Abstract:
A rechargeable battery including: an electrode assembly; a case having an opening to receive the electrode assembly; a cap plate covering the opening of the case; a terminal arranged at the cap plate and electrically connected to the electrode assembly; a current collecting member coupled to the electrode assembly and the terminal and including a fuse unit; and a supporting member coupled to the current collecting member and supporting the fuse unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2011-0129665, filed on Dec. 6, 2011 in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     Aspects of embodiments of the present invention relate to a rechargeable battery. 
     2. Description of the Related Art 
     A rechargeable battery is a battery that can be recharged and discharged, unlike a primary battery that cannot be recharged. A low-capacity rechargeable battery may be used for small portable electronic devices, such as a mobile phone, a notebook computer, and a camcorder, and a large-capacity rechargeable battery may be used as a power supply for driving a motor of an electric vehicle, a hybrid vehicle, or the like, or as a large-capacity power storage device. 
     Recently, a high-output rechargeable battery using a non-aqueous electrolyte solution of high energy density has been developed. The high-output rechargeable battery is configured as a large-capacity battery module in which a plurality of rechargeable batteries are connected to each other in series, such that the high-output rechargeable battery may be used to drive a motor of a device requiring a large amount of power, such as an electric vehicle, a hybrid vehicle, or the like. The rechargeable battery may have a cylindrical shape, a rectangular shape, or the like. 
     In the rechargeable battery using a non-aqueous electrolyte solution, an abnormal current may be generated inside the rechargeable battery during a time that the charge and the discharge are repeated such that the rechargeable battery may explode. 
     Accordingly, to prevent the explosion of the rechargeable battery by the abnormal current, a positive electrode and a negative electrode may be shorted or a fuse unit including a fuse hole may be installed to a current collecting member electrically connecting the terminal and the electrode assembly to prevent or substantially prevent a flow of the current. 
     However, the fuse unit of the current collecting member including the fuse hole has a smaller cross-sectional area compared with other current collecting members without the fuse hole. Accordingly, a portion formed with the fuse unit of the current collecting member may be more easily damaged by an external impact. 
     Also, an arc may be generated at the fuse unit by a remaining current after the fuse unit is partially melted by the abnormal current. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY 
     According to an aspect of embodiments of the present invention, a rechargeable battery is configured to prevent or substantially prevent damage to a current collecting member formed with a fuse unit by an external impact. According to another aspect of embodiments of the present invention, a rechargeable battery includes a supporting member which improves durability. 
     According to another aspect of embodiments of the present invention, a rechargeable battery is configured to prevent or substantially prevent generation of an arc by a remaining current or stress after the fuse unit formed at the current collecting member is partially melted. 
     A rechargeable battery according to an exemplary embodiment of the present invention includes: an electrode assembly; a case having an opening to receive the electrode assembly; a cap plate covering the opening of the case; a terminal arranged at the cap plate and electrically connected to the electrode assembly; a current collecting member coupled to the electrode assembly and the terminal and including a fuse unit; and a supporting member coupled to the current collecting member and supporting the fuse unit. 
     In one embodiment, the current collecting member may include a terminal coupling unit coupled to the terminal, and an electrode assembly coupling unit coupled to the electrode assembly, the terminal coupling unit may include the fuse unit, and the supporting member may be coupled to the terminal coupling unit thereby supporting the fuse unit. 
     A cross-sectional area of the fuse unit may be less than that of other portions of the terminal coupling unit. 
     The fuse unit may have an opening formed therein. 
     The supporting member may include a supporting protrusion inserted in the opening. 
     The supporting protrusion may include an insulating material. 
     The supporting protrusion may include a high-resistance material. 
     The rechargeable battery may further include a supporting cap coupled to the supporting member and supporting the fuse unit. 
     The supporting cap may include a body unit and a coupling groove formed in the body unit, and the supporting member may be coupled to the supporting cap in the coupling groove. 
     The fuse unit may have an opening formed therein, and the supporting cap may include a coupling protrusion inserted in the opening. 
     The supporting cap may include an insulating material. 
     The supporting cap may include a high-resistance material. 
     The rechargeable battery may further include a lower insulating member between the cap plate and the current collector. The lower insulating member may include a protrusion inserted in an opening of the fuse unit. 
     The rechargeable battery may be adapted for use as a motor-driving power source for propelling an electric vehicle or a hybrid electric vehicle. 
     According to an aspect of embodiments of the present invention, the current collector formed with the fuse unit may be stably supported by the supporting member. As such, a rechargeable battery according to embodiments of the present invention is particularly suited for application in an electric vehicle or a hybrid electric vehicle. 
     According to another aspect of embodiments of the present invention, an arc generated by a remaining current after the fuse unit is melted or partially melted may be prevented or substantially prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, together with the specification, illustrate some exemplary embodiments of the present invention, and, together with the description, serve to explain aspects and principles of the present invention. 
         FIG. 1  is a perspective view of a rechargeable battery according to an exemplary embodiment of the present invention. 
         FIG. 2  is a cross-sectional view of the rechargeable battery of  FIG. 1 , taken along the line II-II. 
         FIG. 3  is an exploded perspective view of a portion of the rechargeable battery of  FIG. 1 . 
         FIG. 4  is a partial cross-sectional view of the rechargeable battery of  FIG. 1 . 
         FIG. 5  is an exploded perspective view of a portion of a rechargeable battery according to another exemplary embodiment of the present invention. 
         FIG. 6  is a partial cross-sectional view of the rechargeable battery of  FIG. 5 . 
         FIG. 7  is an exploded perspective view of a portion of a rechargeable battery according to another exemplary embodiment of the present invention. 
         FIG. 8  is a partial cross-sectional view of the rechargeable battery of  FIG. 7 . 
       
