JP2007329059A - Method of manufacturing electrode group and its manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electrode group and its manufacturing device, capable of improving productivity by reducing winding time and realizing reduction of failures by stable winding. <P>SOLUTION: The electrode group structuring method is so structured that after a band cathode plate 1, a band anode plate 2 facing to the cathode plate 1 and two band separators 3 are pushed and pinched between a pair of main nip rollers 8, the electrode group is made to be wound in spiral around a winding core 7. The winding core 7 is rotated in such a state that a separator 3b on the winding core 7 side of the two separators 3, and the anode plate 2 are pinched by sub nip rollers 9, and, after the remaining separator 3a and the cathode plate 1 are wound, the main nip rollers 8 are released. Then, the cathode plate 1 is pressed and sent by using an auxiliary means with the anode plate 2 and the separator 3b pinched by the sub-nip rollers 9, it is wound around the winding core 7, and finally, the sub-nip rollers 9 are released for winding. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lithium ion secondary battery typified by a secondary battery, wherein a positive electrode plate and a negative electrode plate, which are electrode plates, are wound around a winding core via a separator, and an electrode group is formed by winding in a spiral shape. The present invention relates to an electrode group manufacturing method and a manufacturing apparatus thereof.

  In recent years, portable and cordless electronic devices such as AV devices or personal computers and portable communication devices have been rapidly promoted, and these electronic devices are highly reliable as power sources for driving and easy to maintain. Therefore, nickel cadmium storage batteries, nickel metal hydride storage batteries, lithium ion secondary batteries and the like are representative, and are widely used in various applications.

  In addition, batteries with high-capacity and large-current charge / discharge characteristics are required as driving power sources that require large load characteristics, such as electric tools, bicycles with electric assistance, lawn mowers, and electric vehicles. Development of highly reliable and reliable batteries is demanded. For example, as shown in FIG. 8, the electrode group 6 for a lithium ion secondary battery is configured by winding a positive electrode plate 1 and a negative electrode plate 2 in a spiral shape with a separator 3 interposed therebetween. And the electrode group 6 comprises the terminal for a connection, when the electrode terminals 4 and 5 provided near the front-end | tip of each positive electrode plate 1 and the negative electrode plate 2 protrude from the side surface of the electrode group 6. FIG.

  In the conventional manufacturing method of the electrode group wound in a spiral shape, first, as shown in FIG. 7A, the positive electrode plate 101 between the two separators 103a and 103b is chucked with the pair of nip rollers 108 opened. 105, and the negative electrode plate 102 is sandwiched between chucks 106 and pushed between the nip rollers 108. Next, as shown in FIG. 7B, the separators 103a and 103b, the positive electrode plate 101, and the negative electrode plate 102 are sandwiched between a pair of nip rollers 108, and the separators 103a and 103b are sandwiched between the separated cores 107, thereby separating the separator 103a. 103b is sandwiched between the pressing roller 110 and the fixing plate 111, and the separators 104a and 103b are cut by the separator cutter 104. Subsequently, as shown in FIG. 7C, the core 107 is rotated counterclockwise by one turn as shown by the arrow in the figure, and the core 107 is sandwiched between the positive electrodes 101 by the separators 103a and 103b. Let it wind.

After that, as shown in FIG. 7D, the pair of nip rollers 108 are opened to take up the slack of the separator 103b, the negative electrode plate 102 is sandwiched between the chucks 106, and pushed between the separator 103b and the core 107. As shown in FIG. 7 (e), the separators 103a and 103b, the positive electrode plate 101 and the negative electrode plate 102 are sandwiched between a pair of nip rollers 108, and the positive electrode plate 101 and the negative electrode plate 102 are connected as shown in FIG. 6 (f). A method of winding the separators 103a and 103b, the positive electrode plate 101, and the negative electrode plate 102 by cutting with the electrode plate cutter 109 and rotating the winding core 107 counterclockwise as indicated by the arrow in the figure is proposed. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2001-202949

However, in the prior art of the above-mentioned patent document, as shown in FIGS. 7C and 7D, the pair of nip rollers 108 are opened to take up the slack of the separator 103b on the core side, and the negative electrode plate 102 is used as the core. When pushing between the side separator 103b and the core 107, it is necessary to move in parallel along the core side separator 103b until the tip of the negative electrode plate 102 reaches a predetermined position. Since the tip of 102 is pushed between the core-side separator 103b and the core 107 in an unrestricted free state, bending of the tip of the negative electrode plate 102 and the negative electrode plate 102 and the separator 103b cannot be in close contact with each other, When winding in a spiral shape, a problem of causing a winding shift occurs. Due to the occurrence of winding deviation, there is a problem that the electrode group does not enter the battery case constituting the battery in the process of assembling the battery, or an internal short circuit occurs as the battery.

