Patent Publication Number: US-2015072173-A1

Title: Rechargeable battery pack

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Korean Patent Application No. 10-2013-0023990, filed on Mar. 6, 2013, in the Korean Intellectual Property Office, and entitled: “Rechargeable Battery Pack,” is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     The described technology relates generally to a rechargeable battery pack. 
     2. Description of the Related Art 
     Unlike a primary battery, a rechargeable battery can be recharged and discharged repeatedly. A small-capacity rechargeable battery is used for small portable electronic devices such as mobile phones, notebook computers, camcorders, and the like, and a large-capacity rechargeable battery is used as a motor-driving power source for a hybrid vehicle or the like. 
     Typical rechargeable batteries includes a nickel-cadmium (Ni—Cd) battery, a nickel-hydrogen (Ni—NH) battery, a lithium (Li) battery, a lithium ion (Li-ion) rechargeable battery, and the like. An operating voltage of a lithium ion rechargeable battery may be approximately three times higher than that of the nickel-cadmium battery or the nickel-hydrogen commonly used to portable electronic equipments. In addition, the lithium ion rechargeable battery may be widely used due to advantages in terms of higher energy density per unit weigh. 
     The rechargeable battery may use a lithium-based oxide as a positive active material, and a carbon material as a negative active material. In general, lithium-based rechargeable batteries may be classified into a liquid electrolyte battery and a polymer electrolyte battery depending on the kinds of electrolyte. A battery using the liquid electrolyte is referred to as a lithium ion battery and a battery using the polymer electrolyte is referred to as a lithium polymer battery. 
     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 
     Embodiments are directed to a rechargeable battery pack that includes a rechargeable battery, a mount frame wrapping at least part of the rechargeable battery, an outer case wrapped around the mount frame, the outer case including a first case having a first lead unit protruding therefrom, and a second case having a second lead unit therefrom, the first lead unit and the second lead unit being inserted into and fixed to an inside of the mount frame, and a protective circuit module electrically connected to the rechargeable battery. 
     The mount frame may include a first frame covering opposing sidewall portions of the rechargeable battery, a second frame coupled to the first frame and installed with the protective circuit module, and a third frame coupled to the first frame and including an inserting hole into which the first lead unit and the second lead unit are inserted. 
     The third frame may include a body frame coupled to the first frame, and a protrusion frame protruding from the body frame and including an inserting hole into which the first lead unit and the second lead unit are inserted. 
     The protrusion frame may include a first protrusion portion protruding on the body frame, a second protrusion portion protruding at a location spaced from the first protrusion portion on the body frame, and a cover unit forming the inserting hole by connecting the first protrusion portion with the second protrusion portion at a location spaced from a surface of the body frame. 
     The first lead unit and the second lead unit may be made of a nickel or stainless (SUS) material. 
     The first lead unit and the second lead unit may include at least two first lead units and at least two second lead units. Each of the first lead units and the second lead units may be bent in a direction toward the body frame. 
     One of the first lead units and one of the second lead units may be resistance-welded or laser-welded in a state where the one of the first lead units and the one of the second lead units are inserted into the inserting hole. 
     The cover unit may include a welding hole for welding of the one of the first lead units and the one of the second lead units inserted into the inserting hole. 
     The third frame may include a plurality of recess portions. 
     The recess portions may include a first recess portion into which the one of first lead units and the one of the second lead units are inserted, and a second recess portion including a depression portion at a bottom thereof. 
     The first case may further include a first fixing lead unit inserted into the second recess portion and coupled to the depression portion by an elastic force. 
     The second case may further include a second fixing lead unit inserted into the second recess portion and coupled to the depression portion by an elastic force. 
    
    
     
       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 drawing schematically illustrating a rechargeable battery according to an exemplary embodiment. 
         FIG. 2  illustrates a partial exploded perspective view schematically illustrating a rechargeable battery according to the exemplary embodiment. 
         FIG. 3  illustrates a partial exploded perspective view seen from the bottom part of the rechargeable battery pack of  FIG. 2 . 
         FIG. 4  illustrates a perspective view schematically illustrating a third frame according to the exemplary embodiment. 
         FIG. 5  illustrates a side view of the third frame of  FIG. 4 . 
         FIG. 6  illustrates a partial exploded perspective view schematically illustrating a rechargeable battery according to another exemplary 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. 1  illustrates a drawing schematically illustrating a rechargeable battery according to an exemplary embodiment. 
     As shown in  FIG. 1 , the rechargeable battery  100  may include an electrode assembly  110  and a pouch  120  accommodating the electrode assembly  110 . The electrode assembly  110  may include a structure in which a positive electrode  111 , negative electrode  112 , and a separator  113  interposed between the positive electrode  111  and the negative electrode  112  may be spirally wound. 
