JPH11312509A - Wound electrode type battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance an energy volume density by connecting leads from a electrode body with a simple means without a welding process for save space for the leads in a current collecting processing part. SOLUTION: This wound electrode type battery has an electrode body 10 wound spirally with band-shaped positive and negative electrodes having active materials formed in surfaces of their current correcting bodies, and with a separator sandwiched between the positive and negative electrodes. Plural rectangular leads 14 are formed extended from one end part to be a winding end face of the electrode body 10 in at least one of the positive and negative electrodes to a winding center axis direction of the electrode body 10. A bolt 20 and a nut 30 are arranged in the winding end face of the electrode body 10 so as to sandwich and hold the leads 14 to be collected toward the winding center of the electrode body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode-wound battery having a large energy volume density and a reduced connection space by a simple method.

[0002]

2. Description of the Related Art A cylindrical battery such as a lithium ion secondary battery is formed by forming an electrode active material such as a carbon material or a lithium-containing metal oxide on the surface of a strip-shaped metal foil current collector such as copper or aluminum. A strip-shaped electrode, and the electrode body is formed by spirally winding this electrode via a separator,
This electrode body is stored in a cylindrical case. Hereinafter, such a battery is referred to as an electrode wound battery (spiral battery).

[0003] In a wound electrode type battery, a method of collecting current from the electrode body to the external terminal is generally performed by a plurality of strip-shaped leads (tabs) provided on the current collector. This lead is usually a strip of the same metal as the current collector, and is connected to one end in the width direction of the current collector on which the electrode active material is not formed by means of ultrasonic bonding, resistance welding, or the like. Are joined. Since the thickness of the lead is limited by the thickness of the active material, a thickness of several tens μm or less is often used.
The width of the lead is several mm because the electrode is wound.
It is often suppressed below. As for the number of leads, one having a current capacity of about 1 Ah is sufficient for each of the positive electrode and the negative electrode, but in the case of a relatively large battery having a current capacity of several tens to several hundreds Ah, it is possible to reach every corner of the electrode. It is necessary to join a plurality of leads at regular intervals to some extent over the entire length of the current collector so that charge and discharge occur uniformly without waste. FIG. 1 shows a state in which the electrode to which the lead is joined is wound, and FIG. 2 shows a state of the electrode body after the winding.

When such an electrode assembly is housed in a battery case and a plurality of leads extending from random positions on the winding end surface of the electrode assembly are to be directly connected to one external terminal provided on the battery case, FIG. As shown in (1), each lead has a complicated ribbon shape, and the distance from the winding end face of the electrode body to the external terminal must be considerably large. This results in an increase in the volume of the battery itself as compared to the electrode body, leading to a decrease in the energy density of the battery.

The following techniques are known as conventional techniques for solving this problem. (1) As shown in JP-A-9-92338, a strip-shaped lead is collected on the outer periphery of a disk-shaped terminal component, fixed with a ring from the outside, and the fixed portion is welded by means such as laser welding. . This method is shown in FIG. (2) As shown in Japanese Patent Application Laid-Open No. 9-35201, a hole is drilled at the tip of the lead or a U-shaped cut is made. It is a method of fixing with nuts. This method is described in FIG.
Shown in

[0006]

The above prior arts have achieved certain results in terms of improving the energy volume density of batteries, but at the same time have the following major drawbacks. In the method of fixing with the ring in the above (1), the force of holding the lead is not sufficient with the force of the ring alone, and it is necessary to weld the lead to the terminal and the ring. In order to perform this welding well, it is necessary to eliminate the excess lead protruding from the terminal and the ring surface, and therefore, a step of trimming the leads is required before welding. Also, since heat is generated in the welding process, this welding heat is transmitted to the lead,
It is conceivable that the electrode active material or the separator formed on the current collector is adversely affected. Furthermore, in the welding process, the generation of spatter, which is a particular phenomenon, cannot be avoided, and the generated spatter may enter between the wound electrodes and short-circuit the electrodes.

[0007] The method of (2) engaging with a mandrel is advantageous in that leads are connected without welding, but a circular hole or a U-shaped cut is provided at the tip of each lead. It is necessary to start locking from the leads on the inner periphery of the winding, and to sequentially lock the leads on the outer periphery one by one, and further, The lead is short, and it is necessary to increase the length of the lead as it goes to the outer peripheral portion, which is a very laborious operation.