  Further, as shown in FIG. 7 (c), the winding core 107 is rotated by one rotation in the counterclockwise direction indicated by the arrow in the drawing, and the positive electrode plate 101 is sandwiched between the separators 103a and 103b. As shown in FIG. 7 (d), the rotation is temporarily stopped after winding around the core 107, the nip roller 108 is opened to take up the slack of the separator 103b on the core side, and the negative electrode plate 102 is connected to the separator 103b on the core side. After being pushed between the winding cores 107, the separators 103a and 103b, the positive electrode plate 101 and the negative electrode plate 102 are sandwiched by the nip rollers 108 as shown in FIG. 7E, and the positive electrode plate 101 as shown in FIG. And the negative electrode plate 102 is cut by the electrode plate cutter 109 and the winding core 107 is rotated counterclockwise, so that the separators 103a and 103b and the positive electrode plate 101 and Although the negative electrode plate 102 is wound, it takes a lot of time for winding because of the rotation, temporary stop, and rotation.

  The present invention has been made in view of the above-described conventional problems. After the separator is disposed on both sides of the strip-shaped positive electrode plate, the negative electrode plate is then wound around the strip-shaped negative electrode plate disposed via the separator. It is another object of the present invention to provide a method for manufacturing an electrode group in which a separator is forcibly wound around a positive electrode plate and a manufacturing apparatus therefor.

  In order to achieve the above object, the method for producing an electrode group according to the present invention includes a positive electrode current collector coated with a positive electrode mixture containing at least a positive electrode active material, and a negative electrode current collector that holds lithium. An electrode group manufacturing method for forming an electrode group in which a strip-shaped negative electrode plate coated with a negative electrode mixture as an active material is wound in a spiral manner with a separator interposed between the negative electrode plate and a positive electrode plate After the separators are disposed on both sides of the negative electrode plate, the negative electrode plate and the separator are forcibly wound along the positive electrode plate when the negative electrode plate disposed via the separator is then wound.

  According to the present invention, a strip-shaped positive electrode plate coated with a positive electrode mixture containing at least a positive electrode active material on a positive electrode current collector and a strip-shaped positive electrode mixture coated with a negative electrode mixture as an active material capable of holding lithium on the negative electrode current collector. An electrode group manufacturing method for forming an electrode group in which a negative electrode plate is spirally wound with a separator interposed therebetween, the separator being disposed on both sides of the positive electrode plate, and then disposed via the separator When the negative electrode plate is wound, the negative electrode plate and the separator are forcibly wound around the positive electrode plate to remove the slackness of the separator after winding the separator and the positive electrode plate. It becomes possible to wind the separator around the winding core while restricting, and the negative electrode plate is bent or the negative electrode plate is in close contact with the separator.

In the first invention of the present invention, a strip-like positive electrode plate in which a positive electrode mixture containing at least a positive electrode active material is applied to a positive electrode current collector and a negative electrode mixture as an active material capable of holding lithium in the negative electrode current collector An electrode group manufacturing method for forming an electrode group in which a coated strip-shaped negative electrode plate is spirally wound with a separator interposed therebetween, the separator being disposed on both sides of the positive electrode plate, and then the separator When winding the negative electrode plate disposed via the separator, the separator and the positive electrode plate are wound by forcibly winding the negative electrode plate and the separator along the positive electrode plate. Can be wound around the core around which the separator is wound while regulating the negative electrode plate. Suppression of the negative electrode plate can be prevented and the negative electrode plate can be in close contact with the separator. Low winding misalignment Reduction is possible.

  In the second aspect of the present invention, the compressed air is blown onto the separator or the negative electrode plate along the positive electrode plate so that the negative electrode plate and the separator are along the positive electrode plate. The negative electrode plate and the separator can be brought into close contact with each other, and stable winding can be realized without scratching.