     The separator  113  may be located between the positive electrode  111  and the negative electrode  112  to prevent a short and enable the movement of the lithium ions. The separator  113  may be formed of a polyethylene (PE) or polypropylene polymer film, or their multi-layers. 
     The positive electrode  111  may be electrically connected with a positive electrode tab  114 . In addition, the negative electrode  112  may be electrically connected with a negative electrode tab  115 . The positive electrode tab  114  may be bound with an insulation tape  116  for the positive electrode, and the negative electrode tab  115  may be bound with an insulation tape  117  for the negative electrode. 
     The pouch  120  may be a case that includes an upper case  121  and a lower case  122 . At least one side of the upper case  121  and lower case  122  may be integrally connected. The pouch  120  may have a three-layer structure including a metal foil and an insulating film laminated on both sides of the metal foil, as an example. 
       FIG. 2  illustrates a partial exploded perspective view schematically illustrating a rechargeable battery according to an exemplary embodiment, and  FIG. 3  illustrates a partial exploded perspective view seen from the bottom part of the rechargeable battery pack of  FIG. 2 . 
     As shown in  FIGS. 2 and 3 , the rechargeable battery pack  200  according to this exemplary embodiment includes a rechargeable battery  100 , a mount frame  210  wrapping at least part of the rechargeable battery  100 , an outer case  220  installed to be wrapped around the mount frame  210  and including a first case  221  and a second case  223 , and a protective circuit module  230  electrically connected to the rechargeable battery  100 . 
     The rechargeable battery  100  is provided with the pouch  120  accommodating the electrode assembly  110 . From one side of the pouch  120 , an end portion of the positive electrode tab  114  and an end portion of the negative electrode tab  115  may be exposed to the outside. The pouch  120  may be a case with flexibility, and the pouch may be freely foldable in a state where the electrode assembly  110  is accommodated on the inside of the pouch  120 . At least part of the rechargeable battery  100  may be wrapped by the mount frame  210 . 
     The mount frame  210  may include a first frame  211  to cover two sidewall portions of the rechargeable battery  100 , a second frame  213  to be installed on the first frame  211 , and a third frame  215  to cover the bottom portion of the rechargeable battery  100 . 
     The first frame  211  may be installed to be wrapped around at least two or more parts of the sides of the rechargeable battery  100 . 
     The second frame  213  may be installed on the top of the first frame  211  and may be formed with a through-hole  213   a  in which the positive electrode tab  114  and the negative electrode tab  115  may be exposed in the direction of the protective circuit module  230 . The outer surface of the second frame  213  may be formed with a plurality of inserting holes  213   b.  The term “inserting hole  213   b ” refers to a part in which a coupling protrusion  225  of the outer case  220  is inserted. The coupling protrusion  225  may be inserted into the inserting hole  213   b  and may be physically fixed using a separate fixing means. The bottom of the first frame  211  is provided with a third frame  215 . Selectively, the third frame  215  may be removably installed on the first frame  211 . 
     The third frame  215  may be coupled with a first lead unit  227  protruding from the first case  221  of the outer case  220 , and may include an inserting hole  215   a  into which a second lead unit  229 , which protrudes from the second case  223 , is inserted. The inserting hole  215   a  may be formed at a central location of the length direction of the third frame  215 . The inserting hole  215   a  may be formed for coupling in a state where the first lead unit  227  and the second lead unit  229  are inserted. Hereinafter, the inserting hole  215   a  will be described in more detail together with the third frame  215 . 
       FIG. 4  illustrates a perspective view schematically illustrating a third frame according to the exemplary embodiment, and  FIG. 5  illustrates a side view of the third frame of  FIG. 4 . 
     As shown in  FIGS. 4 and 5 , the third frame  215  may include a body frame  217  and a protrusion frame  219 . The body frame  217  refers to a part directly coupled to the first frame  211 . On the body frame  217 , a plurality of protrusion frames  219  may be installed for formation of the inserting hole  215   a.    
     The protrusion frame  219  may include a first protrusion portion  219   a  protruded on the body frame  217 , a second protrusion portion  219   b  protruded on the body frame  217  at a location spaced apart from the first protrusion portion  219   a,  and a cover unit  219   c  to connect the first protrusion portion  219   a  and the second protrusion portion  219   b.    
