Abstract:
A battery pack that does not utilize an insulating tape simplifies a manufacturing processes of external case and furthermore the battery pack has improved resistance against bending. The battery pack includes a chargeable and dischargeable bare cell, a circuit member electrically coupled to the bare cell, and a frame case to cover an entire outside surface of the bare cell excluding a pair of long sides of the bare cell. The frame case includes at least two round parts.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2009-0127270, filed on Dec. 18, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    An embodiment of the present invention relates to a secondary battery, and more particularly, to a battery pack that does not need an insulating tape in the manufacturing process, thereby simplifying the manufacturing of the external case. Furthermore, the battery pack has improved structural integrity thereby not being easily bent. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, a battery pack includes a chargeable and dischargeable secondary battery. The secondary battery includes a Ni—Cd battery, Ni-MH battery, a Li battery, a Li-ion battery, and a Li polymer battery. 
         [0006]    The battery pack is divided into two types in accordance with an external shape. That is, the battery pack is divided into a hard pack battery in which the housing of plastic resin is integrally molded on the external surface of the battery where an external terminal electrically coupled to an external apparatus is exposed and an inner pack battery in which the housing of plastic resin is not molded on the external surface of the battery where an external terminal is exposed. 
         [0007]    Since a part of the external surface of the hard pack battery is exposed where the hard pack battery is mounted in the external apparatus, at least, a part of the housing of the exposed external surface is made of the same material as the housing of the external apparatus. Therefore, the battery may be easily mounted in the external apparatus. However, the housing of the battery must be manufactured in accordance with the shape and structure of the external apparatus. 
         [0008]    On the other hand, since an additional external case is attached when the inner pack battery is mounted in the external apparatus, it is difficult to mount the inner pack battery in comparison with the hard pack battery. However, the inner pack battery may be used regardless of the shape and structure of the external apparatus. Therefore, the inner pack battery that may be used regardless of the shape and structure of the external apparatus is continuously developed. 
       SUMMARY 
       [0009]    Accordingly, an aspect of the present invention has been made to provide a battery pack that does not need an insulating tape so that processes of manufacturing an external case may be simplified. 
         [0010]    According to another aspect of the present invention there is provided a battery pack having improved structural integrity and thereby not being easily bent. 
         [0011]    In order to achieve the foregoing and/or other aspects of the present invention, there is provided a battery pack, including a bare cell, a protection circuit module electrically coupled to the bare cell, and a frame case to cover the entire outside of the bare cell excluding the pair of long sides of the bare cell. The frame case includes a pair of ribs extended toward the pair of long sides of the bare cell on at least one side. 
         [0012]    According to another aspect of the present invention, there is provided a battery pack, including bare cells, a circuit member electrically coupled to the bare cell, a battery accommodating frame to cover the entire outside of the bare cell excluding the pair of long sides of the bare cell, and a frame case to cover the outer circumference of the battery accommodating frame. The battery accommodating frame includes a pair of ribs extended toward the pair of long sides of the bare cell on at least one side. 
         [0013]    According to still another aspect of the present invention, there is provided a battery pack, including bare cells, a protection circuit module electrically coupled to the bare cell, and a frame case to cover the entire outside of the bare cell excluding the pair of long sides of the bare cell. An under cut is formed on one internal side of the frame case in which the bare cell is settled. 
         [0014]    According to still another aspect of the present invention, there is provided a battery pack, including a bare cell, a protection circuit module electrically coupled to the bare cell, a battery accommodating frame to cover the entire outside of the bare cell excluding the pair of long sides of the bare cell, and a frame case to cover the outer circumference of the battery accommodating frame. The battery accommodating frame includes an under cut on the internal side in which the bare cell is settled. 
         [0015]    The frame case is square or rectangular shaped and is integrally formed. However, it is understood that the frame case can have any other shape or form in which the battery is accommodated. The battery accommodating frame may wrap only a part of the bare cell or may not be included in the battery pack. 
         [0016]    One of the pair of ribs of the frame case or the battery accommodating frame is longer than the other so that the battery pack is easily accommodated and is firmly settled. 
