Patent Publication Number: US-2023137125-A1

Title: Side structure of battery pack for automotive secondary battery

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Application No. 10-2021-0145410 filed on Oct. 28, 2021, which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a side structure of a battery pack for an automotive secondary battery. More particularly, the present disclosure relates to a side structure of a battery pack for an automotive secondary battery that is capable of reducing a loss area caused by gaps between battery cells by reducing the number of battery cells in left and right directions from three to one, in order to increase the efficiency of energy generated from battery cells included in many secondary batteries for automobiles. 
     2. Description of the Related Art 
     Electrification and cordless are key to a future industrial change, and an era in which all things move using lithium polymer batteries is beginning. Specifically, the application areas of secondary batteries are continuously expanding, such as wireless home appliances, robots, drones, energy storage devices, electric vehicles, electric ships, and the like. 
     Secondary batteries are a key means of sustainable growth that may meet eco-friendly global trends, and the secondary battery market is expected to grow rapidly due to increased demand from around the world. According to IHS Markit, secondary batteries are expected to grow into a larger market than memory semiconductors by 2025. 
     In addition, according to SNE Research, the global secondary battery market is expected to grow more than 8 times over the next 10 years from $ 46.1 billion in 2020 to $ 351.7 billion in 2030, thanks to the expansion of electric vehicle supply. 
     In addition, the proportion of secondary batteries for electric vehicles in the total secondary battery market is expected to increase from 65.9% in 2020 to 86.6% in 2030. In particular, secondary batteries for electric vehicles are expected to grow more than ten times over the next 10 years, from $30.4 billion in 2020 to $304.7 billion in 2030. 
       FIG.  1    is a block diagram of a conventional cap assembly, a casing, and a battery cell. 
     With reference to  FIG.  1   , in a conventional secondary battery for an electric vehicle, the interval between battery cells is formed to be spaced apart in the left and right directions, and thus there is a problem in that a loss region occurs in the interval between the battery cells, so the efficiency of energy generated from the battery cells is significantly lowered. 
     With reference to  FIG.  1   , in a conventional secondary battery for an electric vehicle, positive and negative poles are respectively formed on the left and right sides of an upper portion of the cap assembly, and battery cells are disposed under the cap assembly. In addition, since the battery cell provided with the cap assembly is disposed under the driver&#39;s feet, there is a problem in that the size of the space occupied by the battery pack increases. 
     The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art. 
     DOCUMENTS OF RELATED ART 
     Patent Document 
     (Patent Document 1) KR 10-1212552 
     SUMMARY 
     Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and an objective of the present disclosure is to provide a side structure of a battery pack for an automotive secondary battery that is capable of reducing a loss area generated due to gaps between battery cells by reducing the number of battery cells in left and right directions from three to one, in order to increase the efficiency of energy generated from a plurality of battery cells included in secondary batteries for automobiles. 
     In addition, another objective of the present disclosure is to provide the side structure of a battery pack for an automotive secondary battery, in which an anode part cap assembly, in which an anode is protrudingly formed, and a cathode part cap assembly, in which a cathode is formed, are disposed on left and right side surfaces of a battery pack casing, respectively, rather than on an upper part of the battery pack casing. As a result, the present disclosure is capable of reducing a height of a space occupied by a battery pack, thereby being efficiently reflected in a structural design of an automobile and of stabilizing a structure of the battery cell by increasing a capacity of the battery. 
