JPH11111328A - Manufacture of wound type electrode and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the effects of a step difference generated at the beginning of winding a positive electrode sheet and a negative electrode sheet, and to provide a method and device for manufacturing a cylindrical wound electrode having high form accuracy in a high yield. SOLUTION: This manufacturing method comprises a process where an insulation sheet 2 for the insulation between layers is extended to both sides, inserted and installed in a cylindrical wound body which has a roll edge installing part opening toward the direction of a diameter, and whose outer periphery to be wound is subjected to chamfer processings 5a', 5b', 5b1', 5b2' to enable absorbing a step difference generated at the beginning of winding, a process where a positive electrode sheet 3 and a negative electrode sheet 4 is arranged along the insulation sheet 2a, 2b which are extended to the both sides, and the forward end parts of these sheets are respectively disposed at one side and at the other side of the roll edge installing part of the wound core body, wherein these sides face opposite to each other, so as to face and contact to each other, and a process where the insulation sheet 2a, 2b which are extended to the both sides are rotated in a given direction while pressing them from outside to accumulate and wind the positive electrode sheet 3, the insulation sheet 2, and the negative electrode sheet 4 on the circumferential surface of the wound core body 5 for making a wound electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method and a manufacturing apparatus capable of manufacturing a cylindrical wound electrode with high yield.

[0002]

2. Description of the Related Art A wound type electrode (electric generator) formed by winding a laminate of a positive electrode sheet coated with a positive electrode active material, an insulating sheet, a negative electrode sheet coated with a negative electrode active material and an insulating sheet,
2. Description of the Related Art Secondary batteries having a configuration sealed in a liquid-tight manner in a cylindrical outer container have been widely put to practical use. As this type of secondary battery, a nickel-metal hydride secondary battery has recently been put into practical use, in addition to a lead storage battery and a nickel cadmium secondary battery. Among these types of secondary batteries, nickel-metal hydride secondary batteries capable of achieving high capacity have been developed in response to demands for cordless, high-performance, compact, and lightweight electronic devices such as mobile phones and portable personal computers. The improvement of the power supply function is expected.

[0003] The cylindrical electromotive section is formed as follows. For example, as shown in a plan view in FIG. 2, the cylindrical core 1 having a flat surface (opening) 1a that is opposed and separated in the axial direction and in the radial direction is prepared. An insulating sheet (separator) 2 is sandwiched between opposed flat surfaces 1a, and the insulating sheet 2
The positive electrode sheet 3 and the negative electrode sheet 4 are arranged so as to have a required positional relationship, and the winding core is rotated as a virtual center axis (coaxial with the winding core), whereby the insulating sheet 2 is used as a separator. , Wound electrode (electromotive part)
Has been manufactured.

[0004]

However, the conventional method for manufacturing a wound electrode has the following disadvantages. That is, in the case of a nickel-hydrogen secondary battery capable of increasing the capacity, the thickness of the positive electrode sheet and the negative electrode sheet tends to be large. Here, the increase in the thickness of the positive electrode sheet and the negative electrode sheet means that, after the winding (winding) with the separator interposed therebetween or the formation of the wound electrode, as shown in FIG. However, it is difficult to laminate and wind them into a cylindrical shape.

That is, since the steps of the winding start portions 3a and 4a of the thick positive electrode sheet 3 and the negative electrode sheet 4 become large, this portion has a maximum diameter, and consequently concentric winding type electrodes are formed. It will be difficult. Then, depending on the degree of the cylindrical shape and concentricity of the formed wound electrode, it is difficult to constantly insert and arrange the wound electrode into the battery outer can. That is, the outermost peripheral portion of the wound electrode may be damaged when inserted and arranged in the battery outer can, which significantly impairs the reliability or yield of the battery.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a method of producing a cylindrical wound electrode having a high shape accuracy with a reduced yield by reducing the influence of a step at the beginning of winding of a positive electrode sheet and a negative electrode sheet. And production equipment.

[0007]

According to a first aspect of the present invention, there is provided a cylindrical shape having a winding start end mounting portion which opens in a radial direction, and an outer peripheral surface of a material to be wound chamfered so as to absorb a step at the winding start. A step of inserting and disposing an insulating sheet for interlayer insulation on both sides of the core, and placing the insulating sheet along the inside of the insulating sheet extending to both sides, and the opposite winding start end mounting portion of the core. A step of arranging the positive electrode sheet on one side and the tip of the negative electrode sheet on the other side, and rotating the core in a certain direction while applying pressure to the outside of the insulating sheet extending to both sides. A step of laminating and winding a positive electrode sheet, an insulating sheet and a negative electrode sheet on the circumferential surface of the body to form a wound electrode,
And a method for producing a wound electrode.

