Abstract:
A battery pack includes a battery cell; a case housing the battery cell; and an adhesion sheet surrounding at least a portion of an exterior surface of the case, wherein the adhesion sheet includes a base part and an adhesion part, the base part having a bending line corresponding in position to an edge of the case, and the adhesion part being on a bottom surface of the base part and including air exhaustion paths.

Description:
BACKGROUND 
     1. Field 
     One or more embodiments relate to a battery pack. 
     2. Description of the Related Art 
     Due to increasing demand for technical development and need for mobile devices, demand for secondary batteries as an energy source is sharply increasing. 
     Secondary batteries may be widely classified into circular-shaped batteries, angular-shaped batteries, pouch-shaped batteries, and the like according to exterior shapes of the secondary batteries, or may be classified according to types of electrolyte solutions. Recently, as mobile devices become smaller, demand for angular-shape batteries having small thicknesses and pouch-shape batteries increases. 
     In general, secondary batteries are classified into hard packs and inner packs according to how the secondary batteries are mounted on cases. A hard pack forms a part of an exterior shape of an external device on which the hard pack is mounted. However, a case should generally be designed so as to match a corresponding external device while the battery cell is mounted on the case. 
     On the other hand, an inner pack is used by mounting the inner pack in an external device, and a cover forming a part of the external device covers the inner pack. In order to protect contents of the inner pack or to provide information about the inner pack, an insulating sheet may be adhered on a most-exterior surface thereof. 
     SUMMARY 
     Embodiments are therefore directed to a battery pack. 
     According to one or more embodiments, a battery pack includes a battery cell, a case housing the battery cell, and an adhesion sheet surrounding at least a portion of an exterior surface of the case, wherein the adhesion sheet includes a base part and an adhesion part, the base part having a bending line corresponding in position to an edge of the case, and the adhesion part being on a bottom surface of the base part and including air exhaustion paths. 
     The bending line may be formed on a top surface of the base part. A depth of the bending line may be less than a thickness of the base part. The bending line may be groove in a shape of a continuous line extending in one direction. 
     The air exhaustion paths may be fluidically connected to an exterior of the case. The air exhaustion paths may be in fluid communication with each other. 
     The adhesion part may include adhesion sections. Each adhesion section may include an adhesive material. The air exhaustion paths may have grooves adjacent to at least one side of each of the adhesion sections. 
     Each adhesion section may be surrounded by air exhaustion paths. The air exhaustion paths may have a lattice-shape pattern. 
     The bending line may be on an area corresponding to the position of the adhesion sections. 
     The adhesion sheet may include a label of the battery pack. 
     The bending line may be a groove in the shape of an unbroken line extending from an end of the base part toward another end of the base part. 
     The air exhaustion paths may be disposed in parallel with respect to each other. An adhesive material may be disposed between at least two air exhaustion paths. 
     The bending line may overlap and extend along a corner of the case. 
    
    
     
       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 an adhesion sheet according to an embodiment; 
         FIG. 2  illustrates a cross-sectional view of the adhesion sheet of  FIG. 1 , taken along a line II-II of  FIG. 1 ; 
         FIG. 3  illustrates a perspective view of a state of the adhesion sheet of  FIG. 1  in which the adhesion sheet is bent or unbent along a bending line; 
         FIG. 4  illustrates a perspective view of an adhesion sheet according to another embodiment; 
         FIGS. 5A and 5B  illustrate magnified cross-sectional views of an adhesion sheet according to other embodiments; 
         FIG. 6  illustrates a bottom view of the adhesion sheet of  FIG. 1 ; 
         FIG. 7  illustrates a magnified perspective view of a portion of the adhesion sheet of  FIG. 6 ; 
         FIG. 8  illustrates a magnified perspective view of an adhesion sheet according to another embodiment, in which an adhesion part is upwardly exposed; 
         FIG. 9  illustrates a perspective view of a battery pack, according to an embodiment; and 
         FIG. 10  illustrates a cross-sectional view of the battery pack of  FIG. 9 , taken along a line X-X of  FIG. 9  and having an adhesion sheet adhered to an exterior surface of a case of the battery pack. 
