Patent Publication Number: US-2023136385-A1

Title: Hot-press system for folding surface of pouch-type secondary battery

Description:
TECHNICAL FIELD 
     The present disclosure relates to a hot-press system for folding a surface of a pouch-type secondary battery. 
     BACKGROUND ART 
     In general, as illustrated in  FIG.  1   , a pouch-type secondary battery  1  (hereinafter, referred to as a “secondary battery”) includes an electrode assembly  2 , a pouch casing  3  configured to accommodate the electrode assembly  2  and an electrolyte, and electrode tabs  4  extending and protruding to the outside from the electrode assembly  2 . 
     Further, the pouch casing  3  includes an upper pouch  5  and a lower pouch  6 . The upper and lower pouches  5  and  6  define a main chamber M that accommodates the electrode assembly  2  and the electrolyte therein. Edges (hereinafter, referred to as “terraces”)  7  of the upper and lower pouches  5  and  6  are bonded (sealed) to each other. 
     In this case, typically, the upper and lower pouches  5  and  6  may each be provided in the form of a thin aluminum film to protect the electrolyte and the electrode assembly  2 , cope with the electrochemical characteristics of the electrode assembly  2 , and ensure heat dissipation performance. To bond the upper and lower pouches  5  and  6 , polymers, such as casted polypropylene (CPP) resin or polypropylene (PP) resin, are applied onto the thin aluminum films constituting the upper and lower pouches  5  and  6 , and the applied polymers are fused to define bonding layers. 
     Meanwhile, the terrace  7  formed by bonding the upper and lower pouches  5  and  6  includes long-side terraces  7   a  supported on two opposite surfaces of the main chamber M, and short-side terraces  7   b  supported on two opposite ends of the main chamber M. The long-side terrace  7   a  is folded in multiple stages (see  FIG.  4   ) to prevent corrosion occurring in a bonded portion, improve rigidity of the pouch casing  3 , reduce an overall size, and minimize a space occupied by the secondary battery  1 . Therefore, the long-side terrace  7   a  has a folded surface  8  folded in multiple stages. 
     However, cracks, cavities, and portions point-fused as illustrated in  FIG.  2    (hereinafter, referred to as “point-fused portions”) are present in a bonding layer of the terrace  7  due to several causes such as defects occurring during a manufacturing process. 
     In particular, as illustrated in  FIGS.  3  and  4   , the point-fused portions are pulled by the expansion of an outer sheath, which defines the folded surface  8 , during a folding process. For this reason, there is a problem in that the bonding layer of the terrace  7  connected to the point-fused portions separates from the thin aluminum film. 
     The above-mentioned problem causes a problem in that the electrical insulation of the secondary battery  1  is broken down because the electrolyte accommodated in the main chamber M comes into contact with the thin aluminum film. Further, there is another problem in that the insulation breakdown of the secondary battery  1  causes a large-scale accident such as ignition or explosion. 
     DISCLOSURE 
     Technical Problem 
     An object of the present disclosure is to provide a hot-press apparatus for folding a surface of a pouch-type secondary battery, which is capable of ensuring electrical insulation of a bonding layer of a folded surface. 
     Another object of the present disclosure is to provide a hot-press apparatus for folding a surface of a pouch-type secondary battery, which is capable of coping with springback of a folded surface. 
     Technical Solution 
     One aspect of the present disclosure provides a hot-press system for folding a surface of a pouch-type secondary battery, the hot-press system including: a first folded surface pressing means configured to hold a main chamber and long-side terraces, which have folded surfaces, of a secondary battery, the first folded surface pressing means being configured to primarily press the folded surfaces while applying heat and pressure to the folded surfaces; and a second folded surface pressing means configured to hold the main chamber and the long-side terraces, which have the folded surfaces, of the secondary battery guided from the first folded surface pressing means, the second folded surface pressing means being configured to secondarily press the folded surfaces while applying heat and pressure to the folded surfaces. 
     The hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure may further include a main chamber alignment means configured to align the main chamber of the secondary battery having the folded surfaces and guide the secondary battery to the first folded surface pressing means, in which the main chamber alignment means includes: a pair of alignment bodies installed to face each other with the main chamber of the secondary battery, which is guided from a preceding process, interposed therebetween, the pair of alignment bodies being configured to align the main chamber while moving to the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the alignment bodies may include: first contact portions configured to come into contact with a lower surface of the main chamber; and second contact portions configured to come into contact with a lateral surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second contact portion may be configured to come into contact with the lateral surface of the main chamber having the long-side terrace connected to the lower surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first contact portion and the second contact portion may intersect each other at a right angle. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, protrusions each protruding in a hemispherical shape may be formed on the first contact portion and disposed in a plurality of columns and rows to minimize friction with the lower surface of the main chamber during a process of aligning the main chamber. 
