Patent Publication Number: US-2016248056-A1

Title: Battery pack

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Korean Patent Application No. 10-2015-0026747, filed on Feb. 25, 2015, in the Korean Intellectual Property Office, and entitled: “Battery Pack,” is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     One or more exemplary embodiments relate to a battery pack. 
     2. Description of the Related Art 
     Unlike primary batteries, secondary batteries may be rechargeable. Secondary batteries may be used as energy sources of devices such as mobile devices, electric vehicles, hybrid electric vehicles, electric bicycles, and uninterruptible power supplies. Single-cell secondary batteries or multi-cell secondary batteries (secondary battery packs) in which a plurality of battery cells are electrically connected may be used according to the types of external devices using the secondary batteries. 
     SUMMARY 
     Embodiments may be realized by providing a battery pack, including two or more battery cells; and a cell holder to which the battery cells are coupled, the cell holder including a base portion extending across the battery cells in an arrangement direction of the battery cells; and a side portion extending downward from the base portion and covering a lateral side of the battery cells, an extended end portion of the side portion including a skirt surface protruding from the lateral side of the battery cells. 
     The side portion may cover an upper portion of the lateral side of the battery cells, and a lower portion of the lateral side of the battery cells may be exposed from the side portion. 
     The skirt surface may be substantially perpendicular to the lateral side of the battery cells. 
     The side portion may include first and second side portions extending from opposite sides of the base portion. 
     The first and second side portions may be on front and rear end portions of the base portion in the arrangement direction of the battery cells. 
     Skirt surfaces of the first and second side portions may be substantially a same height. 
     The battery cells may include electrode tabs, and the base portion may extend across upper sides of terraces of the battery cells from which the electrode tabs extend. 
     The side portion may extend downward from the base portion to a height lower than the terraces of the battery cells so as to cover the terraces. 
     The battery cells may be pouch type battery cells packaged with flexible exterior materials. 
     The battery cells may be coupled to the cell holder in such a manner that electrode tabs of the battery cells are inserted through the cell holder. 
     The battery pack may further include a connection tab disposed above the cell holder and connected to the electrode tabs. 
     The battery pack may further include a case to accommodate the cell holder to which the battery cells are coupled. 
     The case may include may further include first and second cases coupled to each other to face each other with the cell holder being disposed therebetween. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features will become 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 view of a battery pack according to an exemplary embodiment; 
         FIG. 2  illustrates a perspective view of battery cells depicted in  FIG. 1 ; 
         FIG. 3  illustrates an exploded perspective view of the battery pack depicted in  FIG. 1 ; 
         FIGS. 4 and 5  illustrate a perspective view and a side view of a welding support; and 
         FIG. 6  illustrates a perspective view of a case. 
     
    
    
     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 features may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout. 
     As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. 
     A battery pack will now be described in detail with reference to the accompanying drawings, in which exemplary embodiments are shown. 
       FIG. 1  illustrates a view of a battery pack according to an exemplary embodiment.  FIG. 2  illustrates a perspective view of battery cells depicted in  FIG. 1 .  FIG. 3  illustrates an exploded perspective view of the battery pack depicted in  FIG. 1 . 
     Referring to  FIG. 1 , the battery pack may include at least two battery cells C and a cell holder  110  to which the battery cells C may be coupled. The battery cells C may include lithium-ion battery cells. Each of the battery cells C may include an electrode assembly having a stacked structure formed by first and second electrode plates having different polarities and a separator disposed between the first and second electrode plates. A plurality of first and second electrode plates and a plurality of separators may be stacked in the electrode assembly to increase the output power and capacity of the battery cell C. 
     Referring to  FIG. 2 , the battery cells C may include exterior materials  13  to seal the electrode assemblies. The battery cells C may be pouch type battery cells including relatively flexible exterior materials  13  instead of metal cans. Each of the battery cells C may include electrode tabs  10  electrically connected to the electrode assemblies and extending outward from the exterior materials  13 . Each of the battery cells C may include first and second electrode tabs  11  and  12  respectively making electrical connection with the first and second electrode plates, and having different polarities. In this specification, the term “electrode tab(s)  10 ” refers to one or both of the first and second electrode tabs  11  and  12 . The battery cells C may include terraces  15  from which the electrode tabs  10  extend outward. 