     
    
    
     DETAILED DESCRIPTION 
     Korean Patent Application No. 10-2011-0030286, filed on Apr. 1, 2011, in the Korean Intellectual Property Office, and entitled: “Battery Pack,” is incorporated by reference herein in its entirety. 
     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. It will also be understood that when a layer or element is referred to as being “on” another element or substrate, it can be directly on the other element or substrate, or intervening elements may also be present. Further, it will be understood that when an element is referred to as being “under” another element, it can be directly under, and one or more intervening elements may also be present. In addition, it will also 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. Like reference numerals refer to like elements throughout. 
     Furthermore, all examples and conditional language recited herein are to be construed as being without limitation to such specifically recited examples and conditions. Throughout the specification, a singular form may include plural forms, unless there is a particular description contrary thereto. Also, terms such as “comprise” or “comprising” are used to specify existence of a recited form, a number, a process, an operations, a component, and/or groups thereof, not excluding the existence of one or more other recited forms, one or more other numbers, one or more other processes, one or more other operations, one or more other components, and/or groups thereof. While such terms as “first,” “second,” etc., may be used to describe various components, such components must not be limited to the above terms. The above terms are used only to distinguish one component from another. 
       FIG. 1  illustrates a perspective view of an adhesion sheet  100  according to an embodiment.  FIG. 2  illustrates a cross-sectional view of the adhesion sheet  100 , taken along a line II-II of  FIG. 1 .  FIG. 3  illustrates a perspective view of a state of the adhesion sheet  100 , in which the adhesion sheet  100  may be bendable along a bending line  111 . 
     Referring to  FIGS. 1 and 2 , the adhesion sheet  100  may include a base part  110  and an adhesion part  120  disposed on one surface of the base part  110 . 
     The base part  110  is a layer that is externally exposed. The base part  110  may give durability to the adhesion sheet  100  and may function as a protective part that prevents a surface of a target object, on which the adhesion sheet  100  is to be adhered, from being damaged. The base part  110  may be formed of a material having relatively high tensile strength and relatively excellent weather-resistance. 
     The base part  110  may include a resin material. For example, the resin material may include a polyolefin, e.g., polyethylene and/or polypropylene, a polyester, e.g., polyethyleneterepthalate and/or polybutyleneterepthalate, polyvinylchloride, polystyrene, polyurethane, polycarbonate, polyamide, polymethylmethacrylate, polybutene, polybutadiene, or the like. 
     The bending line  111  may prevent a crease from being formed on the base part  110  when the adhesion sheet  100  is bent and then unbent. For this prevention, the bending line  111  may be formed as a groove in the shape of a solid line extending in one direction on a top surface  110   a  of the base part  110 . For example, the bending line  111  may be formed as a solid line extending, e.g., continuously, from an end of the base part  110  toward another end of the base part  110 . In a comparative example with respect to the present embodiment, when an adhesion sheet not having a bending line is bent and then straightened, a crease may be formed in an area where the adhesion sheet was bent. However, according to the present embodiment, the bending line  111  may be formed on the top surface  110   a  of the base part  110 , so that, as illustrated in  FIG. 3 , even when the adhesion sheet  100  is bent and then straightened, a crease is not formed on the base part  110 . 
     Referring back to  FIG. 2 , a depth d g  of the bending line  111  may be less than a thickness D of the base part  110 , i.e., a distance between the top surface  110   a  and a bottom surface  110   b . The bending line  111  may be formed by applying a predetermined amount of pressure to the base part  110  by using a separate pressing member (not shown). Here, the pressing member may have the same shape as a shape of the bending line  111  to be formed, and the depth d g  of the bending line  111  may correspond to a pressure depth to which the pressing member is pressed into the base part  110 . When the depth d g  of the bending line  111  is too great, the base part  110  may be cut into two parts. The pressing member may press the base part  110  so as to allow the depth d g  of the bending line  111  to be less than the thickness D of the base part  110 . 
     In the present embodiment, the bending line  111  may be formed as a solid line or groove extending in one direction but one or more embodiments are not limited thereto. For example, referring to  FIG. 4 , a bending line  411  may be a groove in the shape of a broken line. For example, bending line  411  may include a plurality of lines extending in one direction, with gaps formed between the plurality of lines. In this case, when a gap g between the plurality of bending lines is too large, a crease may be formed when an adhesion sheet  400  is bent and then straightened. Thus, the gap g between the bending lines may be narrow. An adhesion part  420  may be formed on a bottom surface of the adhesion sheet  400 . 