  In the third invention of the present invention, the contact member synchronized with the movement of the separator or the negative electrode plate is pressed against the separator or the negative electrode plate in order to place the negative electrode plate and the separator along the positive electrode plate, and along the positive electrode plate, The negative electrode plate and the separator can be brought into close contact with the positive electrode plate without being scratched while being in contact with the negative electrode plate and the separator, and stable winding can be realized.

  In a fourth aspect of the present invention, there is provided an electrode group manufacturing apparatus for forming an electrode group formed by winding a strip-shaped positive electrode plate and a strip-shaped negative electrode plate in a spiral manner with a separator interposed therebetween, A sub-nip roller sandwiching one separator and the negative electrode plate interposed between the positive electrode plate and the negative electrode plate after the two separators and the tip of the positive electrode plate are spirally wound, and the positive electrode plate and the two separators And a pair of main nip rollers that sandwich the negative electrode plate, a winding core that winds in a spiral, and an auxiliary mechanism that forces the negative electrode plate and the separator to follow the positive electrode plate, so that the main roller is in an open state Nevertheless, it is possible to remove the slack of the separator with the auxiliary mechanism, and to wind it around the core winding the separator while regulating the negative electrode plate. In Rukoto, it is also possible to wound continuously while winding suppressing the occurrence of deviation.

  In the fifth aspect of the present invention, the auxiliary mechanism is configured such that air blow is blown onto the separator or the negative electrode plate, so that the main roller does not come into contact with the positive plate while the main roller is not open. It can be closely attached and can be wound without scratching the negative electrode plate.

  In the sixth aspect of the present invention, as the auxiliary mechanism, the roller type guide is pressed against the separator or the negative electrode plate, so that the roller rolls while contacting the negative electrode plate or the separator, thereby minimizing the contact resistance. Therefore, stable winding can be performed without scratching the negative electrode plate or the separator.

  In the seventh aspect of the present invention, as the auxiliary mechanism, the movable guide is pressed against the separator or the negative electrode plate so that the movable guide is moved at the running speed and the synchronizing speed of the separator and the negative electrode plate. Since it can be pressed against the negative electrode plate, stable winding can be realized without scratching the separator or the negative electrode plate.

  In the eighth invention of the present invention, the sub nip roller is pressed against one of the pair of main nip rollers to sandwich the separator and the negative electrode interposed between the positive electrode plate and the negative electrode plate. It can be pushed into the core without releasing the holding of the plate, and the winding can be performed without stopping the temporary operation. Therefore, the winding can be continuously performed, and the productivity can be improved.

  In the ninth aspect of the present invention, the separator interposed between the positive electrode plate and the negative electrode plate and the negative electrode plate are sandwiched between a pair of independent sub nip rollers, so that the separator between the sub nip roller and the main nip roller The traveling path of the negative electrode plate can be straightened, and the apparatus can be made compact.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an overall view of the embodiment, and FIG. 2 shows a schematic perspective view of a winding portion of the same embodiment. The strip-shaped positive electrode plate 1, the strip-shaped negative electrode plate 2, the strip-shaped separator 3 a, and the separator 3 b are respectively in the hoop state, the positive electrode plate unwinding portion 13, the negative electrode plate unwinding portion 14, the separator unwinding portion 15, and the separator winding Arranged in the outlet 16. The belt-like positive electrode plate 1, the negative electrode plate 2, the separator 3 a, and the separator 3 b that have come out from the unwinding portion are conveyed while being wound around the traveling roller 17.

  In order to make the tension during winding constant, a dancer roller 18 of the positive electrode plate 1, a dancer roller 19 of the negative electrode plate, a dancer roller 20 of the separator 3a, and a dancer roller 21 of the separator 3b are arranged. The chuck 22 is arranged parallel to the traveling direction of the positive electrode plate 1 and the negative electrode plate 2 and is pushed between the nip rollers 8 with the electrode plate interposed therebetween. The electrode plate cutter 23 is arranged perpendicular to the traveling direction of the positive electrode plate 1 and the negative electrode plate 2 to cut the positive electrode plate 1 or the negative electrode plate 2.

  The main nip roller 8 includes a pair of movable main nip rollers 8a and a fixed main nip roller 8b. The movable main nip roller 8a and the fixed main nip roller 8b are closed when they are in contact with each other, and are opened when they are separated from each other. It has become. The sub nip roller 9 is configured as a pair with the fixed main nip roller 8b. The fixed main nip roller 8b and the sub nip roller 9 are closed when they are in contact with each other, and are opened when they are separated from each other.

