JP2002075323A - Secondary battery and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery capable of obtaining a high output by reducing an internal resistance, and its manufacturing method capable of easily assembling the battery without deforming component parts. SOLUTION: The opening part of an armoring can 27 is sealed by a filter 28 forming a first sealing member integrally combined with a positive electrode collector plate 25 and disposed at the opening part of the armoring can 27 through a gasket 33 of an insulating member, and a spacer 31 forming a second sealing member combined with the filter 28 together with an explosion-proof valve body 30 of an explosion-proof means to exhaust internal gas in response to the rise of an internal pressure through an O-ring 29 of a sealing means, and an elastic bonding piece 26b provided on the negative electrode collector plate 26 is bonded to the inner bottom surface of the armoring can 27. Thereby, the output of the battery is increased by reducing its internal resistance, and the battery can be assembled without deforming component parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery in which positive and negative electrode plates are wound around a separator and an electrode group is housed in an outer can together with an electrolytic solution, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, electronic devices have been rapidly becoming smaller and lighter.
Demands for weight reduction and high capacity are increasing. In addition, due to global environmental issues, expectations for electric vehicles are increasing, and there is a demand for smaller and lighter batteries with higher capacity and higher output. In response to these demands, development of lithium ion secondary batteries has been actively carried out.

The structure of a conventional secondary battery will be described below.

In FIG. 5 showing the structure of a conventional lithium ion secondary battery, reference numeral 1 denotes a positive electrode current collector 2b and a positive electrode material 2a.
Negative electrode material 3a on the positive electrode plate 2 and the negative electrode current collector 3b coated with
Is a group of electrode plates in which a negative electrode plate 3 coated with is wound spirally via a separator 4. Reference numerals 5 and 6 denote a positive electrode current collector plate and a negative electrode current collector plate joined to both end surfaces of the electrode plate group 1. A positive electrode tab 5a is welded to the positive electrode current collector plate 5.

[0005] The electrode group 1 is accommodated in an outer can 7 together with an electrolytic solution, and the negative electrode current collector plate 6 is resistance-welded to the inner bottom surface of the outer can 7 so that the outer can 7 becomes a negative electrode terminal of the battery. Numeral 8 denotes a filter having a hole 8a in the center, into which an O-ring 9, an explosion-proof valve body 10, a spacer 11, and a cap 12 are inserted, and a caulking portion 8b on the outer periphery is caulked and integrated. Here, the explosion-proof valve body 10 is a thin film made of aluminum foil. When the battery internal pressure rises to a predetermined pressure or more, the explosion-proof valve body 10 breaks through the hole 11a of the spacer 11 to discharge gas inside the battery to the outside. It is configured. This filter 8 has a positive electrode tab 5
is welded, and the current from the electrode plate group 1 is supplied to the cap 12 from the caulked portion 8b of the filter 8, and the cap 12 becomes a positive electrode terminal of the battery.

Reference numeral 13 denotes a gasket interposed between the outer can 7 and the filter 8. The gasket 13 insulates the two and has a sealing function by caulking the opening of the outer can 7 so as to sandwich the filter 8. are doing.

Next, a method of manufacturing the secondary battery having the above configuration will be described. First, in manufacturing the electrode group 1,
The positive electrode plate 2, the separator 4, and the negative electrode plate 3 are slightly shifted up and down and wound, for example, so that the positive electrode current collector 2 b of the wound positive electrode plate 2 projects at the upper end side, and The negative electrode current collector 3b of the wound negative electrode plate 3 is made to protrude. The positive electrode current collecting plate 5 to which the positive electrode tab 5a is previously joined by welding is welded to the upper end surface of the electrode plate group 1 thus configured, and the negative electrode current collecting plate 6 is welded to the lower end surface. At this time, the positive electrode tab 5a welded to the positive electrode current collector plate 5 is in a straight state as shown in FIG.

Next, as shown in FIG. 6, the electrode plate group 1 is accommodated in an outer can 7, and the negative current collector plate 6 and the inner bottom surface of the outer can 7 are resistance-welded. At this time, the welding electrode 14a is inserted from the space 1a of the core portion of the electrode plate group 1, and a current flows between the electrode 14b and the electrode 14b in contact with the outer bottom surface of the outer can 7, thereby performing resistance welding. Thereafter, the exterior can 7 containing the electrode plate group 1 is subjected to plastic working using a jig or the like so that the groove 7a is disposed at a position below the opening 7b by an appropriate distance.