         
           
                 
               
                 
                 
               
             
                 
                     
                 
                 
                   Description of Reference Numerals Indicating 
                 
                 
                   Some Elements in the Drawings 
                 
                 
                     
                 
               
               
                 
                     
                 
               
            
             
                 
                   100, 200, 300: rechargeable battery 
                   10: electrode assembly 
                 
                 
                   11: first electrode 
                   12: second electrode 
                 
                 
                   13: separator 
                   30: first terminal unit 
                 
                 
                   31: first rivet 
                   32: first terminal plate 
                 
                 
                   33: first terminal insulating member 
                   40: second terminal unit 
                 
                 
                   50: first current collecting member 
                   51: first electrode coupling unit 
                 
                 
                   52: first terminal coupling unit 
                 
                 
                   60, 610, 620, 630: first lower 
                 
                 
                   insulating member 
                 
                 
                   61, 611, 621, 631: first current 
                 
                 
                   collecting member coupling unit 
                 
                 
                   70: second current collecting member 
                   80: second lower insulating 
                 
                 
                     
                   member 
                 
                 
                   90: supporting member 
                 
                 
                     
                 
               
            
           
         
       
     
    
    
     DETAILED DESCRIPTION 
     The present invention is described more fully hereinafter with reference to the accompanying drawings, in which some exemplary embodiments of the invention are shown and described. However, as those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. 
       FIG. 1  is a perspective view of a rechargeable battery according to an exemplary embodiment of the present invention, and  FIG. 2  is a cross-sectional view of the rechargeable battery of  FIG. 1 , taken along the line II-II. 
     Referring to  FIG. 1  and  FIG. 2 , a rechargeable battery  100  according to an exemplary embodiment of the present invention includes an electrode assembly  10 , a case  26 , a first terminal unit  30 , a second terminal unit  40 , a cap plate  20 , first and second lower insulating members  60  and  80 , first and second current collecting members  50  and  70 , and a supporting member  90 . 
     The rechargeable battery  100  according to one embodiment may be a lithium ion rechargeable battery. Also, a rectangular rechargeable battery is described herein by way of example. However, the present invention is not limited thereto, and may be applied to another rechargeable battery, such as a lithium polymer battery or other battery, as well as to a battery other than a rectangular rechargeable battery. 
     The electrode assembly  10 , in one embodiment, may be formed as a jelly roll type by spirally winding a first electrode  11  and a second electrode  12  with a separator  13  interposed therebetween. 
     In one embodiment, the first electrode  11  may be formed as a negative electrode, and the second electrode  12  may be formed as a positive electrode. However, in another embodiment, the first electrode  11  may be formed as a positive electrode, and the second electrode  12  may be formed as a negative electrode. However, for purposes of description herein, they will be described as the first electrode  11  and the second electrode  12 . 
     In one embodiment, the first electrode  11  and the second electrode  12  may respectively include first and second current collectors formed as a thin metal foil with an active material coated on a surface of the respective current collector. 
     In one embodiment, the first electrode  11  and the second electrode  12  may include a coated part on which the active material is coated on the respective current collector, and a first electrode uncoated region  11   a  and a second electrode uncoated region  12   a  on which the active material is not coated on the respective current collector. 
     The coated parts form a substantial portion of the first electrode  11  and the second electrode  12  in the electrode assembly  10 , and the first electrode uncoated region  11   a  and the second uncoated region  12   a  are disposed at respective sides of the coated parts in the jelly roll state. 