     In order to achieve the above objectives, according to one aspect of the present disclosure, there may be provided a side structure  10  of a battery pack for an automotive secondary battery coupled to a left side and a right side of a casing  5  provided on an outer side of the battery pack including a plurality of battery cells, the side structure  10  of a battery pack for an automotive secondary battery, including: an anode part cap assembly  20  provided with an anode protrudingly formed on one surface thereof and fixedly coupled to a left side of the casing  5 ; and a cathode part cap assembly  30  provided with a cathode protrudingly formed on one surface thereof and fixedly coupled to a right side of the casing  5 , wherein the anode part cap assembly  20  may include: a terminal plate  21  provided with upper coupling holes  21   a  recessed to be formed on opposite sides of a lower surface thereof, respectively; a conductor  22  provided under the terminal plate  21  and provided with an upper seating part  22   a,  on which a lower portion of the terminal plate  21  may be seated, and which may be recessed to be formed on a center of an upper surface thereof; a first cap plate  23  coupled by welding to the casing  5 , thereby protecting an inner side of the casing  5 ; and an insulator  24  provided under the first cap plate  23  and provided with a mounting portion  24   b  recessed to be formed under a lower surface thereof, wherein the first cap plate  23  may be provided with a lower portion seating part  23   a,  on which a lower portion of the conductor  22  may be seated, and which may be recessed to be formed on a center of an upper surface thereof. 
     In addition, the upper seating part  22   a  may be provided with upper protrusion parts  22   b  fixedly coupled to the upper coupling holes  21   a  and protrudingly formed on opposite sides of an upper surface thereof, respectively, the conductor  22  may be provided with lower protrusion parts  22   c  protrudingly formed on opposite sides of a lower surface thereof, respectively, the lower seating part  23   a  may be provided with lower coupling holes  23   b,  to which the lower protrusion parts  22   c  may be fixedly coupled, and which may be recessed to be formed on opposite sides of an upper surface thereof, respectively, the first cap plate  23  is provided with upper protrusion parts  23   c  protrudingly formed on opposite sides of a lower surface thereof, respectively, and the insulator  24  is provided with insertion holes  24   a  recessed to be formed on opposite sides of an upper surface thereof, respectively, corresponding to the upper protrusion parts  23   c.    
     In addition, the terminal plate  21  may be provided with a first through hole  21   b  formed through on a center of an upper surface thereof, the upper seating part  22   a  may be provided with a second through hole  22   d  having a larger diameter than the first through hole  21   b  and formed through on a center of the upper surface thereof, the first cap plate  23  may be provided with a third through hole  23   d  having the same diameter as the second through hole  22   d  formed through on a center of the upper surface thereof, the insulator  24  may be provided with a fourth through hole  24   c  having the same diameter as the third through hole  23   d  formed through on a center of the upper surface thereof, and the anode part cap assembly  20  may include: a seal gasket  25  closely coupled to the second through hole  22   d,  the third through hole  23   d,  and the fourth through hole  24   c,  and provided with an upper through hole  25   a  formed through on a center of an upper surface thereof; a rivet terminal  26  having an upper portion coupled to the first through hole  21   b  by caulking and welding, thereby being connected in series with the terminal plate  21 ; and an anode current collector  27  coupled to a lower portion of the rivet terminal  26  by caulking and welding, thereby being connected in series with the rivet terminal  26 , wherein the rivet terminal  26  may have an upper portion inserted passing through the first through hole  21   b  and the upper through hole  25   a,  and the anode current collector  27  may be seated under the mounting portion  24   b.    
     In addition, the seal gasket  25  may be provided with a base portion  25   b  protrudingly formed in a circumferential direction at a lower portion thereof, the rivet terminal  26  may include: an upper body portion  26   a  protrudingly formed in an opposite direction of gravity, thereby being fixedly coupled to the first through hole  21   b  and the upper through hole  25   a;  an edge portion  26   b  provided at a lower portion of the upper body portion  26   a  and protrudingly formed in a circumferential direction; and a lower body portion  26   c  provided under the edge portion  26   b  and protrudingly formed in a direction of gravity, wherein the anode collector  27  may be provided with a lower through hole  27   a,  to which the lower body portion  26   c  may be fixedly coupled, and which may be formed through on a center of an upper surface thereof. 
