JP2023072499A - Method for manufacturing power storage device - Google Patents

Abstract

To provide a method for manufacturing a power storage device, with which manufacturing quality can be improved.SOLUTION: There is provided a method 1 for manufacturing a power storage device 100 that comprises a laminate 101 enclosed in a film-like exterior body 102, the laminate being formed by laminating sheet-like positive and negative electrodes together with a separator. In an initial charge/discharge step S2, initial charge/discharge is performed for a workpiece 10. The workpiece 10 comprises the laminate 101 enclosed in the exterior body 102, and has a laminate part 11 in which the exterior body 102 and the laminate 101 overlap in a thickness direction X, and a gas pocket part 12 where the exterior body 102 extends outward from an outer edge of the laminate part 11. In a degassing step S3, after the initial charge/discharge step S2, gas is removed from the workpiece 10 by opening the gas pocket part 12 to reduce the inner pressure of the workpiece 10, while at least part of the laminate part 11 is pressed against a reference surface 50a. In a resealing step S4, a boundary part 12a between the laminate part 11 and the gas pocket part 12 is sealed in a decompressed state.SELECTED DRAWING: Figure 10

Description

The present invention relates to a method for manufacturing an electricity storage device.

Conventionally, in a method for manufacturing an electricity storage device in which a laminate obtained by laminating a sheet-like positive electrode and a negative electrode together with a separator is enclosed in a film-like outer package, a method of removing the gas generated in the outer package during the initial charging and discharging has been used. Various proposals have been made. For example, in Patent Document 1, a gas reservoir in which gas in the exterior body is accumulated is provided in a part of the periphery of the exterior body, and after the first charge and discharge, an opening is formed in the gas reservoir to remove the gas in the exterior body. A method is disclosed for sealing the opening after the opening.

JP 2015-220199 A

However, in the method disclosed in Patent Literature 1, when the gas in the exterior is removed, the laminate in the exterior may be warped and deformed. If such deformation of the laminate is left as it is, the thickness of the completed electricity storage device may vary excessively, or the metal foil inside the outer package may peel off, resulting in a decrease in manufacturing quality.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object thereof is to provide a method of manufacturing an electricity storage device that can improve manufacturing quality.

One aspect of the present invention is a method for producing an electricity storage device in which a laminate obtained by laminating a sheet-shaped positive electrode and a negative electrode together with a separator is enclosed in a film-shaped outer package,
A work in which the laminate is enclosed in the exterior body, and includes a laminate portion in which the exterior body and the laminate overlap in a thickness direction, and the exterior body extends outward from the outer edge of the laminate portion. an initial charging/discharging step of performing initial charging/discharging on a workpiece having a gas pocket portion configured to extend and store gas generated inside the exterior body;
After the initial charging/discharging step, in a pressed state in which at least a part of the laminate portion is pressed against a reference surface, the gas pocket portion is opened and the internal pressure of the work is lowered to remove the gas from the work. a degassing process;
a resealing step of sealing a boundary portion between the laminate portion and the gas pocket portion while maintaining the pressed state and the state in which the internal pressure of the work is reduced;
A method for manufacturing an electricity storage device including

In the above electricity storage device manufacturing method, since the pressed state in which at least a part of the laminate portion is pressed against the reference surface is maintained from the degassing step to the completion of the resealing step, degassing from the exterior body is continued. Deformation of the laminate portion can be suppressed until resealing. As a result, it is possible to reduce variations in the thickness dimension of the completed electricity storage device, prevent breakage of the metal foil forming the electrodes and the like in the exterior body, and improve manufacturing quality.

As described above, according to the above aspect, it is possible to provide a method for manufacturing an electricity storage device that improves manufacturing quality.