         [0017]    The outline frame further includes at least one opening formed in a region corresponding to the external terminal in a plane of the outline frame so that the external terminal including the circuit member is exposed. The battery pack further includes a label for wrapping the outside of the battery pack. 
         [0018]    When one side of the frame case or the battery accommodating frame is the under cut, one side of the bare cell is forcedly settled in the under cut. One side of the under cut is formed to be longer than the other side toward the long sides of the bare cell. 
         [0019]    The battery pack according to an aspect of the present invention does not need an insulating tape, simplifying the processes of manufacturing an external case and further reducing the number of parts. 
         [0020]    In addition, since the battery pack according to an aspect of the present invention is formed by coupling the frame case including the under cut or the battery accommodating frame to the bare cell, the battery pack is not easily bent and is firmly fixed. 
         [0021]    Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0023]      FIG. 1  is a perspective view illustrating a battery pack according to an embodiment of the present invention; 
           [0024]      FIG. 2  is an exploded perspective view illustrating the battery pack according to an embodiment of the present invention; 
           [0025]      FIG. 3  is a vertical sectional view illustrating a bare cell in the battery pack according to an embodiment of the present invention; and 
           [0026]      FIG. 4A  is a sectional view illustrating a frame case and a bare cell in the battery pack according to an embodiment of the present invention before the frame case and the bare cell are coupled to each other; 
           [0027]      FIG. 4B  is a sectional view illustrating the frame case and the bare cell in the battery pack according to an embodiment of the present invention after the frame case and the bare cell are coupled to each other; 
           [0028]      FIG. 5  is an enlarged perspective view illustrating the part A illustrated in  FIG. 4B ; 
           [0029]      FIG. 6  is an exploded perspective view illustrating the battery pack according to an embodiment of the present invention; 
           [0030]      FIG. 7  is an exploded perspective view illustrating the battery pack according to an embodiment of the present invention; and 
           [0031]      FIG. 8  is an exploded perspective view illustrating the battery pack of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures. Here, when a first element is described as being coupled to a second element, the first element may be not be only directly coupled to the second element but may also be indirectly coupled to the second element via a third element.  FIG. 8  is an exploded perspective view illustrating the battery pack. As illustrated in  FIG. 8 , a battery pack  100  includes a bare cell  10 , which may be rechargeable, a protection circuit module  20  which may include a circuit member electrically coupled to the bare cell to control charge and discharge of the bare cell  10  and to block a circuit during over charge and discharge, an auxiliary case  60  coupled between the bare cell  10  and the circuit member  20  so that the circuit member  20  is not separated from the bare cell  10 , an insulating tape  50  to couple the auxiliary case  60  and the bare cell  10  to each other, and an external case  70  to pack the bare cell, the circuit member, and resin to be molded in a shape that may be mounted in an external set. 
         [0033]    In order to manufacture the battery pack  100 , so that a lead (not shown) is coupled to the positive electrode of the bare cell  10  and a PTC  22  is coupled to the negative electrode, the circuit member  20  is electrically coupled to the lead and the PTC  22 . Then, the auxiliary case  60  is coupled between the circuit member  20  and the bare cell  10  to be mechanically fixed so that the circuit member  20  is not separated from the bare cell  10  and packs the bare cell  10  and the circuit member  20  that are integrated with each other using the external case  70  having a shape that may be mounted in an external apparatus. Here, the external case  70  may include various cases such as a case for wrapping the circuit member  20  to prevent a short and for protecting the circuit member  20  from external shock and a case for wrapping the bare cell  10  to protect edges of the bare cell  10  from external shock. In this embodiment, the external case  70  is hook coupled to the circuit member  20  and is coupled to the circuit member  20  by bonding, adhesion, and taping to form a cover case shaped battery pack. In addition, the external case  70  is coupled to the circuit member  20  and may be wrapped by a label  80  together with the bare cell  10 . 
         [0034]    In addition, an insulating tape  50  is formed between the above shaped auxiliary case  60  and the bare cell  10  so that the auxiliary case  60  may be coupled to the bare cell  10 . The tape used to manufacture an inner pack battery is coupled to the bare cell  10  in order to fix and insulate the case  60 . In a common taping work, in the instance of a double-sided tape, two operations are added to the processes of manufacturing the inner pack battery and, in the case of a single-sided tape, one operation is added to the process of manufacturing the inner pack. These additional processes however complicate the manufacturing process of the battery pack. 