     According to the present embodiment, a cross-sectional area of the bending line  111  may be quadrangular, as illustrated in  FIG. 2 , but one or more embodiments are not limited thereto. For example, referring to  FIGS. 5A and 5B  illustrating other embodiments, cross-sectional areas of bending lines  111   a  and  111   b  may be inverted-triangular or may be U-shaped, respectively. 
       FIG. 6  is a bottom view of the adhesion sheet  100  of  FIG. 1 , illustrating the adhesion sheet  100  from its bottom.  FIG. 7  is a magnified perspective view of a portion of the adhesion sheet  100  of  FIG. 6 . 
     Referring to  FIGS. 6 and 7 , the adhesion part  120  may be formed on the bottom surface  110   b  of the base part  110  (see  FIG. 2 ), and may include adhesion sections  121  and air exhaustion paths  122  through which air passes. For example, the adhesion sections  121  may be a plurality of discrete portions spaced apart from each other, e.g., two adjacent adhesion sections  121  may be separated via the air exhaustion paths  122 . 
     The adhesion sections  121  may include an adhesive material that allows the adhesion sheet  100  to be adhered to the target object. For example, the adhesion sections  121  may include an acryl-based material, a polyester-based material, a polyurethane-based material, a rubber-based material, a silicon-based material, or the like. 
     The adhesion sections  121  may be formed on an area corresponding to the bending line  111  by having the base part  110  formed therebetween, e.g., the adhesion sections  121  may overlap the bending line  111 . The adhesion sheet  100  may be disposed in such a manner that the bending line  111  corresponds to a corner or edge of the target object, and in this case, the adhesion sections  121  formed on the area corresponding to the bending line  111  may adhere the adhesion sheet  100  to the target object, so that it is possible to prevent the adhesion sheet  100  from coming off of the corner or edge of the target object. 
     The air exhaustion paths  122  may prevent air from being confined between the adhesion sheet  100  and the target object, and bubbles from being formed, when the adhesion sheet  100  is adhered to the target object. The air exhaustion paths  122  may have a groove shape with respect to the adhesion sections  121  and may extend to an end, e.g., an external edge, of the adhesion sheet  100 . Thus, the adhesion sections  121  may be fluidically connected to the outside, e.g., an exterior of the adhesion sheet  100 . For example, air may travel between the adhesion sheet  100  and the target object via the air exhaustion paths  122 . 
     The air exhaustion paths  122  may be in fluid communication with each other, thereby forming a network. For example, the air exhaustion paths  122  may form a lattice-shape pattern. The air in the adhesion sheet  100  may be distributed and may move in various directions via the air exhaustion paths  122 , which are connected to each other, so that it is possible to prevent bubbles from being formed in the adhesion sheet  100  and to increase an air exhaustion efficiency. 
     The air exhaustion paths  122  may form the lattice-shape pattern. As such, the adhesion sections  121  may be surrounded by the air exhaustion paths  122 . Unlike the air exhaustion paths  122 , which are connected to each other, the adhesion sections  121  may be separate from each other. 
     In the present embodiment, the air exhaustion paths  122  may form the lattice-shape pattern, and the adhesion sections  121  may be quadrangular. However, one or more embodiments are not limited thereto. For example, the air exhaustion paths  122  may be fluidically connected to each other while the adhesion sections  121  may be round, oval, or polygonal. 
       FIG. 8  is a perspective view of an adhesion sheet  800  according to another embodiment, in which an adhesion part  820  is upwardly exposed. 
     Referring to  FIG. 8 , the adhesion sheet  800  may include a base part  810 , and the adhesion part  820  may be arranged on one surface of the base part  810 . The adhesion part  820  may be the same as the adhesion part  120  described with reference to  FIGS. 6 and 7  in that the adhesion part  820  may include adhesion sections  821  and air exhaustion paths  822 . However, according to the present embodiment, the adhesion part  820  may be different from the adhesion part  120  with respect to the shapes of the air exhaustion paths  822  and the adhesion sections  821 . Hereinafter, the differences between the adhesion part  820  and the adhesion part  120  will be described. 