1(a) is a perspective view of an electric storage device, and (b) is a conceptual cross-sectional view taken along the line Ib-Ib in FIG. 1(a) in Embodiment 1. FIG. 4 is a flowchart of a method for manufacturing an electricity storage device according to Embodiment 1. FIG. 1(a) is a conceptual front view for explaining a pre-process and an initial charging/discharging process in a method for manufacturing an electricity storage device, and (b) a cross-sectional view taken along line IIIb-IIIb of FIG. 1(a) in Embodiment 1; 4A and 4B are front conceptual views for explaining a degassing step in the method for manufacturing an electricity storage device in Embodiment 1. FIG. 4(a) and 4(b) are conceptual top views for explaining a degassing step in the method for manufacturing an electricity storage device, according to Embodiment 1. FIG. 4 is another conceptual front view for explaining the degassing step in the method for manufacturing an electricity storage device according to Embodiment 1. FIG. 7A and 7B are schematic cross-sectional views taken along the line VIIa-VIIa of FIG. 6 and FIG. 7B are other conceptual top views for explaining the degassing step in the method for manufacturing an electricity storage device, according to Embodiment 1. FIG. (a) Another conceptual cross-sectional view taken along the line VIIa-VIIa in FIG. 6, and (b) Another conceptual top view for explaining the degassing step in the method for manufacturing an electricity storage device, according to Embodiment 1. FIG. 7A and 7B are still another conceptual cross-sectional view taken along the line VIIa-VIIa of FIG. 6 and FIG. 7B are still another conceptual top view for explaining the degassing step in the method for manufacturing an electricity storage device, according to Embodiment 1; (a) a cross-sectional view taken along line VIIa-VIIa in FIG. 6 for explaining the resealing step, and (b) a top surface for explaining the resealing step in the method for manufacturing an electricity storage device, in Embodiment 1. Conceptual diagram. FIG. 3 is a conceptual cross-sectional view taken along line IIIb-IIIb of FIG.

(Embodiment 1)
An embodiment of a method for manufacturing an electricity storage device will be described with reference to FIGS. 1 to 10. FIG.
In Embodiment 1, an electricity storage device 100 shown in FIG. 1A includes a laminate 101 formed by laminating sheet-like positive and negative electrodes together with a separator as shown in FIG. Enclosed in And the manufacturing method 1 of the said electrical storage device 100 includes initial charging/discharging process S2, degassing process S3, and resealing process S4, as shown in FIG.
In the initial charge/discharge step S2, the workpiece 10 shown in FIG. 3(a) is subjected to the initial charge/discharge. As shown in FIG. 3B, the workpiece 10 is formed by enclosing a laminate 101 in an exterior body 102. The exterior body 102 and the laminate 101 overlap each other in the thickness direction X, and the exterior body 102 has a gas pocket portion 12 extending outward from the outer edge of the laminate portion 11 and configured to store gas generated inside the exterior body 102 .
In the degassing step S3, after the initial charging/discharging step S2, as shown in FIGS. The internal pressure of is lowered to open the gas pocket portion 12 and remove the gas from the workpiece 10 .
Then, in the resealing step S4, as shown in FIGS. 10(a) and 10(b), the laminated body portion 11 and the gas pocket are kept in the pressed state and the state in which the internal pressure of the workpiece 10 is lowered. The boundary portion 12a with the portion 12 is sealed.

Hereinafter, the manufacturing method 1 of the electric storage device 100 of this embodiment will be described in detail.
First, as shown in FIGS. 1A and 1B, an electricity storage device 100 according to the present embodiment is configured by enclosing a laminate 101 in a film-like exterior body 102 . The laminate 101 is formed by laminating a sheet-like positive electrode and a negative electrode together with a separator (not shown). In this embodiment, the electricity storage device 100 includes a capacitor, a secondary battery, and the like. And a lithium ion obtained by sealing a laminated body 101 in which a plurality of negative electrodes are alternately laminated with a separator interposed and the negative electrode is pre-doped with lithium ions, together with an electrolytic solution containing a lithium salt as an electrolyte, in an outer package 102. It uses a capacitor. As shown in FIG. 1( a ), the electricity storage device 100 has a flat rectangular outer shape, and includes a laminate portion 11 , an outer peripheral seal portion 13 and a current collecting tab 14 . The laminated body part 11 is located in the central part of the electric storage device 100, and is formed by overlapping the outer package 102 and the laminated body 101 in the thickness direction Y as shown in FIG. 1(b). The outer peripheral seal portion 13 surrounds the outer periphery of the laminate portion 11, and is formed by heat-sealing a front-side outer package 102a and a back-side outer package 102b to each other. It should be noted that the outer peripheral seal portion 13 at the upper end of the electricity storage device 100 is configured by a reseal portion 70a, which will be described later. A pair of current collecting tabs 14 are provided, and protrude outward from a later-described third side portion 10c that is an outer edge on one side in the width direction X of the exterior body 102 . The pair of current collecting tabs 14 are connected to the positive electrode and the negative electrode that constitute the laminate 101 , although not shown. Moreover, although not shown, the interior of the exterior body 102 is filled with the above-described electrolytic solution.