     The hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure may further include a first air spray unit configured to spray air toward an upper surface of the main chamber to prevent the main chamber from being lifted up from the alignment bodies when the alignment bodies align the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first air spray unit may include: a first compressor configured to generate compressed air; and first spray nozzles configured to spray compressed air, which is supplied from the first compressor, toward the upper surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first spray nozzles may be connected to the first compressor through a flow path, and the first spray nozzles may be installed in branch flow paths that branch off from a flow path and face the upper surface of the main chamber, or the first spray nozzles may be installed on a lower surface of a plate that has therein a flow path chamber connected to the flow path and faces the upper surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the main chamber alignment means may further include second air spray units configured to spray air toward a lower surface of the main chamber to move the main chamber when the alignment bodies align the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second air spray unit may include: a second compressor configured to generate compressed air; and second spray nozzles configured to spray the compressed air, which is supplied from the second compressor, toward the lower surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second spray nozzles may be connected to the second compressor through a flow path, and the second spray nozzles may be installed on first contact portions of the alignment bodies that come into contact with the lower surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first folded surface pressing means may include: a first grip unit configured to hold the main chamber and the long-side terraces, which have the folded surfaces, of the secondary battery guided from the main chamber alignment means; a first pressing unit configured to primarily press the folded surfaces while applying heat and pressure to the folded surfaces; and a first cell transfer shuttle configured to load the secondary battery at the main chamber alignment means and unload the secondary battery onto the first grip unit. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first grip unit may include: first station tables configured to suck the main chamber; first lower props configured to come into contact with lower surfaces of the long-side terraces; and first upper props configured to hold the long-side terraces together with the first lower props while coming into contact with upper surfaces of the long-side terraces exposed between the folded surfaces and a lateral surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first station tables may be provided as a pair of first station tables and installed to face the lower surface of the main chamber guided from the main chamber alignment means, and the first station tables may extend in the longitudinal direction of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first lower props may be provided as a pair of first lower props, the first lower props may be installed to face the lower surfaces of the long-side terraces of the secondary battery vacuum-sucked by the first station tables, and the first lower props may extend in a longitudinal direction of the long-side terraces and be installed to be movable upward or downward toward the lower surfaces of the long-side terraces. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, first lower cutting-edge portions may be formed on the first lower props and configured to come into contact with the lower surfaces of the long-side terraces and extend vertically, and edges of extension ends of the first lower cutting-edge portions may be rounded. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, first lower protruding support portions may be formed on the first lower cutting-edge portions and configured to come into contact with lower surfaces of short-side terraces connected to the long-side terraces, and the first lower protruding support portions may hold the short-side terraces together with the first upper protruding support portions formed on the first upper props. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first upper props may be provided as a pair of first upper props, the first upper props may be installed to face the upper surfaces of the long-side terraces of the secondary battery vacuum-sucked by the first station tables, and the first upper props may extend in the longitudinal direction of the long-side terraces and be installed to be movable upward or downward toward the upper surfaces of the long-side terraces. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, first upper cutting-edge portions may be formed on the first upper props and configured to come into contact with the upper surfaces of the long-side terraces and extend vertically, and edges of extension ends of the first upper cutting-edge portions may be rounded. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, first upper protruding support portions may be formed on the first upper cutting-edge portions and configured to come into contact with upper surfaces of short-side terraces connected to the long-side terraces, and the first upper protruding support portions may hold the short-side terraces together with the first lower protruding support portions formed on the first lower props. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, first contact protrusion portions may be formed on outer surfaces of the first upper cutting-edge portions facing the folded surfaces and configured to come into contact with non-bonded areas of the long-side terraces folded along the folded surfaces, and the first contact protrusion portions may extend in a longitudinal direction of the first upper cutting-edge portions. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the first pressing unit may include a pair of first pressing heads installed to face lateral surfaces of the folded surfaces of the secondary battery held by the first grip unit, and the first pressing heads horizontally may extend in a longitudinal direction of the folded surfaces and be installed to be movable to press the folded surfaces. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, tip portions of the first pressing heads may each be formed to have a thickness that faces a bonding layer of the folded surface and a non-bonded area of the long-side terrace folded along the folded surface, and the tip portions of the first pressing heads may be vertically formed to press the folded surfaces toward the vertical first upper cutting-edge portions of the first upper props. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, first heaters may be embedded in the first pressing heads and melt bonding layers of the folded surfaces when the folded surfaces are pressed. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, first heat pads may be attached to the tip portions of the first pressing heads and uniformly transfer heat of the first heaters to the folded surfaces while serving as a buffer at the time of pressing the folded surfaces. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second folded surface pressing means may include: a second grip unit configured to hold the main chamber and the long-side terraces, which have the folded surfaces, of the secondary battery guided from the first folded surface pressing means; a second pressing unit configured to secondarily press the folded surfaces while applying heat and pressure to the folded surfaces; and a second cell transfer shuttle configured to load the secondary battery at the first folded surface pressing means and unload the secondary battery onto the second grip unit. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second grip unit may include: second station tables configured to suck the main chamber; second lower props configured to come into contact with lower surfaces of the long-side terraces; and second upper props configured to hold the long-side terraces together with the second lower props while coming into contact with upper surfaces of the long-side terraces exposed between the folded surfaces and a lateral surface of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second station tables may be provided as a pair of second station tables and installed to face the lower surface of the main chamber guided from the first folded surface pressing means, and the second station tables may extend in the longitudinal direction of the main chamber. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second lower props may be provided as a pair of second lower props, the second lower props may be installed to face the lower surfaces of the long-side terraces of the secondary battery vacuum-sucked by the second station tables, and the second lower props may extend in a longitudinal direction of the long-side terraces and be installed to be movable upward or downward toward lower surface of the long-side terraces. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, second lower cutting-edge portions may be formed on the second lower props and configured to come into contact with the lower surfaces of the long-side terraces and extend vertically, and edges of extension ends of the second lower cutting-edge portions may be rounded. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, second lower protruding support portions may be formed on the second lower cutting-edge portions and configured to come into contact with lower surfaces of short-side terraces connected to the long-side terrace, and the second lower protruding support portions may hold the short-side terraces together with the second upper protruding support portions formed on the second upper props. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second upper props may be provided as a pair of second upper props, the second upper props may be installed to face the upper surfaces of the long-side terraces of the secondary battery vacuum-sucked by the second station tables, and the second upper props may extend in the longitudinal direction of the long-side terraces and may be installed to be movable upward or downward toward the upper surfaces of the long-side terraces. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, second upper cutting-edge portions may be formed on the second upper props and configured to come into contact with the upper surfaces of the long-side terraces and extend vertically, the second upper cutting-edge portions may extend to be inclined downward from lateral surface of the main chamber to the folded surfaces adjacent thereto, and edges of extension ends of the second upper cutting-edge portions may be rounded. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, second upper protruding support portions may be formed on the second upper cutting-edge portions and configured to come into contact with upper surfaces of short-side terraces connected to the long-side terraces, and the second upper protruding support portions may hold the short-side terraces together with the second lower protruding support portions formed on the second lower props. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, second contact protrusion portions may be formed on outer surfaces of the second upper cutting-edge portions facing the folded surfaces and configured to come into contact with non-bonded areas of the long-side terraces folded along the folded surfaces, and the second contact protrusion portions may extend in a longitudinal direction of the second upper cutting-edge portions. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, the second pressing unit may include a pair of second pressing heads installed to face lateral surfaces of the folded surfaces of the secondary battery held by the second grip unit, and the second pressing heads horizontally may extend in a longitudinal direction of the folded surfaces and be installed to be movable to press the folded surfaces. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, tip portions of the second pressing heads may each be formed to have a thickness that faces a bonding layer of the folded surface and a non-bonded area of the long-side terrace folded along the folded surface, and the tip portions of the second pressing heads may be formed to be inclined with the same inclination as the second upper cutting-edge portions to press the folded surfaces toward the inclined second upper cutting-edge portions of the second upper props. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, second heaters may be embedded in the second pressing heads and melt bonding layers of the folded surfaces when the folded surfaces are pressed. 
