JP2015115161A - Manufacturing method and manufacturing apparatus of secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing apparatus for secondary battery suitable for preventing liquid leakage when outgassing.SOLUTION: A boring process for boring a degassing hole 5 between the peripheral side of an exterior body 1 and a power generation element 2 includes a press step of pressing a part of the exterior body 1, where the degassing hole 5 is formed, so that the exterior films superposed from both sides of the exterior body 1 adhere each other, before the degassing hole 5 is bored in the exterior body 1, and a peeling step of peeling the exterior films from each other.

Description

  The present invention relates to a method and an apparatus for manufacturing a secondary battery having an exterior body formed of a thin and lightweight exterior film such as a laminate film, and in particular, prevents liquid leakage when venting a gas generated in a conditioning process or the like. In particular, the present invention relates to a method and apparatus for manufacturing a secondary battery.

  It has been described that gas can be reliably vented with conditioning and the like of a secondary battery having an exterior body formed of a thin and lightweight exterior film such as a laminate film, and the sealing performance after degassing can be sufficiently secured. A method for manufacturing a secondary battery has been proposed (see Patent Document 1).

  This includes an encapsulating step of joining the opening of the exterior film and enclosing the power generation element inside the exterior body so as to form an unjoined portion that communicates with the inside and is isolated from the outside, and the unjoined portion A degassing step of opening a degassing hole and constraining the unbonded portion to enclose the power generation element. And as a method of suppressing the expansion of the unjoined part and relaxing the stress concentration, the thickness of the unjoined part is regulated when the internal pressure of the exterior body is high. As a result, a large expansion or deformation occurs in the unjoined part due to an increase in internal pressure due to the generated gas, and when the unjoined part is joined, it does not return to its original form. By concentrating stress around the part, part of the joint is prevented from peeling off.

JP 2004-342520 A

  In the above conventional example, in the degassing step of releasing the generated gas to the outside, the degassing holes are formed in the unjoined portion while restricting the swelling due to the internal pressure. However, when the electrolyte remains in the unjoined part, the electrolyte remaining in the unjoined part jumps out together with the gas through the opened gas vent hole, and the built-in amount of the electrolyte is reduced. there were. Moreover, when the electrolyte solution which protrude | jumped out adhered to the surface of an exterior body, the wiping process was needed and there existed a malfunction which raised production cost.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a method and apparatus for manufacturing a secondary battery suitable for preventing liquid leakage at the time of degassing.

  The present invention is a process of storing and sealing a power generation element inside an exterior body configured by overlapping exterior films, wherein the power generation element is between at least a part of the peripheral sides of the exterior body. A first sealing step arranged at a distance; Subsequently, an opening process for opening a gas vent hole between the peripheral side of the exterior body and the power generation element, a gas vent process for discharging the gas in the exterior body through the gas vent hole, and a second for sealing the gas vent hole. The manufacturing method of the secondary battery which has a sealing process is assumed. Then, in the opening step, before opening the gas venting hole in the exterior body, the part that forms the gas venting hole of the exterior body is pressed so that the exterior films stacked from both sides of the exterior body are in close contact with each other And a peeling step of pulling apart the exterior films that are in close contact with each other by the pressing step.

  Therefore, in the present invention, the electrolyte solution remaining in the vicinity of the gas vent hole is opened in order to open the gas vent hole in a state where the electrolyte solution in the vicinity of the portion where the gas vent hole of the exterior body is formed is moved to the power generation element side. Can be prevented from leaking. Furthermore, an increase in production cost due to the electrolytic solution adhering to the exterior body surface can be suppressed.

1 is a schematic plan view of a secondary battery to which a secondary battery manufacturing method and a manufacturing apparatus according to an embodiment of the present invention are applied. It is process drawing for demonstrating the manufacturing method of the secondary battery which concerns on this embodiment. It is a side view of an opening device. It is a top view of an opening apparatus. It is explanatory drawing which shows the operating state of a hole opening apparatus. It is explanatory drawing which shows the operating state of the opening apparatus following FIG. It is explanatory drawing explaining the change state (A)-(C) of the exterior body processed by the aperture device. It is explanatory drawing which shows the exterior body in the step in which degassing is performed. It is explanatory drawing explaining the gas vent part around the gas vent hole of the stage in which the press process was performed. It is a graph explaining the amount of residual gas after a press process and a peeling process. It is a schematic side view of the opening apparatus in the manufacturing method and manufacturing apparatus of the secondary battery of 2nd Embodiment of this invention. It is a side view which shows the operation state of the opening apparatus of FIG. It is explanatory drawing explaining the change state (A)-(D) of the exterior body processed by the aperture device. It is a side view explaining the operating state (A)-(D) of the opening apparatus in the manufacturing method and manufacturing apparatus of the secondary battery of 3rd Embodiment of this invention. It is explanatory drawing explaining the state (A), (B) before and behind the process of the vent hole in a comparative example, and the adhesion state (C) of the electrolyte solution after venting.

  Hereinafter, the manufacturing method and manufacturing apparatus of the secondary battery of this invention are demonstrated based on each embodiment.

(First embodiment)
A secondary battery to which the method for producing a secondary battery of the present invention is applied is a battery including an exterior body made of a thin and lightweight exterior film.