  In addition, the winding core 7 is configured to rotate in the vicinity of the main nip roller 8. The positive electrode plate 1 and the separator 3a, the separator 3b and the negative electrode plate 2 are sandwiched between a pair of main nip rollers 8, and the one separator 3b and the negative electrode plate 2 interposed between the positive electrode plate 1 and the negative electrode plate 2 are sandwiched between the sub nip rollers 9. After that, the leading ends of the separator 3a and the separator 3b are sandwiched between the core auxiliary pin 7a and the core pin 7b and wound in a spiral shape. As shown in FIG. 1, the turret 25 is rotated 90 degrees counterclockwise to pull the separator 3 a and separator 3 b and the separator 3 a and separator 3 b are cut by the separator cutter 24. To do. At the same time, the core 7 sandwiches the separator 3a and the separator 3b in a state where the next winding is possible.

  Next, the operation will be described with reference to FIG. 3. As shown in FIG. 3A, the positive electrode plate 1, the negative electrode plate 2, the separator 3a, and the separator 3b are sandwiched between the movable main nip roller 8a and the fixed main nip roller 8b. After sandwiching the negative electrode plate 2 and the separator 3b on the core 7 side between the sub nip roller 9 and the fixed main nip roller 8b, the core auxiliary pin 7a and the core pin 7b come into contact with each other to form a circular shape, The separator 3a and the separator 3b were sandwiched between the cores 7 and the core 7 was rotated counterclockwise, and the separators 3a and 3b were wound around the core 7.

  As shown in FIG. 3B, when the positive electrode plate 1 is wound around the core 7 while being sandwiched between the separator 3a and the separator 3b, sagging of the separator 3b on the core 7 side occurs. Here, as shown in FIG. 3C, the movable main nip roller 8a is opened, and the winding core 7 rotates counterclockwise in the direction of the arrow, so that the separator 3b on the winding core 7 side is slackened. It was wound around the core 7.

Thereafter, the blowing unit 10 attached to the front end of the front / rear drive cylinder 26 moves forward to open the compressed air opening / closing valve 28 to the negative electrode plate 2 sandwiched by the sub nip roller 9 and the separator 3b on the core 7 side to generate compressed air. The dry compressed air generated in the section 29 is sprayed from the spraying section 10, and the negative electrode plate 2 and the separator 3b are pressed against the positive electrode plate 1, and the spraying section 10 moves up and down as shown in FIGS. 3 (d) to 3 (e). The negative electrode plate 2 and the separator 3 were assisted along the positive electrode plate 1 by being lowered by the drive cylinder 27 and wound around the winding core 7. And as shown in FIG.3 (f), the subnip roller 9 was open | released and the electrode group was produced. The present invention is not limited to the following description.

  In the first embodiment, as shown in FIG. 3A, the positive plate 1, the negative plate 2, the separator 3a, and the separator 3b are sandwiched between the movable main nip roller 8a and the fixed main nip roller 8b, and the sub nip roller 9 and the fixed main nip roller 8b. After sandwiching the negative electrode plate 2 and the separator 3b on the core 7 side between them, the core auxiliary pin 7a and the core pin 7b come into contact with each other to form a circular shape, and the separator 3a and the separator 3b are sandwiched therebetween. At the same time, the core 7 was rotated counterclockwise at a speed of 1200 revolutions per minute, and the separator 3a and the separator 3b were wound around the core 7.

  As shown in FIG. 3B, when the positive electrode plate 1 is wound around the core 7 while being sandwiched between the separators 3a and 3b, sagging of the separator 3b on the core 7 side occurs. Here, as shown in FIG. 3C, the movable main nip roller 8a is opened, and the core 7 rotates counterclockwise at a speed of 1200 rotations per minute, so that the separator 3b on the core 7 side is It was wound around the core 7 while removing the slack.

  Thereafter, the blowing part 10 attached to the front end of the front / rear drive cylinder 26 is advanced to the separator 3b on the negative electrode plate 2 and the core 7 side sandwiched by the sub nip roller 9 at a speed of 200 mm / s, and the compressed air on-off valve 28 is opened. Then, the compressed air of 0.2 MPa generated and dried by the compressed air generation unit 29 is sprayed for 1.6 seconds to press the negative electrode plate 2 and the separator 3b on the core 7 side against the positive electrode plate 1, and from FIG. As shown in (e), the blowing part 10 is lowered by the vertical drive cylinder 27 at a speed of 400 mm / s to assist the negative electrode plate 2 and the separator 3 along the positive electrode plate 1 and wound around the core 7. .