According to a second aspect of the present invention, there is provided a cylindrical core having a winding start end mounting portion which is opened in the radial direction, and an outer peripheral surface of a winding target being chamfered so as to absorb a step at the winding start. A step of inserting and arranging an insulating sheet for insulation extending to both sides and inserting and arranging the same, along the inside of the insulating sheet extending to both sides, and a positive electrode sheet on one of the opposite winding start end mounting portions of the core, and the other. A step of arranging the leading end of the negative electrode sheet in contact with the outer surface of the insulating sheet, while applying pressure to the outer side of the insulating sheet extending to both sides, rotating the core in a certain direction to the circumferential surface of the core. Laminating and winding the positive electrode sheet, the insulating sheet and the negative electrode sheet to form a wound electrode, and after forming the wound electrode, rotate the core in the opposite direction to remove the positive and negative electrodes. Swinging in the reverse rotation direction. It is a manufacturing method of an electrode.

According to a third aspect of the present invention, there is provided a cylindrical core comprising a pair of semi-circular members having a flat surface, and a pair of semicircular members having a cross section between the opposing surfaces. A rotation drive mechanism for pivotally supporting and rotating the core so that the core can be rotated forward and backward, and a pair of reciprocally disposed reciprocally arranged pressing the insulating sheets stacked and wound by the rotation of the core to the surface of the core. A pressure roller, and a sheet guide mechanism for respectively guiding the laminated and wound insulating sheet, the positive electrode sheet and the negative electrode sheet, wherein the core has a semicircular member having one cross-section at one end of a plane. The other half-circular member is cut out almost perpendicularly to the plane at the other end of the plane and obliquely and parallelly in other areas. It is processed and formed to be able to absorb the step at the beginning of winding. An apparatus for manufacturing a wound electrode.

In the above invention, a columnar core is rotated,
An insulating sheet, a positive electrode sheet, and a negative electrode sheet are laminated and wound on the outer peripheral surface of the core, and the outer peripheral surface of the cylindrical core is selectively chamfered by means of forming a wound electrode, and winding is started. The essence is to absorb as much as possible a step due to the part and to avoid or reduce the concentricity collapse caused by the step. Here, the surfaces facing each other are planes,
The selective chamfering of the outer peripheral surface of the cylindrical core made of a pair of semicircular members having a pair of semicircular cross-sections in which the facing surfaces form a winding start end mounting portion is performed, for example, as shown in FIG. (b) is shown in plan view.

That is, one of the semicircular members 5a of the cross-section forming the columnar core 5 is cut out 5a 'at one end of the opposing plane substantially perpendicularly to the plane. Here, the amount of the notch 5a 'is determined by the amount of the insulating sheet to be laminated and wound,
The thickness depends on the thickness of the positive electrode sheet or the negative electrode sheet, and is about the thickness of the overlap of the two.

The other semicircular member 5b has a cross section 5b 'which is substantially perpendicular to the plane at the other end of the opposing plane, and which is oblique 5b ₁ ' to the plane in other regions. Parallel 5b
₂ 'is notched. Here, vertical cutout 5b 'amount, oblique and orthogonal cutout 5b _1' weight and translationally cutout 5b ₂ 'amount is dependent on the thickness of the insulating sheet to be laminated and MekuSo, general In addition, the step at the beginning of winding is substantially absorbed by the chamfering of the outer peripheral surface by the thickness of the insulating sheet.

According to the first aspect of the present invention, when winding the positive electrode sheet and the negative electrode sheet along the insulating sheet, a step caused by overlapping of the winding start ends of the relatively thick positive electrode sheet and the negative electrode sheet is easily absorbed. Therefore, a wound electrode having a substantially circular cross section can be manufactured with high yield. In other words, it is possible to provide a wound electrode that has high external dimensions and accuracy and can be easily inserted and mounted in a predetermined cylindrical battery outer can, so that highly reliable cylindrical battery productivity and low cost can be provided. Contributes to

According to the second aspect of the present invention, the wound electrode is formed in a laminated and wound form having a substantially circular cross section, and the winding start portion is smoothly removed from the winding core. Without any damage or damage
A highly reliable cylindrical wound electrode can be obtained with a high yield, and as a result, the cost of a highly reliable battery can be reduced.

According to the third aspect of the invention, the first and second aspects of the invention can be easily implemented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS.