  The thin and lightweight exterior film is, for example, a polymer-metal composite laminate film having a three-layer structure, and includes a metal layer and a polymer resin layer disposed on both surfaces of the metal layer. A metal layer is comprised from metal foil, such as aluminum, stainless steel, nickel, copper, for example. The polymer resin layer is composed of, for example, a heat-welding resin film such as polyethylene, polypropylene, modified polyethylene, modified polypropylene, ionomer, and ethylene vinyl acetate. It is desirable that the exterior film can be easily bonded by heat welding or ultrasonic welding, and has excellent airtightness and moisture impermeability.

  As shown in FIG. 1, the exterior film is in the form of a bag by joining the power generating element 2 of the secondary battery and joining the fusion portions A at the three peripheral edges thereof into a “U-shape” by heat welding. The bag-shaped opening B is joined by thermal welding in a state where the electrolytic solution is injected into the bag-shaped interior, and the exterior body 1 is configured. As will be described later, the bonding by the thermal welding of the opening B is the first sealing portion C by the first sealing step, the second sealing portion D by the second sealing step and the main sealing step, and the main sealing portion. Each of the three stages of E is performed.

  As an example of the power generation element 2 of the secondary battery, a lithium ion secondary battery will be described as an example. The power generation element 2 of the lithium ion secondary battery is obtained by superposing a positive electrode and a negative electrode via a separator. That is, the power generation element 2 is configured by laminating a positive electrode plate made of a current collector coated with a positive electrode active material layer and a negative electrode plate made of a current collector coated with a negative electrode active material layer via a separator. Is formed. The lithium ion secondary battery is a non-aqueous battery, and gas is generated by the reaction of moisture mixed during manufacture. Further, gas is generated due to evaporation of an organic solvent contained in the electrolytic solution and electrode reaction in conditioning after manufacturing the battery.

  The positive electrode plate includes, for example, a current collector made of an aluminum foil, and a positive electrode active material layer formed in a double-sided region excluding the tab region of the current collector. In FIG. 1, only the tab region 2 </ b> A is illustrated in a state of being drawn out of the power generation element 2. As a positive electrode active material layer, the positive electrode active material which consists of lithium-transition metal complex oxides, such as LiMn2O4, a conductive support agent, a binder, etc. are included, for example.

  The negative electrode plate includes, for example, a current collector made of copper foil and a negative electrode active material layer formed in a double-sided region excluding the tab region of the current collector. In FIG. 1, only the tab region 2 </ b> B is illustrated in a state of being drawn out of the power generation element 2. The negative electrode active material layer includes a negative electrode active material, a conductive additive, a binder, and the like. The negative electrode active material is, for example, hard carbon (non-graphitizable carbon material), graphite-based carbon material, or lithium-transition metal composite oxide.

  A separator is formed from polyolefin, such as polyethylene and polypropylene, polyamide, and polyimide, for example.

  The liquid electrolyte (electrolytic solution) contains an organic solvent, a supporting salt, and the like. Examples of the organic solvent include cyclic carbonates such as propylene carbonate (PC) and ethylene carbonate (EC), chain carbonates such as dimethyl carbonate, and ethers such as tetrahydrofuran. The supporting salt is an inorganic acid anion salt such as lithium salt (LiPF6) or an organic acid anion salt such as LiCF3SO3.

  As shown in FIG. 1, the tab regions 2A and 2B that are the same polarity of the current collector plates of the plurality of positive plates and the negative plates are connected to each other in order to draw a current from the power generation element 2. Connected to the positive terminal 3A and the negative terminal 3B. The positive electrode terminal 3 </ b> A and the negative electrode terminal 3 </ b> B are drawn out of the exterior body 1 through the fusion part A of the exterior body 1.

  FIG. 2 is a process diagram for explaining the manufacturing method of the secondary battery according to the present embodiment. In the manufacturing method of the secondary battery of the present embodiment, a sealing step, a conditioning step, a degassing / second sealing step, a main sealing / trimming step, and other steps performed as necessary Have Hereinafter, based on FIG. 2, the manufacturing method of the secondary battery of this embodiment is demonstrated.

  In the sealing step, first, the rectangular power generation element 2 is disposed between two substantially rectangular exterior films or bi-fold exterior films. The positive electrode terminal 3A and the negative electrode terminal 3B of the power generation element 2 are positioned so as to be exposed from the exterior film. Thereafter, as shown in FIG. 1, the peripheral edge of the exterior film is joined to the “U-shape” by fusion A, leaving one side, and a bag body in which the one side becomes an opening B is formed. .

  In the electrolytic solution injection step, the electrolytic solution is injected into the bag body via the opening B. The method for injecting the electrolytic solution is not particularly limited, and it is possible to inject directly by inserting a tube or a nozzle into the opening B, or inject by immersing in an electrolyte.

  In a 1st sealing process, the exterior part 1 is sealed by joining the opening B used in order to inject | pour electrolyte solution, and forming the 1st sealing part C. FIG. As shown in FIG. 1, the first sealing portion C is joined at a position close to the peripheral side of the exterior body 1. That is, the gas generating part 2 is joined at a position away from the power generation element 2, and the gas vent part 4 communicating with the power generation element 2 is formed between the joint and the power generation element 2.

  In the conditioning process, an initial charging process and an aging process for stabilizing battery characteristics are performed. Initial gas is generated from the power generation element 2 by the initial charging step. In the aging process, more gas is generated from the power generation element 2. The conditioning process may be only one of the initial charging process and the aging process depending on the application.