Another problem of the above (2) method of locking to a mandrel is that it cannot be used for a large battery having a hollow mandrel designed in consideration of heat radiation. A large battery has a large amount of internal heat generation during charging and discharging, and it is necessary to quickly release the heat generated inside the electrode body to the outside. For this reason, in a large battery, the mandrel around which the electrode is wound is formed with a large diameter and hollow, the mandrel itself protrudes from the wound end surface of the electrode body, and the hollow portion is passed through the outside of the battery case. I have. Therefore, in the battery of this type, the lead width is smaller than the outer diameter of the mandrel, and it is impossible to form a circular hole or the like to fit the tip of the lead to the mandrel having a large diameter and lock the mandrel to the mandrel. The system cannot be adopted.

In order to solve the above-mentioned problems, the present invention connects the leads from the electrode body by simple means without depending on the welding process, and saves the space of the current collection processing unit by the leads. Another object of the present invention is to provide a wound electrode battery having a large energy volume density. At the same time, the present invention also provides a lead current collecting means which can be applied to a large-capacity and large-sized battery.

[0010]

In order to solve the above-mentioned problems, the present inventor has made various studies, and has extended from the current collector by the tightening force of the bolts and nuts without locking the shafts of the bolts. I came up with a way to pinch the lead that is running.
That is, the present invention provides an electrode having an electrode body formed by spirally winding a band-shaped positive electrode and a negative electrode in which an active material is formed on the surface of a current collector, and a separator sandwiched between the positive electrode and the negative electrode. A wound battery, wherein a plurality of strips are formed so as to extend in a winding central axis direction of the electrode body from one end of the electrode body of at least one of the positive electrode and the negative electrode which is a wound end surface. And a bolt and a nut disposed on the winding end surface of the electrode body and holding the lead toward the center of the winding of the electrode body.

In the wound electrode battery according to the present invention, a thin bolt and nut having a relatively wide flange surface and a thin flange are attached to the wound end surface of the electrode body by separating the flange surface from the electrode body. A lead extending perpendicular to the end face of the electrode body is bent in the winding radial direction, and the lead and nut that work in the direction of the center axis of the winding on a wide flange surface without being locked to the bolt shaft is arranged. It is clamped by the tightening force. By this means, the present wound electrode battery can save the space of the current collecting portion by the lead without depending on the welding process and without necessity of processing the tip of the lead and adjusting the lead length.

Further, the means of the present invention can be applied to a large electrode wound type battery in consideration of heat radiation.
In other words, in the case of a battery having a large-diameter hollow mandrel protruding from the wound end surface of the electrode body at the center of the wound electrode body, the shaft of the bolt is formed in a hollow having an inner diameter larger than the outer diameter of the hollow mandrel, By inserting the hollow mandrel through the shaft of the bolt, it is possible to save the space of the current collecting portion by the lead by means similar to the above-described means.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an electrode of a wound electrode battery according to the present invention and a lead joined to the electrode will be described with reference to the drawings. Note that, from here, a lithium ion secondary battery will be described as an example for convenience. FIG. 1 shows how the electrodes are wound. Positive electrode 11a, negative electrode 11
b is formed by coating the electrode active materials 13a and 13b on the surfaces of the current collectors 12a and 12b, respectively. Usually, the anode current collector 12a such as aluminum is
For b, a band-shaped metal foil such as copper is used. Cathode active material 1
3a is a lithium oxide powder such as lithium cobalt oxide,
The mixture of the conductive agent and the binder is made into a paste, which is applied to the surface of the positive electrode current collector 12a and dried, and the negative electrode active material 13b is a mixture of a carbon material powder such as graphite and the binder. It is applied to the surface of the negative electrode current collector 13b and dried. The thickness of the current collector is about 10 μm, and the thickness of one side of the electrode active material is about 50 to 100 μm. The length of the electrode varies depending on the discharge capacity of the battery, but the electrode having a large discharge capacity has a length exceeding several meters to 10 m.

