Abstract:
A battery including a battery case, an electrode assembly in the battery case, the electrode assembly including a plurality of windings that are wound about a winding axis, the winding axis being oriented parallel to a bottom surface of the battery case, and a deformable member between the electrode assembly and the bottom surface of the battery case, the deformable member being pressed between the electrode assembly and the bottom surface of the battery case.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to pending U.S. Provisional Application No. 61/272,880, filed in the U.S. Patent and Trademark Office on Nov. 13, 2009, and entitled “BATTERY MODULE,” which is incorporated by reference herein in its entirety and for all purposes. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments relate to a battery and a battery module including the same. 
     2. Description of the Related Art 
     Unlike primary batteries, secondary batteries generally may be rechargeable. 
     A secondary battery may be used as an energy source for mobile devices such as laptop computers and mobile phones, electric automobiles, hybrid electric automobiles, electric bicycles, and uninterruptible power supplies. 
     In a medium-large sized device, such as in an electric or hybrid electric automobile, a battery module, in which a plurality of battery cells are electrically connected to each other, is generally used due to the need for high output and high-capacity. 
     SUMMARY 
     Embodiments are therefore directed to a battery and a battery module including the same, which substantially overcome one or more of the problems due to the limitations and disadvantages of the related art. 
     It is therefore a feature of an embodiment to provide a battery having provisions to prevent movement of an electrode assembly in a case, so as to reduce the effects of vibration, and a battery module including the same. 
     At least one of the above and other features and advantages may be realized by providing a battery, including a battery case, an electrode assembly in the battery case, the electrode assembly including a plurality of windings that are wound about a winding axis, the winding axis being oriented parallel to a bottom surface of the battery case, and a deformable member between the electrode assembly and the bottom surface of the battery case, the deformable member being pressed between the electrode assembly and the bottom surface of the battery case. 
     The electrode assembly may have an outermost winding, the outermost winding of the electrode assembly may be a separator, and the separator may contact the deformable member. 
     The electrode assembly may include a second plurality of windings that are wound about a second winding axis, the second winding axis being oriented parallel to the winding axis, and the deformable member may have lateral support portions that press against the winding and the second winding. 
     The deformable member may have at least one central support portion disposed between the lateral support portions, the central support portion being configured to press against a central region of the electrode assembly. 
     The deformable member may have a W shape, the center of the W forming a central support portion disposed between the plurality of windings and the second plurality of windings. 
     The deformable member may include lateral support portions that contact lower side regions of the electrode assembly, the lateral support portions of the deformable member may be coupled to one another, and the deformable member may be a single integrated member. 
     The deformable member may be a preformed plate, ends of the plate being bent so as to extend away from the bottom surface of the battery case, the ends of the plate forming the lateral support portions. 
     The lateral support portions of the deformable member may press against sides of the battery case. 
     The deformable member may have a length in the winding axis direction that corresponds to that of the electrode assembly. 
     The deformable member may not be fixed to the electrode assembly and may not be fixed to the battery case, such that the deformable member floats between the electrode assembly and the battery case. 
     The battery may further include a cap plate coupled to the battery case, the cap plate having at least one electrode terminal extending therethrough, the electrode assembly being coupled to the at least one electrode terminal. The cap plate may be disposed at an end of the battery case that is opposite to the deformable member. 
     The deformable member may be electrically insulating. 
     The deformable member may include at least one of silicone, rubber, and polypropylene. 
     At least one of the above and other features and advantages may also be realized by providing a battery, including a battery case, an electrode assembly in the battery case, and a retainer between the electrode assembly and the battery case, the retainer being disposed along an end of the electrode assembly, the retainer having peripheral members that extend away from a bottom surface of the battery case, the peripheral members contacting the electrode assembly and sides of the battery case. 
     The retainer may have a central member that joins the peripheral members, at least a portion of the central member being in contact with the battery case. 
     The peripheral members may be coupled together and the retainer may be a single integrated member. 
     The retainer may be a preformed plate having ends that are bent away from the bottom of the battery case, the ends forming the peripheral members. 
     The deformable member may be electrically insulating. 