Next, a positive electrode tab 5a is provided at a predetermined position of the filter 8 in which the O-ring 9, the explosion-proof valve body 10, the spacer 11, and the cap 12 are integrated, and the gasket 13 is fitted on the outer periphery. Welded. In this state, a predetermined amount of the electrolyte is injected from the opening of the outer can 7. afterwards,
While deforming the positive electrode tab 5a as shown in FIG.
The gasket 13 and the gasket 13 are fitted over the groove 7a of the outer can 7, and the opening 7b of the outer can 7 is swaged as shown in FIG. 5 to complete the secondary battery.

[0010]

However, in the above-described conventional configuration, when the filter 8 and the positive electrode tab 5a are welded, the positional relationship between the electrode plate group 1, the outer can 7, and the filter 8 is determined.
As shown in FIG. 6, the positive electrode tab 5a requires a predetermined length.
When the filter 8 and the gasket 13 are fitted and arranged on the upper portion of the groove 7a of the outer can 7, the deformation of the positive electrode tab 5a is inevitably blind work, so that the shape of the positive electrode tab 5a after the deformation is changed. It was difficult to properly define.

When a high-power battery is required, reducing the internal resistance of the battery is an effective means. However, the predetermined length of the positive electrode tab 5a increases the internal resistance of the battery. Further, if the width and thickness of the positive electrode tab 5a are increased to reduce the internal resistance, the strength of the positive electrode tab 5a is increased, and the deformation becomes difficult. Furthermore, when a large force acts on the welding point between the positive electrode tab 5a and the filter 8 due to the deformation operation, the welding may be removed, leading to a deterioration in the quality of the battery.

Further, as described above, since the current from the electrode plate group 1 is supplied to the cap 12 from the caulked portion 8b of the filter 8, the connection is established by contact and the contact resistance increases the internal resistance of the battery. Had a point.

The present invention solves the above-mentioned conventional problems. The battery can be assembled without deforming the components such as the positive electrode tab, so that the battery can be easily manufactured, and the internal resistance is reduced to increase the output. An object is to provide a secondary battery obtained and a method for manufacturing the same.

[0014]

The secondary battery according to the first invention of the present invention comprises an outer can serving as one electrode terminal, an electrode group formed by winding positive and negative electrodes through a separator, and an electrode plate. The electrolytic solution impregnated inside the group, the positive and negative electrode current collectors bonded to both end surfaces of the electrode group, and integrally fixed to one of the positive and negative electrode current collectors and the outer can A first sealing member disposed at the opening via an insulating member; and a second sealing member fixed to the first sealing member via a sealing means together with explosion-proof means for discharging internal gas in response to an increase in internal pressure. The current collector plate not joined to the first sealing member has an elastic joint piece and is joined to the inner bottom surface of the outer can with a predetermined gap through the elastic joint piece. It is possible to assemble the battery without deforming parts such as the positive electrode tab. It becomes easy, and reduces the internal resistance can be increased output of the battery, a secondary battery of a high output with a reduced internal resistance.

A secondary battery according to a second aspect of the present invention includes an outer can serving as a negative electrode terminal, an electrode group formed by winding positive and negative electrodes through a separator, an electrolytic solution impregnated inside the electrode group, and an electrode. Positive and negative electrode current collectors joined to both end surfaces of the plate group; a first sealing member connected to the positive electrode current collector and disposed at the opening of the outer can via an insulating member; A second sealing member fixed to the first sealing member via sealing means together with explosion-proof means for discharging internal gas in accordance with the rise,
The second sealing member is formed of a clad material made of at least two or more kinds of dissimilar metals in which the metal facing the first sealing member is the same type of metal, and the first and second sealing members. As a result, the same type of metal is welded to each other, so that the internal resistance can be reduced and the output of the battery can be increased.

In the above secondary battery, when the outer can is plastically deformed so that the diameter of the opening is larger than that of the other part before the assembling and is substantially the same as the diameter of the other part after the assembling, the insulating can be insulated by the insulating member. And the seal can be secured by inexpensive means.

