Patent Publication Number: US-2015064548-A1

Title: Battery cell for electronic device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Korean Patent Application No. 10-2013-0104876, filed on Sep. 2, 2013, in the Korean Intellectual Property Office, and entitled: “Battery Cell For Electronic Device,” is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     An aspect relates to a battery cell for an electronic device. 
     2. Description of the Related Art 
     Unlike primary batteries that cannot be charged, secondary batteries can be charged/discharged. Secondary batteries are widely used in compact electronic devices such as cellular phones, PDAs, notebook computers, and tablet PCs. 
     Among various kinds of secondary batteries, a pouch-type secondary battery is manufactured by accommodating an electrode assembly in a pouch outer case and sealing the pouch outer case. The pouch-type secondary battery may have enhanced battery capacity, as compared with a prismatic or cylindrical secondary battery manufactured by accommodating an electrode assembly, using a can made of a metal material. 
     SUMMARY 
     A battery cell for an electronic device including an electrode assembly, an outer case that includes a first outer case and a second outer case that contact each other along an edge of the first outer case and an edge of the second outer case, thereby forming a body portion having a space that accommodates the electrode assembly therein, the edge of the first outer case and the edge of the second outer case together forming a wing portion in at least a portion of an outer circumference of the body portion, and an insulating film that surrounds the wing portion, the insulating film being in a folded state. The insulating film includes an adhesive coated on a first surface and a second surface thereof, the first surface and the second surface of the insulating film being on opposite sides of the insulating film from each other, the first surface of the insulating film adhering to the wing portion, and one portion of a second surface being adherable to an internal frame of the electronic device. 
     The first surface may include a first portion adhering to the edge of the first outer case forming the wing portion and a second portion adhering to the edge of the second outer case forming the wing portion. 
     The insulating film may surround the wing portion by extending toward the body portion from an end of the wing portion, the insulating film being folded along a line in a length direction that divides the first portion and the second portion of the first surface from each other. 
     The one portion of the second surface, being adherable to the internal frame of the electronic device, may be on a directly opposite side of the insulating film from the first portion of the first surface. 
     The second portion of the first surface may be wider than the first portion of the first surface. 
     The first surface may further include a third portion that continues from the second portion of the first surface and adheres to a rear surface of the body portion. 
     Another portion of the second surface may adhere to a side surface of the body portion in a state in which the wing portion is folded toward the body portion. 
     The one portion of the second surface that is adherable to the internal frame of the electronic device may be on a directly opposite side of the insulating film from the third portion of the first surface. 
     The another portion of the second surface, adhering to the side surface of the body portion, may be on a directly opposite side of the insulating film from the first portion of the first surface. 
     The other portion of the second surface may further adhere to a top surface of the body portion. 
     The other portion of the second surface, adhering to the side and top surfaces of the body portion, may be on a directly opposite side of the insulating film from the first portion of the first surface. 
     The electrode assembly may include positive and negative electrode tabs that extend to the outside of the outer case. 
     The electrode assembly may include a positive electrode plate, a negative electrode plate and a separator interposed between the positive and negative electrode plates. The positive electrode tab may be connected to the positive electrode plate, and the negative electrode tab may be connected to the negative electrode plate. 
    
    
     
       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 schematically showing a state in which a general battery cell for an electronic device is installed in the electronic device. 
         FIG. 2A  illustrates a perspective view of a battery cell for an electronic device, viewed from the front side thereof according to an embodiment. 
         FIG. 2B  illustrates a perspective view of the battery cell viewed from the rear side thereof according to the embodiment. 
         FIG. 3  illustrates an exploded perspective view of the battery cell according to the embodiment. 
         FIG. 4  illustrates an exploded perspective view of the battery cell according to the embodiment. 
         FIG. 5  illustrates a sectional view taken along line A-A of  FIG. 2 . 
         FIG. 6A  illustrates a view showing the insulating film in a state before a wing portion is surrounded with the insulating film according to the embodiment. 
         FIG. 6B  illustrates a sectional view taken along line A-A of  FIG. 6A . 
         FIG. 7A  illustrates a view showing the insulating film in a state in which the insulating film surrounds the wing portion according to the embodiment. 
         FIG. 7B  illustrates a sectional view taken along line A-A of  FIG. 7A . 