     The deformable member may include at least one of silicone, rubber, and polypropylene. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features and advantages will become more apparent to those of skill in the art by describing in detail example embodiments with reference to the attached drawings, in which: 
         FIG. 1  illustrates a perspective view of a battery module according to a first embodiment; 
         FIG. 2  illustrates a cross-sectional view of a battery unit cut along a line I-I of  FIG. 1 ; 
         FIG. 3  illustrates aspects of an electrode assembly; 
         FIG. 4  illustrates a cross-sectional view of a battery unit cut along a line II-II of  FIG. 1 ; 
         FIG. 5  illustrates a partial perspective view of the battery unit of  FIG. 4 ; 
         FIG. 6A  illustrates a partial cross-sectional view of the battery unit of  FIG. 4  showing a bottom retainer in a state before the bottom retainer is deformed; 
         FIG. 6B  illustrates a partial cross-sectional view of the battery unit of  FIG. 4  showing the bottom retainer in a state after the bottom retainer is deformed; and 
         FIG. 7  illustrates a cross-sectional view of a battery unit according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the drawing figures, dimensions may be exaggerated for clarity of illustration. It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element, or one or more intervening elements may also be present. It will also be understood that when an element is referred to as being “under” another element, it can be directly under, or one or more intervening elements may also be present. It will also be understood that when an element is referred to as being “between” two elements, it can be the only element between the two elements, or one or more intervening elements may also be present. Like reference numerals refer to like elements throughout. 
       FIG. 1  illustrates a perspective view of a battery module according to a first embodiment. 
     Referring to  FIG. 1 , the battery module  100  may include a battery unit  101 . The battery unit  101  may include one or more electrode assemblies  102 . 
     A positive electrode terminal  103  and a negative electrode terminal  104  may protrude from the battery unit  101 . A washer  106 , a nut  107 , and an insulator  105  may be connected to each of the positive electrode terminal  103  and the negative electrode terminal  104 . 
     In the battery module  100 , a plurality of the battery units  101  may be connected together. For example, the battery units  101  may be electrically connected in series. The battery units  101  may be alternately arranged so that adjacent terminals of adjacent battery units have opposite polarities. The positive electrode terminal  103  of one battery unit  101  may be connected to the negative electrode terminal  104  of another, adjacent battery unit  101  via a bus bar  108 . In an implementation, the positive electrode terminal  103  of the one battery unit  101  and the negative electrode terminal  104  of the other battery unit  101  may be connected to each other by the bus bar  108  with nuts  109  screwed thereon to secure the bus bar  108 . 
       FIG. 2  illustrates a cross-sectional view of a battery unit cut along a line I-I of  FIG. 1 .  FIG. 3  illustrates aspects of an electrode assembly. 
     Referring to  FIGS. 2 and 3 , the battery unit  101  may include the at least one electrode assembly  102 , as well as a case  110  including the at least one electrode assembly  102 . A cap assembly  111  may be installed on the case  110 . 
     As shown in  FIG. 3 , the electrode assembly  102  may include a positive plate  112  and a negative plate  113 . A separator  114  may be interposed between the positive plate  112  and the negative plate  113 . The positive plate  112 , the separator  114 , and the negative plate  113  may be rolled to form a jelly-roll type electrode assembly. Two or more such jelly-roll type electrodes may be housed in the case  110 . 
     For the positive plate  112 , a positive active material layer  112   b  may be formed on at least one surface of a positive current collector  112   a . Further, a positive electrode uncoated part  112   c , on which the positive active material layer  112   b  is not formed, may be provided on one edge of the positive current collector  112   a , e.g., along a longitudinal direction thereof. 
     For the negative plate  113 , a negative active material layer  113   b  may be formed on at least one surface of a negative current collector  113   a . Further, a negative electrode uncoated part  113   c , on which a negative active material layer  113   b  is not formed, may be formed on one edge of the negative current collector  113   a , e.g., along a longitudinal direction thereof. 
     The uncoated part  113   c  of the negative plate  113  may be opposite to the uncoated part  112   c  of the positive plate  112 , such that the positive electrode uncoated part  112   c  and the negative electrode uncoated part  113   c  are arranged at edges that are opposite to each other in a width direction of the electrode assembly  102 . The electrode assembly  102  may be inserted into the case  110  such that the positive electrode uncoated part  112   c  and the negative electrode uncoated part  113   c  are disposed on left and right sides of the electrode assembly  102 , respectively. 
     The positive electrode uncoated part  112   c  may be electrically connected to a positive electrode current collector plate  115 . The negative electrode uncoated part  113   c  may be electrically connected to a negative electrode current collector plate  116 . An end of the positive electrode current collector plate  115  and an end of the negative electrode current collector plate  116  may be located in the upper space S in the case  110 , the space S being formed between the electrode assembly  102  and the cap assembly  111 . The positive electrode uncoated part  112   c  may be combined to the positive electrode current collector plate  115 , and the negative electrode uncoated part  113   c  may be combined to the negative electrode current collector plate  116 , respectively, using, e.g., ultrasonic welding. 