  As shown in FIG. 3F, the sub nip roller 9 was opened to produce an electrode group. Next, as an electrode group for a lithium secondary battery having a diameter of 18 mm and a height of 65 mm, the aluminum coil is coated with a positive electrode mixture containing at least a positive electrode active material and has a width of 57 mm and a thickness of 0. A belt-shaped negative electrode plate having a width of 58.5 mm and a thickness of 0.2 mm, in which a negative electrode mixture as an active material capable of holding lithium is applied to a 2 mm strip-shaped positive electrode plate and a copper current collector, has a width of 62 mm. The electrode group is formed by winding with a separator having a thickness of 0.02 mm.

  Further, as shown in FIG. 3C, the spraying portion 10 is provided between the core 7 and the main nip roller 8, and after moving at a speed of 200 mm / s in the direction approaching the negative electrode plate 2, the negative electrode plate 2 In order to be able to move at a speed of 400 mm / s in synchronization with the same direction as the direction of travel, the structure is a metal block shape in which air blow can be blown from at least one hole. The air blown from the blowing unit 10 is preferably dry compressed air. In the present invention, dry compressed air is blown. The electrode group produced by the above method was defined as Example 1.

  In the second embodiment, parts different from the first embodiment will be described with reference to FIG. Other contents are the same as those of the electrode group manufacturing method described in the first embodiment. As shown in FIG. 4, the movable main nip roller 8a is opened, and the winding core 7 rotates counterclockwise at a speed of 1200 rotations per minute, so that the winding is performed while taking up the slack of the separator 3b on the winding core 7 side. It was wound around the core 7.

Thereafter, the negative electrode plate 2 sandwiched by the sub nip roller 9 and the separator 3b on the core 7 side
The roller guide 11 attached to the tip of the front / rear drive cylinder 26 is advanced and pressed at a speed of 200 mm / s. The roller guide 11 is provided between the core 7 and the main nip roller 8, and is movable at a speed of 200 mm / s in a direction approaching the negative electrode plate 2, and then synchronized with the same direction as the negative electrode plate 2 in the direction of 400 mm. It is configured to include at least one roller so as to be able to move at a speed of / s. The roller is preferably made of metal having a small rotational resistance, a large number of rollers, and a small roller diameter. In the present invention, five metal bearings having a roller diameter of 6 mm are provided. Finally, the roller guide 11 assists the negative electrode plate 2 and the separator 3 along the positive electrode plate 1, and the electrode group wound around the winding core 7 is referred to as Example 2.

  In the third embodiment, parts different from the first embodiment will be described with reference to FIG. Other contents are the same as those of the electrode group manufacturing method described in the first embodiment. As shown in FIG. 5, the movable main nip roller 8a is opened, and the winding core 7 rotates counterclockwise at a speed of 1200 rotations per minute, whereby the slack of the negative electrode plate separator 3b on the winding core 7 side is reduced. It was wound around the core 7 while taking.

  Thereafter, the movable guide 12 attached to the front end of the front / rear drive cylinder 26 is pushed forward and pressed against the negative electrode plate 2 sandwiched by the sub nip roller 9 and the separator 3b on the core 7 side at a speed of 200 mm / s. The movable guide 12 is provided between the winding core 7 and the main nip roller 8, and is movable at a speed of 200 mm / s in a direction approaching the negative electrode plate 2, and then synchronized with the same direction as the traveling direction of the negative electrode plate 2. It is configured to be able to move at a speed of / s. The movable guide 12 has an L-shaped configuration, and a resin is preferable as a material. In the present invention, a resin L-shaped movable guide is used. Finally, the negative electrode plate 2 and the separator 3 were assisted along the positive electrode plate 1 with the movable guide 12, and the electrode group wound around the winding core 7 was taken as Example 3.

