Abstract:
A battery pack includes a plurality of battery units that are side by side along a first direction, a connection member that connects the battery units in series, in parallel, or in series and parallel, the connection member being adjacent to one surface of each battery unit of the plurality of battery units, an upper cap on and accommodating the connection member, upper portions of all of the battery units being inserted into the upper cap, a lower cap that is spaced apart from the upper cap by a predetermined gap, lower portions of all of the battery units being inserted into the lower cap, and a label that at least partially surrounds the battery units exposed between the upper cap and the lower cap. The upper cap and the lower cap fix an arrangement of the battery units.

Description:
RELATED APPLICATIONS 
       [0001]    Korean Patent Application No. 10-2014-0015641, filed on Feb. 11, 2014, in the Korean Intellectual Property Office, and entitled: “Battery Pack,” is incorporated by reference herein in its entirety. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    One or more embodiments relate to a battery pack. 
         [0004]    2. Description of the Related Art 
         [0005]    Use of portable computers that operate based on internal power supplied from batteries has dramatically increased due to the development of wireless communication technologies such as the Internet. In general, since the portable computers are small and easy to carry, that is, have high mobility, the portable computers are widely used for business or personal purposes in various places. As the portable computers include battery packs, they may be used irrespective of the area of use and connection to land power sources. A battery pack may include a plurality of battery units that may be repeatedly charged/discharged so as to provide sufficient output. 
       SUMMARY 
       [0006]    Embodiments are directed to a battery pack including a plurality of battery units that are side by side along a first direction, a connection member that connects the battery units in series, in parallel, or in series and parallel, the connection member being adjacent to one surface of each battery unit of the plurality of battery units, an upper cap on and accommodating the connection member, upper portions of all of the battery units being inserted into the upper cap, a lower cap that is spaced apart from the upper cap by a predetermined gap, lower portions of all of the battery units being inserted into the lower cap, and a label that at least partially surrounds the battery units exposed between the upper cap and the lower cap. The upper cap and the lower cap fix an arrangement of the battery units. 
         [0007]    Each of the battery units may include sides that are perpendicular to the one surface. The sides may include a pair of first sides, the first sides of each battery unit being side by side with the first sides of the other battery units, and a pair of second sides that connect the pair of first sides to each other, the second sides having a smaller width than the first sides. The plurality of battery units may be arranged such that the second sides of adjacent battery units face each other. 
         [0008]    The battery pack may further include a spacer between the second sides of adjacent battery units that face each other. 
         [0009]    The spacer may include a first portion that insulates the second sides of the adjacent battery units from each other and a second portion that extends from the first portion to the connection member and supports the connection member. 
         [0010]    At least one of the upper cap and the lower cap may include a skirt portion that extends toward the pair of first sides. The label may be attached to the skirt portion. 
         [0011]    The battery pack may further include an insulating film between at least one of the pair of first sides and the label. 
         [0012]    Each battery unit may include a can that accommodates an electrode assembly and a cap plate that is combined with the can, the cap plate forming the one surface. Each battery unit may include an electrode pin located on the cap plate, the electrode pin being insulated from the cap plate. 
         [0013]    Each battery unit may include a holder on the cap plate, the holder accommodating a temperature-sensing element connected to the electrode pin. 
         [0014]    The connection member may be electrically connected to the electrode pin and the cap plate. 
         [0015]    The connection member may include circuit boards and protective elements mounted on the circuit boards. 
         [0016]    The holder may be coupleable with the upper cap. 
         [0017]    One of the holder and the upper cap may include a protrusion that protrudes in a direction perpendicular to the first direction, and the other one of the holder and the upper cap may include a hole that is coupleable with the protrusion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    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: 
           [0019]      FIG. 1  illustrates a schematic perspective view of a battery pack according to an embodiment; 
           [0020]      FIG. 2  illustrates an exploded perspective view of one of a plurality of battery units illustrated in  FIG. 1 ; 
           [0021]      FIG. 3  illustrates a perspective view depicting a state in which battery units, a protective circuit module, an upper cover, and a lower cover illustrated in  FIG. 1  are assembled; 
           [0022]      FIG. 4  illustrates an exploded perspective view of a portion IV of  FIG. 3 ; and 
           [0023]      FIG. 5  illustrates a cross-sectional view taken along a line V-V of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    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. 