In the method of manufacturing a secondary battery according to a third aspect of the present invention, an outer can serving as one of the electrode terminals, an electrode group formed by winding positive and negative electrodes through a separator, and the inside of the electrode group is impregnated. An electrolytic solution, a positive and negative electrode current collector bonded to both end surfaces of the electrode plate group, and one of the positive and negative electrode current collectors connected via an insulating member to an opening of the outer can. A secondary battery comprising: a first sealing member provided as described above; and a second sealing member fixed to the first sealing member via sealing means together with explosion-proof means for discharging internal gas in response to an increase in internal pressure. After bonding the positive and negative electrode current collectors to both end surfaces of the electrode group and connecting the first sealing member to one of the current collectors, inserting the electrode group into an outer can Then, the other current collector plate is joined to the bottom surface of the outer can, and the electrolytic solution is placed through a hole provided in the first sealing member. After the amount injected is intended to fix the second sealing member in a first sealing member through the sealing means,
The battery can be assembled without deforming parts for connecting the current collector plate and the sealing member by blind work, thereby facilitating manufacture.

[0018] In addition, an outer can is used in which the portion into which the insulating member is inserted has a larger diameter than the other portions. After the second sealing member is fixed to the first sealing member, the opening of the outer can is opened. When the large-diameter portion is plastically deformed to approximately the diameter of the other portion after caulking the portion, insulation and sealing can be reliably performed by inexpensive means.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which a secondary battery of the present invention is applied to a lithium ion battery will be described below with reference to FIGS.

In FIG. 1 showing the configuration of the secondary battery of the present embodiment, reference numeral 1 denotes an electrode group, which has the same configuration as that described in the conventional example. The positive electrode plate 2 and the negative electrode plate 3 will be described in detail. The positive electrode current collector 2b is made of aluminum foil, and the positive electrode plate 2 is formed by applying a positive electrode material 2a containing a positive electrode active material and a binder on both surfaces thereof. As the positive electrode active material,
LiCoO ₂ , LiMn ₂ O ₄ , LiNiO _{2 and the} like are used. The negative electrode current collector 3b is made of copper foil, and a negative electrode plate 3 is formed by applying a negative electrode material 3a containing a negative electrode active material and a binder on both surfaces thereof, and the negative electrode active material is graphite, petroleum oil, or the like. Carbonaceous materials such as cokes and carbon fibers are used.

Reference numerals 25 and 26 denote a positive electrode current collector and a negative electrode current collector joined to both ends of the electrode plate group 1, respectively. The positive electrode current collector plate 25 has a projection 25a formed on the upper surface around the center and a hole 25b formed at the center. A hole 26a is formed at the center position of the negative electrode current collector plate 26, and an elastic joint piece 26b is provided at one end of the negative electrode current collector plate 26 so as to be bent substantially 180 degrees and extend to a position where the tip end faces the hole 26a. I have.

Reference numeral 27 denotes an outer can, and a predetermined section of the opening 27a has a larger diameter than other portions. 28
Is a filter made of aluminum or an aluminum alloy as a first sealing member. A hole 28a is formed at a central position, and a hole 28b that fits with the projection 25a of the positive electrode current collector 25 is formed around the hole 28a. ing. 29 is an O-ring as sealing means, 30 is an explosion-proof valve body made of aluminum foil as explosion-proof means, and 31 is a spacer as a second sealing member. In the spacer 31, the member 31b on the surface facing the filter 28 is the same aluminum or aluminum alloy as the filter 28, and the member 31c on the other surface is the same nickel or iron as the cap 32 described later, or an alloy thereof, It is made of a clad material which is bonded by cold pressure welding. If the internal pressure of the battery rises above a predetermined value, the explosion-proof valve body 30 is inserted into a hole 31 a formed in the center of the spacer 31.
The gas in the battery is further broken and the gas inside the battery is discharged to the outside. Reference numeral 32 denotes a cap serving as a positive electrode terminal of the battery. This cap 3
When the battery is used as an assembled battery, it is made of nickel, iron, or an alloy thereof so that the connection plate (not shown) is often welded and the welding is easy. . Reference numeral 33 denotes a gasket serving as an insulating member, and reference numeral 35 denotes an insulating plate.