  In Example 4, as shown in FIG. 6A, the positive plate 1, the negative plate 2, the separator 3a, and the separator 3b are sandwiched between the movable main nip roller 8a and the fixed main nip roller 8b, and the fixed sub nip roller 9a and the movable sub nip roller are sandwiched. After sandwiching the negative electrode plate 2 and the separator 3b on the core 7 side between 9b, the core auxiliary pin 7a and the core pin 7b come into contact with each other to form a circular shape, and the separator 3a and separator 3b are interposed therebetween. The core 7 was rotated counterclockwise at a speed of 1200 revolutions per minute, and the separator 3a and the separator 3b were wound around the core 7.

  As shown in FIG. 6B, when the positive electrode plate 1 is wound around the core 7 while being sandwiched between the separator 3a and the separator 3b, sagging of the separator 3b on the core 7 side occurs. Here, as shown in FIG. 6C, the movable main nip roller 8a is opened, and the core 7 is rotated counterclockwise at a speed of 1200 rotations per minute, whereby the separator 3b on the core 7 side. It was wound around the core 7 while removing the slack.

  Thereafter, the blowing part 10 attached to the tip of the front / rear drive cylinder 26 is advanced at a speed of 200 mm / s to the negative electrode plate 2 and the separator 3b on the side of the core 7 sandwiched between the fixed sub nip roller 9a and the movable sub nip roller 9b. The on-off valve 28 is opened, and the compressed air of 0.2 MPa generated and dried by the compressed air generator 29 is blown and pressed for 1.6 seconds. As shown in FIGS. 6 (d) to 6 (e), the blower 10 Was lowered by the vertical drive cylinder 27 at a speed of 400 mm / s, so that assistance along the positive electrode plate 1 was performed with compressed air and wound around the core 7. Then, as shown in FIG. 6 (f), the movable sub-nip roller 9 b was opened, and the produced electrode group was taken as Example 4.

(Comparative example)
First, after the positive electrode plate 101 and the negative electrode plate 102 are pushed between the separator 103a and the separator 103b with the nip roller 108 opened as shown in FIG. 7A, the separator as shown in FIG. 103a, separator 103b, positive electrode plate 101, and negative electrode plate 102 are sandwiched by nip roller 108, separator 103a and separator 103b are sandwiched by winding core 107, and excess separator 103a and separator 103b are pushed onto the surface of turret 111 by separator cutter 104. Cut by hitting. Subsequently, as shown in FIG. 7C, the winding core 107 was rotated counterclockwise by one turn, and the positive electrode plate 101 was wound around the winding core 107 with the separator 103a and the separator 103b sandwiched therebetween.

  Thereafter, as shown in FIG. 7D, the nip roller 108 is opened, the slack of the separator 103b on the core side is taken, and the negative electrode plate 102 is pushed between the separator 103b on the core side and the core 107, As shown in FIG. 7E, the separator 103a, the separator 103b, the positive electrode plate 101, and the negative electrode plate 102 are sandwiched between the nip rollers 108, and as shown in FIG. An electrode group in which the separator 103a, the separator 103b, the positive electrode plate 101, and the negative electrode plate 102 were wound by cutting at 109 and rotating the winding core 107 counterclockwise was used as a comparative example. In this way, the electrode group 6 shown in FIG. 8 was completed.

  In order to compare the manufacturing method of the electrode group of the comparative example and the manufacturing method of the electrode group of the example of the present invention, the winding time when the electrode group was configured and the winding misalignment of the positive electrode plate and the negative electrode plate were evaluated.

  As a winding time, a long positive electrode plate and a negative electrode plate and two long separators are sandwiched between a pair of main nip rollers and wound around a core to measure the winding time constituting the electrode group. The production method of the present invention was compared with the production method of the electrode group of the present invention.

  The winding misalignment is defined as the ratio between the number of defects and the number of inspections as a defect rate, and X-ray inspection is performed on 10,000 electrode groups configured by the electrode group manufacturing method, and the heights of the positive electrode plate and the negative electrode plate are determined. In the vertical cross section, the positive electrode plate did not come out of the negative electrode plate in the longitudinal section, and those that came out were selected as defective products, and the quantity of discharged defective products was compared and examined. Comparison data between the conventional method for manufacturing an electrode group and the method for manufacturing an electrode group of the present invention is shown in Table 1.