  In the initial charging step, charging is performed until the power generation element 2 generates a predetermined ratio of the battery capacity of the power generation element 2, for example, the battery voltage obtained when the power generation element 2 is fully charged. The initial charge temperature is preferably 45 to 70 ° C., when the temperature is lower than 45 ° C., gas generation becomes insufficient, and when it is higher than 70 ° C., battery characteristics may be deteriorated. . Moreover, the predetermined ratio of the battery capacity is selected as necessary. In the aging process, the power generation element 2 is held in a charged state.

  In the degassing / second sealing step, the opening step is performed in an atmosphere of dry gas such as atmospheric dry air or inert gas, and then the degassing step and the second sealing step are performed in a decompressed atmosphere. To be implemented.

  In the opening step, as shown in FIG. 1, slit-like gas vent holes 5 are formed in the gas vent portion 4 of the first sealing portion C so that the gas vent portion 4 communicates with the outside.

  In the degassing step, the gas dissolved in the electrolyte is separated from the electrolyte by setting the atmosphere to a reduced pressure state with respect to the secondary battery in which the gas vent 4 is opened by the gas vent 5. Discharge outside. This degassing process is executed until a predetermined time set in advance elapses.

  Next, in a vacuum atmosphere, as shown in FIG. 1, bonding by thermal fusion is performed at a portion closer to the power generation element 2 than the first sealing portion C to form the second sealing portion D (first 2 sealing process).

  Next, the secondary battery that has undergone the second sealing step is taken out of the vacuum atmosphere, and is subjected to main sealing by bonding by thermal welding wider than the second sealing portion D (main sealing step, FIG. 1). (See sealing section E). Next, a trimming process for cutting an unnecessary region in the peripheral portion of the outer package 1 is performed, and a shipping adjustment process such as an inspection process and charge / discharge is performed, thereby completing the secondary battery.

  By the way, the comparative example currently performed in the opening process is demonstrated with reference to FIG. In the comparative example, as shown in FIG. 15A, when the electrolytic solution remains in the gas vent 4, as shown in FIG. Forming. In the illustrated example, the gas vent 4 is slightly swollen due to an increase in internal pressure due to gas. For this reason, as shown in FIG. 15B, the remaining electrolyte may sometimes jump out of the gas vent hole 5. Thus, when the electrolytic solution jumps out of the exterior body 1, the amount of the electrolytic solution remaining in the exterior body 1 is reduced, and the life of the battery is reduced.

  Moreover, the electrolyte solution which jumped out of the exterior body 1 adheres to the surface of the exterior body 1 as shown in FIG. 15C. When the electrolytic solution adheres to the surface of the exterior body 1 in this way, a new wiping process is required, and there is a problem of increasing the production cost. In addition, when the electrolyte solution is wiped off, problems such as lowering the adhesive strength of the adhesive occur when the side surfaces of a plurality of secondary batteries are bonded to each other and used as a battery pack.

  In the present embodiment, a hole-opening device 10 shown in FIGS. 3 and 4 is used to prevent the electrolyte from jumping out in the hole-opening step. The opening device 10 includes a restraining pad 11 that supports one side of the gas vent 4 of the exterior body 1, a clamping body 12 that swings and supports the roller 13 facing the other side of the gas vent 4, A cutter 14 for forming a gas vent hole 5 by making a cut in the gas vent portion 4 and a peeling device 30 for peeling the exterior films of the gas vent portion 4 are provided.

  In the standby state, the restraint pad 11 and the sandwiching body 12 approach each other with the standby position away from the gas vent 4 of the exterior body 1 and the gas vent 4 disposed therebetween, and the gas vent 4 It is comprised so that movement is possible between the operation position which pinches | interposes. Hereinafter, the movement from the standby position to the operating position is defined as the forward direction, the movement from the operating position to the standby position is defined as the backward direction, and the horizontal direction perpendicular to these directions is defined as the left-right direction.

  The sandwiching body 12 is integrally provided with an auxiliary shaft 18 that extends in the front-rear direction and is slidably guided by the base member 17 at both ends in the left-right direction. The rod 19A is advanced and retracted by a cylinder 19 provided in the base member 17. It is connected to the tip. Thereby, the clamping body 12 is guided by the auxiliary shaft 18 and moved in the forward / backward direction between the standby position and the operating position by the forward / backward movement of the rod 19 </ b> A by the cylinder 19.

  Although not shown, the restraint pad 11 is integrally provided with an auxiliary shaft that extends in the front-rear direction and is slidably guided to the base member, and is advanced and retracted by a cylinder provided on the base member, as with the sandwiching body 12. It is connected to the tip. The restraint pad 11 is guided by the auxiliary shaft and moved in the forward / backward direction between the standby position and the operating position by the forward / backward movement of the rod by the cylinder. In the operating position, the restraint pad 11 contacts one surface of the gas vent 4 and supports the gas vent 4 from one side. The restraint pad 11 is provided with a through-hole 11 </ b> A formed by a lateral slit provided so as to penetrate the cutting blade of the cutter 14 and protrude from the front surface of the restraint pad 11. The through-hole 11A has a width that does not accumulate even when the electrolytic solution adheres.

  The cutter 14 is disposed behind the restraint pad 11 at the standby position, and is movable to an operating position that penetrates the through hole 11A of the restraint pad 11 and projects the cutting blade forward of the restraint pad 11. Further, the cutter 14 is capable of moving the cutting blade laterally along the through hole 11A at the operating position. The thickness of the cutter 14 is a thickness that passes through the through hole 11A. Thus, the gas vent hole 5 is formed in the gas vent portion 4 within the range supported by the restraint pad 11.