Next, a method of manufacturing the secondary battery having the above configuration will be described. The electrode plate group 1 is manufactured in the same manner as in the description of the conventional example, and includes the positive electrode plate 2, the separator 4, and the negative electrode plate 3.
Are wound slightly up and down, respectively, so that, for example, the positive electrode current collector 2b of the wound positive electrode plate 2 protrudes toward the upper end side, and the negative electrode current collector 2b of the wound negative electrode plate 3 projects toward the lower end side. The electric body 3b is made to protrude. Since the positive electrode current collector 2b is an aluminum foil on the upper end surface of the electrode plate group 1, a positive electrode current collector plate 25 made of aluminum or an aluminum alloy is welded to the lower end surface thereof. . next,
With the filter 28 inserted in the gasket 33, the filter 28 is placed on the positive electrode current collector plate 25, and the projections 25a of the positive electrode current collector plate 25 are fitted into the holes 28b, and laser welding is performed from the upper portion, thereby collecting the positive electrode current. It is fixed integrally with the plate 25.

Next, as shown in FIG. 2, the electrode plate group 1 to which the filter 28 is integrally fixed is inserted into the outer can 27 together with the gasket 33, and the elastic joining piece 26b of the negative electrode current collector plate 26 is inserted.
And the inner bottom surface of the outer can 27 are joined by resistance welding. At this time, as shown in FIG. 3, the welding electrode 34a is connected to the hole 28a at the center of the filter 28, the hole 25b of the positive electrode current collector 25,
The space 1a of the core part of the electrode plate group 1 and the hole 2 of the negative electrode current collector plate 26
6a and comes into contact with the elastic joining piece 26b. Then, a current is applied between the electrode 34b in contact with the outer bottom surface of the outer can 27, and the outer can 27 is joined by resistance welding.

Next, a predetermined amount of an electrolytic solution is injected from the hole 28a of the filter 28 to impregnate the inside of the electrode plate group 1. In addition, as this electrolyte, as a solute, lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ),
Lithium salts such as lithium borofluoride (LiBF ₄ ),
Ethylene carbonate (EC), propylene carbonate (PC), diethylene carbonate (DE
C), a non-aqueous solvent such as ethylene methyl carbonate (EMC) or the like is used, and a solute dissolved in this solvent is used.

After that, the O-ring 29 and the explosion-proof valve body 30 made of aluminum foil are arranged at predetermined positions of the filter 28. A cap 32 made of nickel, iron, or an alloy thereof is resistance-welded in advance to a member 31c made of nickel, iron, or an alloy thereof of the spacer 31, and the cap 32 is overlapped on the explosion-proof valve body 30 of the filter 28, The spacer 31 and the filter 28 are laser-welded at the position A in FIG. 1 while pressing with a jig or the like, and the filter 28 as the first sealing member and the spacer 31 as the second sealing member are fixed. Further, sealing is performed by an O-ring 29 interposed between the two. At this time, the laser is irradiated from the member 31c side of the spacer 31, and the heat thereof causes the member 31b made of aluminum or aluminum alloy, the explosion-proof valve body 30 made of aluminum foil,
The welding is completed by melting the filter 28 made of aluminum or aluminum alloy.

Next, after attaching the insulating plate 35, the outer can 2
7 is swaged as indicated by arrow B. At this time, since the gasket 33 is fitted to the large diameter portion of the outer can 27, the gasket 33 is fixed by being received at the diameter change portion C.

In this state, the negative electrode current collector plate 26 is formed by connecting the elastic joining pieces 26 b by being bent substantially 180 degrees, so that the negative electrode current collector plate 26 is provided between the surface welded to the electrode group 1 and the inner bottom surface of the outer can 27. Is located in a state where the gap H exists. Due to the gap H and the elasticity of the elastic joining pieces 26b, even when the positions of the gasket 33 and the filter 28 and the width of the electrode plate group 1 vary, it is possible to absorb variations, and unnecessary load is applied to the electrode plate group 1. I will not give.

Next, as shown in FIG. 4, the secondary battery manufactured as described above is pressed in the direction of arrow D and passed through a diameter reducing jig 36 so that the large-diameter portion of the outer can 27 is removed. It is plastically deformed to almost the diameter of other parts. At this time, gasket 33
Is the outer can 27 and the filter 2
8 to insulate the outer can 27 and the filter 28 and have a sealing function.