         FIGS. 8A and 8B  illustrate sectional views showing an insulating film according to another embodiment. 
         FIG. 8C  illustrates a sectional view showing an insulating film according to another embodiment. 
         FIG. 9A  illustrates a view schematically showing a state in which the battery cell is installed in an electronic device according to the embodiment. 
         FIG. 9B  illustrates a perspective view showing a state in which the battery cell is installed in an electronic device according to an 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. 
       FIG. 2A  illustrates a perspective view of a battery cell  100  for an electronic device, viewed from the front side thereof according to an embodiment.  FIG. 2B  illustrates a perspective view of the battery cell  100  viewed from the rear side thereof according to the embodiment. 
       FIGS. 3 and 4  illustrate exploded perspective views of the battery cell  100  according to the embodiment. 
       FIG. 5  illustrates a sectional view taken along line A-A of  FIG. 2 . 
     As shown in  FIGS. 2 to 5 , the battery cell  100  includes an electrode assembly  110 , an outer case  120 , and an insulating film  130 . 
     The electrode assembly  110  may include a positive electrode plate  111 , a negative electrode plate  112 , and a separator  113  interposed therebetween. 
     The positive electrode plate  111  may include a positive electrode active material portion formed by coating a positive electrode active material on a surface of a positive electrode collector made of aluminum or the like, and a positive electrode non-coating portion on which the positive electrode active material is not coated. The positive electrode active material may include, for example, a transition metal oxide containing lithium, such as LiCoO 2 , LiNiO 2 , LiMnO 2 , or LiMnO 4 , or a lithium chalcogenide compound. A positive electrode tab  114  having a predetermined length may be bonded to the positive electrode non-coating portion. 
     The negative electrode plate  112  may include a negative electrode active material portion formed by coating a negative electrode active material on a surface of a negative electrode collector made of nickel or the like, and a negative electrode non-coating portion on which the negative electrode active material is not coated. The negative electrode active material may include, for example, a carbon material such as crystalline carbon, amorphous carbon, carbon complex or carbon fiber, a lithium metal, a lithium alloy, etc. A negative electrode tab  115  having a predetermined length may be bonded to the negative electrode non-coating portion. 
     The electrode assembly  110  may be manufactured by forming a stacked structure in which the separator  113  is interposed between the positive and negative electrode plates  111  and  112  and then winding the stacked structure. 
     The electrode assembly  110  may be electrically connected to the outside through the positive and negative electrode tabs  114  and  115 . The positive electrode tab  114  may be electrically connected to the positive electrode plate  111 , and the negative electrode tab  115  may be electrically connected to the negative electrode plate  112 . 
     The positive and negative electrode tabs  114  and  115  may be provided with insulating tapes  116  and  117  for insulating the positive and negative electrode tabs  114  and  115  from upper and lower outer case  120   a  and  120   b,  respectively. 
     The outer case  120  according to this embodiment accommodates the electrode assembly  110  therein, and includes the upper and lower outer case  120   a  and  120   b.    
     The upper and lower outer cases  120   a  and  120   b  may contact each other along edges thereof, thereby forming a body portion  124  provided with a space in which the electrode assembly  110  is accommodated. A wing portion  126  may be formed at one or more portions of the outer circumference of the body portion  124 . 
     According to this embodiment, the upper and lower outer cases  120   a  and  120   b  may form the body portion  124  when the upper and lower outer cases  120   a  and  120   b  are integrally bonded to each other along the edges thereof, thereby hermetically sealing the electrode assembly  110 . 
     The space for accommodating the electrode assembly  110  therein may be formed in the lower outer case  120   b  by a press machining method. 
     As illustrated in  FIG. 4 , the space for accommodating the electrode assembly  110  therein may be formed in the lower outer case  120   b,  and the upper and lower outer cases  120   a  and  120   b  may be integrally bonded along the edges thereof, thereby forming the body portion  124 . In other implementations, the body portion may be formed such that the space for accommodating the electrode assembly  110  therein is formed in each of the upper and lower outer cases, and the upper and lower outer cases may be integrally bonded along the edges thereof. 
     The outer case  120  may have a stacked structure in order to serve as a pouch for the battery cell. For example, the outer case  120  may have a multi-layered structure including a thermal fusion layer  121  having a thermal fusion property to act as a sealing material, a metal layer  122  including a metal material to act as a barrier of moisture and oxygen while maintaining a mechanical strength, and an insulating layer  123 . 