  The sandwiching body 12 has a roller 13 that sandwiches the gas vent 4 by contacting the other surface of the gas vent 4. As shown in FIG. 3, the roller 13 is rotatably supported at the distal end of an arm 15 whose base end side is swingably supported by the holding body 12 via a shaft 12A. For this reason, the roller 13 is swingable with respect to the sandwiching body 12. The end face on the base end side of the arm 15 is formed in a flat surface, and the tip end of the leaf spring 16 with the base fixed to the sandwiching body 12 is in surface contact with the base end side end face. The position in the vertical direction is restricted to the initial position. At the initial position, the arm 15 is in a state where it is most upwardly rotated, and the roller 13 is protruded from the sandwiching body 12.

  The position of the roller 13 in the initial state in the initial state is offset so as to be positioned below the position of the shaft 12A on the base end side of the arm 15, for example, several degrees with respect to the horizontal plane including the position of the shaft 12A. It is arranged on a surface having an angle of (2-3 °). Then, as shown in FIG. 5, when the roller 13 comes into contact with the gas vent 4 by advancing the holding body 12 to the operating position, the roller 13 is biased downward by an offset from the position of the shaft 12A. As shown in FIG. 3, the arm 15 is operated to roll downward while squeezing the gas vent 4 while rotating the arm 15 downward. The leaf spring 16 is engaged with the arm 15 by the downward rotation of the arm 15 from the surface contact state to the end surface on the base end side of the arm 15 to the point contact state to the lower corner R portion of the end surface. The urging force in the direction of returning to the initial position is applied to the arm 15 from the leaf spring 16.

  The peeling device 30 has a pair of suction pads 31 disposed on both sides of the gas venting part 4 and a base 17 that advances and retracts the suction pad 31 between a standby position and an operating position in contact with the gas venting part by a rod 33. And a cylinder 32 fixed to the cylinder. The suction pad 31 can introduce the negative pressure from the negative pressure generator 34 and the atmosphere via the switching valve 35. When the switching valve 35 is switched and the atmosphere is introduced, the suction operation is canceled and the switching is performed. When the negative pressure from the negative pressure generator 34 is introduced by the valve 35, the adsorption operation is executed. Then, when the suction pad 31 is moved to the operating position, the negative film introduced through the switching valve 35 is used to suck the exterior film of the gas vent 4 and the rod 32 is moved backward by the cylinder 32. Operate to peel apart from each other.

  The peeling device 30 is disposed below the restraining pad 11 and the sandwiching body 12. Then, at the stage where the opening operation of the gas vent hole 5 to the gas vent portion 4 by the restraint pad 11, the sandwiching body 12 and the cutter 14 is completed, the base 17 is lifted by the lift cylinder 36 so as to sandwich the restraint pad 11. In conjunction with raising the body 12 and the cutter 14, the peeling device 30 is raised on the operating line (position indicated by a two-dot chain line in FIG. 3). Then, the above-described peeling operation is performed, and after the operation is completed, the base member 17 is lowered by the elevating cylinder 36 to return to the initial position (the position indicated by the solid line in FIG. 3).

  In the present embodiment, the opening process is performed as described below. As shown in FIG. 3, when the secondary battery from the conditioning process is set in the opening device 10 in the standby state in which the restraint pad 11, the sandwiching body 12, and the cutter 14 are all in the standby position, First, the restraint pad 11 is advanced from the standby position and set to the operating position. The restraint pad 11 is in contact with one surface of the gas vent 4 and supports the gas vent 4.

  In the exterior body 1 of the secondary battery that has passed through the conditioning process, the gas vent 4 is slightly swollen due to an increase in the internal pressure of the gas, and the electrolyte remains in the gas vent 4. In addition, although the gas vent part 4 is slightly inflated due to the internal pressure in the exterior body 1, here, since it describes the process of opening work, in the following, it will be described in a state without swelling as shown in the figure. .

  Next, as shown in FIG. 5, the clamping body 12 is advanced from the standby position to the operating position. As the clamping body 12 advances, the roller 13 comes into contact with a portion of the gas vent 4 away from the power generating element 2, and the roller 13 is slightly swollen with the front surface of the restraining pad 11. 4 is sandwiched. When the clamping body 12 further advances, the roller 13 is urged downward by an offset with respect to the shaft position, and rolls downward while squeezing the gas vent 4 while rotating the arm 15 downward against the leaf spring 16. . As a result, the roller 13 at the tip descends to the power generation element 2 side while rolling on the surface of the gas vent 4 of the outer package 1, and accordingly, the gas vent 4 slightly swollen out of the outer package 1 is moved to the roller 13. Therefore, it operates like a power generator 2 side.

  Then, as shown in FIG. 6, when the roller 13 reaches the lowermost end, the degassing portion 4 is crushed by the restraining pad 11 and the roller 13, and the electrolytic solution remaining in the inside becomes the power generation element 2. Returned in. The returned electrolytic solution is combined with the electrolytic solution around the power generation element 2 to promote gas-liquid separation between the gas and the electrolytic solution.