     In the hot-press system for folding a surface of a pouch-type secondary battery according to one aspect of the present disclosure, second heat pads may be attached to the tip portions of the second pressing heads and uniformly transfer heat of the second heaters to the folded surfaces while serving as a buffer at the time of pressing the folded surfaces. 
     Advantageous Effects 
     According to the present disclosure, the bonding layer of the folded surface may be melted through the primary and secondary melting processes, and the melted bonding layer may flow to the portion where the electrical insulation is broken down. Therefore, it is possible to restore the insulating layer, of which the electrical insulation is broken down. Therefore, it is possible to ensure the electrical insulation of the bonding layer of the folded surface. 
     According to the present disclosure, the folded surface may be bent toward the main chamber through the primary and secondary bending processes. Therefore, it is possible to cope with springback of the folded surface. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a view illustrating a pouch-type secondary battery related to the present disclosure. 
         FIGS.  2 ,  3  and  4    are views schematically illustrating examples in which a bonding layer of a terrace separates, and insulation is broken down during a process of folding a long-side terrace of the pouch-type secondary battery illustrated in  FIG.  1   . 
         FIG.  5    is a view schematically illustrating a hot-press system for folding a surface of a pouch-type secondary battery according to the present disclosure. 
         FIG.  6    is a view schematically illustrating a main chamber alignment means illustrated in  FIG.  5   . 
         FIG.  7    is a view schematically illustrating an operating state of the main chamber alignment means illustrated in  FIG.  6   . 
         FIG.  8    is a view schematically illustrating a first folded surface pressing means illustrated in  FIG.  5   . 
         FIG.  9    is a perspective view schematically illustrating another embodiment of a first lower prop illustrated in  FIG.  8   . 
         FIG.  10    is a perspective view schematically illustrating another embodiment of a first upper prop illustrated in  FIG.  8   . 
         FIG.  11    is a view schematically illustrating an operating state of the first folded surface pressing means illustrated in  FIG.  8   . 
         FIG.  12    is a view schematically illustrating a second folded surface pressing means illustrated in  FIG.  5   . 
         FIG.  13    is a perspective view schematically illustrating another embodiment of a second lower prop illustrated in  FIG.  12   . 
         FIG.  14    is a perspective view schematically illustrating another embodiment of a second upper prop illustrated in  FIG.  12   . 
         FIG.  15    is a view schematically illustrating an operating state of the second folded surface pressing means illustrated in  FIG.  8   . 
     
    
    
     MODES OF THE INVENTION 
     Hereinafter, an embodiment of a hot-press system for folding a surface of a pouch-type secondary battery according to the present disclosure will be described in detail with reference to the drawings. 
     However, it should be noted that the intrinsic technical spirit of the present disclosure is not limited by the following exemplary embodiment, and the following exemplary embodiment may easily be substituted or altered by those skilled in the art based on the intrinsic technical spirit of the present disclosure. 
     In addition, the terms used herein are selected for convenience of description and should be appropriately interpreted as a meaning that conform to the technical spirit of the present disclosure without being limited to a dictionary meaning when recognizing the intrinsic technical spirit of the present disclosure. 
     Among the accompanying drawings,  FIGS.  5  to  11    are views schematically illustrating a hot-press system for folding a surface of a pouch-type secondary battery according to the present disclosure. 
     Referring to  FIG.  5   , the hot-press system for folding a surface of a pouch-type secondary battery according to the present disclosure includes a main chamber alignment means  100 , a first folded surface pressing means  200 , and a second folded surface pressing means  300 . 
     First, the main chamber alignment means  100  aligns a main chamber M of a secondary battery  1  having a folded surface  8  folded at 270 degrees. 
     In this case, the secondary battery  1  having the folded surface  8  is mounted on a cell transfer shuttle (not illustrated) and guided to the main chamber alignment means  100 . 
     The main chamber alignment means  100  includes alignment bodies  110   a  and  110   b , a first air spray unit  120 , and second air spray units  130 . 
     As illustrated, the alignment bodies  110   a  and  110   b  are provided as a pair of alignment bodies. The alignment bodies  110   a  and  110   b  installed to face each other with the main chamber M interposed therebetween, and the main chamber M of the secondary battery  1  is mounted on the cell transfer shuttle and guided. In this case, the alignment bodies  110   a  and  110   b  are installed to face each other in a longitudinal direction of the main chamber M of the secondary battery  1 . 
     Meanwhile, the alignment bodies  110   a  and  110   b  are formed to come into contact with a lower surface of the main chamber M of the secondary battery  1  and a lateral surface of the main chamber M connected to the lower surface of the main chamber M without interfering with the folded surface  8  and the lower surface of the main chamber M. 
     To this end, the alignment bodies  110   a  and  110   b  include: first contact portions  112   a  and  112   b  configured to come into contact with a lower portion of the main chamber B; and second contact portions  114   a  and  114   b  configured to come into contact with the lateral surface of the main chamber B. The first contact portions  112   a  and  112   b  intersect the second contact portions  114   a  and  114   b  at a right angle, respectively. 
     Further, when the secondary battery  1  is positioned between the alignment bodies  110   a  and  110   b  respectively having the first contact portions  112   a  and  112   b  and the second contact portions  114   a  and  1145   b , the alignment bodies  110   a  and  110   b  align the main chamber M by coming into contact with the lower surface of main chamber M and the lateral surface of the main chamber M while moving in the direction in which the alignment bodies  110   a  and  110   b  face each other. When the alignment of the main chamber M is completed, the alignment bodies  110   a  and  110   b  rectilinearly reciprocate in a direction in which the alignment bodies  110   a  and  110   b  move away from each other. 