         [0025]    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. 
         [0026]      FIG. 1  is a schematic perspective view of a battery pack according to an embodiment,  FIG. 2  is an perspective view of one of a plurality of battery units and a holder illustrated in  FIG. 1 , and  FIG. 3  is a perspective view illustrating a state in which a plurality of battery units  100 , a protective circuit module  200 , an upper cover  400 , and a lower cover  500  are assembled. In  FIG. 3 , a label  600  and an insulating film  700  are omitted in  FIG. 3  for convenience of explanation. 
         [0027]    Referring to  FIGS. 1 through 3 , the battery pack according to the current embodiment may include the plurality of battery units  100 , the protective circuit module  200 , which is electrically connected to each of the plurality of battery units  100 , a spacer  300  that electrically insulates the battery units  100  from each other, the upper cover  400 , the lower cover  500 , the label  600 , and the insulating film  700 . 
         [0028]    The plurality of battery units  100  may be disposed side by side along a first direction (x-direction). For example, the plurality of battery units  100  may be disposed side by side so that their top surfaces are in the same direction. Sides of adjacent battery units  100  may face each other. Each of the battery units  100  may be a lithium-ion battery, that is, a secondary battery that may be recharged. 
         [0029]    Referring to  FIG. 2 , each of the battery units  100  may include a bare cell B and a holder  140  fixed to an upper portion of the bare cell B. 
         [0030]    The bare cell B may include a can  110  having an opening formed therein, an electrode assembly  104  accommodated in the can  110  through the opening, a cap plate  120  that seals the opening of the can  110 , and an electrode pin  122  formed on the cap plate  120 . 
         [0031]    The can  110  may have an opened, approximately hexahedral top surface and may be manufactured of a metallic material so as have a suitable resistance. For example, the can  110  may be manufactured of aluminum (Al) or an Al alloy. After the electrode assembly  104  is inserted into the can  110  through the opening, the opening may be sealed by the cap plate  120 . Like the can  110 , the cap plate  120  may be manufactured of a metallic material, such as aluminum or an Al alloy. Portions at which the cap plate  120  and the can  110  contact each other may be combined with each other through laser welding so that an internal air-tight state of the bare cell B may be maintained. 
         [0032]    The electrode assembly  104  may include a first electrode plate  101  and a second electrode plate  102  onto which an electrode active material is coated, and a separator  103  interposed therebetween. The first electrode plate  101  and the second electrode plate  102  may have different polarities. The electrode assembly  104  may be manufactured in such a way that the first electrode plate  101 , the separator  103 , and the second electrode plate  102  may be sequentially stacked on the electrode assembly  104  and then be wound in a jelly roll shape. In other implementations, the electrode assembly  104  may be a stack structure where the first electrode plate  101 , the separator  103 , and the second electrode plate  102  are sequentially stacked. 
         [0033]    The electrode pin  122  may be formed on the cap plate  120 . The first electrode plate  101  may be electrically connected to the cap plate  120 , and the second electrode plate  102  may be electrically connected to the electrode pin  122 . The first electrode plate  101  and the second electrode plate  102  may have different polarities. Accordingly, the electrode pin  122  and the cap plate  120  may have different polarities. For example, the electrode pin  122  may have a negative electrode polarity, and the cap plate  120  may have a positive electrode polarity. A gasket  125  may be provided between the electrode pin  122  and the cap plate  120  so as to prevent a short circuit between the electrode pin  122  and the cap plate  120 . The gasket  125  may be manufactured of an insulating material and may prevent an electrical short circuit between the electrode pin  122  and the cap plate  120 . 
         [0034]    The battery unit  100  may include first and second electrode tabs  131  and  132 . The first and second electrode tabs  131  and  132  may serve as a positive electrode terminal and a negative electrode terminal of a secondary battery. 
         [0035]    For example, the first electrode tab  131  may be disposed on the cap plate  120  and may be electrically connected to the cap plate  120 . When the cap plate  120  has a positive electrode polarity, the first electrode tab  131  welded onto the cap plate  120  may also have a positive electrode polarity. 