     The first protrusion portion  219   a  and the second protrusion portion  219   b  may protrude to be spaced apart from each other on the body frame  217 . A recess portion  217   a  may be formed between the first protrusion portion  219   a  and the second protrusion portion  219   b  on the body frame  217   b.  A hook part  217   b  may protrude from the ends of both edges of the body frame  215   b.  Accordingly, the recess portion  217   a  can be formed at a central portion of the length direction of the third frame  215  and at both sides of the length direction of the third frame  215 , respectively. Herein, three recess portions  217   a  formed into the third frame  215  will be described as an example. In other implementations, the number of recess portions  217   a  may vary according to the number of the protrusion portions. 
     In the exemplary embodiment, the recess portion  217   a  formed at the central portion of the third frame  215  among three recess portions  217   a  in the length direction may be formed with the cover unit  219   c.  One end of the cover unit  219   c  may be connected to the side of the first protrusion portion  219   a  and other end of the cover unit  219   c  may be connected to the side of the second protrusion portion  219   b  to cover the recess portion  217   a  formed at the central portion of the third frame  215 . The inserting hole  215   a  into which the first lead unit  227  and the second lead unit  229  are inserted may be formed out of the first protrusion portion  219   a,  the second protrusion portion  219   b  and the cover unit  219   c.    
     In the present exemplary embodiment, it will be illustrated as an example that the first lead unit  227  and the second lead unit  229  is fixed by a resistance welding or laser welding in a state where the first lead unit  227  and the second lead unit  229  are inserted into the inserting hole  215   a.  In other implementations, the first lead unit  227  and the second lead unit  229  may be fixed by a fitting within the inside of the inserting hole  215   a.    
     The cover unit  219   c  may be formed with a welding hole  219   d  for welding of the first lead unit  227  and the second lead unit  229 . The welding hole  219   d  may be formed on the upper side of the cover unit  219   c  such that the welding heat may be easily delivered to the first lead unit  227  and the second lead unit  229 . The welding hole  219   d  may be formed in an oval shape corresponding to the length of the cover unit  219   c  to easily deliver the welding heat. In other implementations, the welding hole  219   d  may have other shapes such as a polygonal or circular. In the present exemplary embodiment, the first lead unit  227  and the second lead unit  229  may be resistance-welded or laser-welded. 
     As such, the first lead unit  227  and the second lead unit  229  may be fixed by welding heat in a state where they are inserted into the inserting hole  215   a  of the third frame  215 , and thus, even if impact is delivered to the rechargeable battery pack  200 , coupling durability of the outer case  220  is not deteriorated. 
     The first lead unit  227  and the second lead unit  229  may protrude in a state where they are bent at the edges of the first case  221  and the second case  223 . The outer case  220  will be described in more detail below. 
     Referring again to  FIGS. 2 and 3 , the outer case  220  includes the first case  221  to protect one opened side of the mount frame  220  and the second case  223  to protect another opened side of the mount frame  220 . 
     The first case  221  is installed to cover a first exposed side of the rechargeable battery  100  that is not protected by the mount frame  220 . The second case  223  is installed to cover a second exposed side of the rechargeable battery  100  that is not protected by the mount frame  220 . The first case  221  and the second case  223  may be installed on opposing sides of the rechargeable battery  100  to protect the rechargeable battery  100  from external impacts. 
     The first case  221  and the second case  223  may be made of metal materials and may be fixed by welding in a state where portions of the edges of the sides overlap to each other. The first case  221  and the second case  223  may be fixed by resistance welding or laser welding in a state where a portion of the corner of the first case  221  is located to be overlapped with a portion of the corner of the second case  223 . In other implementations, the first case  221  and the second case  223  may be coupled with each other by a physical fitting. When the first case  221  and the second case  223  are coupled by such a fitting, the sides of the first case  221  and the second case  223  may be formed with an uneven parts (not shown) to be fixed using an elastic force. In addition, the first case  221  and the second case  223  can be coupled to the mount frame  210  with the fitting. 
     The first lead unit  227  inserted into the inserting hole  215   a  of the third frame  215  protrudes from the first case  221 . A plurality of first lead units  227  may protrude to the external side of the edge of the first case  221 . One of the first lead units  227  may be inserted into the inserting hole  215   a  formed on the third frame  215 , and other ones of the first lead unit  227  may be inserted into the one of the recess portions  217   a  formed on the third frame  215 . As such, the first lead unit  227  may be bent at the edge of the first case  221  in a direction of the third frame  215  such that the first lead unit may be easily inserted into the inserting hole  215   a  and the recess portion  217   a  of the third frame  215 . 
     Another first fixing lead unit  227   a  may protrude from the first case  221  and may be bent along the length direction to be coupled to the third frame  215  by an elastic hook operation. 
     For combining with the first fixing lead unit  227   a,  one of recess portions  217   a  of the third frame  215  may be formed to have an uneven part  222 . 