  Next, as shown in FIG. 7A, the cutting blade of the cutter 14 passes through the through hole 11A of the restraining pad 11 and is pushed to the operating position, and the cutting blade cuts the gas vent 4 of the exterior body 1. Put in. Next, the cutting blade moves laterally along the through-hole 11A of the restraint pad 11 to cut the gas vent 4 in the lateral direction, and forms the gas vent hole 5 by cutting in the gas vent 4 and then the restraint pad. 11 moves backward to return to the standby position. Next, the restraint pad 11 and the sandwiching body 12 are returned to the standby position. As described above, the exterior films constituting the degassing portion 4 are overlapped and closely adhered to each other, and the degassing holes 5 are formed in a state where no electrolyte remains.

  By the way, in this state, since the exterior films constituting the gas vent 4 are wet with the electrolyte, they are stuck to each other by the ironing operation by the restraint pad 11 and the roller 13 as shown in FIG. It is in a state. The exterior films stuck to each other by the electrolytic solution inhibit the passage of the gas returned together with the electrolytic solution around the power generation element 2 to the gas vent hole 5. For this reason, for example, as shown in the graph on the left side of FIG. 10, the exterior body 1 is filled with a large amount of residual gas.

  For this reason, in this embodiment, the base 17 is raised by the elevating cylinder 36 at the stage when the opening operation of the gas vent hole 5 to the gas vent portion 4 by the restraint pad 11, the sandwiching body 12 and the cutter 14 is completed. Then, the restraining pad 11, the sandwiching body 12 and the cutter 14 are raised. In conjunction with this, the peeling device 30 is raised on the operating line (position indicated by a two-dot chain line in FIG. 3). Next, the rod 33 is operated by the cylinder 32 to advance the suction pad 31 to the operating position, and as shown in FIG. 7B, the suction pad 31 is brought into contact with the exterior film of the degassing portion 4 and negative pressure is applied. The exterior film is adsorbed by the adsorption pad 31 by the negative pressure introduced from the generator 34. Next, as shown in FIG. 7 (C), the suction pad 31 is retracted by the cylinder 32 to peel off the exterior films stuck to each other by the electrolytic solution. Next, by stopping the introduction of the negative pressure from the negative pressure generator 34 and introducing the atmosphere, the suction pad 31 is detached from the exterior film, the suction pad 31 is returned to the standby position by the cylinder 32, and the lift cylinder 36 is used. The base member 17 is lowered to return to the initial position.

  As a result, as shown in FIG. 8, the gas that is pushed into the power generation element 2 side in the exterior body 1 passes through the expanded gas vent 4 and is discharged to the outside through the gas vent 5. The For this reason, for example, as shown in the graph on the right side of FIG. 10, most of the residual gas can be discharged into the exterior body 1. Further, the electrolytic solution present in the gas vent 4 is returned to the power generation element 2 side by the ironing action of the restraining pad 11 and the roller 13, and united with the electrolyte around the power generation element 2. For this reason, even when the gas vent 4 is expanded by the suction pad 31, it is possible to prevent the electrolyte from being discharged to the outside through the gas vent 4 and the gas vent 5.

  In the above embodiment, the restraint pad 11, the sandwiching body 12 and the cutter 14, and the peeling device 30 are operated by switching between the vertical operation position and the standby position by raising and lowering the base member 17. It explains about. However, the restraint pad 11, the sandwiching body 12 and the cutter 14, and the peeling device 30 may be moved up and down independently. Further, it is assumed that the restraint pad 11, the sandwiching body 12 and the cutter 14 are fixed without being lifted and lowered, and in the state where they are returned to the standby position, only the suction pad 31 of the peeling device 30 is lifted and lowered to remove the gas. The film for exterior 4 may be adsorbed and peeled off from each other.

  Moreover, in the said embodiment, what cuts only the gas vent part 4 with the cutter 14 and forms the gas vent hole 5 is demonstrated. However, the front end side may be separated from the exterior body 1 by cutting not only the gas vent 4 but also including the extended portion.

  In addition, as the timing for cutting only the gas venting portion 4 by the cutter 14, the case where the gas vent hole 5 is formed by the cutter 14 when the roller 13 is lowered to the lowermost end is described. However, when the roller 13 passes through the through hole 11 </ b> A of the restraining pad 11, the gas vent hole 5 by the cutter 14 may be formed while the gas vent portion 4 is squeezed to the power generation element 2 side by the roller 13.

  In the present embodiment, the following effects can be achieved.

  (A) A step of storing and sealing the power generation element 2 inside the exterior body 1 configured by overlapping the exterior films, and the power generation element 2 includes at least a part of the peripheral side of the exterior body 1 A first sealing step disposed at a distance between the first sealing step and the second sealing step. Subsequently, an opening process for opening the gas vent hole 5 between the peripheral side of the outer package 1 and the power generation element 2, a gas vent process for discharging the gas in the outer package 1 through the gas vent hole 5, and a gas vent hole And a second sealing step for sealing 5. Then, in the opening step, before opening the gas vent hole 5 in the outer package 1, the exterior film that is overlapped from both sides of the outer package 1 is adhered to the portion of the outer package 1 where the gas vent hole 5 is formed. And a peeling process for separating the exterior films that are in close contact with each other by the pressing process. That is, since the gas vent hole 5 is opened in a state in which the electrolytic solution in the vicinity of the portion where the gas vent hole 5 of the outer package 1 is formed is moved to the power generation element 2 side, the electrolysis remaining in the vicinity of the gas vent hole 5 is formed. The liquid can be prevented from leaking. Furthermore, an increase in production cost due to the electrolytic solution adhering to the surface of the outer package 1 can be suppressed.

