Abstract:
A rechargeable battery is disclosed. In one embodiment, the battery includes: i) a first current collecting plate, ii) a plurality of electrode assemblies electrically connected in parallel with each other via the first current collecting plate, wherein each of the electrode assemblies comprises two opposing ends and an outer side formed between the two ends, and wherein the first current collecting plate is electrically connected to one of the two ends of the electrode assemblies and iii) a can configured to accommodate the first current collecting plate and the plurality of electrode assemblies, wherein the can comprises at least one non-linear portion, and wherein an inner surface of the non-linear portion faces the outer side of at least one electrode assembly.

Description:
RELATED APPLICATIONS 
     This application claims priority to and the benefit of Provisional Patent Application No. 61/241,288 filed on Sep. 10, 2009 in the U.S Patent and Trademark Office, the entire contents of which are incorporated herein by reference. This application relates to U.S. patent application entitled “Rechargeable battery”, which is concurrently filed as this application and incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field 
     This disclosure relates to a rechargeable battery. More particularly, this disclosure relates to a rechargeable battery having high-capacity. 
     2. Description of the Related Technology 
     A rechargeable battery can be recharged and discharged, unlike a primary battery that cannot be recharged. For example, a large-sized cylindrical battery is required for a high-capacity 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 
     An exemplary embodiment provides a rechargeable battery. Another embodiment provides a rechargeable battery solving the safety problem of high-capacity electrode assembly, decreasing the number of parts connecting cells and circuit devices, and preventing the cell swelling. 
     Another embodiment is a rechargeable battery, comprising: a first current collecting plate; a plurality of electrode assemblies electrically connected in parallel with each other via the first current collecting plate, wherein each of the electrode assemblies comprises two opposing ends and an outer side formed between the two ends, and wherein the first current collecting plate is electrically connected to one of the two ends of the electrode assemblies; and a can configured to accommodate the first current collecting plate and the plurality of electrode assemblies. The can may comprise at least one non-linear portion, and wherein an inner surface of the non-linear portion faces the outer side of at least one electrode assembly. 
     In the above battery, each of the electrode assemblies has a cylindrical shape. In the above battery, the non-linear portion comprises at least one curved shape. In the above battery, the curvature of the at least one curved side is substantially similar to that of the outer side of each electrode assembly. In the above battery, the at least one curved side contacts the outer side of at least one electrode assembly. 
     The above battery further comprises a second current collecting plate electrically connected to the other ends of the electrode assemblies. In the above battery, each of the electrode assemblies comprises a positive electrode, a negative electrode and a separator interposed between the positive and negative electrodes, and wherein the positive and negative electrodes are electrically connected to the first and second current collecting plates, respectively. 
     In the above battery, each of the positive and negative electrodes comprises a coated region and an uncoated region, and wherein the width of the positive electrode coated region is less than the width of the negative electrode coated region. The above battery further comprises: a cap plate configured to close the can; an electrode terminal formed on the cap plate; and a connection member configured to electrically connect the electrode terminal and the first current collecting plate, wherein the connection member is further configured to support the electrode assemblies so that the electrode assemblies do not move in the can. 
     In the above battery, the can comprises two opposing ends, wherein the cap plate is located on one end, wherein the electrode terminal is configured to perform as one of the positive and negative terminals of the battery, and wherein the other end of the can is configured to perform as the other terminal of the battery. In the above battery, the electrode assemblies are arranged so as to form a single row inside the can. In the above battery, the electrode assemblies are arranged so as to form a plurality of rows inside the can. 
     Another embodiment is a rechargeable battery, comprising: a first current collecting plate; a plurality of cylinder-type electrode assemblies electrically connected in parallel with each other via the first current collecting plate, wherein each of the electrode assemblies comprises two opposing ends and a cylindrical side, wherein the first current collecting plate is electrically connected to one of the two ends of the electrode assemblies, respectively, and wherein the electrode assemblies are not surrounded by an adhesive medium; and a can configured to accommodate the first current collecting plate and the plurality of cylinder-type electrode assemblies, wherein the can is configured to sufficiently tightly support the electrode assemblies so that the electrode assemblies do not move inside the can. 
     The above battery further comprises a second current collecting plate electrically connected to the other ends of the electrode assemblies. In the above battery, the can comprises two opposing ends, and wherein the battery further comprises a cap plate configured to close one end of the can, and wherein the second current collecting plate is directly connected to the other end of the can. The above battery further comprises: a cap plate configured to close the can; an electrode terminal formed on the cap plate; and a connection member configured to electrically connect the electrode terminal and the first current collecting plate, wherein the connection member is further configured to support the electrode assemblies so that the electrode assemblies do not move in the can. 