     In addition, the first cap plate  23  may be provided with a fixing hole  23   e  formed through on one side of the upper surface thereof, an upper insertion hole  23   f  formed through on an opposite side of the upper surface thereof, and a lower insertion hole  23   g  configured to inject an electrolyte into a plurality of battery cells accommodated at the inner side of the casing  5 , and the anode part cap assembly  20  may further include: a vent  28  fixedly coupled to the fixing hole  23   e;  a seal ball  29  fixedly coupled to the lower insertion hole  23   g,  thereby sealing the lower insertion hole  23   g  so that the electrolyte may not flow out to an outside through the lower insertion hole  23   g;  and a seal ball cover  29   a  fixedly coupled to the upper insertion hole  23   f  so that the seal ball  29  may not be separated to an outer side. 
     In addition, the vent  28  may be provided with a plurality of through holes  28   a  formed through on an upper surface thereof so that a gas inside the casing  5  may be able to be discharged. 
     As described above, a side structure of a battery pack for an automotive secondary battery according to the present disclosure can reduce the number of battery cells in left and right directions in the battery pack from three to one, thereby reducing a loss area generated due to gaps between battery cells. Accordingly, there is an effect that can dramatically increase the efficiency of energy generated from the battery cell. 
     In addition, the side structure of a battery pack for an automotive secondary battery according to the present disclosure disposes an anode part cap assembly, in which an anode is protrudingly formed, and a cathode part cap assembly, in which a cathode is formed, on left and right side surfaces of a battery pack casing, respectively, rather than on an upper part of the battery pack casing. As a result, there is an effect in that the present disclosure can reduce a height of a space occupied by a battery pack, thereby being efficiently reflected in a structural design of an automobile. 
     In addition, the side structure of a battery pack for an automotive secondary battery according to the present disclosure can increasing a capacity of the battery, thereby providing an effect of stabilizing the structure of the battery cell. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objectives, features, and other advantages of the present disclosure will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a block diagram of a conventional cap assembly, a casing, and a battery cell; 
         FIG.  2    is a layout view of a side structure of a battery pack for a secondary battery for a vehicle according to the present disclosure; 
         FIG.  3    is a block diagram of the side structure of a battery pack for a secondary battery for a vehicle shown in  FIG.  2   ; 
         FIG.  4    is an assembly view of an anode part cap assembly; 
         FIG.  5    is an exploded view of the anode part cap assembly shown in  FIG.  4   ; 
         FIG.  6    is an exploded view of a terminal plate, a conductor, a first cap plate, and an insulator; 
         FIG.  7    is an exploded view of a seal gasket, a rivet terminal, and an anode current collector; 
         FIG.  8    is an exploded view of a cap plate, a seal ball, and a seal ball cover; 
         FIG.  9    is an assembly view of a cathode part cap assembly; and 
         FIG.  10    is an exploded view of the cathode part cap assembly shown in  FIG.  9   . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings in order to describe in detail enough that a person of ordinary skill in the art to which the present disclosure pertains may easily implement the technical idea of the present disclosure. 
     However, the following examples are merely examples to help the understanding of the present disclosure, thereby not reducing or limiting the scope of the present disclosure. In addition, the present disclosure may be embodied in several different forms and is not limited to the embodiments described herein. 
       FIG.  2    is a layout view of a side structure  10  of a battery pack for a secondary battery for a vehicle according to the present disclosure, and  FIG.  3    is a block diagram of a side structure of a battery pack for a secondary battery for a vehicle shown in  FIG.  2   . 
     With reference to  FIGS.  2  and  3   , the side structure  10  of a battery pack for a secondary battery for a vehicle according to the present disclosure is coupled to left and right sides of a battery pack casing  5  including a plurality of battery cells. 
     The side structure  10  of a battery pack for a secondary battery for a vehicle according to the present disclosure includes an anode part cap assembly  20  and a cathode part cap assembly  30 . 
     First, the anode part cap assembly  20  is provided with an anode protrudingly formed on one surface thereof and fixedly coupled to a left side of the battery pack casing  5 . 