     However, the present invention is not limited thereto. For example, in another embodiment, the electrode assembly  10  may have a structure in which the first electrode  11  and the second electrode  12  formed of a plurality of sheets are stacked, having the separator  13  therebetween. 
     As shown in  FIG. 2 , the first electrode uncoated region  11   a  of the electrode assembly  10  is electrically connected to the first terminal unit  30  via the first current collecting member  50 , and the second electrode uncoated region  12   a  is electrically connected to the second terminal unit  40  via the second current collecting member  70 . 
     In one embodiment, the first current collecting member  50  may include a first electrode coupling unit  51  coupled with the first electrode  11 , and a first terminal coupling unit  52  coupled with a first rivet  31  of the first terminal unit  30 . 
     The case  26 , according to one embodiment, has a generally rectangular parallelepiped shape and includes an opening formed at one end thereof. However, the present invention is not limited thereto, and in other embodiments, the case may have any of various shapes, such as a cylindrical shape, a pouch shape, or any other suitable shape. 
     In one embodiment, the cap plate  20  may include an electrolyte injection opening  21 , a sealing cap  22  sealing the electrolyte injection opening  21 , and a vent hole  23  installed with a vent plate  24 . 
     The cap plate  20 , in one embodiment, is made of a thin plate and is coupled with the opening of the case  26  such that the opening is closed and sealed. The electrolyte solution may be inserted inside the closed and sealed case  26  through the electrolyte injection opening  21 , and the vent plate  24  may be configured to be broken when an internal pressure of the case  26  is greater than a certain pressure (e.g., a predetermined value). 
     In one embodiment, the first and second terminal units  30  and  40  may respectively include first and second rivets  31  and  41 , first and the second terminal plates  32  and  42 , first and second terminal insulating members  33  and  43  installed between the first and second terminal plates  32  and  42  and the cap plate  20 , and first and second gaskets  34  and  44 . 
     The first and second terminal units  30  and  40  may include a terminal (not shown) made of a circular cylindrical shape rather than a terminal of a plate type. 
     The first and second lower insulating members  60  and  80  may be positioned and installed adjacent to the cap plate  20  inside the case  26 . 
     The supporting member  90  according to one embodiment is coupled with the first current collecting member  50  to support the first current collecting member  50 . 
     In one embodiment, structures of the first and second terminal units  30  and  40 , structures of the first and second current collecting members  50  and  70 , and structures of the first and second lower insulating members  60  and  80  are the same or similar, and, therefore, descriptions of the second terminal unit  40 , the second current collecting member  70 , and the second lower insulating member  80  are omitted. 
       FIG. 3  is an exploded perspective view of a portion of the rechargeable battery  100 , and  FIG. 4  is a partial cross-sectional view of the rechargeable battery  100 . 
     Referring to  FIG. 3  and  FIG. 4 , the first rivet  31 , according to one embodiment, may include a column  31   a , a flange  31   b , a first coupling protrusion  31   c , and a second coupling protrusion  31   d.    
     The first current collecting member  50 , in one embodiment, includes the first electrode coupling unit  51  coupled with the first electrode  11 , and the first terminal coupling unit  52  coupled with the first rivet  31 . 
     The first terminal coupling unit  52  of the first current collecting member  50  may include a fuse unit including a first coupling groove  521 , a second coupling groove  522 , and a fuse hole  523 . A cross-sectional area of the fuse unit where the fuse hole  523  is formed is smaller than that of other portions of the first terminal coupling unit  52 . That is, in one embodiment, the first terminal coupling unit has a smallest cross-sectional area and greatest resistance at the fuse unit where the fuse hole  523  is formed, and is configured to melt at the portion of the fuse unit where the fuse hole  523  is formed under an abnormal current condition. 
     The first lower insulating member  60 , in one embodiment, includes a first current collecting member coupling unit  61 , fixing protrusions  62  and  64 , a flange fixing groove  63 , a protrusion  65  formed at the first current collecting member coupling unit  61 , and a through-hole  66 . 
     The supporting member  90 , in one embodiment, includes a first fixing groove  91 , a second fixing groove  92 , and a supporting protrusion  93 . 