     Referring to  FIG. 3 , the battery cells C may be coupled to the cell holder  110 . The battery cells C may be coupled to the cell holder  110  in such a manner that the electrode tabs  10  of the battery cells C are exposed on an upper surface of the cell holder  110 . The cell holder  110  may support and hold the battery cells C, and the battery cells C may be maintained at proper positions when inserted into the cell holder  110 . The cell holder  110  may structurally combine the battery cells C as a single module. 
     The cell holder  110  may include a plurality of tab holes  110 ′ corresponding to the battery cells C. The electrode tabs  10  extending from the battery cells C may be inserted through the tab holes  110 ′ and exposed to the outside. The tab holes  110 ′ may be paired such that the first and second electrode tabs  11  and  12  extending from each of the battery cells C may be inserted through a pair of the tab holes  110 ′. For example, the first and second electrode tabs  11  and  12  extending from one of the battery cells C may be inserted through a pair of the tab holes  110 ′, and then the first and second electrode tabs  11  and  12  may be bent forward and backward in opposite directions to make electrical connection with neighboring battery cells C disposed in front and rear directions. 
     Battery cells C neighboring each other in a front-to-rear direction may be electrically connected to each other through connection tabs  120  superposed on the first and second electrode tabs  11  and  12  of the battery cells. Battery cells C arranged in the front-to-rear direction may be structurally modularized by the cell holder  110  and then may be electrically modularized by the connection tabs  120 . 
     The connection tabs  120  may be superposed on the electrode tabs  10  which extend from the cell holder  110  through the tab holes  110 ′. Then, the connection tabs  120  may be coupled to the electrode tabs  10 , for example, by welding. 
     The connection tabs  120  may include a pair of first and second connection tabs  121  and  122 , e.g., first and second connection tab portions  121  and  122 , and each pair of first and second connection tabs  121  and  122  may be disposed on lower and upper sides of the electrode tabs  10  to place the electrode tabs  10  therebetween. As described above, the electrode tabs  10  may be sandwiched between the first and second connection tabs  121  and  122  of the connection tabs  120  disposed on the lower and upper sides of the electrode tabs  10 , and electric connection between the electrode tabs  10  and the connection tabs  120  may be made more smoothly. The electric contact area between the connection tabs  120  and the electrode tabs  10  may be increased, and moreover, the coupling strength between the connection tabs  120  and the electrode tabs  10  may be improved. 
     For example, the electrode tabs  10  extending from the battery cells C may be inserted through the tab holes  110 ′ of the cell holder  110  and tab holes  121 ′ of the first connection tabs  121  and exposed on upper surfaces of the first connection tabs  121 , and the second connection tabs  122  may be superposed on the upper surfaces of the first connection tabs  121  on which the electrode tabs  10  are exposed. 
     The cell holder  110  may include the support ribs  115  protruding toward the battery cells C. The support ribs  115  may protrude downward toward the battery cells C. The support ribs  115  may support portions of the battery cells C, for example, the terraces  15  of the battery cells C. For example, the battery cells C may be coupled to the cell holder  110  through a lower side of the cell holder  110 , the support ribs  115  may prevent the terraces  15  of the battery cells C from colliding with a lower surface of the cell holder  110  and may maintain a proper distance between the cell holder  110  and the terraces  15  of the battery cells C, and the electrode tabs  10  may be prevented from being damaged during a welding process. The support ribs  115  may protrude from the cell holder  110  toward the terraces  15  of the battery cells C, the coupling height of the battery cells C may be regulated to maintain a proper distance between the cell holder  110  and the battery cells C, and the cell holder  110  may be damaged less by collision, and the electrode tabs  10  may be damaged less during welding. 
       FIGS. 4 and 5  illustrate a perspective view and a side view of a welding support  180 . 