         [0036]    The second electrode tab  132  may be connected to the electrode pin  122  and a temperature-sensing element, such as a temperature cutoff (TCO). For example, the second electrode tab  132  may include a first portion  132   a  and a second portion  132   b.  One end of the first portion  132   a  may be connected to the electrode pin  122 , and the other end of the first portion  132   a  may be connected to the temperature-sensing element. One end of the second portion  132   b  may be connected to the temperature-sensing element so that the second electrode tab  132  including the temperature-sensing element may be electrically connected to the electrode pin  122 . 
         [0037]    The first and second electrode tabs  131  and  132  may be disposed on the cap plate  120 . Since the cap plate  120  has a positive electrode polarity, as described above, an electrical short circuit between the cap plate  120  and the second electrode tab  132  having a negative electrode polarity could occur easily. Thus, the second electrode tab  132  may be disposed on the holder  140  put on the cap plate  120 . 
         [0038]    The holder  140  may accommodate the second electrode tab  132  and the temperature-sensing element. The holder  140  may include an opening op formed in a position corresponding to a position of the temperature-sensing element so as to sensitively react to a change in temperature of the battery unit  100 . 
         [0039]    The holder  140  may be fixed onto the battery unit  100  using a fixing member, such as a tape  150 , while accommodating the second electrode tab  132  and the temperature-sensing element. 
         [0040]    The holder  140  may include a protrusion  145 . The protrusion  145  may extend and protrude from the holder  140  along a thickness direction (y-direction) of the battery unit  100  and may be combined with a hole  405  formed in the upper cover  400  that will be described below. For example, the protrusion  145  of the holder  140  may be combined with the hole  405  of the upper cover  400  through interference fit. 
         [0041]    In the current embodiment, the protrusion  145  is formed on the holder  140 , and the hole  405  is formed in the upper cover  400 . In other implementations, a hole may be formed in the holder  140 , and a protrusion may be formed on the upper cover  400  so that the protrusion and the hole may be combined with each other through an interference fit. Considering the overall thickness of the battery pack, for example, the protrusion  145  may be formed on the holder  140  and the hole  405  may be formed in the upper cover  400 , such that the thickness of the battery pack may be reduced. 
         [0042]    Referring back to  FIGS. 1 through 3 , the protective circuit module  200  may be disposed on a top surface of each battery unit  100 , for example, on the cap plate  120 , and may be electrically connected to the battery unit  100  such that charging/discharging of the battery unit  100  may be controlled. The protective circuit module  200  may prevent overheating and explosion that occur due to overcharging, overdischarging, or overcurrent of the battery unit  100 . 
         [0043]    The protective circuit module  200  may include circuit boards  210 , protective elements  220  mounted on the circuit boards  210 , and external terminals  230 . The circuit boards  210  may extend long along an arrangement direction of the plurality of battery units  100 . The protective elements  220  may be one selected from the group of safety elements including passive elements, such as resistors and capacitors of the circuit boards  210 , or active elements, such as field effect transistors (FETs), or integrated circuits (ICs). 
         [0044]    Each of the circuit boards  210  may include a connection hole  241 . The first and second electrode tabs  131  and  132  provided on each of the battery units  100  may be inserted into the connection hole  241  formed in each circuit board  210 . The first and second electrode tabs  131 ,  132  and the respective circuit board  210  may be soldered together. Patterns through which the battery units  100  may be connected in series and/or in parallel, may be formed on the circuit board  210 . The first and second electrode tabs  131  and  132  of each battery unit  100  may be directly connected to the connection hole  241  formed in the circuit board  210  such that the plurality of battery units  100  may be charge/discharge-controlled according to driving of the protective element  220  and simultaneously may be connected in series and/or in parallel. 
         [0045]    The spacer  300  may be interposed between adjacent battery units  100 . One end of the spacer  300  may extend toward the protective circuit module  200  so as to support the protective circuit module  200 . For example, the spacer  300  may include a first portion  310  interposed between the adjacent battery units  100 , and a second portion  320  that extends from the first portion  310  to the protective circuit module  200 . 
         [0046]    The first portion  310  of the spacer  300  may electrically insulate the adjacent battery units  100  from each other. As described above with reference to  FIG. 2 , the can  110  and the cap plate  120  of the battery unit  100  may be manufactured of a metallic material, and the can  110  may be welded to the cap plate  120  such that the can  110  may have the same polarity as that of the cap plate  120 . When the battery units  100  are disposed side by side, as illustrated in  FIG. 1 , an undesired electrical connection between the adjacent battery units  100  could be formed. According to an embodiment, the first portion  310  of the spacer  300  may be interposed between the adjacent battery units  100 . Accordingly, an undesired electrical connection between the adjacent battery units  100  may be prevented. 