     In the above battery, the can comprises two curved sides, wherein each curved side has a curvature, and wherein the two curvatures are different. In the above battery, the electrode assemblies are arranged so as to form a plurality of rows. In the above battery, each of the electrode assemblies comprises a positive electrode, a negative electrode and a separator interposed between the positive and negative electrodes, wherein each of the positive and negative electrodes comprises a coated region and an uncoated region, and wherein the width of the positive electrode coated region is less than the width of the negative electrode coated region. 
     Another embodiment is a rechargeable battery, comprising: a first current collecting plate; a second current collecting plate; a plurality of electrode assemblies electrically connected in parallel with each other via the first and second current collecting plates, wherein each of the electrode assemblies comprises two opposing ends and an outer side formed between the two ends, and wherein the first and second current collecting plates are electrically connected to the two ends of the electrode assemblies; a can, comprising two opposing ends, configured to accommodate the two current collecting plates and the plurality of electrode assemblies, wherein the can comprises at least one non-linear portion, and wherein an inner surface of the non-linear portion faces the outer side of at least one electrode assembly; and a cap plate configured to close one end of the can, wherein one of the two current collecting plates is directly connected to the other end of the can. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a rechargeable battery according to a first embodiment. 
         FIG. 2  is an exploded perspective view of  FIG. 1 . 
         FIG. 3  is an exploded perspective view of an electrode assembly. 
         FIG. 4A  is a cross-sectional view taken along the line IV-IV of  FIG. 1 , and  FIG. 4B  is a cross-sectional view of a rechargeable battery according to a modification of the first embodiment. 
         FIG. 5  is a cross-sectional view taken along the line V-V of  FIG. 1 . 
         FIG. 6  is a cross-sectional view of a rechargeable battery according to another modification of the first embodiment. 
         FIG. 7  is a cross-sectional view of a rechargeable battery according to a second embodiment. 
         FIG. 8  is a flow chart showing a manufacturing process of a rechargeable battery according to the first embodiment. 
         FIG. 9  is a flow chart showing a manufacturing process of a rechargeable battery according to the second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Assuming that they provide the same capacity, one large-sized cylindrical battery may be advantageous over a plurality of a smaller-sized cylindrical batteries which are connected to each other, because the number of parts connecting cells or circuit devices is reduced. How ever, the large-sized cylindrical battery can cause several problems. 
     For example, when the electrode assembly is spiral-wound in a Jelly Roll shape in order to provide a high-capacity rechargeable battery, the more number of revolutions is needed than that of a low-capacity rechargeable battery. 
     As the number of spiral-winding revolutions increases, the difference between the area of the positive electrode and that of the negative electrode in the electrode assembly increases and provides a safer cylindrical battery. However, as the large-sized cylindrical battery has a high-capacity electrode assembly, it may increase the explosive power of a cylindrical battery which deteriorates the safety of a rechargeable battery. 
     Embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. 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. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
       FIG. 1  is a perspective view of a rechargeable battery according to a first embodiment, and  FIG. 2  is an exploded perspective view of  FIG. 1 . Referring to  FIG. 1  and  FIG. 2 , the rechargeable battery  100  according to one embodiment includes a plurality of electrode assemblies  10 , a first current collecting plate  20  (hereinafter, interchangeably used with “lower current collecting plate”), a second current collecting plate  30  (hereinafter, interchangeably used with “upper current collecting plate”), a can  40 , a cap plate  50 , and an electrode terminal  60 . The rechargeable battery  100  may be formed by housing a plurality of electrode assemblies  10  in the can  40 . 
     The rechargeable battery  100  can accomplish high-capacity, and provide safety by connecting a plurality of low-capacity electrode assemblies  10  in parallel. The rechargeable battery  100  can also minimize or prevent explosion, as the explosive power of the smaller batteries is significantly less than that of a large sized rechargeable battery.  FIG. 3  is an exploded perspective view of an electrode assembly, and  FIG. 4A  is a cross-sectional view taken along the line IV-IV of  FIG. 1 . In one embodiment, as shown in  FIGS. 3 and 4A , the electrode assembly  10  is formed in a Jelly Roll shape by spiral-winding the negative electrode  11 , the positive electrode  12 , and an insulator separator  13  interposed therebetween. In one embodiment, the electrode assembly  10  may be cylindrical. In one embodiment, a sector pin  14  is disposed in the center of the cylindrical electrode assembly  10  to maintain the cylinder shape of the electrode assembly  10  (See  FIG. 4A ). 