     The case  110  may be formed of a metal, e.g., aluminum, an aluminum alloy, nickel-plate steel, etc. In another implementation, the case  110  may be formed of an electrically insulating material. The case  110  may or may not be polarized, i.e., the case  110  itself may or may not form part of the electrical circuit of the battery. The size of the case  110  may be such that at least one electrode assembly  102  may be included therein. The case  110  may have a square shape or another suitable shape. 
     The cap assembly  111  may include a cap plate  112  that seals an upper opening  110   b  of the case  110 . A bottom surface of the cap plate  112  may be combined to the case  110  along edges of an upper part of the case  110  and may seal an inner space of the case  110 . 
     The cap plate  112  may include a safety vent  123 . The safety vent  123  may open, e.g., irreversibly, to rapidly discharge gas out from the case  110  when an internal pressure of the case  110  is excessively increased. 
     The cap plate  112  may include an electrolyte injection hole  124  for injecting an electrolyte into the case  110 . The electrolyte injection hole  124  may include a pin  125  that seals the electrolyte injection hole  124  after injection of an electrolyte. 
     The positive electrode current collector plate  115  may be electrically connected to the positive electrode terminal  103 , which may be formed of a bolt. The positive electrode terminal  103  may protrude past a hole in the cap plate  112  by a predetermined amount from inside the case  110 . At the hole of the cap plate  112  through which the positive electrode terminal  103  protrudes, the insulator  105  and a seal gasket  117  may be respectively inserted thereon and thereunder, to insulate the positive electrode terminal  103  from the cap plate  112 . The positive electrode terminal  103  may extend through the insulator  105  and the seal gasket  117 . 
     A washer  106  and a nut  107  may be placed onto the positive electrode terminal  103  protruding from the cap plate  112  and screwed thereon. The bus bar  108  may be fixed to the positive electrode terminal  103  protruding from the nut  107  so as to electrically connect to an adjacent battery unit  101 . The nut  109  may be screwed on the bus bar  108  and thus the bus bar  108  may be fixed on the positive electrode terminal  103 . 
     The positive electrode current collector plate  115  may be fixed on the positive electrode terminal  103  in the upper space S of the case  110 , e.g., by caulking and laser welding. An insulating case  118  may be further installed around the positive electrode terminal  103  by being interposed between the positive electrode current collector plate  115  and the cap plate  112 . 
     The negative electrode current collector plate  116  may be electrically connected to the negative electrode terminal  104 , which may be formed of a bolt. The negative electrode terminal  104  may protrude past a hole in the cap plate  112  by a predetermined amount from inside of the case  110 . An insulator  105 , a seal gasket  117 , and an insulating case  118  may be installed between the negative electrode terminal  104  and the cap plate  112  for insulating the negative electrode terminal  104  from the cap plate  112 . 
     The at least one electrode assembly  102  may be installed in the battery unit  101 . A bottom retainer  400  may be installed at a bottom of the case  110  in order to prevent movement of the electrode assembly  102 , which will be described more fully below. 
       FIG. 4  illustrates a cross-sectional view of a battery unit cut along a line II-II of  FIG. 1 .  FIG. 5  illustrates a partial perspective view of the battery unit of  FIG. 4 . 
     Hereinafter, connections regarding a positive plate are described in the current embodiment; however, the current embodiment may be also applied to a negative plate. 
     As shown in  FIGS. 4 and 5 , the electrode assembly  102  is included in the case  110 . The electrode assembly  102  according to the current embodiment includes a first electrode assembly  102   a  and a second electrode assembly  102   b . However, the current embodiment is not limited thereto, and one or more electrode assemblies  102  may be included in the case  110 . 
     The positive electrode current collector plate  115  may include a plurality of collector leads, e.g., first and second positive electrode current collector leads  115   a  and  115   b , as well as a positive electrode current collector connector  115   c  that connects the positive electrode current collector leads  115   a  and  115   b.    
     The first positive electrode current collector lead  115   a  may be electrically connected to the first electrode assembly  102   a  and the second positive electrode current collector lead  115   b  may be electrically connected to the second electrode assembly  102   b . The first positive electrode current collector lead  115   a  and the second positive electrode current collector lead  115   b  may be connected to a positive electrode current collector of the first electrode assembly  102   a  and a positive electrode current collector of the second electrode assembly  102   b , respectively, using, e.g., ultrasonic welding. The first positive electrode current collector lead  115   a  and the second positive electrode current collector lead  115   b  may be connected to the positive electrode current collector at one edge of the first electrode assembly  102   a  and the positive electrode current collector at one edge of the second electrode assembly  102   b , respectively. 