     According to one embodiment, the column  31   a  of the first rivet  31  is inserted into the through-hole  66  formed at the first lower insulating member  60 , and the first flange  31   b  may be fixed to the flange fixing groove  63  formed at the first lower insulating member  60 . 
     In one embodiment, the column  31   a  of the first rivet  31  is rivet-coupled with the first terminal plate  32  and coupled with the cap plate  20  to be fixed such that the first lower insulating member  60  is coupled with the first rivet  31  to be fixed inside the case  26 . 
     The first terminal coupling unit  52  of the first current collecting member  50  is inserted into the first current collecting member coupling unit  61 , and the first coupling groove  521  of the first terminal coupling unit  52  may be coupled with the first coupling protrusion  31   c  formed at the first rivet  31 . 
     In one embodiment, the second coupling groove  522  is coupled with the second coupling protrusion  31   d  of the first rivet  31 , and the protrusion  65  formed at the first lower insulating member  60  is inserted in the fuse hole  523  formed at the first terminal coupling unit  52 . 
     In one embodiment, the first coupling protrusion  31   c  and the first coupling groove  521 , and the second coupling protrusion  31   d  and the second coupling groove  522 , may be adhered by welding, or may be coupled by a friction-fit or press-fit. 
     The supporting member  90  according to one embodiment may be inserted into the first current collecting member coupling unit  61  of the first lower insulating member  60 . 
     The first coupling protrusion  31   c  of the first rivet  31  is coupled to the first fixing groove  91  of the supporting member  90 , and the second coupling protrusion  31   d  of the first rivet  31  may be coupled to the second fixing groove  92 . 
     The supporting protrusion  93  of the supporting member  90  may be inserted into the fuse hole  523  of the first current collecting member  50 . 
     Accordingly, the supporting member  90  according to an exemplary embodiment of the present invention is coupled with the first terminal coupling unit  52  of the first current collecting member  50  via the first rivet  31 , thereby supporting the first current collecting member  50 . 
     In one embodiment, the supporting protrusion  93  of the supporting member  90  is inserted into the fuse hole  523  formed at the first terminal coupling unit  52  such that the mechanical strength of a portion of the fuse unit of the first current collecting member  50  where the fuse hole  523  is formed may be reinforced. 
     Accordingly, the first current collecting member  50  formed with the fuse hole  523  may be stably fixed inside the case  26 , and damage to the first current collecting member  50  (e.g., to the fuse unit where the fuse hole  523  is formed) by an external impact may be prevented or substantially prevented. As such, a rechargeable battery according to embodiments of the present invention is particularly suited for application in an electric vehicle or a hybrid electric vehicle. 
     According to an exemplary embodiment of the present invention, at least one of the supporting member  90  and the supporting protrusion  93  of the supporting member  90  is made of an insulating material. 
     Accordingly, a distance between fractured or broken surfaces of the fuse unit after an abnormal current is generated under the charge or discharge of the rechargeable battery  100  such that the circumference of the fuse hole  523  of the first current collecting member  50  is melted may be great enough because of the supporting protrusion  93  of the supporting member  90  such that the current does not flow. 
     Further, according to an exemplary embodiment, the supporting protrusion  93  of the supporting member  90  may be made of a high-resistance material in which only a current greater than a certain current (e.g. a critical current) will flow. 
     Accordingly, a current that may otherwise generate an arc between the fractured or broken surfaces after the abnormal current is generated under the charge or the discharge of the rechargeable battery  100  such that the fuse unit of the first current collecting member  50  where the fuse hole  523  is formed is melted may flow through the supporting protrusion  93  of the supporting member  90 , and thereby an arc being generated between the fractured surfaces may be prevented or substantially prevented. 
       FIG. 5  is an exploded perspective view of a portion of a rechargeable battery according to another exemplary embodiment of the present invention, and  FIG. 6  is a partial cross-sectional view of the rechargeable battery of  FIG. 5 . 