     In one embodiment, each of the negative electrode  11  and positive electrode  12  includes a current collector, for example, formed of thin film metal foil. The electrodes  11  and  12  may also include coated regions  11   a  and  12   a  where the active material is coated on the current collector and uncoated regions  11   b  and  12   b  where the active material is not coated on the current collector. In one embodiment, as shown in  FIG. 3 , the uncoated regions  11   b  and  12   b  are disposed in the opposite end sides with respect to the coated regions  11   a  and  12   a , respectively. 
     A first lead tab  11   c  (hereinafter, interchangeably used with “negative lead tab”) is connected to the uncoated region  11   b  of the negative electrode  11 ; a second lead tab  12   c  (hereinafter, interchangeably used with “positive lead tab”) is connected to the uncoated region  12   b  of the positive electrode  12 . 
     Accordingly, in the cylindrical electrode assembly  10  in which the negative electrode  11 , the separator  13 , and the positive electrode  12  are wound, the negative lead tab  11   c  is protruded toward one direction (e.g., downward) in the exterior surface of the electrode assembly  10 ; the positive lead tab  12   c  is protruded toward the opposite direction (e.g., upward) of the negative lead tab  11   c  in the center of the electrode assembly  10  (See  FIG. 2 ). 
     In addition, since a plurality of electrode assemblies  10  are disposed in one can  40 , it is formed in a cylinder having smaller volume than the entire volume of the cap  40 . 
     Accordingly, as the number of winding the electrode assembly  10  is decreased, it is possible to minimize the width difference (W 11 -W 12 ) between the negative electrode  11  and positive electrode  12  for maintaining the safety of the rechargeable battery  100 . Thereby, it is possible to prevent the rechargeable battery  100  from deteriorating the capacity while maintaining a smaller size. 
     The safety of the rechargeable battery  100  is ensured by preventing the coated region  12   a  of the positive electrode  12  and the coated region  11   a  of the negative electrode  11  from being a short-circuit each other. 
     For this purpose, the width (W 12 ) of the coated region  12   a  of the positive electrode  12  is formed to be less (W 12 &lt;W 11 ) than the width (W 11 ) of the coated region  11   a  of the negative electrode  11 . As the number of winding the electrode assembly  10  is decreased, the width difference (W 11 -W 12 ) required for maintaining the safety of the rechargeable battery  100  may be minimized. In one embodiment, the can  40  may include at least one non-linear portion. The non-linear portion may include at least one curved shape. The curvature of the at least one curved side may be substantially similar to or substantially the same as that of the outer side of each electrode assembly  10 . The at least one curved side may contact the outer side of at least one electrode assembly  10 . The can may include two curved sides. In one embodiment, each curved side has a curvature, and the two curvatures are substantially the same as or substantially similar to each other, for example, as shown in  FIG. 4A . In a rechargeable battery  100 ′ according to a modification of the first embodiment, the two curvatures may be different, for example, as shown in  FIG. 4B . The description of this paragraph also applies to FIGS.  2  and  4 - 7 . 
       FIG. 5  is a cross-sectional view taken along the line V-V of  FIG. 1 . In one embodiment, as shown in  FIG. 5 , in each electrode assembly  10 , the negative lead tabs  11   c  are protruded toward the upward of the electrode assembly  10  and welded and connected to a lower current collecting plate  20  disposed under the electrode assemblies  10 . 
     In one embodiment, the positive lead tabs  12   c  are protruded toward the upside of the electrode assembly  10  and welded and connected to an upper current collecting plate  30  disposed above the electrode assemblies  10 . In one embodiment, the electrode assemblies  10  are connected in parallel by the lower current collecting plate  20  and the upper current collecting plate  30 , so as to accomplish a high-capacity battery. 
     As shown in the first embodiment, the can  40  may be provided in a modified prismatic shape such that one side is open in order to insert and accommodate a plurality of electrode assemblies  10 . The corner part of the prismatic shape may be modified into the curved surface corresponding to the exterior shape of the electrode assembly  10 . 
     As the can  40  has space capable of accommodating a plurality of low-capacity cylindrical electrode assemblies  10 , it is possible to provide a high-capacity rechargeable battery. Accordingly, when a plurality of rechargeable batteries  100  are connected to each other, it is possible to decrease the number of parts or circuit devices and to prevent the cell swelling. 