  Moreover, in order to provide the peeling process which pulls apart the film for exterior | packing closely_contact | adhered by the press process in the separation | separation direction, the gas vent part 4 which expanded the gas which was pushed in the power generation element 2 side in the exterior body 1 is expanded. The gas can be passed through and quickly discharged from the vent hole 5 to the outside.

  (A) In the pressing step, one side of the portion where the gas vent hole 5 is formed is supported by the restraint pad 11, the roller 13 is pressed against the other side of the power generation element 2, and the roller 13 is pressed against the power generation element side 2. It is intended to roll toward That is, since the degassing part 4 is squeezed by the restraining pad 11 and the roller 13, the electrolyte remaining in the degassing part 4 can be reliably returned to the power generation element 2 side. Further, since the gas vent 4 is supported by the restraint pad 11, the gas vent hole 5 can be easily formed in the gas vent 4 by the cutter 14.

  (C) In the peeling process, the exterior film is separated from each other by the suction pads 31 as suction means. That is, since the exterior films are separated from each other by the adsorbing means, the adhered exterior films can be surely separated, and the gas that is pushed into the power generation element 2 side in the exterior body 1 can be expanded. The gas vent 4 can be passed through the gas vent hole 5 and reliably discharged to the outside.

(Second Embodiment)
FIGS. 11-13 is explanatory drawing which shows the opening process which shows 2nd Embodiment of the manufacturing method and manufacturing apparatus of the secondary battery to which this invention is applied. In the opening device of this embodiment, as a peeling device, instead of the suction pad in the first embodiment, one of the exterior films constituting the gas venting portion by pressing a roller against the base of the gas venting portion. It is set as the structure peeled off by shifting with respect to the other. The same devices as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As in the first embodiment, the opening device 10 of the present embodiment has a restraint pad 11 that supports one side of the gas vent 4 of the exterior body 1 and a roller facing the other side of the gas vent 4. And a cutter 14 that forms a gas vent hole 5 by making a cut in the gas vent portion 4. Then, as in the first embodiment, as shown in FIG. 11, the clamping body is advanced, and the gas vent 4 is squeezed by the restraining pad 11 and the roller 13, and as shown in FIG. Is configured to reach the lowermost end and press the base of the degassing portion 4 by the roller 13. Other configurations are the same as those in the first embodiment.

  In the present embodiment, as shown in FIG. 11, as in the first embodiment, the holding body is advanced, and the gas vent 4 is squeezed by the restraining pad 11 and the rolling roller 13 to release the gas. The portion 4 is crushed so that the electrolyte remaining in the degassing portion 4 is returned into the power generation element 2 as shown in FIG. When the roller 13 reaches the lowermost end, as shown in FIG. 12, the gas vent 4 is crushed by the restraining pad 11 and the roller 13, and the electrolyte remaining in the interior is put into the power generation element 2. Returned. At the time of this operation, since the exterior films constituting the gas vent 4 are wet with the electrolyte solution, as shown in FIG. 9, the state where they are stuck to each other by the ironing operation by the restraint pad 11 and the roller 13 It has become.

  Then, when the roller 13 passes through the through-hole 11A of the restraining pad 11, or at the stage where the roller 13 is lowered to the lowermost end, as shown in FIG. A cut is made in 4 to open the vent hole 5.

  When the roller 13 is lowered to the lowermost end, the roller 13 presses the base of the gas vent 4 downward as shown in FIG. 13B. By this pressing, one of the stuck exterior films constituting the gas venting portion 4 is shifted downward relative to the other by the ironing operation by the restraint pad 11 and the roller 13. By this displacement movement, as shown in FIG. 13D, one and the other of the exterior film are peeled from the stuck state. Moreover, even if the exterior films constituting the gas vent 4 are intertwined by the burrs or the like of the gas vent holes 5 formed by the cutter 14, one of the exterior films is below the other. By being shifted to the side, the entanglement of the burr is released, and the burr is peeled off.

  Thereby, the gas that is pushed into the power generation element 2 side in the exterior body 1 spreads the pair of exterior films of the gas vent 4 and is discharged to the outside through the gas vent 5. Further, the electrolytic solution present in the gas vent 4 is returned to the power generation element 2 side by the ironing action of the restraining pad 11 and the roller 13, and united with the electrolyte around the power generation element 2. For this reason, even when the gas vent 4 is expanded and the gas is discharged, it is possible to prevent the electrolyte from being discharged to the outside through the gas vent 4 and the gas vent 5.

  In the embodiment described above, the roller 13 is pressed against the base of the gas vent 4 to peel off one of the exterior films from the sticking state. However, if the vertical stroke of the roller 13 is restricted by the length of the arm 15 and does not reach the base of the degassing portion 4 even if the stroke reaches the lowermost end, the base member 17 is moved along with the downward movement of the roller 13. It may be lowered by an actuator.

  Moreover, in the said embodiment, what pressed off the roller 13 to the base of the gas vent part 4 and peeled off one side and the other of the film for an exterior from a sticking state was demonstrated. However, the peel-off of the closely attached exterior film may be performed as long as it presses the base portion of the gas vent portion 4 toward the power generation element 2 and shifts one of the exterior films with respect to the other, and the roller 13 is used. For example, you may press the base part of the degassing part 4 to the electric power generation element 2 side with the member expanded-contracted by a cylinder apparatus. Furthermore, in the said embodiment, it replaces with the suction pad in 1st Embodiment, and it is set as the structure which shifts one of the films for exteriors with respect to the other, However, It is not limited to this, One of a suction pad and exterior films You may use together the structure which shifts with respect to the other.