     As shown in  FIGS. 4 and 5 , a bottom of the recess portion  217   a  may be formed with a plurality of uneven parts  222 . Accordingly, the end of the first fixing lead unit  227   a  may be inserted into the recess portion  217   a  and hook-coupled to the uneven part  222 . Thus, the first case  221  may be fixed more stably. 
     The second lead unit  229  to be inserted into the inserting hole  215   a  of the third frame  215  may protrude from the second case  223 . 
     At least two the second lead units  229  may protrude to the outside of the edge of the second case  223 . One of the second lead units  229  may be inserted into the inserting hole  215   a  formed in the third frame  215  and another ones of the second lead units  223   a  may be inserted into the recess portion  217   a  formed in the third frame  215 . As such, the second lead unit  229  may be bent at the edge of the second case  223  in a direction of the third frame  215  such that the second lead unit  229  may be easily inserted into the inserting hole  215   a  and the recess portion  217   a  of the third frame  215 . The second lead unit  229  may be inserted in a state where the second lead unit  229  overlaps with the first lead unit  227  at the inserting holes  215   a  Thus, the first lead unit  227  and the second lead unit  227  can be fixed by welding. 
     The second fixing lead unit  229   a  may protrude from the second case  223 . The second fixing lead unit  229   a  may be bent along the length direction to be hook-coupled to the third frame  215  by an elastic hook operation. 
     The second fixing lead unit  229   a  may be fixed to the uneven part  222  of the recess portion  217   a  of the third frame  215  described above by an elastic force. The second fixing lead unit  229   a  may be hook-coupled with the same recess portion  217   a  together with the first fixing lead unit  227   a.  A length protruding from the first fixing lead unit  227   a  and the length protruding from the second fixing lead unit  229   a  may each be formed to be less than half the length of the recess portion  217   a  such that the first fixing lead unit  227   a  and the second fixing lead unit  229   a  may both be hook-fixed to the one of the recess portions  217   a.  As a result, the first fixing lead unit  227   a  may be hook-fixed to a portion of the recess portion  217   a  by hook coupling, and the second fixing lead unit  229   a  may be hook-fixed by hook coupling together with the other portion of the recess portion  217   a.    
     The first case  221  and the second case  223  of the present exemplary embodiment may be stably fixed to improve durability of the cases wherein the first lead unit  227  and the second lead unit  229  are coupled by welding, and the first fixing lead unit  227   a  and the second fixing lead unit  229   a  are hook-coupled. 
       FIG. 6  is a partial exploded perspective view schematically illustrating a rechargeable battery according to another exemplary embodiment. The same reference numbers of  FIGS. 1 to 5  refer as to the same members having the same functions. Hereinafter, detail description of the same reference numbers will not be repeated. 
     As shown in  FIG. 6 , in the rechargeable battery pack  300  according to the this exemplary embodiment, a first lead unit  327  protrudes from the center portion of the edge of the first case  321  in the length direction, and first fixing lead units  327   a  protrude from edges of the first case  321  at respective sides spaced from the center portion. 
     In addition, the second lead unit  329  protrudes from the center portion of the edge of the second case  323  in the length direction, and second fixing lead units  329   a  protrude edges of the second case  323  at respective sides spaced from the center portion. 
     The recess portions  317   a  into which uneven parts  322  are formed on the bottoms thereof may be present at the respective sides of the third frame  315  in the length direction. 
     Fixing of the first fixing lead units  327   a  and the second fixing lead units  329   a  with the uneven parts  322  from the recess portion  317   a  formed on the both sides of the third frame  315  may be achieved by the elastic hook function. In addition, the first lead unit  327  and the second lead unit  329  may be stably fixed by resistance welding or laser welding in a state where the first lead unit  327  and the second lead unit  329  are inserted into the inserting hole  315  of the third frame  315 . As such, the first case  321  and the second case  323  can be hook-fixed to the mount frame  220  by welding or hook fixture to improve durability in response to external impacts. 
     By way of summation and review, rechargeable batteries may be provided with a protective circuit module to control charging and discharging. The protective circuit module may prevent over-charging and over-discharging of the rechargeable battery and may improve the safety and cycle-life of the rechargeable battery. 
     The rechargeable battery and protective circuit module may include a case to wrap the outside of the rechargeable battery, as a way to protect the rechargeable battery from external impact or the like. In addition, the protective circuit module may be physically coupled to a frame to protect the rechargeable battery. 
     When the case is physically coupled, there is a risk that the durability thereof may be deteriorated due to deformation of the fixed part in the event of an external impact. 
     Embodiments provide a rechargeable battery pack that may have enhanced durability with respect to external impacts of the rechargeable battery pack. A case to protect the rechargeable battery may be welded and hook-coupled to a mount frame to improve durability in response to such external impacts. 
     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.