     In one embodiment, the can  40  having curved both end surfaces in a row direction of electrode assemblies  10  may contact the exterior shape of the outermost electrode assemblies  10  (See  FIGS. 2 and 4 ), so it is possible to effectively prevent the shaking of the electrode assemblies  10  in the inserted state of the electrode assemblies  10 . In the inserted state of the electrode assembly  10  in the can  40 , the can  40  may be welded to the lower current collecting plate  20 . 
     In one embodiment, when a negative lead tab  11   c  is connected to the lower current collecting plate  20 , the can  40  connected to the lower current collecting plate  20  may play a role of a negative terminal in the rechargeable battery  100 . In addition, when a positive lead tab is connected to the lower current collecting plate in the electrode assembly, the can  40  connected to the lower current collecting plate may play a role of a positive terminal in the rechargeable battery (not shown). The can  40  may be formed of a conductive metal such as iron or aluminum. 
     In one embodiment, when the can  40  is connected to the negative electrode  11  of the electrode assemblies  10  to play a role of a negative terminal, the can  40  may be formed of iron. In addition when the can is connected to the positive electrode of the electrode assemblies  10  to play a role of a positive terminal, the can  40  may be formed of aluminum having superior conductivity to iron (not shown). 
     The cap plate  50  is connected to the opening of the can  40  where the electrode assemblies  10  are inserted. The cap plate  50  may seal the can  40  which accommodates the electrode assemblies  10  and an electrolyte solution. 
     An electrode terminal  60  is mounted in the cap plate  50  to connect the positive electrode  12  of the electrode assembly  10  inside the can  40 . The electrode terminal  60  is connected to an upper current collecting plate  30  through a connecting member  31 . For example, the connection member  31  is welded and connected to an upper current collecting plate  30  in one end, and the other end thereof is electrically connected to the electrode terminal  60  with providing a connecting opening  32 . In other words, the electrode terminal  60  may be electrically connected to the positive electrodes  12  of the electrode assemblies  10  through the connection member  31  and the upper current collecting plate  30 . 
     In addition, the cap plate  50  may be electrically connected to the negative electrode  11  of the electrode assemblies  10  through the can  40 . Accordingly, the connecting member  31  and the electrode terminal  60  electrically connected to the positive electrode  12  may provide an electrical insulation structure together with the cap plate  50 . For example, a lower insulator  33  is interposed between the cap plate  50  and the connecting member  31  to electrically insulate between the connecting member  31  and the cap plate  50 . 
     An upper insulator  34  is interposed between the upper surface of the cap plate  50  and the electrode terminal  60  and between an electrode terminal opening  51  of the cap plate  50  and the electrode terminal  60  to electrically insulate the cap plate  50  and the electrode terminal  60  and to electrically insulate the electrode terminal opening  51  and the electrode terminal  60 .  FIG. 6  is a cross-sectional view of a rechargeable battery  100 ″ according to another modification of the first embodiment. Referring to the rechargeable battery  100 ″ shown in  FIG. 6 , can  40 ″ may be provided in a cuboid prismatic shape such that one side is open in order to insert and accommodate a plurality of electrode assemblies  10 . The other elements may be provided similar to those of the first embodiment. 
       FIG. 7  is a cross-sectional view of a rechargeable battery according to a second embodiment. Referring to  FIG. 7 , the rechargeable battery  200  according to the second embodiment includes the electrode assemblies  10  which are arranged so as to form a plurality of rows. 
     The rechargeable battery  100  according to the first embodiment is provided with electrode assemblies  10  in one row, and the can  40  is corresponding to the first row electrode assemblies  10  (See  FIG. 4 ). In the rechargeable battery  200  according to the second embodiment, a plurality of rows of electrode assemblies  10  (for example, three rows) are provided, and the can  240  may be formed to have a structure corresponding to a plurality of rows of electrode assemblies  10  (See  FIG. 6 ). 
     The rechargeable battery  200  according to the second embodiment shows the different disposition of the electrode assemblies  10  in a can  240  and accommodates more electrode assemblies  10  compared to the rechargeable battery  100  according to the first embodiment. Accordingly, the circuit devices and parts connecting to rechargeable batteries  200  from the outside may be decreased compared to the first embodiment. 
       FIG. 8  is a flow chart showing a manufacturing process of a rechargeable battery according to the first embodiment. For convenience, a method of manufacturing the rechargeable battery  100  according to the first embodiment is described. Depending on the embodiments, additional processes may be added, others removed, or the order of the processes changes. This applies to  FIG. 9 . 