     Particularly, protrusions (domes) each protruding in a hemispherical shape may be formed on the first contact portions  112   a  and  112   b  of the alignment bodies  110   a  and  110   b  and disposed in a plurality of columns and rows to minimize friction with the lower surface of the main chamber M during the process of aligning the main chamber M. 
     The first air spray unit  120  sprays compressed air to an upper surface of the main chamber M while the main chamber M is aligned by the alignment bodies  110   a  and  110   b , thereby preventing the main chamber M from being raised or lifted up. 
     The first air spray unit  120  includes a typical first compressor  124  configured to generate compressed air, and first spray nozzles  122  configured to spray the compressed air supplied from the first compressor  124 . 
     As illustrated, the first spray nozzles  122  are installed between the alignment bodies  110   a  and  110   b  without interfering with the secondary battery  1  guided between the alignment bodies  110   a  and  110   b . The first spray nozzles  122  are installed to spray the compressed air toward the upper surface of the main chamber M of the secondary battery  1 . 
     In this case, as can be seen by anyone, the first spray nozzles  122  are connected to the first compressor  124  through a flow path (tube). The first spray nozzles  122  may be installed in branch flow paths that branch off from a single flow path and face the upper surface of the main chamber M. Alternatively, the first spray nozzles  122  may be installed on a lower surface of a plate that has a flow path chamber therein and faces the upper surface of the main chamber M. 
     In addition, the first spray nozzles  122  may be installed to spray the compressed air toward the entire area of the upper surface of the main chamber M. 
     The second air spray units  130  serve to move the main chamber M by spraying compressed air toward the lower surface of the main chamber M while the main chamber M is aligned by the alignment bodies  110   a  and  110   b.    
     The second air spray units  130  each include a typical second compressor  134  configured to generate compressed air, and second spray nozzles  132  configured to spray the compressed air supplied from the second compressor  134 . 
     As illustrated, the second spray nozzles  132  are installed on the first contact portions  112   a  and  112   b  of the alignment bodies  110   a  and  110   b  and installed to spray the compressed air toward the lower surface of the main chamber M of the secondary battery  1 . 
     In this case, as can be seen by anyone, the second spray nozzles  132  are connected to the second compressor  134  through a flow path (tube). A spray pressure of the compressed air sprayed from the second spray nozzles  132  may be equal to or lower than a spray pressure of the compressed air sprayed from the first spray nozzles  122 . 
     That is, when the secondary battery  1 , which has the folded surface  8  formed in a folding process that is a preceding process, is guided in a state in which the secondary battery  1  is mounted on a movable robot (sucked by a vacuum), the secondary battery  1  moves first in the direction in which the secondary battery  1  faces the alignment bodies  110   a  and  110   b.    
     When the secondary battery  1  moves in the direction in which the secondary battery  1  faces the alignment bodies  110   a  and  110   b  as described above, the first contact portions  112   a  and  112   b  of the alignment bodies  110   a  and  110   b  come into contact with the lower surface of the main chamber M first. In this case, the movable robot unloads the secondary battery  1  onto the first contact portions  112   a  and  112   b  of the alignment bodies  110   a  and  110   b  and then moves toward the folding process. In this case, the compressed air is sprayed from the second spray nozzles  132  of the second air spray units  130 , such that the main chamber M of the secondary battery  1  is floated. 
     Further, when the second contact portions  114   a  and  114   b  of the alignment bodies  110   a  and  110   b , which move in the direction in which the second contact portions  114   a  and  114   b  face each other, come into contact with the lateral surface of the main chamber M, the main chamber M of the secondary battery  1  is aligned. In this case, the first spray nozzles  122  of the first air spray unit  120  spray the compressed air toward the upper surface of the main chamber M being aligned to prevent the main chamber M from being raised or lifted up. 
     Meanwhile, when the alignment of the main chamber M is completed, the aligned main chamber M is mounted on a first cell transfer shuttle D 1  guided from the first folded surface pressing means  200 . In this case, the operations of the first and second air spray units  120  and  130  are stopped, the alignment bodies  110   a  and  110   b  are returned, and the secondary battery  1  with the aligned main chamber M is guided to the first folded surface pressing means  200  along the first cell transfer shuttle D 1 . 
     The first folded surface pressing means  200  holds the main chamber M and the long-side terraces  7   a  of the secondary battery  1  guided to the main chamber alignment means  100  and primarily presses the spring-backed folded surfaces  8  while applying heat and pressure to the folded surfaces  8 . The first folded surface pressing means  200  vertically bends the folded surface  8  and melts the bonding layer of the folded surface  8  so that the melted bonding layer flows to a portion where insulation is broken down. 
     The first folded surface pressing means  200  includes the first cell transfer shuttle D 1 , a first grip unit  210 , and a first pressing unit  230 . 
     The first cell transfer shuttle D 1  is installed to reciprocate between the first folded surface pressing means  200  and the main chamber alignment means  100 . 
     The first cell transfer shuttle D 1 , which is installed as described above, moves to the main chamber alignment means  100  while moving upward or downward, vacuum-sucks the lower surface of the main chamber M of the secondary battery  1 , moves to the first grip unit  210 , and unloads the held secondary battery  1  onto the first grip unit  210 . 
     The first grip unit  210  holds the main chamber M and the long-side terraces  7   a , which have the folded surfaces  8 , of the secondary battery  1  guided from the main chamber alignment means  100 . 
     The first grip unit  210  includes first station tables  212   a  and  212   b , first lower props  214   a  and  214   b , and first upper props  218   a  and  218   b.    
     The first station tables  212   a  and  212   b  vacuum-suck the main chamber M of the secondary battery  1  guided from the main chamber alignment means  100 . 
     As illustrated, the first station tables  212   a  and  212   b  are provided as a pair of first station tables. Further, the first station tables  212   a  and  212   b  are installed to face the lower surface of the main chamber M of the secondary battery  1  that is vacuum-sucked by the first cell transfer shuttle D 1  and guided from the main chamber alignment means  100 . 
     In addition, the first station tables  212   a  and  212   b  extend in the longitudinal direction of the main chamber M to safely vacuum-suck the main chamber M without swaying the main chamber M. 