     Referring to  FIGS. 4 and 5 , the cell holder  110  may include: a base portion  113  disposed on top of the battery cell and extending in an arrangement direction of the battery cells C; and first and second side portions  111  and  112  extending from the base portion  113  to cover lateral sides of the battery cells C. 
     The base portion  113  may occupy the largest portion of the area of the cell holder  110  and provide basic functions of the cell holder  110 . For example, the base portion  113  may combine the battery cells C as a single module and may support the connection tabs  120  electrically connecting the battery cells C. For example, the base portion  113  may extend across upper sides of the battery cells C, for example, upper sides of the terraces  15  of the battery cells C. 
     The first and second side portions  111  and  112  may extend downward from the base portion  113 . For example, the first and second side portions  111  and  112  may extend from front and rear ends of the base portion  113  in the arrangement direction of the battery cells C. The first and second side portions  111  and  112  may cover and protect lateral sides CS of the outermost battery cells C in the arrangement direction of the battery cells C. For example, the first and second side portions  111  and  112  may extend longer than the terraces  15  of the battery cells C and may protect portions of the battery cells C. The first and second side portions  111  and  112  may cover upper portions of the lateral sides CS of the battery cells C, and lower portions of the lateral sides CS of the battery cells C may be exposed from the first and second side portions  111  and  112 . 
     The first and second side portions  111  and  112  may cover the electrode tabs  10  extending from the terraces  15  of the battery cells C for insulating the electrode tabs  10 . In an exemplary embodiment, as described above, the battery cells C may be pouch type battery cells packaged with the flexible exterior materials  13 , which may be relatively weak compared to metal cans, and the first and second side portions  111  and  112  may enhance the structural rigidity of the battery cells C. 
     The first and second side portions  111  and  112  may extend downward from both end portions of the base portion  113 , and extended end portions of the first and second side portions  111  and  112  may include skirt surfaces SK protruding from the lateral sides CS of the battery cells C. As described later, the skirt surfaces SK of the first and second side portions  111  and  112  may be brought into contact with the welding support  180 . 
     The connection tabs  120  may be welded, and the first and second side portions  111  and  112  may support the cell holder  110  at a constant height. For example, a structure for supporting the cell holder  110  at a certain height from the floor may be used when a welding electrode is pushed against the cell holder  110  in a welding process. If the battery cells C are pushed by a welding electrode in a state in which the battery cells are directly placed on the floor, the battery cells C may be compressed and damaged. The first and second side portions  111  and  112  may support the cell holder  110  at a certain height. 
     The connection tabs  120  and the electrode tabs  10  may be welded, and the welding support  180  may be disposed under the first and second side portions  111  and  112  of the cell holder  110 . The first and second side portions  111  and  112  may be placed on the welding support  180 , and welding may be performed in a state in which the cell holder  110  is supported by the welding support  180 . The first and second side portions  111  and  112  may have a skirt shape protruding from the battery cells C for coupling with the welding support  180 . The skirt surfaces SK of the first and second side portions  111  and  112  may be brought into contact with upper surfaces  180   a  of the welding support  180  when the cell holder  110  is supported by the welding support  180 . The skirt surfaces SK of the first and second side portions  111  and  112  may be substantially perpendicular to the lateral sides CS of the battery cells C. For example, in a state in which the skirt surfaces SK of the first and second side portions  111  and  112  are in tight contact with the upper surfaces  180   a  of the welding support  180 , the cell holder  110  may be securely supported for a welding process. The skirt surfaces SK of the first and second side portions  111  and  112  and the upper surfaces  180   a  of the welding support  180  may be parallel with each other and perpendicular to the lateral sides CS of the battery cells C, and surface contact with each other may be made. 
     The skirt surfaces SK of the first and second side portions  111  and  112  may be formed substantially at the same height (h). For example, the cell holder  110  may be uniformly supported in the front-to-rear direction, and welding may be stably performed. The upper surfaces  180   a  of the welding support  180  that make contact with the skirt surfaces SK of the first and second side portions  111  and  112  may also be located at the same height (h). The welding support  180  may have a symmetric shape in the front-to-rear direction, and the welding support  180  may be coupled to the first and second side portions  111  and  112  without having to consider the orientation of the welding support  180  relative to the first and second side portions  111  and  112 . 