And the manufacturing method 1 of the said electrical storage device 100 in this embodiment, as shown in FIG. 2, includes a pre-process S1, an initial charging/discharging process S2, a degassing process S3, a resealing process S4, and a cutting process S5. In the pre-process S1, a workpiece 10 is prepared. The workpiece 10 includes a laminate portion 11, a gas pocket portion 12, an outer peripheral seal portion 13, and a current collecting tab 14, as shown in FIGS. 3(a) and 3(b). The gas pocket portion 12 is formed by extending the exterior body 102 upward in the vertical direction Z from the laminate portion 11 . As shown in FIG. 3(b), in the gas pocket portion 12, the exterior body 102a on the front side and the exterior body 102b on the back side are not welded to each other, and a space is formed between them. Moreover, although not shown, the exterior body 102 is filled with an electrolytic solution. As shown in FIG. 3A, the workpiece 10 includes a first side portion 10a provided with the gas pocket portion 12 and a second side opposite to the first side portion 10a. Four side portions consisting of a side portion 10b, a third side portion 10c provided with a current collecting tab 14, and a fourth side portion 10d located on the opposite side of the third side portion 10c. 10a-10c. All of the side portions 10a to 10c are sealed by an outer peripheral seal portion 13. As shown in FIG.

Next, in the initial charge/discharge step S2 shown in FIG. 2, the workpiece 10 is subjected to initial charge/discharge. The mode of the initial charging/discharging is not limited, and can be performed by a known method. In the initial charging/discharging step S2, gas is generated from the laminate 101 in the exterior body 102 by performing charging/discharging. The generated gas accumulates in the space between the exterior body 102 a on the front side and the exterior body 102 b on the back side in the gas pocket section 12 . In addition, in order to pre-dope the negative electrode with lithium ions, a pre-doping step may be performed before the initial charge/discharge step S2. Moreover, you may perform a desired aging process after initial charge/discharge process S2.

Thereafter, in the degassing step S3 shown in FIG. 2, first, as shown in FIG. 4(a), the workpiece 10 is moved as indicated by an arrow P, and then moved vertically from the stage 20 as shown in FIG. 4(b). It is supported at a predetermined position on the stage 20 by the supporting portion 30 which rises in Z direction. The support portion 30 has a first support portion 31 and a second support portion 32 , and the first support portion 31 and the second support portion 32 are arranged between the third side portion 10 c of the workpiece 10 and the second support portion 32 . They are horizontally spaced apart from each other by a spacing corresponding to the fourth side portion 10d. As shown in FIG. 5B, the first support portion 31 and the second support portion 32 are arranged in the thickness direction Y of the work 10 so that a pair of rod-like members rising from the stage 20 form a slit S. They are spaced apart from each other in a certain depth direction. The size of the slit S is not limited, and may be slightly larger than the thickness of the third side portion 10c and the fourth side portion 10d of the workpiece 10. FIG. In addition, as shown in FIGS. 5A and 5B, the pair of rod-shaped members that constitute the first support portion 31 and the second support portion 32 extend in the thickness direction Y at the upper ends in the vertical direction Z. The upper ends of the slits S in the vertical direction Z are widened. This makes it easier to insert the third side portion 10c and the fourth side portion 10d of the workpiece 10 into the slit S. As shown in FIG.

Then, as shown in FIGS. 5A and 5B, the third side portion 10c and the third side portion 10c of the workpiece 10 are inserted into the slits S of the first support portion 31 and the second support portion 32, respectively. By inserting the four side portions 10d respectively, the work 10 is supported in a state of being loosely fitted in the support portion 30. As shown in FIG. In the state in which the work 10 is loosely fitted to the support portion 30 as described above, as shown in FIGS. The work 10 is positioned in the vertical direction Z by contacting the upper surface of the stage 20 with the work 10b. The height of the first support portion 31 and the second support portion 32 in the vertical direction Z is such that the upper ends of the first support portion 31 and the second support portion 32 are the laminated body in the state where the work 10 is supported. It is set so as not to exceed the upper end of the portion 11 .

Subsequently, in the degassing step S3 shown in FIG. 2, as shown in FIGS. be placed on. Then, the reference plate 50 having the reference surface 50a shown in FIGS. 7(a) and 7(b) is moved toward the laminate portion 11 to a preset reference position, and the reference plate 50 shown in FIGS. As shown in 8(b), one surface 11a of the laminate portion 11 of the work 10 is brought into contact with the reference surface 50a. Along with this, the pressure plate 51 having the pressure surface 51a shown in FIGS. Then, the pressure surface 51a is pressed against the other surface 11b of the laminate portion 11 of the workpiece 10. As shown in FIG. As a result, the laminate portion 11 is sandwiched between the reference surface 50a and the pressure surface 51a, and as a result, the laminate portion 11 is pressed against the reference surface 50a.