         [0035]    In addition, in the above shaped battery pack, since an external case is integrally formed, the battery pack may not be easily bent or twisted. 
         [0036]      FIG. 1  is a perspective view illustrating a battery pack according to an embodiment of the present invention.  FIG. 2  is an exploded perspective view illustrating the battery pack according to the embodiment of the present invention shown in  FIG. 1 . 
         [0037]    As illustrated in  FIGS. 1 and 2 , the battery pack  100  according to an embodiment of the present invention includes the chargeable and dischargeable bare cell  10 , the circuit member  20  electrically coupled to the bare cell  10 , and a frame case  30  to wrap the outer circumference of the bare cell  10  including the circuit member  20 . The frame case  30  has an under cut  30   g  formed in a part where one side of the bare cell is disposed. In one embodiment, the under cut  30   g  may have a round shape, but it will be appreciated that the under cut is not restricted to a particular shape, but rather may be any suitable shape. 
         [0038]    As illustrated in  FIG. 2 , the frame case  30  has the round shaped under cut  30   g , in which one side of the bare cell  10  is disposed and to which one side of the bare cell  10  may be firmly fixed, formed on one side so that the bare cell  10  is forcedly inserted into the round shaped under cut  30   g . When the under cut  30   g  is formed, both sides of the under cut  30   g  naturally wrap the bare cell  10 . First, the placing of the bare cell  10  in the frame case  30  may be difficult due to the ribs of the frame case  30 . However, once the bare cell  10  is positioned in, the bare cell  10  may be firmly coupled to the under cut  30   g  without using an additional tape. 
         [0039]    According to an aspect of the present invention, the frame case  30  may include a pair of ribs extended toward the pair of long sides of the bare cell  10  on at least one side. When the pair of ribs may be formed to be long to wrap a predetermined part of the long sides of the bare cell  10 , it is possible to obtain a similar effect of forming the under cut  30   g.    
         [0040]    According to an embodiment of the present invention, the bare cell  10  may be pouch shaped or can shaped. However, as illustrated in the figures, the bare cell  10  is can shaped. 
         [0041]      FIG. 3  is a vertical sectional view illustrating a bare cell  10  in the battery pack  100  according to an embodiment of the present invention. 
         [0042]    As illustrated in  FIG. 3 , the bare cell  10  includes an electrode assembly  11 , a can  12  in which the electrode assembly  11  is accommodated, and a can assembly  13  for sealing the upper end opening of the can  12 . 
         [0043]    The electrode assembly  11  is formed by laminating and winding a positive electrode plate  11   a  coated with a positive electrode active material, a negative electrode plate  11   b  coated with a negative electrode active material, and a separator  11   c  interposed between the positive electrode plate  11   a  and the negative electrode plate  11   b.    
         [0044]    A positive electrode tab  11   d  is electrically coupled to the positive electrode plate  11   a  in the region of a positive electrode collector where a positive electrode active material layer is not formed. A negative electrode tab  11   e  is electrically coupled to the negative electrode plate  11   b  in the region of a negative electrode collector where a negative electrode active material layer is not formed. Insulating tapes to prevent a short between an electrode tab and two electrode plates may be wound around boundaries on which the positive electrode tab  11   d  and the negative electrode tab  11   e  are withdrawn from the electrode assembly  11 . In addition, the width of the separator  11   c  is formed to be larger than the widths of the positive electrode plate  11   a  and the negative electrode plate  11   b  to prevent a short between the electrode plates. 
         [0045]    On the other hand, an insulating case  14  to electrically insulate the electrode assembly  11  and the can assembly  13  from each other and to cover the upper end of the electrode assembly  11  may be provided on the top of the electrode assembly  11 . The insulating case  14  having an insulation property is made of polymer resin. In addition, a through hole is formed in the center of the insulating case  14  so that the negative electrode tab passes through, and an electrolyte passing hole  14   a  is formed on the side of the insulating case  14 . 