     Before a welding process, the positions of the connection tabs  120  and the electrode tabs  10  may be temporarily fixed relative to each other owing to a support structure provided by the first and second side portions  111  and  112  and the welding support  180 . The welding support  180  may support the battery cells C to adjust relative heights of the electrode tabs  10  and the connection tabs  120 . In a stable state in which the positions of the connection tabs  120  and the electrode tabs  10  are temporarily fixed relative to each other as described above, welding may be performed, and uniform welding strength and a high degree of welding quality may be obtained. The welding support  180  may be removed after the welding process. After the battery pack is completely manufactured, the welding support  180  may not constitute a part of the battery pack. 
       FIG. 6  illustrates a perspective view of a case  190 . 
     Referring to  FIG. 6 , the cell holder  110  to which the battery cells C may be coupled may be disposed in the case  190 , and the case  190  may form the exterior of the battery pack. For example, the case  190  may include first and second cases  191  and  192  that may be coupled to each other. The first and second cases  191  and  192  may be coupled to each other in mutually-facing directions in a state in which the cell holder  110  to which the battery cells C may be coupled may be disposed between the first and second cases  191  and  192 . The battery cells C may be disposed in the first and second cases  191  and  192  and protected from environmental agents. 
     With reference to  FIGS. 3, 5, and 6 , processes for manufacturing the battery pack of an exemplary embodiment will be described. First, referring to  FIG. 3 , the battery cells C may be coupled to the cell holder  110 . For example, the battery cells C may be coupled to the cell holder  110  from the lower side of the cell holder  110  so that the electrode tabs  10  of the battery cells C may be inserted into the tab holes  110 ′ of the cell holder  110 . 
     Next, the connection tabs  120  may be coupled to the cell holder  110 . For example, the connection tabs  120  may be disposed on pairs of neighboring electrode tabs  10 . 
     Next, as shown in  FIG. 5 , the welding support  180  may be disposed under the cell holder  110 . The welding support  180  may be placed in such a manner that the upper surfaces  180   a  of the welding support  180  may make contact with the skirt surfaces SK of the first and second side portions  111  and  112  of the cell holder  110 . 
     After the cell holder  110  is securely supported at a certain height from the floor by the welding support  180  as described above, a welding process may be performed. The connection tabs  120  and the electrode tabs  10  may be coupled to each other through the welding process. After the connection tabs  120  are completely welded, the welding support  180  may be removed. Then, the manufacturing of the battery pack may be completed in a state in which the battery cells C are structurally and electrically combined as a module. 
     As shown in  FIG. 6 , the cell holder  110  to which the battery cells C may be coupled may be disposed in the case  190 . For example, the first and second cases  191  and  192  of the case  190  may be coupled to each other to face each other in a state in which the cell holder  110  to which the battery cells C may be coupled may be disposed between the first and second cases  191  and  192 . 
     In a comparative example, the connection tabs  120  and the electrode tabs  10  may be welded together by using a welding jig. According to the comparative example, a welding jig having a complicated structure may be used, additional processes and time may be required to assemble the welding jig and remove the welding jig, and manufacturing costs may be increased. 
     In an exemplary embodiment, a welding process may be performed by using the cell holder  110  constituting a part of the battery pack in a state in which the cell holder  110  may be sufficiently supported by the welding support  180  having a simple structure. The welding support  180  may be simply assembled and removed, and the welding process may be easily performed. 
     By way of summation and review, one or more exemplary embodiments include a battery pack that may have an improved degree of weldability by providing a stable welding support for a cell holder structurally combining a plurality of battery cells. 
     As described above, according to the one or more of the above exemplary embodiments, the cell holder structurally combining a plurality of battery cells may be securely supported at a certain height by the welding support, and a welding process may be stably performed above the cell holder. 
     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 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.