Leads (tabs) 14a, 14 for current collection
b is a strip-shaped member, which is usually made of the same metal as the current collector, and is made of aluminum or the like for the positive electrode and copper or the like for the negative electrode. The thickness of the lead must not be greater than the thickness of the active material, and is usually about 40 to 70 μm, and the width of the lead is about several mm to 10 mm in consideration of the fact that the electrode itself is wound. Things are adopted. The current collectors 12a and 12b are provided with active material uncoated portions 17a and 17b at one end in the width direction, and the leads 14a and 14b are joined to these portions. As a joining method, any method such as ultrasonic joining, resistance welding, and caulking is possible, but ultrasonic joining is preferable in consideration of heat influence, spatter, workability, and the like. The length of the lead can be arbitrarily set according to the current collection processing method up to the external terminal. Also, the number of leads needs to be increased as the discharge capacity increases, and a large capacity leads to several tens of leads. Furthermore, in order to cause charge and discharge uniformly and without waste to every corner of the electrode, it is necessary to join them at equal intervals to some extent.

The thus formed positive electrode 11a and negative electrode 1
1b are stacked so that the positive electrode lead 14a and the negative electrode lead 14b are on the opposite sides, respectively, with two separators 15a and 15b being insulators, and these are integrally wound around the mandrel 16 in a spiral. . The power generating element in which the positive and negative electrodes and the separator are thus integrally formed is referred to as an electrode body 10. The electrode body 10 is sealed in a battery case together with the electrolyte after performing a current collection process, that is, a connection process to an external terminal. FIG. 2 shows a state of the lead 14 of the electrode body 10 after the electrode winding. The wound electrode body 10 has a plurality of strip-shaped leads extending in the direction of the center axis of the winding from the entire wound end face 18 toward the outside of the electrode body.

Referring to the drawings, embodiments of various systems different from the prior art will be described below with respect to the lead current collecting process which is the main point of the present invention. <First Embodiment> FIG. 3 schematically shows the most basic power collection processing method. A bolt 20 and a nut 30 are provided at positions apart from the winding end surface 18 of the electrode body, and a lead 1 is provided between a flange surface 21 of the bolt and a flange surface 31 of the nut.
4 are sandwiched. Bolt 20 and nut 30
Are thin and flange surfaces 21 and 31 to save space.
Use a wide one. The bolt 20 is attached to the center of the winding end face 18 of the electrode body, and the flange face 21 is connected to the winding end face 18 of the electrode body.
It is arranged almost in parallel with. The lead 14 is folded toward the bolt shaft 22 and is held by the tightening force of the nut 30 acting in the direction of the winding center axis.
In consideration of lead damage and workability during tightening,
It is desirable to insert a washer 40 between the lead 14 and the nut 30. If the bolts 20 and the nuts 30 have a role as terminals, a conductive material can be used for the bolts 20 and the nuts 30. If the lead wire is held together with the lead 14, an insulating material can be used.

With this configuration, it is possible to save the space of the power collection processing unit by a simple method irrespective of welding. Also, unlike the conventional connection method in which a circular hole or the like is formed at the tip of the lead and locked to the bolt shaft, no special processing is required at the tip of the lead, and the length of the lead depends on the position of the lead. There is no need to perform complicated processing such as adjusting Furthermore, since it is sandwiched by a wide flange surface, the contact area of the lead can be widened and the electric resistance can be reduced.

<Second Embodiment> FIG. 4 shows another embodiment of a lead current collection processing system excellent in workability. In this embodiment, the lead 14 is formed to be slightly longer, and the lead 14 gathered toward the bolt shaft 22 is separated from the winding center of the electrode at a position in contact with the bolt shaft 22, that is, radially. Fold it back to the bolt 20 and nut 30
Are sandwiched between the flange surfaces 21 and 31 of FIG.
Since the number of the leads 14 increases in accordance with the length of the electrode 11, it is difficult to sandwich the leads 14 between the bolt 20 and the nut 30 with a large battery. Therefore, before fastening with the nut 30, a method is adopted in which the lead 14 is previously bound to the bolt 20 by the wire (string) 50 and bound to the bolt shaft 22 before fastening with the bolt 20. Thereby, the work for current collection processing becomes extremely easy.