         [0047]    The second portion  320  of the spacer  300  may be interposed in a space (or a gap) between the protective circuit module  200  and the battery unit  100  and may support the protective circuit module  200 . The battery unit  100  may include the electrode pin  122  that protrudes upward and the holder  140  may be interposed on the battery unit  100 . Accordingly, a space may be formed between the top surface of the battery unit  100  and a bottom surface of the protective circuit module  200 . When the second portion  320  of the spacer  300  is interposed in the space, the protective circuit module  200  may be supported and simultaneously may be protected from an external force applied to the protective circuit module  200 . 
         [0048]    The upper cover  400  may be disposed on the protective circuit module  200 . The upper cover  400  may include an opening  410  through which the external terminal  230  formed on the protective circuit module  200  is exposed. 
         [0049]    The upper cover  400  may have a length that is substantially the same as the entire length of the plurality of battery units  100  disposed side by side along the first direction. The upper cover  400  may be combined with the battery units  100  such that the protective circuit module  200  may be interposed between the battery units  100 . For example, the upper cover  400  and the holder  140  provided at each of the battery units  100  may be combined with each other through an interference fit, as described above. 
         [0050]    The lower cover  500  may be disposed at an opposite side to a side at which the upper cover  400  is disposed, so as to face the upper cover  400 . The upper cover  400  may be disposed to cover the top surface of each battery unit  100 , with the protective circuit module  200  being interposed between the battery units  100 . The lower cover  500  may be disposed to cover the bottom surface of each battery unit  100 . 
         [0051]    The label  600  may be disposed to surround sides of each battery unit  100 . For example, the label  600  may be attached to the sides of the battery unit  100 . An insulating film  700  may be interposed between the label  600  and the sides of the battery unit  100 . 
         [0052]    Portions of the label  600  may be attached to the upper cover  400  and the lower cover  500 . To this end, skirt portions  420  and  520  may be provided at the upper cover  400  and the lower cover  500  and may extend toward the battery unit  100 . The portions of the label  600  may be attached onto the skirt portions  420  and  520  such that the upper cover  400 , the lower cover  500 , and the label  600  may be insulated from the battery unit  100  and simultaneously, such that the battery unit  100  may be prevented from being exposed to the outside. 
         [0053]    Hereinafter, a combination of the upper cover  400  and the battery unit  100 , for example, a combination of the upper cover  400  and the holder  140  of the battery unit  100  will be descried with reference to  FIGS. 4 and 5 . 
         [0054]      FIG. 4  is an partial exploded perspective view of a portion IV of  FIG. 3 , and  FIG. 5  is a cross-sectional view taken along a line V-V of  FIG. 3 . 
         [0055]    Referring to  FIGS. 4 and 5 , the protective circuit module  200  may be disposed on the battery unit  100 , and the upper cover  400  may be disposed on the protective circuit module  200 . The protective circuit module  200  may be placed on the cap plate  120  on which the electrode pin  122  is formed. The first and second electrode tabs  131  and  132  included in each battery unit  100  may be inserted into the connection holes  241  formed in the protective circuit module  200  and then the first and second electrode tabs  131  and  132  and the protective circuit module may be soldered together., Thus, the first and second electrode tabs  131  and  132  may be electrically connected to the protective circuit module  200 . 
         [0056]    The upper cover  400  may be combined with the battery unit  100  such that the protective circuit module  200  is interposed between the battery unit  100  and the upper cover  400 . For example, the upper cover  400  may include the hole  405 , and the holder  140  of the battery unit  100  may include the protrusion  145 . The protrusion  145  may be combined with the hole  405  through an interference fit such that the upper cover  400  and the holder  140  are combined with each other. The protrusion  145  may extend and protrude from the battery unit  100  along the thickness direction (y-direction) of the battery unit  100  and thus may be combinable with the hole  405  of the upper cover  400 . 
         [0057]    As described above, according to the one or more of the above embodiments provide a compact battery pack having improved assembling characteristics may be provided. 
         [0058]    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. 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 as set forth in the following claims.