In the degassing step S3 shown in FIG. 2, the reference position of the reference surface 50a is set to the support portion so that the workpiece 10 is positioned at a predetermined position in the thickness direction Y when the reference surface 50a contacts the surface 11a. 30 can be set. In the present embodiment, as shown in FIG. 8B, the current collecting tab 14 is attached to the laminate portion 11 with the reference surface 50a in contact with the surface 11a of the laminate portion 11 when viewed from above in the vertical direction Z. 11, and is set at a position where both are parallel to each other while being overlapped with the center line 11c in the thickness direction Y. The reference position can be appropriately set according to the thickness T of the laminate portion 11 .

On the other hand, in the present embodiment, as shown in FIGS. 8A and 8B, the pressure plate 51 is applied by the load control unit 52 from the pressure surface 51a to the other surface 11b of the laminate unit 11. A target load, which is a load, is controlled. The configuration of the load control unit 52 is not limited, and can be configured by a known pump or the like. The magnitude of the target load is also not limited. It can be the minimum value of the range that can be suppressed. In this embodiment, the target load is a value within the range of 50-100 kg.

The shape of the reference plate 50 and the pressure plate 51 is not limited, and any shape may be employed as long as at least a part of the laminate portion 11 can be pressed against the reference surface 50a. In the first embodiment, as shown in FIGS. 6 and 8B, the shape of the reference plate 50 and the pressure plate 51 is set over the entire side portion 11d of the laminate portion 11 on the side from which the current collecting tab 14 protrudes. It has a flat plate shape that overlaps. As a result, the entire side portion 11d is configured to be in a pressed state. Furthermore, as shown in the figure, the shape of the reference plate 50 and the pressure plate 51 is a flat plate shape overlapping the entire area of the laminate portion 11 . As a result, the entire laminate portion 11 is sandwiched between the reference plate 50 and the pressure plate 51 in the thickness direction so that the entire laminate portion 11 is pressed. Note that the reference plate 50 and the pressure plate 51 are formed of, for example, a punching boat having a large number of through holes, a mesh sheet, or the like, so that they substantially overlap the entire area of the laminate portion 11. 11 may be substantially pressed.

Next, in the degassing step S3 shown in FIG. 2, as shown in FIGS. A predetermined position of the gas pocket portion 12 is opened to reduce the internal pressure of the workpiece 10 . The piercing degassing device 60 includes a piercing nozzle portion 61 having a sharp tip and a hollow portion opening at the tip; and a pump 63 for sucking gas from the opening of the portion 61 . Then, as shown in FIG. 9(a), the perforated nozzle portion 61 is pressed against the gas pocket portion 12, the receiving portion 62 is applied to the opposite side, and the perforated nozzle portion 61 is inserted into the gas pocket portion 12, thereby forming a gas pocket. A perforation 60 a is formed in the portion 12 , and the opening of the perforated nozzle portion 61 and the inside of the gas pocket portion 12 are communicated with each other. Then, by operating the pump 63 and reducing the pressure in the chamber 40 by the pump 41 connected to the chamber 40, the internal pressure of the workpiece 10 is lowered and the gas in the exterior body 102 including the gas pocket portion 12 is removed. . The pressure within chamber 40 may be less than atmospheric pressure, and in this embodiment is substantially a vacuum.

After that, in the resealing step S4 shown in FIG. 2, the internal pressure of the work 10 is lowered while the laminate portion 11 is pressed against the reference surface 50a as shown in FIGS. 10(a) and 10(b). In this state, the boundary portion 12a between the laminate portion 11 and the gas pocket portion 12 is sealed. As a result, the exterior body 102 released by the perforations 60a is resealed. The sealing of the boundary portion 12a is performed by a thermal welding device 70. As shown in FIG. As shown in FIG. 10(b), the thermal welding device 70 heats the boundary portion 12a while pressing it in the thickness direction Y to thermally weld the exterior body 102. As shown in FIG. Thereby, a resealing portion 70 a is formed between the laminate portion 11 and the gas pocket portion 12 . Then, as shown in FIG. 11, a cutter 80 is used to cut above the resealing portion 70a to remove the gas pocket portion 12 from the laminate portion 11. As shown in FIG. After that, a confirmation test of the sealed state is performed, and the device that has been confirmed to have a good sealed state is completed as the electricity storage device 100 shown in FIG. 1(a).