The wire 50 is preferably made of a wire such as aluminum or a string made of ethylene propylene rubber which is electrically inactive at the positive electrode, and a wire made of copper, SUS or the like at the negative electrode. The wire 50 may remain as a part of the battery while remaining in the folded portion of the lead 14 even after the nut 30 is tightened. However, in order to reduce electric resistance, the contact area of the lead may be reduced. If it is desired to increase the width, the wire 50 may be used as a temporary fixing and removed when the nut 30 is tightened. And wire 5
Insert a jig from the outer circumferential direction instead of
It is also possible to adopt a method of performing temporary fixing.

<Third Embodiment> FIG. 5 shows an embodiment in which an external terminal is provided on a nut. This embodiment eliminates the need for another lead wire connecting the collected leads to the external terminals, and achieves further space saving. External terminal 6
Numeral 0 may be attached to the nut 30 at any position and at any angle as long as it is fixed to the nut 30 and its tip protrudes outside the battery case 70 in which the electrode body is housed. However, in consideration of space saving and stable mounting, the nut 30 is mounted upright on the surface opposite to the flange surface 31 that holds the lead 14 of the nut 30, and the tip is inserted through the terminal hole 72 provided in the battery case cover 71. It is desirable. The distal end of the external terminal 60 can have various shapes such as a male screw depending on what is connected. If insulation from the battery case 70 is to be considered, it is preferable to dispose the insulator 80 between the nut 30 and the battery case cover 71.

<Fourth Embodiment> Next, an embodiment in which external terminals are attached to washers is shown in FIG. In this embodiment, a washer 40 inserted between the bolt 20 and the nut 30 is used.
Is formed so that a part thereof protrudes from the side surface of the nut 30,
The external terminal 60 is mounted upright on the protruding portion, and the tip is inserted through a terminal hole 72 provided in the battery case cover 71. When the nut 30 is attached to the nut 30 as in the above-described <Third Embodiment>, the position of the external terminal 60 differs due to the tightening of the nut 30, which may hinder the design of the battery case 70. In particular, it is difficult to align the external terminal with the opposite pole provided on the opposite winding end face. Therefore, the present embodiment has an effect that the nut can be tightened while the position of the external terminal is specified.

<Fifth Embodiment> This embodiment relates to a large battery having a large discharge capacity, and has a large-diameter metal hollow mandrel in order to release the internal heat generation of the battery from the center. The purpose of the present invention is to perform a lead current collection process. This embodiment is shown in FIG. The electrode is wound around a hollow mandrel 90 to form an electrode body 10. This hollow mandrel 9
0 has an end inserted through a hole provided in the battery case lid 71, and the inner wall surface of the hollow mandrel 90 has a structure to be exposed to outside air. The heat generated inside the battery is discharged from the inner wall surface and the entire surface of the battery case lid and the outer cylinder surface of the battery case, through which heat is easily transmitted by adopting the welded structure. The above embodiment cannot be adopted from the structure of this battery.

Therefore, in the present embodiment, the shaft portion 22 of the bolt 20 is formed in a hollow having an inner diameter larger than the outer diameter of the hollow mandrel 90, and the hollow mandrel 90 is inserted through this hollow portion. The combination of the bolts 20 and the nuts 30 enables the same lead current collection processing as in the above embodiment. In addition, if insulation between the hollow mandrel 90 and the bolt 20 is considered, a cylindrical insulator 80 can be arranged between the two. Furthermore, in this embodiment, the lead is folded back and tightened with a wire (second embodiment), an external terminal is attached to a nut (third embodiment), and an external terminal is attached to a washer (fourth embodiment).
Can be combined.

<Sixth Embodiment> The embodiment shown in FIG.
It also relates to a large battery having a hollow mandrel. This is an embodiment that can be adopted as a lead current collection process for the opposite electrode when either the positive electrode or the negative electrode is configured by the method of the <Fifth Embodiment>. One pole is hollow mandrel 9
In the case where the current collection process is performed in <Fifth Embodiment> insulated from zero, it is not necessary to insulate the opposite pole from the hollow mandrel. Therefore, in this embodiment, the lead 14 is sandwiched between the nut portion 30 and the flange portion 91 formed on the hollow mandrel 90 instead of using the bolt. An electrode body 10 is formed by winding an electrode around a hollow mandrel 90 in which a flange portion 91 is previously formed at one end portion and a male screw 92 is formed from the flange 91 to the end portion. I do. By employing this method, the number of parts can be reduced. In the present embodiment, the above-described <Second Embodiment>, <Third Embodiment>, <Fourth Embodiment>
Embodiment> can be combined.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electrode-wound battery according to the present invention and a conventional electrode-wound battery in which leads are directly connected to external terminals are described below.
The superiority of the wound electrode battery according to the present invention will be demonstrated by comparing the energy densities when configured in the same size battery case. Diameter 80mm, length 252mm
FIG. 9 shows the electrode wound type battery of the embodiment and FIG. 10 shows the conventional electrode wound type battery in the case where each battery is formed in a cylindrical battery case having a distance between the inner surfaces of the case lid of 248 mm. Shown in Hereinafter, description will be made based on these drawings.