     In addition, the cathode part cap assembly  30  is provided with a cathode protrudingly formed on one surface thereof and fixedly coupled to a right side of the battery pack casing  5 . 
       FIG.  4    is an assembly view of an anode part cap assembly  20 ,  FIG.  5    is an exploded view of the anode part cap assembly  20  shown in  FIG.  4   , and  FIG.  6    is an exploded view of a terminal plate  21 , a conductor  22 , a first cap plate  23 , and an insulator  24 . 
     With reference to  FIGS.  4  to  6   , the anode part cap assembly  20  includes the terminal plate  21 , the conductor  22 , the first cap plate  23 , and the insulator  24 . 
     First, the terminal plate  21  provided with upper coupling holes  21   a  recessed to be formed on opposite sides of a lower surface thereof, respectively. 
     At this time, the terminal plate  21  is formed in a shape of a rectangular parallelepiped having a predetermined height. In addition, the terminal plate  21  may be made of a material having high electrical conductivity. 
     In addition, the conductor  22  is provided under the terminal plate  21  and provided with an upper seating part  22   a,  on which a lower portion of the terminal plate  21  is seated, and which is recessed to be formed on a center of an upper surface thereof. 
     At this time, the conductor  22  is formed in a shape of a rectangular parallelepiped having a predetermined height. In addition, the conductor  22  may be made of a material having no electrical conductivity. 
     In addition, the upper seating part  22   a  is formed in a shape of a rectangular parallelepiped having a predetermined height, and a width and a length of the upper seating part  22   a  are formed to be larger than a width and a length of the terminal plate  21  to allow a lower portion of the terminal plate  21  to be inserted thereinto. 
     In addition, the first cap plate  23  is provided under the conductor  22  and coupled by welding to the casing  5 , thereby serving to protect an inside of the casing  5 . At this time, the first cap plate  23  is formed to be elongated in left-right directions in a shape of a square plate having a predetermined thickness. In addition, the first cap plate  23  may be made of an aluminum material. 
     In addition, the first cap plate  23  is provided with a lower seating part  23   a,  on which a lower portion of the conductor  22  is seated, and which is recessed to be formed on a center of an upper surface thereof. At this time, the lower seating part  23   a  is formed in a rectangular parallelepiped shape having a predetermined height, and a width and a length of the lower seating part  23   a  are formed to be larger than a width and a length of the conductor  22  to allow a lower portion of the conductor  22  to be inserted thereinto. 
     In addition, the insulator  24  is provided at a lower surface of the first cap plate  23  and provided with a mounting portion  24   b  recessed to be formed at a lower surface of the insulator  24 . 
     At this time, the insulator  24  is formed in a rectangular shape having a predetermined height. In addition, the insulator  24  may be made of a plastic material. 
     Meanwhile, the upper seating part  22   a  is provided with upper protrusion parts  22   b  fixedly coupled to the upper coupling holes  21   a  of the terminal plate  21  and protrudingly formed on opposite sides of an upper surface thereof, respectively, 
     In addition, the conductor  22  is provided with lower protrusion parts  22   c  protrudingly formed on opposite sides of a lower surface thereof, respectively, 
     In addition, the lower seating part  23   a  is provided with lower coupling holes  23   b,  to which the lower protrusion parts  22   c  are fixedly coupled, and which are recessed to be formed on opposite sides of an upper surface thereof, respectively. 
     In addition, the first cap plate  23  is provided with upper protrusion parts  23   c  protrudingly formed on opposite sides of a lower surface thereof, respectively, 
     In addition, the insulator  24  is provided with insertion holes  24   a  recessed to be formed on opposite sides of an upper surface thereof, respectively, corresponding to the upper protrusion parts  23   c.  At this time, each of the insertion holes  24   a  is formed in a shape of a cone with a diameter that increases toward a bottom. 