     In the stacked structure, the thermal fusion layer  121  may be formed on one surface of the metal layer  122 , and the insulating layer  123  may be formed on the other surface of the metal layer  122 . 
     The metal layer  122  may include a material such as aluminum, steel, or stainless steel. The thermal fusion layer  121  may include an olefin-based resin material such as modified polypropylene. The insulating layer  123  may include a material such as polyethyleneterephthalate (PET) or nylon. 
     After the electrode assembly  110  is accommodated in the accommodating space of the lower outer case  120   b,  the edges of the upper and lower outer cases  120   a  and  120   b  may be bonded using a method such as thermal fusion. 
     The positive and negative electrode tabs  114  and  115  may be extracted through a terrace portion  128 , which may be any one of the bonding surfaces of the upper and lower outer cases  120   a  and  120   b.  First and second wing portions  126   a  and  126   b  may be respectively provided at both sides vertical to the terrace portion  128 . 
     The first and second wing portions  126   a  and  126   b,  as described below, may be bent to surround a side surface of the body portion  124 . 
     Referring to enlarged views illustrated in  FIGS. 5 and 6 , each of the first and second wing portions  126   a  and  126   b  may be in a state in which the upper and lower outer cases  120   a  and  120   b  overlap with each other. The metal layer  122  may be exposed at the end portions of the first and second wing portions  126   a  and  126   b.  Accordingly, if the insulating film  130 , as described below, were not present, and if an electrolyte were to leak as the battery cell is used for a long period of time, a short circuit could occur through the metal layer  122 . Therefore, it is desirable to insulate the metal layer  122 . 
     More specifically, the insulating film  130  may surround the wing portion  126  in such a manner that a first surface  132  of the insulating film  130  adheres to the wing portion  126 . The insulating film  130  may include an adhesive that is coated on both a first surface  132  and a second surface  134 , located on opposite sides of the insulating film. The insulating film  130  may be folded along the length direction thereof. One portion of a second surface  134  positioned at the opposite side of the first surface  132  may adhere to an internal frame of the electronic device  10 . 
     The insulating film  130  may insulate the wing portion  126 , and simultaneously may enable the battery cell  100  to be attached to the inside of the electronic device  10  without any separate fixing member or adhesive. 
     The battery cell  100  may include two insulating films  130   a  and  130   b  that surround the respective first and second wing portions  126   a  and  126   b.  Herein, the configuration of one of the insulating films will be mainly described for convenience of illustration, and it is to be understood that the same description may be applied to the other insulating film. 
     Herein, it is assumed that, for convenience of illustration, the electrode device  10  having the battery cell  100  installed therein is a tablet PC. 
     Hereinafter, the configuration of the insulating film  130  according to the embodiment will be described in detail with reference to  FIGS. 6 to 9 . 
       FIG. 6A  illustrates a view showing the insulating film  130  a state before the wing portion  126  is surrounded with the insulating film  130  according to the embodiment.  FIG. 6B  illustrates a sectional view taken along line A-A of  FIG. 6A . 
       FIG. 7A  illustrates a view showing the insulating film  130  in a state in which the wing portion  126  is surrounded with the insulating film  130  according to the embodiment.  FIG. 7B  illustrates a sectional view taken along line A-A of  FIG. 7A . 
     As shown in  FIGS. 6 and 7 , the first surface  132  of the insulating film  130  may include a first portion  1321  that adheres to an edge of the upper outer case  120   a  forming the wing portion  126 , and a second portion  1322  that to an edge of the lower outer case  120   b  forming the wing portion  126 . 
     The insulating film  130  may surround the wing portion  126  by extending inwardly from an end of the wing portion  126 . The insulating film  130  may be folded along the line in the length direction that divides the first portion  1321  and the second portion  1322  from each other. 
     One portion  1341  of the second surface  134  positioned at the opposite side of the first surface  132  of the insulating film  130  may adhere to the internal frame of the electronic device. 