FIG. 2 is a side view showing a schematic configuration example of a wound electrode manufacturing apparatus, and FIG. 3 is a plan view schematically showing an embodiment of a wound electrode manufacturing method example.

In FIGS. 2 and 3, reference numeral 5 denotes a columnar core, the surfaces facing each other are flat, and a pair of semicircular members 5a, 5a, 5b
It is composed of Here, one of the semicircular members 5a
The notch amount 5 is approximately perpendicular to the plane at one end 5a 'of the opposing plane, and is approximately the thickness of the stacked insulating and positive electrode sheets (or negative electrode sheets).
At a ', a part of the outer peripheral surface is notched.

The other semicircular member 5b has a cross section 5b 'which is almost perpendicular to the plane at the other end of the opposing plane, and 5b ₁ ' which is oblique to the plane in other regions. Parallel 5b
₂ ′, a part of the outer peripheral surface is chamfered to the thickness of the insulating sheet to be laminated and wound.

Reference numerals 6a and 6b denote bearing portions for supporting the cylindrical winding core 5, and reference numeral 7 denotes a rotary drive mechanism having a servomotor 7a and a rotation transmitting portion 7b. Here, the core body 5 is opened in the radial direction along the axial direction, and between the opposed flat separation surfaces.
For example, a winding start end mounting portion capable of inserting and holding a tape-like sheet is formed.

Reference numerals 8a and 8b denote wound electrode holding blocks in which the surface facing the core 5 rotatably supported in the forward and reverse directions is processed into a concave surface, and is disposed facing the wound core. Although not shown, a pair of pressure rollers advance and retreat in order to press the tape-like insulating sheet (separator) laminated and wound by the rotation of the core 5 against the outer peripheral surface of the core 5. It is arranged as possible. That is, the pressure roller appropriately presses the tape-shaped insulating sheet from the opposite surface side to the outer peripheral surface side of the core body 5 by the roller pressing cylinder, thereby contributing to the winding.

Further, the tape-shaped insulating sheet, the tape-shaped positive electrode sheet, the tape-shaped negative electrode sheet, etc., which are laminated and wound on the outer peripheral surface of the winding core 5, are each configured to be guided by a sheet running guide. Further, there are provided core body pull-out mechanisms 10a and 10b for moving the core body 5 to one end side and removing the wound electrode 9 wound and formed on the outer peripheral surface.

Next, a specific example of a method for manufacturing a wound electrode will be described.

First, as shown in a plan view in FIG. 3, the winding start end formed between the separated and opposed flat surfaces of the core body 5, that is, between the opposed flat surfaces of the semicircular member 5a and the semicircular member 5b. An insulating sheet 2 having a thickness of, for example, 0.2 mm and a width of 60 mm is inserted or sandwiched into the mounting portion, while an insulating sheet, for example, having a thickness of 0.8 mm,
The leading end of the 57 mm wide positive electrode sheet 3 is brought into contact with and aligned with one end of the winding start end mounting portion, and the leading end of the negative electrode sheet 4 having a thickness of 0.5 mm and a width of 57 mm, for example, is wound. And is positioned along the insulating sheets 2a and 2b, respectively.

After the insulating sheets 2a and 2b, the positive electrode sheet 3 and the negative electrode sheet 4 are positioned and arranged as described above, the rotating mechanism drive 7 is driven to rotate the core 5 in a predetermined direction. By this rotation, the positive electrode sheet 3, the insulating sheet 2a,
Lamination and winding of the negative electrode sheet 4 and the insulating sheet 2b progress.
Further, in the laminated and wound process, step of the winding start portion of the positive electrode sheet 3 and the negative electrode sheet 4, chamfered portion 5a of the outer peripheral surface of Makishintai _{5 ', 5b', 5b 1} ', 5
Since the shape absorbed by b ₂ ′ is adopted, winding or winding is performed in a substantially circular cross section, and a good cylindrical wound electrode 9 is formed.

After the required wound electrode 9 is formed by lamination and winding, the core 5 is wound by the rotation drive mechanism 7 in the lamination and winding direction of the wound electrode 9. By reverse rotation, the winding start part of the wound electrode 9 around the winding core 5 is partially loosened. Next, the core extracting mechanism 10a, 10b is operated to shift to an operation of extracting the core 5 from the wound electrode 9, while the rotation driving mechanism 7 slightly rotates the core in the forward and reverse directions. Rotate the body 5 forward and backward in the range of about 3 to 20 ° to swing.