     Referring to  FIG. 5  and  FIG. 6 , a rechargeable battery  200  according to another exemplary embodiment is the same or substantially the same as the rechargeable battery  100  described above, except for a supporting member  90   a  and a supporting cap  90   b , and further description of the same structures is therefore omitted. 
     According to another exemplary embodiment, the supporting member  90   a  may include a first fixing groove  91   a  coupled to the first coupling protrusion  31   c  of the first rivet  31 , and a second fixing groove  92   a  coupled to the second coupling protrusion  31   d  of the first rivet  31 . 
     Also, a curved or offset portion  93   a  may be formed at one end of the supporting member  90   a  at a location corresponding to an end of the first current collecting member  50  having the fuse hole  523  formed therein. 
     The supporting cap  90   b , according to one embodiment, is coupled to the end of the supporting member  90   a  having the curved portion  93   a  to support the fuse unit formed with the fuse hole  523 . 
     In one embodiment, the supporting cap  90   b  includes a body unit  91   b  and a coupling groove  92   b.    
     As shown in  FIG. 5  and  FIG. 6 , the curved portion  93   a  formed at one end of the supporting member  90   a  may be inserted into the coupling groove  92   b  to be fixed to the supporting cap  90   b.    
     Accordingly, the circumference of the fuse portion formed with the fuse hole  523  and the first current collecting member  50  may be supported by the supporting member  90   a  coupled with the supporting cap  90   b  such that the mechanical rigidity and strength of the first current collecting member  50  may be reinforced. 
     In one embodiment, the supporting cap  90   b  may be made of a high-resistance material through which only a current greater than a certain current (e.g., a critical current) will flow. 
     Accordingly, a current that may otherwise generate an arc between the fractured or broken surfaces after the abnormal current is generated under the charge or the discharge of the rechargeable battery  200  such that the fuse unit of the first current collecting member  50  where the fuse hole  523  is formed is melted may flow through the supporting cap  90   b , and thereby an arc being generated between the fractured surfaces may be prevented or substantially prevented. 
       FIG. 7  is an exploded perspective view of a rechargeable battery according to another exemplary embodiment of the present invention, and  FIG. 8  is a partial cross-sectional view of the rechargeable battery of  FIG. 7 . 
     Referring to  FIG. 7  and  FIG. 8 , a rechargeable battery  300  according to another exemplary embodiment is the same or substantially the same as the rechargeable battery  200  described above except for a supporting cap  90   c , and further description of the same structures is therefore omitted. 
     The supporting cap  90   c  according to another exemplary embodiment includes a body unit  91   c , a coupling groove  92   c , and a cap protrusion  93   c.    
     The curved or offset portion  93   a  formed at one end of the supporting member  90   a  may be inserted in the coupling groove  92   c , and the cap protrusion  93   c  may be inserted in the fuse hole  523  formed at the first terminal coupling unit  52  of the first current collecting member  50 . 
     Accordingly, the first current collecting member  50  may be supported by the supporting member  90   a  and the supporting cap  90   c  formed with the cap protrusion  93   c  coupled with one end of the supporting member  90   a  such that the mechanical strength of the first current collecting member  50  may be reinforced. 
     According to an exemplary embodiment, the supporting cap  90   c  may be made of an insulating material. 
     Accordingly, a distance between fractured or broken surfaces of the fuse unit after an abnormal current is generated under the charge or the discharge of the rechargeable battery  300  such that the fuse unit at the circumference of the fuse hole  523  of the first current collecting member  50  is melted may be great enough by the cap protrusion  93   c  of the supporting cap  90   c  such that the current does not flow. 
     According to an exemplary embodiment, the supporting cap  90   c  may be made of a high-resistance material through which only a current greater than a certain current (e.g., a critical current) will flow. 
     Accordingly, a current that may otherwise generate an arc between the fractured or broken surfaces of the fuse unit after the abnormal current is generated under the charge or the discharge of the rechargeable battery  300  such that the fuse unit of the first current collecting member  50  where the fuse hole  523  is formed is melted may flow through the supporting cap  90   c , and thereby an arc being generated between the fractured surfaces may be prevented or substantially prevented. 
     While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, and equivalents thereof.