     That is, when the secondary battery  1 , which has the main chamber M aligned in the main chamber alignment means  100 , is mounted on the first cell transfer shuttle D 1 , guided to upper portions of the first station tables  212   a  and  212   b , and then seated on the first station tables  212   a  and  212   b , the first station tables  212   a  and  212   b  vacuum-suck the main chamber M of the secondary battery  1 . When the first station tables  212   a  and  212   b  vacuum-suck the main chamber M of the secondary battery  1 , the first cell transfer shuttle D 1  releases the vacuum-suction of the main chamber M of the secondary battery  1 . 
     The first lower props  214   a  and  214   b  and the first upper props  218   a  and  218   b  come into contact with lower and upper surfaces of the long-side terraces  7   a  having the folded surfaces  8  and hold the long-side terraces  7   a  having the folded surfaces  8 . 
     As illustrated, the first lower props  214   a  and  214   b  are provided as a pair of first lower props, and the first lower props  214   a  and  214   b  are installed to face the lower surfaces of the long-side terraces  7   a  vacuum-sucked by the first station tables  212   a  and  212   b.    
     In this case, the first lower props  214   a  and  214   b  are each provided in the form of an approximately vertical plate extending in the longitudinal direction of the long-side terraces  7   a . The first lower props  214   a  and  214   b  are installed to be movable upward or downward toward the lower surfaces of the long-side terraces  7   a.    
     Meanwhile, the first lower props  214   a  and  214   b  have first lower cutting-edge portions  216   a  and  216   b  configured to come into contact with the lower surfaces of the long-side terraces  7   a  having the folded surfaces  8 , and the first lower cutting-edge portions  216   a  and  216   b  extend vertically. Edge portions of extension ends of the first lower cutting-edge portions  216   a  and  216   b  are rounded to prevent the occurrence of scratches when the first lower cutting-edge portions  216   a  and  216   b  come into contact with the long-side terraces  7   a.    
     As illustrated, like the first lower props  214   a  and  214   b , the first upper props  218   a  and  218   b  are provided as a pair of first upper props, and the first upper props  218   a  and  218   b  are installed to face the upper surfaces of the long-side terraces  7   a  vacuum-sucked by the first station tables  212   a  and  212   b.    
     That is, the first upper props  218   a  and  218   b  are installed to face the upper surfaces of the long-side terraces  7   a  exposed between the folded surfaces  8  and the lateral surfaces of the main chamber M of the secondary battery  1 . 
     In this case, the first upper props  218   a  and  218   b  are each provided in the form of an approximately vertical plate extending in the longitudinal direction of the terraces  7   a . The first upper props  218   a  and  218   b  are installed to be movable upward or downward toward the upper surfaces of the long-side terraces  7   a.    
     Meanwhile, the first upper props  218   a  and  218   b  have first upper cutting-edge portions  220   a  and  220   b  configured to come into contact with the upper surfaces of the long-side terraces  7   a  having the folded surfaces  8 , and the first upper cutting-edge portions  220   a  and  220   b  extend vertically. Edge portions of extension ends of the first upper cutting-edge portions  220   a  and  220   b  are rounded to prevent the occurrence of scratches when the first upper cutting-edge portions  220   a  and  220   b  come into contact with the long-side terraces  7   a.    
     In addition, first contact protrusion portions  226  are formed on outer surfaces of the first upper cutting-edge portions  220   a  and  220   b  facing the folded surfaces  8 , and the first contact protrusion portions  226  extend in the longitudinal direction of the first upper cutting-edge portions  220   a  and  220   b.    
     When the first pressing unit  230  presses the folded surfaces  8 , the first contact protrusion portions  226 , which are formed as described above, come into contact with non-bonded areas (see  FIG.  2   ) of the long-side terraces  7   a  folded along the folded surfaces  8 , such that the non-bonded areas are bonded. 
     Meanwhile, the first lower cutting-edge portions  216   a  and  216   b  and the first upper cutting-edge portions  220   a  and  220   b  have first lower protruding support portions  222  and first upper protruding support portions  214 , respectively. 
     As illustrated, the first lower protruding support portions  222  are formed on the inner surfaces of the first lower cutting-edge portions  216   a  and  216   b  connected to the two opposite ends of the first lower cutting-edge portions  216   a  and  216   b , and the first lower protruding support portions  222  protrude in a direction in which the first lower protruding support portions  222  face each other. Likewise, the first upper protruding support portions  224  are formed on the inner surfaces of the first upper cutting-edge portions  220   a  and  220   b  connected to the two opposite ends of the first upper cutting-edge portions  220   a  and  220   b , and the first upper protruding support portions  224  protrude in a direction in which the first upper protruding support portions  224  face each other. 
     When the first lower cutting-edge portions  216   a  and  216   b  and the first upper cutting-edge portions  220   a  and  220   b  hold the long-side terraces  7   a , upper surfaces of the first lower protruding support portions  222  and lower surfaces of the first upper protruding support portions  224  hold the short-side terraces  7   b  while coming into contact with the lower and upper surfaces of the short-side terraces  7   b  connected to the long-side terraces  7   a.    
     That is, the first lower protruding support portions  222  and the first upper protruding support portions  224  prevent the short-side terraces  7   b  from being pushed and deformed when the first pressing unit  230  presses the folded surfaces  8 . 
     Particularly, the first lower props  214   a  and  214   b  and the first upper props  218   a  and  218   b  may each be made of stainless steel (SUS), aluminum (Al), an aluminum alloy, or the like. 
     The first pressing unit  230  processes the folded surfaces  8  and the bonding layers of the folded surfaces  8  while applying heat and pressure to the folded surfaces  8  of the secondary battery  1  held by the first grip unit  210 . 
     As illustrated, the first pressing unit  230  includes a pair of first pressing heads  232   a  and  232   b.    
     The first pressing heads  232   a  and  232   b  are installed to face the lateral surfaces of the folded surfaces  8  of the secondary battery  1  held by the first grip unit  210 . The first pressing heads  232   a  and  232   b  are installed to be movable to press the folded surfaces  8  toward the main chamber M, i.e., toward the first upper cutting-edge portions  220   a  and  220   b  of the first upper props  218   a  and  218   b  that hold the long-side terraces  7   a.    