As described above, according to this embodiment, the outer can 27 serving as the negative electrode terminal and the positive / negative plates 2 and 3 are
, A positive electrode current collector 25 and a negative electrode current collector 26 joined to both end surfaces of the electrode group 1, and an electrolytic solution impregnated inside the electrode group 1. A filter 28 serving as a first sealing member, which is integrally fixed to the positive electrode current collector plate 25 and disposed at an opening of the outer can 27 via a gasket 33 serving as an insulating member, An explosion-proof valve body 30 as an explosion-proof means for discharging gas and a spacer 31 as a second sealing member fixed to a filter 28 via an O-ring 29 as a sealing means. Since the joining piece 26b is joined to the inner bottom surface of the outer can 27 with a predetermined gap H, parts such as a positive electrode tab for connecting the positive electrode current collector and the filter can be eliminated, and the output of the battery can be reduced due to a decrease in internal resistance. Can be increased.

Further, since the spacer 31 is made of a clad material made of at least two kinds of different metals in which the metal facing the filter 28 is the same kind of metal,
The same kind of metal can be welded, thereby reducing the internal resistance and increasing the output of the battery.

The positive and negative electrode current collectors 25 and 26 are joined to both end surfaces of the electrode group 1, and the filter 2 is attached to the positive electrode current collector 25.
8, the electrode group 1 is inserted into the outer can 27, the elastic joining piece 26 b of the negative electrode current collector 26 is welded to the bottom of the outer can 27, and the electrolytic solution is passed through a hole 28 a provided in the filter 28. After the injection of a predetermined amount, the spacer 31 is fixed to the filter 28, thereby assembling the battery without deforming the components such as the positive electrode tab for connecting the positive electrode current collector plate and the filter by blind work. It is easy to manufacture, and at the same time, the quality can be improved.

The portion of the outer can 27 into which the gasket 33, which is an insulating member, is inserted has a larger diameter than the other portions. After the spacer 31 is fixed to the filter 28, the opening of the outer can 27 is opened. After caulking, the large-diameter portion is plastically deformed to almost the diameter of the other portion, whereby reliable insulation and sealing can be achieved by inexpensive means.

In the above description, the explosion-proof valve body 30 which is an explosion-proof means for discharging the internal gas in accordance with the rise of the internal pressure.
Is a single component made of aluminum foil, but the spacer 31 serving as the second sealing member may be a clad material formed by cold pressing including the aluminum foil.

In the above description, the filter 28 is on the positive electrode side and the outer can 27 is on the negative electrode side.
The filter 28 may be on the negative electrode side and the outer can 27 may be on the positive electrode side. In that case, the outer can 27 is made of aluminum or an aluminum alloy.

[0036]

According to the secondary battery of the present invention, the positive and negative electrode current collectors are joined to both end surfaces of the electrode plate group as described above, and either one of the positive and negative electrode current collectors is connected to one of the positive and negative electrode current collectors. Integrally first
Explosion-proof means for fixing the first sealing member, disposing the first sealing member at the opening of the outer can via an insulating member, and discharging the first gas to the first sealing member in response to an increase in internal pressure. At the same time, the second sealing member is fixed via the sealing means, and the current collector plate which is not joined to the first sealing member has an elastic joining piece, and is attached to the inner bottom surface of the outer can through the elastic joining piece. Since the bonding is performed with a predetermined gap, the battery can be assembled without deforming parts such as the positive electrode tab that connects the positive electrode current collector plate and the sealing member. Therefore, the internal resistance can be reduced to increase the output of the battery, and a high-output secondary battery with reduced internal resistance can be obtained.

Further, when the second sealing member is made of a clad material made of at least two or more kinds of different metals in which the metal facing the first sealing member is the same kind of metal, the first and second sealing members are formed. Welding of the same kind of metal with the sealing member,
The internal resistance can be reduced and the output of the battery can be increased.

In the above secondary battery, if the outer can is plastically deformed such that the diameter of the opening before assembly is larger than that of the other parts and becomes substantially the same diameter as the other parts after assembly, insulation by the insulating member is achieved. And the seal can be secured by inexpensive means.

According to the method of manufacturing a secondary battery of the present invention, the positive and negative electrode current collectors are joined to both end surfaces of the electrode group, and then the first sealing member is connected to one of the current collectors. After doing
The electrode group is inserted into the outer can, the other current collector is joined to the bottom surface of the outer can, and after injecting a predetermined amount of electrolyte through a hole provided in the first sealing member, the second sealing member is removed. Since the battery is fixed to the first sealing member via the sealing means, the battery can be assembled without deforming parts for connecting the current collector plate and the sealing member by blinding, thereby facilitating manufacture.