     With reference to  FIG.  6   , a first through hole  21   b  is formed through on a center of the upper surface of the terminal plate  21 . 
     In addition, the upper seating part  22   a  of the conductor  22  is provided with a second through hole  22   d  having a larger diameter than the first through hole  21   b  and formed through on a center of the upper surface thereof. 
     In addition, the first cap plate  23  is provided with a third through hole  23   d  having the same diameter as the second through hole  22   d  formed through on a center of the upper surface thereof. 
     In addition, the insulator  24  is provided with a fourth through hole  24   c  having the same diameter as the third through hole  23   d  formed through on a center of the upper surface thereof. 
       FIG.  7    is an exploded view of a seal gasket  25 , a rivet terminal  26 , and an anode current collector  27 . 
     With reference to  FIGS.  6  and  7   , the anode part cap assembly  20  further includes the seal gasket  25 , the rivet terminal  26 , and the anode current collector  27 . 
     First, the seal gasket  25  is closely coupled to the second through hole  22   d  of the conductor  22 , the third through hole  23   d  of the first cap plate  23 , and the fourth through hole  24   c  of the insulator  24 . At this time, the seal gasket  25  serves to seal current moving inside the rivet terminal  26  not to be leaked to the outside. In addition, the seal gasket  25  may be made of a material not having electrical conductivity. 
     In addition, the seal gasket  25  is provided with an upper through hole  25   a  formed through on a center of an upper surface thereof. 
     In addition, the rivet terminal  26  is coupled to the first through hole  21   b  of the terminal plate  21  by caulking and welding and is connected in series with the terminal plate  21 . At this time, the rivet terminal  26  may be made of a copper material thinly plated with nickel. 
     Specifically, an upper portion of the rivet terminal  26  is inserted through the upper through hole  25   a  of the seal gasket  25  and the first through hole  21   b  of the terminal plate  21 , then is coupled to the first through hole  21   b  of the terminal plate  21  by caulking and welding. 
     In addition, the anode current collector  27  is coupled to a lower portion of the rivet terminal  26  by caulking and welding, thereby being connected in series with the rivet terminal  26 . At this time, the anode current collector  27  is formed to be elongated in the left-right directions in a shape of a rectangular plate having a predetermined thickness. In addition, the anode current collector  27  may be made of a material having high electrical conductivity. 
     Meanwhile, a current collected by the anode current collector  27  passes through the rivet terminal  26  and moves to the terminal plate  21 . 
     In addition, the seal gasket  25  is provided with a base portion  25   b  protrudingly formed in a circumferential direction at a lower portion thereof. 
     In addition, the rivet terminal  26  further includes an upper body portion  26   a,  an edge portion  26   b,  and a lower body portion  26   c.    
     First, the upper body portion  26   a  protrudingly formed in an opposite direction of gravity, thereby being fixedly coupled to the first through hole  21   b  of the terminal plate  21  and the upper through hole  25   a  of the seal gasket  25 . At this time, the upper body portion  26   a  is formed in a shape of a cylinder having a predetermined height. 
     In addition, the edge portion  26   b  is provided at a lower portion of the upper body portion  26   a  and protrudingly formed in a circumferential direction. 
     In addition, the lower body portion  26   c  is provided under the edge portion  26   b  and protrudingly formed in a direction of gravity. At this time, the lower body portion  26   c  is formed in a shape of a cylinder having a predetermined height. 
     At this time, a diameter of the lower body portion  26   c  is formed to be larger than a diameter of the upper body portion  26   a,  and a height of the lower body portion  26   c  is formed to be smaller than a height of the upper body portion  26   a.    
     In addition, the anode current collector  27  is provided with a lower through hole  27   a,  to which the lower body portion  26   c  of the rivet terminal  26  is fixedly coupled, and which is formed through on a center of the upper surface thereof. 
       FIG.  8    is an exploded view of the first cap plate  23 , a seal ball  29 , and a seal ball cover  29   a.    