     Referring to  FIG. 8 , a method of manufacturing a rechargeable battery  100  includes a first step (ST 11 ) to a sixth step (ST 16 ). The first step (ST 11 ) is to weld each first lead tab  11   c  (negative lead tab) of the electrode assemblies  10  to a first current collecting plate  20  (lower current collecting plate). 
     The second step (ST 12 ) is to insert the electrode assemblies  10  in the can  40  in the state of welding the lower current collecting plate  20  to the negative lead tap  11   c.    
     The third step (ST 13 ) is to weld and electrically connect the inserted lower current collecting plate  20  of the electrode assemblies  10  with the can  40 . The second and third steps (ST 12  and ST 13 ) are to electrically connect the negative lead tabs  11   c  of the electrode assemblies  10  to the can  40  with interposing the lower current collecting plate  20 . 
     The fourth step (ST 14 ) is to weld a second lead tap  12   c  (positive lead tap) of the electrode assemblies  10  to a second current collecting plate  30  (upper current collecting plate) in the state of being inserted in the can  40 . The fifth step (ST 5 ) is to connect the upper current collecting plate  30  to an electrode terminal  60  of the cap plate  50  using a connection member  31 . In other words, one end of the connection member  31  is welded to the upper current collecting plate  30  and rivet-connects a connecting opening  32  of the connection member  31  to the electrode terminal  60 . The fourth and fifth steps (ST 14  and ST 15 ) electrically connect the positive lead tabs  12   c  of the electrode assemblies  10  to the electrode terminal  60  with interposing the connection member  31  and the upper current collecting plate  30 . The sixth step (ST 16 ) is to bind the cap plate  50  with the can  40  and to accommodate the electrode assemblies  10  in the can  40  and to seal the same. 
       FIG. 9  is a flow chart showing a manufacturing process of a rechargeable battery according to a second embodiment. The manufacturing method according to the first embodiment is to insert the electrode assembly  10  in which the lower current collecting plate  20  is connected to the negative lead tap  11   c  in the can  40  and to connect the positive lead tap  12   c  of the electrode assembly  10  to the upper current collecting plate  30 . 
     The manufacturing method according to the second embodiment is to connect a lower current collecting plate  20  to a negative lead tap  11   c  and to insert the electrode assembly in which an upper current collecting plate  30  is connected to the positive lead tap  12   c  in a can  40 . 
     Referring to  FIG. 9 , in the manufacturing method according to the second embodiment, the first step (ST 21 ) is to weld each first lead tap  11   c  (negative lead tap) of the electrode assemblies  10  to the first current collecting plate  20  (lower current collecting plate). 
     The first step (ST 21 ) is to electrically connect the negative lead taps  11   c  of the electrode assemblies  10  to the can  40  with interposing the lower current collecting plate  20 . The second step (ST 22 ) is to weld each second lead tap  12   c  (positive lead tap) of the electrode assemblies  10  to the second current collecting plate  30  (upper current collecting plate). The second step (ST 22 ) is also to electrically connect the positive lead tap  12   c  of electrode assemblies  10  to the electrode terminal  60  with interposing a connection member  31  and the upper current collecting plate  30 . 
     The third step (ST 23 ) is to weld the negative lead tab  11   c  with the lower current collecting plate  20  and to insert the electrode assemblies  10  in the can  40  in the state of welding the positive lead tap  12   c  with the upper current collecting plate  30 . The fourth step (ST 24 ) is to weld the lower current collecting plate  20  to the can  40 . 
     The fifth step (ST 25 ) is to connect the upper current collecting plate  30  to an electrode terminal  60  of cap plate  50  using a connecting member  31 . The sixth step (ST 26 ) is to bind the cap plate  50  to the can  240 , to accommodate the electrode assembly  10  in the can  40 , and to seal the same. 
     According to at least one embodiment, it is possible to accomplish the high-capacity rechargeable battery having a unit cell by accommodating a plurality of low-capacity cylinder electrode assemblies in one can and coupling the same in parallel to minimize the width difference between positive electrode and negative electrode. Further, it is possible to decrease the number of circuit devices and parts connecting the rechargeable batteries from the outside, to ensure the safety of electrode assemblies even though the rechargeable battery is high-capacity, and to prevent the cell swelling generated in the conventional prismatic rechargeable battery. 
     While the above description has pointed out novel features of the invention as applied to various embodiments, the skilled person will understand that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made without departing from the scope of the invention. Therefore, the scope of the invention is defined by the appended claims rather than by the foregoing description. All variations coming within the meaning and range of equivalency of the claims are embraced within their scope.