     In this case, the first pressing heads  232   a  and  232   b  horizontally extend in the longitudinal direction of the folded surfaces  8 . Tip portions of the first pressing heads  232   a  and  232   b  facing the lateral surfaces of the folded surfaces  8  are each formed to have a thickness that faces the folded surface  8 , i.e., the bonding layer of the folded surface  8  and the non-bonded area of the long-side terrace  7   a  folded along the folded surface  8 . 
     Further, like the first upper cutting-edge portions  220   a  and  220   b , the tip portions of the first pressing heads  132   a  and  132   b  are vertically formed to press the folded surfaces  8  toward the first upper cutting-edge portions  220   a  and  220   b  of the first upper props  218   a  and  218   b.    
     Meanwhile, first heaters  234   a  and  234   b  may be embedded in the first pressing heads  232   a  and  232   b  and heat the first pressing heads  232   a  and  232   b  to a predetermined temperature, i.e., to a temperature that may melt the bonding layer of the folded surface  8 . First heat pads  236   a  and  236   b  may be attached to the tip portions of the first pressing heads  232   a  and  232   b  and uniformly transfer heat of the first heaters  234   a  and  234   b  to the entire folded surfaces  8  while serving as a buffer at the time of pressing the folded surfaces  8 . 
     The first pressing heads  232   a  and  232   b  of the first pressing unit  230 , which are formed as described above, completely form the shapes of the folded surfaces  8  by bending the folded surfaces  8  toward the main chamber M by pressing the folded surfaces  8  against the first upper cutting-edge portions  220   a  and  220   b  while coming into contact with the lateral surfaces of the folded surfaces  8 . Further, the first pressing heads  232   a  and  232   b  of the first pressing unit  230  restore the insulating layers, of which the electrical insulation is broken down, by transferring heat to the bonding layers of the folded surfaces  8  to melt the bonding layers and allowing the melted bonding layers to the portion where the electrical insulation is broken down. 
     Meanwhile, when the first pressing heads  232   a  and  232   b  press the folded surfaces  8 , the non-bonded areas of the long-side terraces  7   a  folded along the folded surfaces  8  are pressed by the first contact protrusion portions  226  and the first pressing heads  232   a  and  232   b  and bonded as the polymer is melted by heat transferred from the first pressing heads  232   a  and  232   b.    
     In addition, in the present disclosure, the first heaters  234   a  and  234   b  are not particularly limited. However, the first heaters  234   a  and  234   b  may have any configuration as long as the first heaters  234   a  and  234   b  may generate heat and heat the first pressing heads  232   a  and  232   b  to melt the bonding layers of the folded surfaces  8 . 
     Particularly, the first heating heads  232   a  and  232   b  may each be made of stainless steel (SUS), aluminum (Al), an aluminum alloy, or the like. 
     In this case, operating states of the first folded surface pressing means  200  will be briefly described. 
     The secondary battery  1  having the folded surfaces  8  folded at 270 degrees on the long-side terraces  7   a  is mounted on the first cell transfer shuttle D 1  in the state in which the main chamber M is aligned in the main chamber alignment means  100 , and the secondary battery  1  is guided to the upper portions of the first station tables  212   a  and  212   b  and seated on the first station tables  212   a  and  212   b . In this case, the first station tables  212   a  and  212   b  vacuum-suck the main chamber M of the secondary battery  1 , and the first cell transfer shuttle D 1  releases the vacuum-suction of the main chamber M of the secondary battery  1 . 
     When the first station tables  212   a  and  212   b  vacuum-suck the main chamber M of the secondary battery  1 , the first lower cutting-edge portions  216   a  and  216   b  of the first lower props  214   a  and  214   b  and the first upper cutting-edge portions  220   a  and  220   b  of the first upper props  218   a  and  218   b  hold the long-side terraces  7   a  while moving upward or downward and coming into contact with the lower and upper surfaces of the long-side terraces  7   a  having the folded surfaces  8 . In this case, the first cell transfer shuttle D 1  returns to the preceding process. 
     When the first station tables  212   a  and  212   b  vacuum-suck the main chamber M and the first lower props  214   a  and  214   b  and the first upper props  218   a  and  218   b  hold the long-side terraces  7   a  as described above, the first pressing heads  232   a  and  232   b  moves to the folded surfaces  8  adjacent thereto. In this case, the first pressing heads  232   a  and  232   b  bend the folded surfaces  8  toward the main chamber M by coming into contact with the lateral surfaces of the folded surfaces  8  and pressing the folded surfaces  8  toward the first upper cutting-edge portions  220   a  and  220   b , thereby completely forming the shapes of the folded surfaces  8 . 
     Further, at the same time, the first pressing heads  232   a  and  232   b  melt the bonding layers by transferring heat to the bonding layers of the folded surfaces  8 . In this case, as the folded surfaces  8  are pressed by the first pressing heads  232   a  and  232   b  and the first upper cutting-edge portions  220   a  and  220   b , the melted bonding layer flows to the portion where the electrical insulation is broken down. Therefore, the insulating layer is restored at the portion where the electrical insulation is broken down on the bonding layer of the folded surface  8 . 
     Meanwhile, when the insulating layer is restored at the portion where the electrical insulation is broken down as described above, the first pressing heads  232   a  and  232   b , the first lower props  214   a  and  214   b , and the first upper props  218   a  and  218   b  are returned. At the same time, the main chamber M of the secondary battery  1  is vacuum-sucked and mounted on a second cell transfer shuttle D 2  guided from the second folded surface pressing means  300 . 
     Further, at the same time, the first station tables  212   a  and  212   b  release the vacuum-suction of the main chamber M of the secondary battery  1 . In this case, the secondary battery  1  is guided to the second folded surface pressing means  300  along the second cell transfer shuttle D 2 . 
     The second folded surface pressing means  300  holds the main chamber M and the long-side terraces  7   a  of the secondary battery  1  guided from the first folded surface pressing means  200  and secondarily presses the folded surfaces  8  while applying heat and pressure to the folded surfaces  8 . The second folded surface pressing means  300  vertically bends the folded surface  8  so that the folded surface  8  is inclined toward the lateral surface of the main chamber M. The second folded surface pressing means  300  melts the bonding layer of the folded surface  8  so that the melted bonding layer flows to the portion where the insulation is broken down. 