<Embodiment> This embodiment has a configuration in which the <second embodiment> and the <third embodiment> are combined among the above embodiments. That is, the lead 14 is the bolt 20
And the wire (string) 50 temporarily fixes the folded portion to the shaft of the bolt 20, performs a current collection process so as to be sandwiched between the bolt 20 and the flange surface of the nut 30, and attaches to the nut 30. It is of a type that is connected to the outside by an external terminal 60.

The electrode 11 has a length of 8 m for both the positive electrode and the negative electrode, and the current collector has one end at one end in the width direction for both electrodes.
It has an uncoated portion 17 of an electrode active material having a width of 0 mm, and the lead 14 is joined to the uncoated portion 17 over the entire length of the electrode. The lead 14 has a thickness of 50 μm and a width of 10 mm. Also, the interval between the leads is about 200m
m, each of the positive electrode and the negative electrode has 41 leads 14, each of which is wound with a separator 15 interposed therebetween.
The electrode body 10 was obtained. This electrode body 10 is the same as that shown in FIG.
become that way.

As shown in FIG. 4, the electrode assembly 10 collects the leads 14 toward the shaft portion 22 of the bolt 20 and radially folds the lead at the position of the shaft portion 22.
At 0, a current collecting process was performed in which the shaft was temporarily fixed to the shaft 22, the washer 40 was sandwiched, and the washer 40 was sandwiched between the flange surfaces 21 and 31 of the bolt 20 and the nut 30. The thickness of the flange portion of the bolt 20 is 1.5 mm, and the thickness of the washer 40 is 1 m.
m, the thickness of the nut 30 was 4 mm, and the overlapping thickness of the leads was about 0.5 mm. As a result, the space required for the current collecting process in the winding axis direction became about 7 mm thick. A space of 1 mm is provided on both the positive electrode side and the negative electrode side to secure a current collection processing space of 8 mm, and the inner surface distance of the battery case lid 71 is 2 mm.
When calculated backward from 48 mm, the coating width of the current collector on the electrode active material was 212 mm.

<Comparative Example> This comparative example is a conventional electrode wound type battery. Unlike the above-described embodiment, the lead 14 is directly connected to one external terminal 60 attached to the battery case cover 71. Things. In this method, since the leads 14 are entangled in a complicated ribbon shape, the connection processing cannot be performed unless the position is far from the winding end surface of the electrode body. Therefore, in the conventional method, it is necessary to increase the space for current collection processing, and in the case of this comparative example, a space having a thickness of 41 mm was required. Then, in the same manner as in the above example, the application width of the electrode active material to the current collector was calculated.
mm.

Table 1 shows comparison data between the example and the comparative example. Since the discharge capacity is proportional to the area of the electrode active material, the energy volume density of the battery can be compared by comparing the application area of the electrode active material that can be secured by each method. As shown in the comparative table, the coated area of the electrode active material is 11680 cm ² in the case of the wound electrode battery of the comparative example,
In the case of the wound electrode type battery of the example, it was 16960 cm ² . From this result, it is understood that the wound electrode battery of the present invention has a larger energy volume density by 43% than that of the conventional system.

[0031]

[Table 1]

[0032]

As described above, the wound electrode battery of the present invention can save the space of the current collecting portion of the lead without using the conventional technique of collecting the current of the lead by welding. Things. Further, space saving is achieved by a very simple current collection process without the need for processing of the tip of the lead and adjustment of the length of the lead as performed by another conventional technique. As a result, the present invention has an effect that a wound electrode battery having a large energy volume density can be easily supplied as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a wound state of an electrode body.

FIG. 2 is a perspective view showing an electrode body after winding.