         [0046]    The can  12  is made of aluminum or an aluminum alloy and has a roughly cuboid shape to accommodate the electrode assembly  11  through the opened upper end and to function as the container of the electrode assembly  11  and an electrolyte. In addition, the can  12  may function as a terminal. 
         [0047]    The can assembly  13  includes a flat plate shaped cap plate  15  having the size and shape corresponding to the opened top of the can  12 . At this time, a terminal through hole  15   a  is formed in the center of the cap plate  15  and a tube shaped gasket  17  is provided between an electrode terminal  16  that passes through the terminal through hole  15   a  and the cap plate  15 . In addition, an insulating plate  18  is provided on the bottom of the cap plate  15  and a terminal plate  19  is provided on the bottom of the insulating plate  18 . In addition, the bottom of the electrode terminal  16  is electrically coupled to the terminal plate  19 . The positive electrode tab  11   d  extending from the positive electrode plate  11   a  is welded to the bottom of the cap plate  15  and the negative electrode tab  11   e  extending from the negative electrode plate  11   b  is welded to the bottom of the electrode terminal  16  while having a zigzag shaped curved part. 
         [0048]    An electrolyte injecting hole  15   b  is formed on one side of the cap plate  15 . After an electrolyte is injected, in order to seal the injecting hole  15   b , a stopper  15   c  is provided. The stopper  15   c  that is a ball shaped material is made of aluminum or an aluminum containing metal and is put on the electrolyte injecting hole  15   b  and is mechanically pressed inserted into the electrolyte injecting hole  15   b . In addition, for sealing, the stopper  15   c  is welded to the cap plate  15  around the electrolyte injecting hole  15   b . On the other hand, a safety vent  15   d  is formed on the other side of the cap plate  15 . The safety vent  15   d  is broken when the pressure in the battery rises to be no less than a predetermined pressure to prevent the battery from being ignited and exploding. 
         [0049]    On the other hand, according to an aspect of the present invention, the bare cell  10  may be rectangular and the direction in which the positive electrode tab  11   d  and the negative electrode tab  11   e  of the bare cell  10  are formed is referred to as an “upper” direction. 
         [0050]    As illustrated in  FIG. 2 , the circuit member  20  is electrically coupled to the bare cell  10 . The circuit member  20  includes a protective circuit module (PCM)  21  and the positive temperature coefficient (PTC)  22 . The PTC  22  is electrically coupled between the negative electrode of the circuit member  20  and the electrode terminal  16  so that electrical coupling between the negative electrode of the circuit member  20  and the electrode terminal  16  may be blocked when temperature excessively rises or an excessive amount of current flows. 
         [0051]    The frame case  30  is coupled to the bare cell  10  which is electrically coupled to the circuit member  20  to form a part of the external appearance of the battery pack  100  as illustrated in  FIGS. 1 and 2 . 
         [0052]    Referring to  FIG. 2 , the frame case  30  has a rectangular or square shaped to cover the top  10   a  of the bare cell  10 , the bottom  10   f  of the bare cell  10 , and a pair of short sides  10   b  and  10   c  coupled to the top  10   a  of the bare cell  10 . The frame case  30  may be integrally formed. 
         [0053]    In addition, the frame case  30  includes the round shaped under cut  30   g  on one side. In addition, the frame case  30  may further include an opening  30   c.    
         [0054]    The plane  30   a  of the frame case  30  is formed to cover the top  10   a , the pair of short sides  10   b  and  10   c , and the bottom  10   f  of the bare cell  10 . Here, in order to cover the top  10   a , the pair of short sides  10   b  and  10   c , and the bottom  10   f  of the bare cell  10 , the plane  30   a  may have the same width. 
         [0055]      FIG. 2  illustrates the step difference  30   b  of the frame case  30 . The step difference  30   b  is the part extending from the end of the plane  30   a  to the inside of the frame case  30  to cover the edges of the pair of long sides  10   d  and  10   e  of the bare cell  10 . 