     The second folded surface pressing means  300  includes the second cell transfer shuttle D 2 , a second grip unit  310 , and a second pressing unit  330 . 
     The second cell transfer shuttle D 2  is installed to reciprocate between the second folded surface pressing means  300  and the first folded surface pressing means  200 . 
     The second cell transfer shuttle D 2 , which is installed as described above, moves to the first folded surface pressing means  200  while moving upward or downward and vacuum-suck the lower surface of the main chamber M of the secondary battery  1  with the primarily pressed folded surfaces  8 , moves to the second grip unit  310 , and unloads the held secondary battery  1  onto the second grip unit  310 . 
     In this case, an operation of the second cell transfer shuttle D 2  may be synchronized with the operation of the first cell transfer shuttle D 1 . That is, to ensure efficiency of the process time, the first cell transfer shuttle D 1  may transfer the secondary battery  1  while the second cell transfer shuttle D 2  transfers the secondary battery  1 . 
     The second grip unit  310  holds the main chamber M and the long-side terraces  7   a , which have the folded surfaces  8 , of the secondary battery  1  guided from the first folded surface pressing means  200 . 
     The second grip unit  310  includes second station tables  312   a  and  312   b , second lower props  314   a  and  314   b , and second upper props  318   a  and  318   b.    
     The second station tables  312   a  and  312   b  vacuum-suck the main chamber M of the secondary battery  1  guided from the first folded surface pressing means  200 . 
     As illustrated, the second station tables  312   a  and  312   b  are provided as a pair of second station tables. Further, the second station tables  312   a  and  312   b  are installed to face the lower surface of the main chamber M of the secondary battery  1  that is vacuum-sucked by the second cell transfer shuttle D 2  and guided from the first folded surface pressing means  200 . 
     In addition, the second station tables  312   a  and  312   b  extend in the longitudinal direction of the main chamber M to safely vacuum-suck the main chamber M without swaying the main chamber M. 
     That is, when the secondary battery  1 , which has the folded surface  8  primarily pressed by the first folded surface pressing means  200 , is mounted on the second cell transfer shuttle D 2 , guided to the upper portions of the second station tables  312   a  and  312   b , and then seated on the second station tables  312   a  and  312   b , the second station tables  312   a  and  312   b  vacuum-suck the main chamber M of the secondary battery  1 . When the second station tables  312   a  and  312   b  vacuum-suck the main chamber M of the secondary battery  1 , the second cell transfer shuttle D 2  releases the vacuum-suction of the main chamber M of the secondary battery  1 . 
     The second lower props  314   a  and  314   b  and the second upper props  318   a  and  318   b  come into contact with lower and upper surfaces of the long-side terraces  7   a  having the folded surfaces  8  and hold the long-side terraces  7   a  having the folded surfaces  8 . 
     The second lower props  314   a  and  314   b  are provided as a pair of second lower props, and the second lower props  314   a  and  314   b  are installed to face the lower surfaces of the long-side terraces  7   a  vacuum-sucked by the second station tables  312   a  and  312   b.    
     In this case, the second lower props  314   a  and  314   b  are each provided in the form of an approximately vertical plate extending in the longitudinal direction of the long-side terraces  7   a . The second lower props  314   a  and  314   b  are installed to be movable upward or downward toward the lower surfaces of the long-side terraces  7   a.    
     Meanwhile, the second lower props  314   a  and  314   b  have first lower cutting-edge portions  316   a  and  316   b  configured to come into contact with the lower surfaces of the long-side terraces  7   a  having the folded surfaces  8 , and the first lower cutting-edge portions  316   a  and  316   b  extend vertically. Edge portions of extension ends of the second lower cutting-edge portions  316   a  and  316   b  are rounded to prevent the occurrence of scratches when the second lower cutting-edge portions  316   a  and  316   b  come into contact with the long-side terraces  7   a.    
     As illustrated, like the second lower props  314   a  and  314   b , the second upper props  318   a  and  318   b  are provided as a pair of second upper props, and the second upper props  318   a  and  318   b  are installed to face the upper surfaces of the long-side terraces  7   a  vacuum-sucked by the second station tables  312   a  and  312   b.    
     That is, the second upper props  318   a  and  318   b  are installed to face the upper surfaces of the long-side terraces  7   a  exposed between the folded surfaces  8  and the lateral surfaces of the main chamber M of the secondary battery  1 . 
     In this case, the second upper props  318   a  and  318   b  are each provided in the form of an approximately vertical plate extending in the longitudinal direction of the terraces  7   a . The second upper props  318   a  and  318   b  are installed to be movable upward or downward toward the upper surfaces of the long-side terraces  7   a.    
     Meanwhile, the second upper props  318   a  and  318   b  have second upper cutting-edge portions  320   a  and  320   b  configured to come into contact with the upper surfaces of the long-side terraces  7   a  having the folded surface  8 . The second upper cutting-edge portions  320   a  and  320   b  extend to be inclined downward from the lateral surface of the main chamber M toward the folded surfaces  8  adjacent thereto. 
     Further, edge portions of extension ends of the second upper cutting-edge portions  320   a  and  320   b  are rounded to prevent the occurrence of scratches when the second upper cutting-edge portions  320   a  and  320   b  come into contact with the long-side terraces  7   a.    
     In addition, second contact protrusion portions  326  are formed on outer surfaces of the second upper cutting-edge portions  320   a  and  320   b  facing the folded surfaces  8 , and the second contact protrusion portions  326  extend in the longitudinal direction of the second upper cutting-edge portions  320   a  and  320   b.    
     When the second pressing unit  330  presses the folded surfaces  8 , the second contact protrusion portions  326 , which are formed as described above, come into contact with non-bonded areas (see  FIG.  2   ) of the long-side terraces  7   a  folded along the folded surfaces  8 , such that the non-bonded areas are bonded. 
     Meanwhile, the second lower cutting-edge portions  316   a  and  316   b  and the second upper cutting-edge portions  320   a  and  320   b  have second lower protruding support portions  322  and second upper protruding support portions  314 , respectively. 