Next, the effects of the manufacturing method 1 of the electricity storage device 100 of the present embodiment will be described in detail.
According to the manufacturing method 1 of the electricity storage device 100 of the present embodiment, the pressed state in which at least a part of the laminate portion 11 is pressed against the reference surface 50a is maintained from the degassing step S3 to the resealing step S4. Therefore, it is possible to suppress the deformation of the laminate part 11 from degassing in the exterior body 102 to resealing. As a result, it is possible to reduce variations in the thickness dimension of the completed electricity storage device 100 and prevent breakage of the metal foil forming the electrodes and the like in the exterior body 102, thereby improving manufacturing quality.

Further, in the present embodiment, in the degassing step S3, at least a portion of one surface 11a of the laminate portion 11 is brought into contact with the reference surface 50a, and at least a portion of the other surface 11b of the laminate portion 11 is applied. By pressing the pressing surface 51a, the pressing state is brought about. As a result, since the laminate portion 11 is sandwiched between the reference surface 50a and the pressure surface 51a, deformation of the thickness due to expansion of the laminate portion 11 can be suppressed, and variations in the thickness dimension of the electric storage device 100 can be suppressed. can be further reduced, and damage to the metal foil in the exterior body 102 can be further prevented, thereby further improving manufacturing quality.

Further, in the present embodiment, in the degassing step S3, the work 10 is supported at a predetermined position on the stage 20 by the support portion 30 standing up from the stage 20, and the reference surface 50a is positioned at a predetermined position with respect to the support portion 30. to bring it into the pressed state. As a result, the workpiece 10 is positioned at a predetermined position by the support portion 30 and the reference surface 50a, and the thickness of the laminate portion 11 can be easily managed to a predetermined size, so that the thickness dimension of the electric storage device 100 is reduced. can be further reduced, and breakage of the metal foil in the exterior body 102 can be further prevented, thereby further improving manufacturing quality.

Further, in the present embodiment, in the degassing step S3, the pressurizing surface 51a is pressed against at least a part of the other surface 11b of the laminate portion 11 with a predetermined target load so as to be in the pressed state. This makes it easier to control the load applied to the laminate section 11, and prevents excess or deficiency of the load, thereby further improving the manufacturing quality.

Further, in the present embodiment, the workpiece 10 has a current collecting tab 14 that is connected to the outer edge of the laminate 101 and protrudes outward from the exterior body 102. The reference surface 50a is positioned at a predetermined position with respect to the support portion 30 so as to be positioned on the center line 11c in the thickness direction of the support member 11, and the pressing state is set. As a result, peeling of the current collecting tab 14 and deformation of the current collecting tab 14 can be prevented, and the manufacturing quality can be further improved.

Further, in the present embodiment, the workpiece 10 has a first side portion 10a provided with the gas pocket portion 12 and a second side portion 10a located on the opposite side of the first side portion 10a on the outer periphery of the laminate portion 11. a side portion 10b, a third side portion 10c provided with a current collecting tab 14, and a fourth side portion 10d located on the opposite side of the third side portion 10c. It has sides. The support portion 30 has a slit-shaped space portion which is erected above the stage 20 in the vertical direction Z, and a first support portion 31 and a second support portion 31 and a second support portion 31 which are horizontally separated from each other. and a support portion 32 of . Then, in the degassing step S3, the work 10 is positioned so that the first side portion 10a is positioned above the vertical direction Z, and the second side portion 10b is positioned below the vertical direction Z, so that the work 10 is positioned on the second side. At least part of the side portion 10b abuts on the stage 20, the third side portion 10c is loosely fitted on the first support portion 31, and the fourth side portion 10d is on the second support portion 32. It is supported by the support portion 30 in a loosely fitted state. Accordingly, the workpiece 10 can be accurately and easily positioned in the thickness direction Y and the vertical direction Z simply by setting the workpiece 10 on the support portion 30 . When the reference surface 50a and the pressure surface 51a are misaligned with respect to the workpiece 10 and the current collecting tab 14, the metal foil in the exterior body 102 is likely to be damaged. , the manufacturing quality can be further improved.

Further, in the present embodiment, in the degassing step S3, the entirety of the third side portion 10c, which is the side portion of the laminate portion 11 from which the current collecting tab 14 protrudes, is pressed. When the area where the current collecting tab 14 is connected and the surrounding area in the laminate part 11 are deformed, stress is generated in the current collecting tab 14 by the deformation, and the current collecting tab 14 is deformed or the current collecting tab 14 is laminated. Although there is a risk of peeling from the body 101, by adopting this configuration, deformation and peeling of the current collecting tab 14 can be effectively suppressed, and the manufacturing quality can be further improved.