         [0056]    The at least one opening  30   c  of the frame case  30  is formed in the region corresponding to an external terminal  23  provided in the circuit unit  20  provided on the top  10   a  of the bare cell  10  in the plane  30   a  in order to expose the external terminal  23 . 
         [0057]    The battery pack  100  is not easily bent when the bare cell  10  is mounted in the frame case  30 . As illustrated in  FIG. 5 , the frame case  30  has the round shaped under cut  30   g  formed on one side thereof. The under cut  30   g  of the frame case  30  starts from the part where the plane  30   a  of the frame case  30  contacts the step difference  30   b  and is formed with a predetermined radius so that the bare cell  10  is naturally mounted in the frame case  30 . As illustrated in  FIGS. 4A and 4B , when the round shaped under cut  30   g  is formed from the region in which the plane  30   a  and the step difference  30   b  of the frame case  30  contact each other, interference may occur when the bare cell  10  is first coupled as compared to the frame case  30  having the structure in which the above under cut  30   g  is not formed However, when the bare cell  10  is placed in the round shape under cut  30   g , the bare cell  10  is more firmly coupled to the frame case  30  and the battery pack  100  is not easily bent. Accordingly, the insulating tape is not necessary, thereby simplifying the manufacturing process of the external case and furthermore reducing the number of parts of the battery pack  100 . 
         [0058]    In addition, the frame case  30  may be wrapped by the label  80  together with the bare cell  10 . 
         [0059]      FIGS. 6 and 7  are exploded perspective views illustrating the battery pack according to another embodiment of the present invention. 
         [0060]    As illustrated in  FIGS. 6 and 7 , the battery pack  100  according to another embodiment of the present invention includes the bare cell  10 , the circuit member  20 , and the frame case  30 . According to the present embodiment, since the bare cell  10 , the circuit member  20 , and the frame case  30  were described above, a description thereof will be omitted. Therefore, according to the present embodiment, a battery accommodating frame  40  that wraps a part or the entire outer circumference of the bare cell  10  will be described in detail. 
         [0061]    As illustrated in  FIG. 6 , the battery pack  100  according to another embodiment of the present invention includes the battery accommodating frame  40  that partially wraps the external circumference of the bare cell  10 . The battery accommodating frame  40  is coupled between the bare cell  10  and the circuit member  20  to prevent the circuit member  20  from being separated from the bare cell  10 . The battery accommodating frame  40  has a rectangular or square shaped with a missing side to cover the top  10   a , one short side  10   b , and the bottom  10   f  of the bare cell  10 . 
         [0062]    As illustrated in  FIG. 7 , the battery pack  100  according to still another embodiment of the present invention includes the battery accommodating frame  40  that wraps the outer circumference of the bare cell  10 . The battery accommodating frame  40  is rectangular or square shaped so as to cover the top  10   a , the pair of short sides  10   b  and  10   c , and the bottom  10   f  of the bare cell  10 . 
         [0063]    The battery accommodating frame  40  includes a round shaped under cut  40   g  on the internal side of where the bare cell is settled. In addition, the battery accommodating frame  40  further includes a pair of ribs extended from a plane  40   a  to the long sides of the bare cell. 
         [0064]    The plane  40   a  of the battery accommodating frame  40  covers the top  10   a , the pair of short sides  10   b  and  10   c , and the bottom  10   f  of the bare cell  10 . The plane  40   a  for covering the top  10   a , the pair of short sides  10   b  and  10   c , and the bottom  10   f  of the bare cell  10  may have the same width. 
         [0065]    The step difference  40   b  of the battery accommodating frame  40  is illustrated in  FIG. 7 . The step difference  40   b  is a portion of the body accommodating frame  40  which extends in a direction from the end of the plane  30   a  to the inside of the battery accommodating frame  40  to cover the edges of the pair of long sides  10   d  and  10   e  of the bare cell  10 . According to an aspect of the present invention, the internal side of the one side of the battery accommodating frame  40  wraps predetermined parts of the long sides  10   d  and  10   e  of the bare cell  10  by forming the round shape under cut  30   g  or the pair of ribs. The bare cell  10  is firmly coupled to the battery accommodating frame  40  without using an additional insulating tape. The battery pack is not easily bent. 
         [0066]    Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.