Further, after using the outer can having the portion where the insulating member is inserted having a diameter larger than that of the other portions, the second sealing member is fixed to the first sealing member, and then the opening of the outer can is opened. When the large-diameter portion is plastically deformed to approximately the diameter of the other portion after caulking the portion, insulation and sealing can be reliably performed by inexpensive means.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a secondary battery according to an embodiment of the present invention.

FIG. 2 is a perspective view of a manufacturing process of the secondary battery of the embodiment.

FIG. 3 is a longitudinal sectional view of a subsequent manufacturing process of the secondary battery according to the embodiment.

FIG. 4 is a longitudinal sectional view of a subsequent manufacturing process of the secondary battery of the embodiment.

FIG. 5 is a longitudinal sectional view of a conventional secondary battery.

FIG. 6 is a longitudinal sectional view of a manufacturing process of a conventional secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode group 2 Positive electrode plate 3 Negative electrode plate 4 Separator 25 Positive current collector 26 Negative current collector 26b Elastic joining piece 27 Outer can 28 Filter (first sealing member) 29 O-ring (sealing means) 30 Explosion-proof valve ( Explosion-proof means) 31 Spacer (second sealing member) 33 Gasket (insulating member)

Continued on the front page F term (reference) 5H011 AA09 CC06 DD11 DD15 FF02 GG02 HH02 JJ11 5H012 AA01 BB02 CC01 DD04 EE01 GG01 5H022 AA09 CC12 CC13 CC30 EE01 EE09 5H029 AJ06 AJ12 AK03 AL07 AM03 AM05 DJ07 BJ01 DJ02

Claims (5)

[Claims] 1. An exterior can serving as one electrode terminal, an electrode group formed by winding positive and negative electrodes through a separator, an electrolyte impregnated inside the electrode group, and both end surfaces of the electrode group And a first sealing member integrally fixed to one of the positive and negative electrode current collector plates and disposed at an opening of the outer can via an insulating member. And a second sealing member fixed to the first sealing member via sealing means together with explosion-proof means for discharging the internal gas in response to an increase in the internal pressure, and joined to the first sealing member. A secondary battery, characterized in that the current collecting plate having no one has an elastic joining piece and is joined to the inner bottom surface of the outer can with a predetermined gap through the elastic joining piece. 2. An exterior can serving as a negative electrode terminal, an electrode group formed by winding positive and negative electrodes through a separator, an electrolyte impregnated inside the electrode group, and joined to both end surfaces of the electrode group. Current collector plates of the positive electrode and the negative electrode, a first sealing member connected to the positive electrode current collector plate and disposed at an opening of the outer can via an insulating member, and an internal gas of A second sealing member fixed to the first sealing member via sealing means together with explosion-proof means for discharging, wherein the second sealing member is made of the same type of metal as opposed to the first sealing member. A secondary battery comprising a clad material made of at least two or more different kinds of metals. 3. The outer can according to claim 1 or 2, wherein the outer can is plastically deformed so that the diameter of the opening before assembly is larger than that of the other portion, and is substantially the same as that of the other portion after assembly. Rechargeable battery. 4. An exterior can serving as one of the electrode terminals, an electrode group formed by winding positive and negative electrodes through a separator, an electrolyte impregnated inside the electrode group, and both end surfaces of the electrode group. A first sealing member connected to one of the positive and negative electrode current collecting plates, and a first sealing member disposed at an opening of the outer can via an insulating member; A method for manufacturing a secondary battery comprising: an explosion-proof means for discharging an internal gas in response to a rise in pressure; and a second sealing member fixed to a first sealing member via a sealing means, comprising: After connecting the first sealing member to one of the current collector plates after joining the positive and negative current collector plates to both end surfaces of the negative electrode, the electrode plate group is inserted into the outer can, and the other current collector plate is connected to the outer can. After a predetermined amount of electrolyte is injected from a hole provided in the first sealing member,
A method for manufacturing a secondary battery, comprising: fixing a second sealing member to a first sealing member via sealing means. 5. An outer can having a portion into which an insulating member is inserted having a diameter larger than that of another portion, and a second sealing member is fixed to the first sealing member. 5. The method for manufacturing a secondary battery according to claim 4, wherein after the portion is caulked, the large-diameter portion is plastically deformed to substantially the diameter of another portion.