     As illustrated, the second lower protruding support portions  322  are formed on the inner surfaces of the second lower cutting-edge portions  316   a  and  316   b  connected to the two opposite ends of the second lower cutting-edge portions  316   a  and  316   b , and the second lower protruding support portions  322  protrudes in a direction in which the second lower protruding support portions  322  face each other. Likewise, the second upper protruding support portions  324  are formed on the inner surface of the second upper cutting-edge portions  320   a  and  320   b  connected to the two opposite ends of the second upper cutting-edge portions  320   a  and  320   b , and the second upper protruding support portions  324  protrude in a direction in which the second upper protruding support portions  324  face each other. 
     When the second lower cutting-edge portions  316   a  and  316   b  and the second upper cutting-edge portions  320   a  and  320   b  hold the long-side terraces  7   a , upper surfaces of the second lower protruding support portion  322  and lower surfaces of the second upper protruding support portion  324  hold the short-side terraces  7   b  while coming into contact with the lower and upper surfaces of the short-side terraces  7   b  connected to the long-side terraces  7   a.    
     That is, the second lower protruding support portions  322  and the second upper protruding support portions  324  prevent the short-side terraces  7   b  from being pushed and deformed when the second pressing unit  230  presses the folded surfaces  8 . 
     Particularly, the second lower props  314   a  and  314   b  and the second upper props  318   a  and  318   b  may each be made of stainless steel (SUS), aluminum (Al), an aluminum alloy, or the like. 
     The second pressing unit  330  processes the folded surfaces  8  and the bonding layers of the folded surfaces  8  while applying heat and pressure to the folded surfaces  8  of the secondary battery  1  held by the second grip unit  310 . 
     As illustrated, the second pressing unit  330  includes a pair of first pressing heads  332   a  and  332   b.    
     The second pressing heads  332   a  and  332   b  are installed to face the lateral surfaces of the folded surfaces  8  of the secondary battery  1  held by the second grip unit  310 . The second pressing heads  332   a  and  332   b  are installed to be movable to press the folded surfaces  8  toward the main chamber M, i.e., toward the second upper cutting-edge portions  320   a  and  320   b  of the second upper props  318   a  and  318   b  that hold the long-side terraces  7   a.    
     In this case, the second pressing heads  332   a  and  332   b  horizontally extend in the longitudinal direction of the folded surfaces  8 . Tip portions of the second pressing heads  332   a  and  332   b  facing the lateral surfaces of the folded surfaces  8  are each formed to have a thickness that faces the folded surface  8 , i.e., the bonding layer of the folded surface  8  and the non-bonded area of the long-side terrace  7   a  folded along the folded surface  8 . 
     Further, the tip portions of the second pressing heads  332   a  and  332   b  may be formed to be inclined to have the same inclination angle as the second upper cutting-edge portions  320   a  and  320   b  so that the tip portions of the second pressing heads  332   a  and  332   b  may press the folded surfaces  8  toward the second upper cutting-edge portions  320   a  and  320   b  of the second upper props  318   a  and  318   b.    
     Meanwhile, second heaters  334   a  and  334   b  may be embedded in the second pressing heads  332   a  and  332   b  and heat the second pressing heads  332   a  and  332   b  to a predetermined temperature, i.e., to a temperature that may melt the bonding layer of the folded surface  8 . Second heat pads  336   a  and  336   b  may be attached to the tip portions of the second pressing heads  332   a  and  332   b  and uniformly transfer heat of the second heaters  334   a  and  334   b  to the entire folded surfaces  8  while serving as a buffer at the time of pressing the folded surfaces  8 . 
     The second pressing heads  332   a  and  332   b  of the second pressing unit  330 , which are formed as described above, completely form the shapes of the folded surfaces  8  by bending the folded surfaces  8  toward the main chamber M by pressing the folded surfaces  8  against the second upper cutting-edge portions  320   a  and  320   b  while coming into contact with the lateral surfaces of the folded surfaces  8 . Further, the second pressing heads  332   a  and  332   b  of the second pressing unit  330  restore the insulating layers, of which the electrical insulation is broken down, by transferring heat to the bonding layers of the folded surfaces  8  to melt the bonding layers and allowing the melted bonding layers to flow to the portion where the electrical insulation is broken down. 
     Meanwhile, when the second pressing heads  332   a  and  332   b  press the folded surfaces  8 , the non-bonded areas of the long-side terraces  7   a  folded along the folded surfaces  8  are pressed by the second contact protrusion portions  326  and the second pressing heads  332   a  and  332   b  and bonded as the polymer is melted by heat transferred from the second pressing heads  332   a  and  332   b.    
     In addition, in the present disclosure, the second heaters  334   a  and  334   b  are not particularly limited. However, the second heaters  334   a  and  334   b  may have any configuration as long as the second heaters  334   a  and  334   b  may generate heat and heat the second pressing heads  332   a  and  332   b  to melt the bonding layers of the folded surfaces  8 . 
     Particularly, the second heating heads  332   a  and  332   b  may each be made of stainless steel (SUS), aluminum (Al), an aluminum alloy, or the like. 
     Because an operation of the second folded surface pressing means  300 , which is formed as described above, is substantially identical to the operation of the first folded surface pressing means  200 , a detailed description thereof will be omitted. 
     Meanwhile, when the operation of the second folded surface pressing means  300  is completed, the secondary battery  1  is mounted on a third cell transfer shuttle D 3  guided from a subsequent process, and the secondary battery  1  is guided to the subsequent process by an operation of the third cell transfer shuttle D 3 . 
     The hot-press system for folding a surface of a pouch-type secondary battery according to the present disclosure configured as described above may melt the bonding layer of the folded surface  8  through the primary and secondary melting processes and allow the melted bonding layer to the portion where the electrical insulation is broken down. Therefore, it is possible to restore the insulating layer, of which the electrical insulation is broken down. Therefore, it is possible to ensure the electrical insulation of the bonding layer of the folded surface  8 . 
     In addition, the hot-press apparatus for folding a surface of a pouch-type secondary battery according to the present disclosure may bend the folded surface  8  toward the main chamber M through the primary and secondary bending processes. Therefore, it is possible to cope with springback of the folded surface M.