     With reference to  FIG.  8   , the first cap plate  23  is provided with a fixing hole  23   e  formed through on one side of the upper surface thereof. 
     In addition, the first cap plate  23  is provided with an upper insertion hole  23   f  formed through on an opposite side of the upper surface thereof. In addition, a lower insertion hole  23   g  configured to inject an electrolyte into a plurality of battery cells accommodated at the inner side of the casing  5  is formed through under a lower portion of the upper insertion hole  23   f.  In this case, a diameter of the lower insertion hole  23   g  is formed to be smaller than a diameter of the upper insertion hole  23   f.    
     In addition, the anode part cap assembly  20  further includes a vent  28 , the seal ball  29 , and the seal ball cover  29   a.    
     First, the vent  28  is fixedly coupled to the fixing hole  23   e  of the first cap plate  23 . At this time, the vent  28  is formed in a shape of a plate having a predetermined thickness. 
     In addition, the vent ( 28 ) is provided, in order to improve the stability of the battery cell, with a plurality of through holes ( 28   a ) formed through on an upper surface thereof so that a gas inside the casing  5  is able to be discharged. 
     In addition, the seal ball  29  is insertedly coupled to the lower insertion hole  23   g  of the first cap plate  23 , thereby serving to seal the lower insertion hole  23   g  to prevent the electrolyte from flowing out through the lower insertion hole  23   g.  At this time, the seal ball  29  is formed in a shape of a sphere having a predetermined diameter. 
     In addition, the seal ball cover  29   a  is fixedly coupled to the upper insertion hole  23   f  of the first cap plate  23  so that the seal ball  29  is not separated to an outer side. At this time, the seal ball cover  29   a  is formed in a shape of a disk having a predetermined thickness. 
       FIG.  9    is an assembly view of a cathode part cap assembly  30 , and  FIG.  10    is an exploded view of the cathode part cap assembly  30  shown in  FIG.  9   . 
     With reference to  FIGS.  9  and  10   , the cathode part cap assembly  30  includes a second cap plate  31 . 
     Differently from the first cap plate  23 , the second cap plate  31  is not formed with the fixing hole  23   e,  the upper insertion hole  23   f,  and the lower insertion hole  23   g.  In other words, the second cap plate  31  is formed in the same shape as the first cap plate  23  from which the fixing hole  23   e,  the upper insertion hole  23   f,  and the lower insertion hole  23   g  are removed. 
     In addition, the cathode cap assembly  30  does not include the vent  28 , the seal ball  29 , and the seal ball cover  29   a  included in the anode part cap assembly  20 . 
     A side structure  10  of a battery pack for an automotive secondary battery according to the present disclosure can reduce the number of battery cells in left and right directions in the battery pack from three to one, thereby reducing a loss area generated due to gaps between battery cells. Accordingly, there is an effect that can dramatically increase the efficiency of energy generated from the battery cell. 
     In addition, the side structure  10  of a battery pack for an automotive secondary battery according to the present disclosure disposes an anode part cap assembly  20 , in which an anode is protrudingly formed, and the cathode part cap assembly  30 , in which a cathode is formed, on left and right side surfaces of a battery pack casing  5 , respectively, rather than on an upper part of the battery pack casing  5 . As a result, there is an effect in that the present disclosure can reduce a height of a space occupied by a battery pack, thereby being efficiently reflected in a structural design of an automobile. 
     In addition, the side structure  10  of a battery pack for an automotive secondary battery according to the present disclosure can increasing a capacity of the battery, thereby providing an effect of stabilizing the structure of the battery cell. 
     As described above, the present disclosure has a main technical idea to provide the side structure of a battery pack for an automotive secondary battery, and the embodiment described above with reference to the drawings is only one embodiment. In addition, a true scope of the present disclosure is based on the claims but will also extend to even equivalent embodiments that may exist in various ways.