     The one portion  1341  of the second surface  134  may be located at a position corresponding to the second portion  1322  of the first surface  132 . Herein, the terms “corresponds” or “corresponding,” when referring to specific portions of the insulating film  130  indicate that the specific portions are located at the same position of the insulating film  130  at opposite sides of the insulating film  130  from each other. For example, the one portion  1341  of the second surface  134  and the second portion  1322  of the first surface  132  may be located at the same position on opposite surfaces of the insulating film  130 . 
     The second portion  1322 , adhering to the edge of the lower outer case  120   b,  may be wider than the first portion  1321 , adhering to the edge of the upper outer case  120   a.  Accordingly, the one portion  1341  of the second surface  134 , located at a position corresponding to the second portion  1322  of the first surface  132 , may be relatively wide. The adhesion area between the one portion  1341  of the second surface  134  and the internal frame of the electronic device  10  may be increased. Accordingly, the battery cell  100  may be more stably attached to the inside of the electronic device  10 . 
       FIGS. 8A and 8B  illustrate sectional views showing an insulating film  130 ′ according to another embodiment. 
     As shown in  FIG. 8 , the first surface  132  of the insulating film  130 ′ according to this embodiment may further include, in addition to the configuration shown in  FIGS. 6 and 7 , a third portion  1323  that continues from the second portion  1322  and adheres to a rear surface of the body portion  124 . 
     Such a structure may allow the adhesion area between the insulating film  130 ′ and the outer case  120  to be wider, such that it may be possible to stably insulate the wing portion  126  and to increase the adhesion area between the insulating film  130 ′ and the internal frame of the electronic device  10 . Accordingly, the battery cell  100  may be more firmly attached to the inside of the electronic device  10 . 
     In a case where the insulating film  130 ′ further includes the third portion  1323  as shown in  FIG. 8B , the other portion  1342  of the second surface  134  of the insulating film may adhere to the side surface of the body portion  124  in a state in which the wing portion  126  is folded toward the body portion  124 . 
     The other portion  1342  of the second surface  134  of the insulating film  130 ′ may be located at a position corresponding to the first portion  1321  of the first surface  132  of the insulating film  130 ′. The other portion  1342  of the second surface and the first portion  1321  of the first surface  132  may be located at the same position on opposite sides of the insulating film  130 ′. The one portion  1341  of the second surface  134  adhered to the internal frame of the electronic device  10  may be located at a position corresponding to the third portion  1323 . The one portion  1341  of the second surface  134  and the third portion  1323  of the first surface  132  may be located at the same position on opposite surfaces of the insulating film  130 ′. 
       FIGS. 8C  illustrates a sectional view showing an insulating film  130 ′ according to another embodiment. As shown in  FIG. 8C , the other portion  1342  of the second surface  132  of the insulating film  130 ′ may further adhere to not only the side surface of the body portion  124  but also may adhere to a front area of the body portion  124 . 
     The other portion  1342  of the second surface  134  of the insulating film  130 ′ may be formed sufficiently longer than the height of the body portion  124 , so as to be adhere to the side surface and the front area of the body portion  124  in the state in which the wing portion  126  is folded toward the body portion  124 . 
     As the adhesion area is increased, the wing portion  126  may be stably attached to the body portion  124 , thereby increasing the reliability of insulation for the insulating film. 
       FIGS. 9A and 9B  illustrate a state in which the battery cell  100  is installed in an electronic device  10  according to the embodiment. As shown in  FIGS. 9A and 9B , the battery cell  100  may be directly installed in an electronic device  10  such as a tablet PC without any separate fixing member. 
     By way of summation and review, a general pouch-type secondary battery may be installed in the electronic device using a separate fixing member  20 , as illustrated in  FIG. 1  or using a separate adhesive. However, using the separate fixing member or adhesive increases the number of processes in the manufacturing of the electronic device, which is disadvantageous in terms of increasing unit costs. In a case where the adhesive is used, a quality risk may be increased due to the occurrence of attachment distribution caused by a change in the size of a battery cell. 
     Embodiments provide a battery cell  100  that may be directly installed in an electronic device through the insulating film  130  for insulating the wing portion  126  without any separate fixing member or adhesive. Accordingly, it may be possible to reduce the manufacturing cost of the battery cell by decreasing the number of working processes when the battery cell is installed in the electronic device. Further, the battery cell may be stably installed in the electronic device even in the event that the size of the battery cell is changed. 
     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 thereof as set forth in the following claims.