cell before the vent of the battery cell is fractured. 
     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.