     The first positive electrode current collector lead  115   a  and the second positive electrode current collector lead  115   b  may be integrally connected to each other by the positive electrode current collector connector  115   c  in the upper space S in the case  110 . The positive electrode current collector connector  115   c  may be bent with respect to the first positive electrode current collector lead  115   a  and the second positive electrode current collector lead  115   b . The positive electrode terminal  103  may be fixed to an upper surface of the positive electrode current collector connector  115   c , e.g., by caulking and laser welding. 
     An insulator  105 , a seal gasket  117 , and an insulating case  118  may be installed around the positive electrode terminal  103  for insulating the positive electrode terminal  103  from the cap plate  112 . 
     The first electrode assembly  102   a  and the second electrode assembly  102   b  may be secured by the connections of the first positive electrode current collector lead  115   a , the second positive electrode current collector lead  115   b , the positive electrode current collector connector  115   c , and the positive electrode terminal  103  in the upper space S in the case  110 , which may help to prevent movement of the internal components of the battery unit  101 . 
     The bottom retainer  400  may be installed at the bottom of the case  110  in order to prevent the first electrode assembly  102   a  and the second electrode assembly  102   b  from moving. The bottom retainer  400  may be configured as a plate having ends that contact outer side surfaces of the electrode assembly  102   a  and/or  102   b . The bottom retainer  400  may be a plate having ends that are bent upward to positively engage the electrode assembly  102   a  and/or  102   b , to thus positively engage the electrode assembly  102   a  and/or  102   b  and resist lateral motion thereof. In an implementation, the bottom retainer  400  may be a preformed and/or solid piece, and may thus provide a more positive engagement with the electrode assembly  102   a  and/or  102   b  than, e.g., a foam piece. The bottom retainer  400  may be an integral member, and may be formed by, e.g., thermoforming a plastic material, stamping a metal material, etc. 
     The bottom retainer  400  may include a first bottom  401  and a second bottom  402 . The first bottom  401  and the second bottom  402  may be flat plates extended from one side to the other side along the bottom of the case  110 . 
     A first transformed part  403  inclined by a predetermined angle towards an upper direction may be formed at an edge of the first bottom  401 , and may extend along the longitudinal direction of the first bottom  401 . In an implementation, opposing first transformed parts  403  may be integrally connected with the first bottom  401  along edges of the first bottom  401 , such that the first electrode assembly  102   a  is located in an inner space formed by combining the first bottom  401  and the first transformed parts  403 . 
     A second transformed part  404  inclined by a predetermined angle towards an upper direction may be formed at an edge of the second bottom  402 , and may extend along the longitudinal direction of the second bottom  402 . In an implementation, opposing second transformed parts  404  may be integrally connected with the second bottom  402  along edges of the second bottom  402 , such that the second electrode assembly  102   b  is located in an inner space formed by combining the second bottom  402  and the second transformed parts  404 . 
     The first bottom  401  and the second bottom  402  may disposed apart from one another, and may be integrally connected to each other at a part  405 . The part  405  may be positioned where the first electrode assembly  102   a  and the second electrode assembly  102   b  are contacted with each other. Accordingly, the bottom retainer  400  may span and stabilize the first electrode assembly  102   a  and the second electrode assembly  102   b , wherein the first electrode assembly  102   a  and the second electrode assembly  102   b  may be in the inner space formed by combining the first bottom  401  and the first transformed parts  403  and the inner space formed by combining the second bottom  402  and the second transformed parts  404 , respectively. 
     The size of the inner space formed by combining the first bottom  401  and the first transformed parts  403 , and the size of the inner space formed by combining the second bottom  402  and the second transformed parts  404 , respectively, may be such that lower parts of the first electrode assembly  102   a  and lower parts of the second electrode assembly  102   b  are forcibly fixed thereto. The bottom retainer  400  may be separate from the electrode assembly  102  and the bottom surface  110   a  of the case  110 . The bottom retainer  400  may not be fixed to the electrode assembly  102  or the bottom surface  110   a  of the case  110 . The bottom retainer  400  may be held in place due to being pressed between the electrode assembly  102  and the bottom surface  110   a  of the case  110 , but may float therebetween. 
     Lengths, i.e., longitudinal dimensions, of the first bottom  401  and the second bottom  402  may be long enough to cover lengths of the first electrode assembly  102   a  and the second electrode assembly  102   b . Moreover, the height of the first transformed parts  403  and the second transformed parts  404  may be high enough to include predetermined areas of the lower parts of the first electrode assembly  102   a  and the second electrode assembly  102   b  therein. 