  In the present embodiment, in addition to the effects (a) and (b) in the first embodiment, the following effects can be achieved.

  (D) In the peeling step, one of the exterior films in the portion where the gas vent hole 5 is formed is shifted to the power generation element 2 side with respect to the other. That is, since only the base part of the degassing part 4 is pressed to the power generation element 2 side, one of the exterior films can be shifted with respect to the other by a simple configuration, and the exterior films can be peeled apart.

  (E) In the peeling step, the roller 13 that presses against the portion where the gas vent hole 5 is formed is pressed toward the power generation element 2 to shift one of the exterior films with respect to the other. That is, since the roller 13 rolled to the power generation element 2 side is used as a member that presses the base of the gas venting section 4 to the power generation element 2 side, the peeling device 30 can be simplified.

(Third embodiment)
FIG. 14 is an explanatory diagram showing an opening process showing a third embodiment of a method and apparatus for manufacturing a secondary battery to which the present invention is applied. In the opening device of the present embodiment, the remaining electrolyte is pushed back to the power generation element side by sandwiching the gas vent portion of the exterior body with an elastic pad having an inclined surface instead of the restraining pad and the sandwiching body. The configuration described above is added to the first embodiment. The same devices as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As shown in FIG. 14A, the opening device 10 according to the present embodiment is formed of an elastic body, for example, a sponge body, which faces both sides of the gas vent 4 of the exterior body 1 and is formed by inclining opposing surfaces. A pair of elastic pads 20, 20 is provided. The illustrated elastic pad 20 shows a state in which it is positioned at the standby position. The opposing surfaces of the opposing elastic pads 20, 20 are provided with inclined surfaces 20 A, 20 A that are close to each other on the distal end side of the gas vent 4 and that are separated from each other on the base side of the gas vent 4. Through holes 20B and 20B are formed in the center of the pair of elastic pads 20 by slits extending in the lateral direction. Similarly to the first embodiment, the cutting blade of the cutter 14 passes through 20B and 20B to release gas. A gas vent hole 5 can be formed by making a cut in a region facing the portion 4. Other configurations are the same as those in the first embodiment.

  As shown in FIG. 14A, the outer battery body 1 of the secondary battery generated by the conditioning process is in a state where the electrolytic solution remains in the gas vent 4 due to the increase in internal pressure due to the gas. As shown in FIG. 14B, the opening device 10 moves the pair of elastic pads 20 to the operating position, and sandwiches the gas vent 4 of the exterior body 1 by the pair of elastic pads 20. Since the opposing surfaces of the pair of elastic pads 20 are inclined surfaces 20 </ b> A and 20 </ b> A, the tip side of the gas vent 4 is sandwiched and the sandwiching range is sequentially expanded toward the base of the gas vent 4. Go. As the clamping range is expanded, the width of the degassing portion 4 is narrowed from the front end side toward the base side, and the degassing portion 4 is narrowed and crushed and remains in the degassing portion 4. The electrolyte solution that has been pushed back into the power generation element 2. The electrolyte solution pushed back is combined with the electrolyte solution around the power generation element 2 to promote gas-liquid separation between the gas and the electrolyte solution.

  Also in this configuration, as in the first embodiment, the pressing force from the elastic pad 20 acting on the gas venting portion 4 during the squeezing operation of the gas venting portion 4 by the elastic pad 20 is a portion away from the power generation element 2. It operates so as to decrease as it approaches the power generation element 2. For this reason, in the elastic pad 20 which contacts the site | part away from the electric power generation element 2, the elastic pad 20 acts so that the degassing part 4 may be squeezed by comparatively big pressing force. As a result, the electrolyte remaining in the gas vent 4 can be reliably sent to the power generation element 2 side together with the mixed gas.

  Next, as shown in FIG. 14C, the cutting blade of the cutter 14 is pushed out, and a cut is made in the gas vent 4 of the exterior body 1. Next, the cutting blade is moved in the horizontal direction to cut the gas vent 4 in the horizontal direction, and a gas vent hole 5 is formed in the gas vent 4 and then moved backward to return to the standby position. Next, the pair of elastic pads 20 are returned to the standby position.

  Next, as shown in FIG. 14D, the rod 33 is actuated by a cylinder (not shown) to advance the suction pad 31 to the working position, the suction pad 31 is brought into contact with the exterior film of the gas vent 4, and a negative pressure (not shown) The exterior film is adsorbed by the adsorption pad 31 by the negative pressure introduced from the generator. Next, the adhering pad 31 is retracted by the cylinder to peel off the attached exterior films. Next, the suction pad 31 is detached from the exterior film by stopping the introduction of the negative pressure from the negative pressure generator and introducing the atmosphere, and the suction pad 31 is returned to the standby position by the cylinder.

  As a result, as shown in FIG. 14D, the gas that is pushed into the power generation element 2 side in the exterior body 1 passes through the expanded gas vent 4 and is discharged to the outside from the gas vent 5. The For this reason, it can be set as the state by which most residual gas was discharged | emitted in the exterior body. In addition, the electrolytic solution present in the gas vent 4 is returned to the power generation element 2 side by the ironing action of the pair of elastic pads 20 and 220 and is combined with the electrolyte around the power generation element 2. For this reason, even when the gas vent 4 is expanded by the suction pad 31, it is possible to prevent the electrolyte from being discharged to the outside through the gas vent 4 and the gas vent 5.