The operation of loosening a part of the winding start portion, the subsequent withdrawal of the core 5 and the forward / reverse rotation of the core 5
By performing both swinging operations in parallel, it is possible to easily manufacture the highly reliable wound electrode 9 having high shape and dimensional accuracy with high yield while eliminating the occurrence of damage to the winding start portion.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, insulation sheet, positive electrode sheet,
The thickness and width of the negative electrode sheet can be appropriately set in accordance with the type and capacity of the target secondary battery.

[0029]

According to the first and second aspects of the present invention, a step at the beginning of winding is reduced and absorbed, and a wound electrode having a uniform outer shape can be easily formed. During the mounting process, the risk of damage to the outer periphery of the wound electrode is completely eliminated. That is, it is possible to obtain a cylindrical wound electrode having a high outer shape accuracy with a high yield, and as a result, it is possible to provide a highly reliable battery with a high yield.

According to the third aspect of the present invention, the step at the beginning of winding is reduced and absorbed, so that a wound electrode having a uniform outer shape can be easily formed. In addition, it is possible to manufacture a wound electrode in which the risk of occurrence of damage on the outer peripheral portion is completely eliminated with good yield and at low cost, and as a result, it greatly contributes to providing a highly reliable battery.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a main configuration of a cylindrical core used in an embodiment, wherein (a) is a side view and (b) is a top view.

FIG. 2 is a side view showing a main structure of a wound electrode manufacturing apparatus according to an embodiment.

FIG. 3 is a plan view schematically showing an example of a manufacturing embodiment of a wound electrode according to the present invention.

FIG. 4 is a plan view schematically showing a manufacturing example of a conventional wound electrode.

[Explanation of symbols]

1, 5 ... cylindrical winding core 1a ... winding start end mounting part 2, 2a, 2b ... insulating sheet 3 ... positive electrode sheet 4 ... negative electrode sheet 5a, 5b ... semicircular member 5a 'in cross section _{, 5b ', 5b 1',} 5b 2 '...... chamfered portion 6a, 6b bearing 7 ...... Makishintai ...... rotation driving mechanism 7a ...... servomotor 7b ...... rotation transmitting portion 8a, 8b ...... wound -Type electrode holding block 9: Wound-type electrodes 10a, 10b-Winding core pull-out mechanism

Claims (3)

[Claims] An insulating sheet for interlayer insulation is provided on a cylindrical core having a winding start end mounting portion that opens in a radial direction and an outer peripheral surface of a winding target being chamfered so as to absorb a step at the winding start. A step of inserting and disposing by extending to both sides, along the inside of the insulating sheet extending to both sides, and a positive electrode sheet on one of the opposite winding start end mounting portions of the core,
A step of arranging the leading end of the negative electrode sheet in contact with the other side, and rotating the core in a certain direction while applying pressure to the outside of the insulating sheet extending to both sides, thereby forming a circumferential surface of the core. And laminating and winding a positive electrode sheet, an insulating sheet, and a negative electrode sheet to form a wound electrode. 2. An insulating sheet for interlayer insulation on a cylindrical core having a winding start end mounting portion that opens in the radial direction and having a chamfered outer peripheral surface to be wound so as to absorb a step at the winding start. A step of inserting and disposing by extending to both sides, along the inside of the insulating sheet extending to both sides, and a positive electrode sheet on one of the opposite winding start end mounting portions of the core,
A step of arranging the leading end of the negative electrode sheet in contact with the other side, and rotating the core in a certain direction while applying pressure to the outside of the insulating sheet extending to both sides, thereby forming a circumferential surface of the core. Laminating and winding a positive electrode sheet, an insulating sheet and a negative electrode sheet to form a wound electrode, and after forming the wound electrode, the core is rotated in the opposite direction to be pulled out in the axial direction to form a positive electrode. A method of manufacturing a wound-type electrode, comprising a step of swinging in the reverse rotation direction. 3. A cylindrical core comprising a pair of semicircular members having a cross-section having a flat surface facing each other, and between the opposing surfaces forming a winding start end mounting portion. A rotation drive mechanism that pivotally supports and rotates in a reverse direction, and a pair of pressure rollers that are arranged to be able to advance and retreat to press the insulating sheet stacked and wound by the rotation of the core body toward the core body surface side, The insulating sheet to be laminated and wound, a sheet guide mechanism for guiding each of a positive electrode sheet and a negative electrode sheet, wherein the core has one semicircular member having a cross section with respect to a plane at one end of the plane. It is cut out almost vertically, and the other semicircular member of the cross section is cut out almost perpendicularly, obliquely and parallel to the plane at the other end of the plane, so that the step at the beginning of winding can be absorbed An apparatus for manufacturing a wound electrode, wherein the apparatus is formed.