     The bottom retainer  400  may be formed of a material that may deform when the first electrode assembly  102   a  and the second electrode assembly  102   b  are inserted thereon, for example, an elastomer such as silicone or rubber, or a polymer resin such as poly propylene (PP). 
     The battery unit  101  is inserted into the case  110  as illustrated in  FIG. 6A  while the first electrode assembly  102   a  and the second electrode assembly  102   b  are respectively electrically connected to the positive electrode terminal  103  and the negative electrode terminal  104  protruding through the cap plate  112 . 
     The bottom retainer  400  may first be installed at the bottom of the case  110 . Then, the lower part of the first electrode assembly  102   a  may be located in the inner space formed by combining the first bottom  401  and the first transformed parts  403 , and the lower part of the second electrode assembly  102   b  may be located in the inner space formed by combining the second bottom  402  and the second transformed parts  404 . 
     As illustrated in  FIG. 6B , when the electrode assembly  102  is installed on the bottom retainer  400 , the lower part of the first electrode assembly  102   a  may deform a part of the bottom retainer  400  where the first bottom  401  and the first transformed parts  403  are connected to each other, and the lower part of the second electrode assembly  102   b  may deform a part of the bottom retainer where the second bottom  402  and the second transformed parts  404  are connected to each other. 
     As illustrated in  FIGS. 6A and 6B , the electrode assembly  102 , when forcibly fixed to the bottom retainer  400  as represented by an arrow in  FIG. 6A , deforms the bottom retainer  400  such that the first transformed parts  403  and the second transformed parts  404  of the bottom retainer  400  are elastically deformed on the left and right sides of the case  110 , as represented by dashed lines in  FIG. 6B . 
     In an implementation, the first transformed parts  403  and the second transformed parts  404  contact inner walls of the case  11 . The first electrode assembly  102   a  and the second electrode assembly  102   b  are elastically supported by the first transformed parts  403  and the second transformed parts  404 . Accordingly, the first electrode assembly  102   a  and the second electrode assembly  102   b  may not be moved. 
       FIG. 7  illustrates a cross-sectional view of a battery unit according to another embodiment. Like reference numerals to those in the previous drawings denote like elements having the same functions. 
     Referring to  FIG. 7 , the first electrode assembly  102   a  and the second electrode assembly  102   b  may be installed in the case  110 . A bottom retainer  700  may be installed at the bottom of the case  110  in order to prevent first electrode assembly  102   a  and the second electrode assembly  102   b  from moving. 
     As compared to the above-described embodiment, separate transformed parts (to include the first electrode assembly  102   a  and the second electrode assembly  102   b  in separate spaces) are not formed where the first electrode assembly  102   a  and the second electrode assembly  102   b  contact each other. Rather, the bottom retainer  700  includes a bottom  701  and lateral, i.e., peripheral, transformed parts  702  inclined by a predetermined angle towards an upper direction at two edges of the bottom  701  in a longitudinal direction. Each transformed part  702  may be integrally connected with the bottom  701 . The first electrode assembly  102   a  and the second electrode assembly  102   b  may both be located in an inner space formed by combining the bottom  701  and the transformed parts  702 . 
     The size of the inner space formed by combining the bottom  701  and the transformed parts  702  may be such that the lower parts of the first electrode assembly  102   a  and the lower part of the second electrode assembly  102   b  are forcibly fixed thereto. The size of the plurality of transformed parts  702  may be such that predetermined areas of the lower parts of the first electrode assembly  102   a  and the second electrode assembly  102   b  may be included therein. 
     Accordingly, when the electrode assembly  102  is installed on the bottom retainer  700 , the bottom retainer  700  may be deformed and the electrode assembly  102  is elastically supported by the bottom retainer  700 . Accordingly, the first electrode assembly  102   a  and the second electrode assembly  102   b  may not be moved. 
     As described above, according to the one or more of the above embodiments, the battery unit may have a bottom retainer formed of an elastomer, the bottom retainer being installed at a bottom of a case where at least one electrode assembly is included. When the electrode assembly inserted into the case, the electrode assembly may push on the bottom retainer and deform the bottom retainer, thereby supporting the electrode assembly by an elastic force of the bottom retainer. Accordingly, the electrode assembly may not be moved, and thus, vibration endurance of battery may be improved. A plurality of battery units, each including at least one electrode assembly and a corresponding bottom retainer, may be prepared and the plurality of battery units may be electrically connected to form a battery module. 
     It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.