FIG. 3 is a cross-sectional view schematically showing a first embodiment of a lead current collecting method for a wound electrode battery according to the present invention.

FIG. 4 is a cross-sectional view schematically showing a second embodiment of a lead current collecting method for a wound electrode battery according to the present invention.

FIG. 5 is a cross-sectional view schematically showing a third embodiment of the lead current collecting method of the wound electrode battery according to the present invention.

FIG. 6 is a cross-sectional view schematically showing a fourth embodiment of a lead current collecting method for a wound electrode battery according to the present invention.

FIG. 7 is a cross-sectional view schematically showing a fifth embodiment of a lead current collecting method for a wound electrode battery according to the present invention.

FIG. 8 is a cross-sectional view schematically showing a sixth embodiment of the lead current collecting method of the wound electrode battery according to the present invention.

FIG. 9 is a cross-sectional view schematically showing a wound electrode battery according to an embodiment of the present invention.

FIG. 10 is a cross-sectional view schematically showing a conventional electrode wound type battery as a comparative example.

FIG. 11 is a cross-sectional view schematically showing a conventional lead current collecting method.

FIG. 12 is a perspective view showing a conventional lead current collecting system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electrode body 11 Electrode 12 Current collector 13 Electrode active material 14 Lead 15 Separator 16 Mandrel 17 Electrode active material uncoated part 18 Winding end face 20 Bolt 21 Flange face 22 Shaft part 30 Nut 31 Flange face 40 Washer 50 Wire (string) 60) External terminal 70 Battery case 71 Battery case lid 72 Terminal hole 80 Insulator 90 Hollow mandrel 91 Flange 92 Male screw part 95 Current collecting terminal 96 Ring 97 Male screw part 98 Lock hole 99 Lock notch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichi Suzuki 41 Toyota Chuo Research Institute, Inc. No. 41, Yokomichi, Toyota Central Research Institute, Inc. (72) Inventor No ▲ Saki ▼ Koichi Toyota Motor Co., Ltd. 1 Toyota Town, Toyota City, Aichi Prefecture

Claims (9)

[Claims] An electrode having an electrode body formed by spirally winding a strip-shaped positive electrode and a negative electrode having an active material formed on the surface of a current collector and a separator sandwiched between the positive electrode and the negative electrode. A wound battery, wherein a plurality of strips formed so as to extend in a direction of a winding center axis of the electrode body from one end of the electrode body of at least one of the positive electrode and the negative electrode which is a wound end surface. An electrode-wound type, comprising: a lead in the shape of a spiral, and a bolt and a nut disposed on a winding end face of the electrode body and holding the lead toward the center of the winding of the electrode body. battery. 2. The electrode wound type battery according to claim 1, wherein the lead is folded back at a shaft portion of the bolt so as to be separated from a winding center of the electrode body. 3. The wound electrode battery according to claim 1, wherein said nut has an external terminal. 4. The wound electrode battery according to claim 1, further comprising a washer sandwiched between said bolt and said nut together with said lead and having an external terminal. 5. The electrode body according to claim 1, wherein the electrode body has a hollow mandrel protruding from a winding end face at a center of the winding, wherein the bolt has a hollow shaft portion and the protruding portion of the mandrel is inserted therethrough. 5. The wound electrode battery according to any one of 4. 6. An electrode having an electrode body formed by spirally winding a strip-shaped positive electrode and a negative electrode having an active material formed on the surface of a current collector and a separator sandwiched between the positive electrode and the negative electrode. A wound battery, wherein a plurality of strips formed so as to extend in a direction of a winding center axis of the electrode body from one end of the electrode body of at least one of the positive electrode and the negative electrode which is a wound end surface. A hollow mandrel arranged at the center of the winding of the electrode body and protruding from the winding end surface, wherein a flange and a male screw are formed at the protruding portion; And a nut that is fitted to the flange and clamps the lead between the flange and the flange toward the center of the winding of the electrode body. 7. The electrode wound type battery according to claim 6, wherein said lead is folded back from said winding center of said electrode body by said hollow mandrel. 8. The battery according to claim 6, wherein the nut has an external terminal. 9. The wound electrode battery according to claim 6, further comprising a washer sandwiched between said flange and said nut together with said lead and having an external terminal.