Furthermore, in this embodiment, in the degassing step S3, the entire area of the laminate portion 11 is pressed. As a result, deformation is effectively suppressed in the entire area of the laminate portion 11, so that it is possible to further improve the manufacturing quality of the entire power storage device 100 while effectively suppressing deformation and peeling of the current collecting tab 14. can.

As described above, according to the present embodiment, it is possible to provide the method 1 for manufacturing the electric storage device 100 that improves manufacturing quality.

The present invention is not limited to the above embodiments and modifications, and can be applied to various embodiments without departing from the scope of the invention.

1: Electric storage device manufacturing method, 10: Work, 10a to 10d: Side part, 11: Laminate part, 12: Gas pocket part, 12a: Boundary part, 14: Current collecting tab, 20: Stage, 30: Support Section 31: First Support Section 32: Second Support Section 50: Reference Plate 50a: Reference Surface 51: Pressing Plate 51a: Pressing Surface 52: Load Control Unit 60: Perforation Degassing Device , 61: drilling nozzle part, 70: thermal welding device, 70a: resealing part, 80: cutter, 100: electricity storage device, 101: laminated body, 102: exterior body

Claims (8)

In a method for manufacturing an electricity storage device, wherein a laminate obtained by laminating a sheet-like positive electrode and a negative electrode together with a separator is enclosed in a film-like exterior body,
A work in which the laminate is enclosed in the exterior body, and includes a laminate portion in which the exterior body and the laminate overlap in a thickness direction, and the exterior body extends outward from the outer edge of the laminate portion. an initial charging/discharging step of performing initial charging/discharging on a workpiece having a gas pocket portion configured to extend and store gas generated inside the exterior body;
After the initial charging/discharging step, in a pressed state in which at least part of the laminate portion is pressed against a reference surface, the gas pocket portion is opened to reduce the internal pressure of the work, thereby removing the gas from the work. a degassing process;
a resealing step of sealing a boundary portion between the laminate portion and the gas pocket portion while maintaining the pressed state and the state in which the internal pressure of the work is reduced;
A method of manufacturing an electricity storage device comprising: In the degassing step, at least a portion of one surface of the laminate portion is brought into contact with the reference surface, and a pressing surface is pressed against at least a portion of the other surface of the laminate portion, thereby removing the pressed state. The method for manufacturing an electricity storage device according to claim 1, wherein 3. In the degassing step, the workpiece is supported at a predetermined position on the stage by a support section rising from the stage, and the reference plane is positioned at a predetermined position with respect to the support section to be in the pressing state. 3. The method for manufacturing the electricity storage device according to 1. 4. The method of manufacturing an electricity storage device according to claim 3, wherein in the degassing step, the pressurized surface is brought into the pressed state by pressing the pressurized surface against at least a part of the other surface of the laminate portion with a predetermined target load. The work has a current collecting tab connected to the outer edge of the laminate and protruding outward from the exterior body,
In the degassing step, the reference surface is positioned at a predetermined position with respect to the support portion so that the current collecting tab is positioned on the center line in the thickness direction of the laminate portion to be in the pressed state. Item 5. A method for manufacturing an electricity storage device according to Item 3 or 4. The workpiece includes a first side portion provided with the gas pocket portion, a second side portion located on the opposite side of the first side portion, and the having four side portions, each of which includes a third side portion provided with a current collecting tab and a fourth side portion located on the opposite side of the third side portion;
The support section has a slit-shaped space which stands vertically upward from the stage, and has a first support section and a second support section which are horizontally separated from each other. death,
In the degassing step, the work has the first side portion positioned vertically upward, the second side portion positioned vertically downward, and at least one of the second side portions. part abuts the stage, the third side part is loosely fitted to the first support part, and the fourth side part is loosely fitted to the second support part. The method for manufacturing an electricity storage device according to claim 5, wherein the electricity storage device is supported by the support portion. 7. The method of manufacturing an electricity storage device according to claim 5, wherein in the degassing step, the entire side portion of the laminate portion on the side from which the current collecting tab protrudes is brought into the pressed state. 8. The method for manufacturing an electricity storage device according to claim 1, wherein in the degassing step, the entire area of the laminate portion is brought into the pressed state.

Images