     The adhesion sections  821  may be formed parallel to each other, so that the air exhaustion paths  822  arranged between the adhesion sections  821  may also be formed parallel to each other. In the present embodiment, the air exhaustion paths  822  may extend to an end of the adhesion sheet  800 , e.g., may extend diagonally between two external edges of the adhesion sheet  100 , and thus may be fluidically connected to the outside or exterior of the adhesion sheet  100 . Air in the adhesion sheet  800  may be externally exhausted along the air exhaustion paths  822 , which are disposed in parallel. In the present embodiment, the air exhaustion paths  822  may not be connected to each other. As such, the adhesion sheet  800  may be adhered to a target object along an extension direction of the adhesion sections  821  so as to facilitate movement of air through the air exhaustion paths  822 . 
     The aforementioned adhesion sheets  100 ,  400 , and  800  may be arranged on an exterior-most layer of a battery pack and then may be used as a label of the battery pack. Hereinafter, a case in which an adhesion sheet is arranged on a battery pack will be described in detail. 
       FIG. 9  illustrates a perspective view of a battery pack  90 , according to an embodiment.  FIG. 10  illustrates a cross-sectional view of the battery pack  90 , taken along a line X-X of  FIG. 9  and having an adhesion sheet  900  adhered to an exterior surface of a case  92  of the battery pack  90 . 
     Referring to  FIGS. 9 and 10 , the battery pack  90  may include a battery cell  91 , the case  92 , and the adhesion sheet  900 . 
     The battery cell  91  may be included in the case  92 . The battery cell  91  may include a cell or may include a plurality of cells so as to provide a battery pack having a high output and high capacity. Although not illustrated in  FIGS. 9 and 10 , the battery cell  91  may be electrically connected to a protective circuit module. 
     Exterior surfaces  92   u ,  92   s  of the case  92  may be surrounded by the adhesion sheet  900 . For example, the adhesion sheet  900  may surround, e.g., overlap, an upper surface  92   u  and side surfaces  92   s  of the case  92 . One of the adhesion sheets described above with reference to  FIGS. 1 through 8  may be used as the adhesion sheet  900 . The adhesion sheet  900  may have a mechanical strength and a surface hardness, so that the adhesion sheet  900  may maintain stability of the battery pack  90  and may prevent deterioration due to an external shock or scratches. The adhesion sheet  900  may be adhered while being bent along the exterior surfaces of the case  92  having a cubic shape. For this adhesion, a bending line  911  may be formed on the adhesion sheet  900  before being adhered to the case  92 , and the adhesion sheet  900  may correspond to a size of the cubic shape of the case  92 . 
     When the adhesion sheet  900  is adhered to the case  92 , air interposed between the adhesion sheet  900  and the case  92  may be exhausted via an air exhaustion path  922  formed in an adhesion part  920 . As such, as described above, bubble formation between the adhesion sheet  900  and the case  92  may be avoided. 
     Also, as described above, the bending line  911  of the adhesion sheet  900  may be formed in an area corresponding to an adhesion section  921 . For example, the bending line  911  may correspond to an edge  92   a , e.g., the bending line  911  may overlap and extend along the edge  92   a . As such, it may be possible to prevent the adhesion sheet  900  from coming off of edges, e.g., corners, of the case  92 . 
     In the present embodiment, the adhesion sheet  900  may completely surround the exterior surfaces of the case  92  but one or more embodiments are not limited thereto. For example, the adhesion sheet  900  may be adhered to only some of the surfaces of the case  92 . 
     According to one or more embodiments, by forming an air exhaustion path in an adhesion part, it may be possible to effectively prevent air from being confined or bubbles from being formed when an adhesion sheet is adhered to a target object. 
     According to one or more embodiments, a bending line may be formed on the base part, so that, even when an adhesion sheet is bent and then straightened, it is possible to effectively prevent a crease from being formed on the adhesion sheet, thereby preventing ruining an exterior of the battery pack. 
     According to various embodiments, the battery pack may be mounted in an external device with relative ease. The battery pack, e.g., inner pack, may be easy to design, low-priced, and have compatibility with an external device. The adhesion sheet of the battery pack does not ruin an exterior of the battery pack and is effectively adhered on the battery pack. 
     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 embodiments as set forth in the following claims.