  In the above-described embodiment, the description has been given of the case where the exterior films that are brought into close contact with each other in the pressing step are separated from each other by the pair of suction pads 31 in the separation direction. However, as shown in the second embodiment, peeling of the adhered exterior film is performed by pressing the base of the gas vent 4 toward the power generation element 2 and shifting one of the exterior films with respect to the other. There may be. In this case, as shown in the second embodiment, the roller 13 is not used, for example, by pressing the base of the gas vent 4 toward the power generation element 2 by a member that is expanded and contracted by a cylinder device. be able to.

  In the present embodiment, in addition to the effects (a) and (c) in the first embodiment, the following effects can be achieved.

  (F) The pressing step is to sandwich the portion where the gas vent hole 5 is formed from both sides by the elastic pads 20 and 20 having the inclined surfaces 20A and 20A which are inclined to approach each other on the side far from the power generating element 2 and away from each other. . That is, since the gas vent 4 is crushed by sandwiching the gas vent 4 between the elastic pads 20 and 20 and the electrolyte is moved to the power generation element 2 side, the structure is simple and the cost can be reduced. Moreover, since the gas vent hole 5 is formed in the gas vent section 4 while the gas vent section 4 is held from both sides, the position of the gas vent section 4 is stabilized, and the gas vent hole 5 is easily formed.

A Thermal welding B Opening C First sealing part D Second sealing part 1 Exterior body 2 Power generation element 3A, 3B Electrode terminal 4 Gas venting part 5 Gas venting hole 10 Opening device 11 Restraint pad 11A Through hole 12 by slit Clamping body 13 Roller 14 Cutter 15 Arm 20 Elastic pad 20A Inclined surface 30 Peeling device 31 Adsorption pad (adsorption means)

Claims (12)

A step of storing and sealing a power generation element inside an exterior body configured by overlapping exterior films, wherein the power generation element has a distance from at least a part of a peripheral side of the exterior body. A first sealing step disposed in the step, an opening step for opening a gas vent hole between a peripheral side of the outer package and the power generation element, and a gas for exhausting the gas in the outer package through the gas vent A secondary battery manufacturing method comprising: a venting step; and a second sealing step of sealing the gas vent hole,
In the opening step, before opening the gas vent hole in the exterior body, the exterior film laminated from both sides of the exterior body is in close contact with a portion of the exterior body where the gas vent hole is formed. A method for producing a secondary battery, comprising: a pressing step for pressing in such a manner; and a peeling step for separating the exterior films that are in close contact with each other in the pressing step in a separation direction.   In the pressing step, one side of the part that forms the gas vent hole is supported by a restraining pad, a roller is pressed against the other side of the power generation element, and the roller rolls toward the power generation element side. The method for manufacturing a secondary battery according to claim 1, wherein:   2. The pressing step includes sandwiching a portion where the gas vent hole is formed from both sides by an elastic pad having inclined surfaces that are inclined to approach each other on the side far from the power generation element and away from each other. The manufacturing method of the secondary battery as described in any one of.   4. The method of manufacturing a secondary battery according to claim 1, wherein in the peeling step, the exterior films are separated from each other in a direction away from each other by an adsorbing unit. 5.   4. The method according to claim 1, wherein in the peeling step, one of the exterior films in a portion where the gas vent hole is formed is shifted to the power generation element side with respect to the other. 5. The manufacturing method of the secondary battery of one description.   The said peeling process presses the roller pressed against the part which forms the said gas vent hole to the said electric power generation element side, and shifts one side of the said exterior film with respect to the other, It is characterized by the above-mentioned. The manufacturing method of the secondary battery of 2. A secondary battery comprising: an exterior body configured by overlapping exterior films; and a power generation element housed in the exterior body at a distance between at least a part of the peripheral sides of the exterior body Manufacturing equipment,
A pressing device that presses the portion of the exterior body where the gas vent holes are formed so that the exterior film overlaid on the exterior body from both sides is in close contact with each other;
An apparatus for manufacturing a secondary battery, comprising: a peeling device that separates the exterior films that are in close contact with each other by the pressing device.   The pressing device supports one side of the portion where the gas vent hole is formed with a restraining pad, presses a roller against a side farther from the power generation element, and rolls the roller toward the power generation element side. The apparatus for manufacturing a secondary battery according to claim 7, wherein:   8. The pressing device is characterized in that a portion for forming the gas vent hole is sandwiched from both sides by an elastic pad having inclined surfaces that are inclined to approach each other on the side far from the power generation element and away from each other. An apparatus for producing a secondary battery according to 1.   The secondary battery manufacturing apparatus according to any one of claims 7 to 9, wherein the peeling device is configured to separate the exterior films in a direction away from each other by an adsorption unit.   The said peeling apparatus shifts one side of the said film for exterior of the part which forms the said vent hole to the said electric power generation element side with respect to the other, The any one of Claim 7 to 9 characterized by the above-mentioned. The manufacturing apparatus of the secondary battery of one description.   The said peeling apparatus presses the roller pressed against the part which forms the said gas vent hole to the said electric power generation element side, and shifts one side of the said film for exterior with respect to the other, It is characterized by the above-mentioned. The secondary battery manufacturing apparatus according to claim 8.