In the case of the comparative example, as shown in FIG. 7 (c), the winding core 107 is rotated by one rotation in the counterclockwise direction indicated by the arrow in the figure, and the positive electrode plate 101 is sandwiched between the separators 103a and 103b. Then, the rotation is temporarily stopped after winding around the core 107, and as shown in FIG. 7D, the nip roller 108 is opened to take up the slack of the core-side separator 103b, and the negative electrode plate 102 is removed from the core-side separator. After being pushed between the core 103b and the core 107, the separators 103a and 103b, the positive electrode plate 101 and the negative electrode plate 102 are sandwiched between the nip rollers 108 as shown in FIG. 7E, and the positive electrode as shown in FIG. The plate 101 and the negative electrode plate 102 are cut by the electrode plate cutter 109 and the winding core 107 is rotated counterclockwise, whereby the separators 103a and 103b, the positive electrode plate 101 and the negative plate 101 Although the electrode plate 102 is wound, it takes a lot of time to wind because it rotates, pauses, and rotates.

  Further, as shown in FIGS. 7C and 7D, the pair of nip rollers 108 are opened to take up the slack of the separator 103b on the core side, and the negative electrode plate 102 is placed between the separator 103b on the core side and the core 107. , It is necessary to move in parallel along the core side separator 103b until the tip of the negative electrode plate 102 reaches a predetermined position. In this case, the tip of the negative electrode plate 102 is not bent and the negative electrode plate 102 and the separator 103b cannot be in close contact with each other. Cause problems. Due to the occurrence of winding deviation, there is a problem that the electrode group does not enter the case constituting the battery in the process of assembling the battery, or an internal short circuit occurs as the battery.

  On the other hand, the electrode group of the present invention is an electrode group that forms an electrode group formed by winding a strip-shaped positive electrode plate and a strip-shaped negative electrode plate in a spiral manner with a separator interposed therebetween, and two separators A sub-nip roller sandwiching one separator and the negative electrode plate interposed between the positive electrode plate and the negative electrode plate, the positive electrode plate, the two separators, and the negative electrode plate Produced by a manufacturing apparatus comprising a pair of main nip rollers that sandwich the winding, a winding core that winds in a spiral shape, and an auxiliary mechanism that assists the winding. It is possible to remove the slack of the separator and wind it around the core winding the separator while regulating the negative electrode plate. Suppressing the occurrence of winding deviation by suppressing the bending of the negative electrode plate and the negative electrode plate closely contacting the separator. Also it is possible to shorten the winding time in succession while.

  From the results of (Table 1), the electrode group manufacturing method of the present invention has unique effects in terms of shortening the winding time and reducing winding misalignment when the electrode group is configured. In particular, in Example 1, the auxiliary mechanism for assisting the winding is constituted by the spraying part 10 as shown in FIG. 3C, and the negative electrode plate 2 is dried in a non-contact manner on the separator 3b on the core 7 side. Compressed air of 0.2 MPa is blown and pressed for 1.6 seconds, and the blowing unit 10 is lowered as shown in FIGS. 3D to 3E to assist along the negative electrode plate 2. Since the electrode group is formed without damaging the negative electrode plate 2 because it is wound around 7, it is excellent in reducing winding misalignment.

  From the above results, by using the present invention, it is an electrode group manufacturing method capable of realizing improvement in productivity and reduction of defects due to stable winding.

The manufacturing method of the electrode group according to the present invention includes rotating the core in a state where the separator on the core side and the negative electrode plate are sandwiched between the sub-nip rollers, and the remaining one located on the outer side of the winding. After winding the separator and the positive electrode plate, the main nip roller is opened, and the negative electrode plate sandwiched by the sub nip roller is pressed against the core side separator using auxiliary means, and then sent out. A plate is wound around the core, then the sub nip roller is opened, and the electrode group is formed. After winding the separator and the positive plate, the separator is loosened, and the separator is wound while regulating the negative plate. It is possible to wind around the winding core, and the negative electrode plate is bent and the negative electrode plate is in close contact with the separator. It is possible. Furthermore, since the winding time can be shortened, it is possible to reduce defects and improve productivity to reduce the cost of the electrode group, which is useful as a highly reliable method for manufacturing an electrode group. .

The schematic perspective view which shows the manufacturing apparatus of the electrode group of this invention Schematic perspective view of the winding part of the manufacturing apparatus (A) State diagram at the beginning of winding in Example 1 of the present invention, (b) State diagram at the time of winding of the separator and positive electrode plate in Example 1, (c) Start of operation of air blow in Example 1 (D) State diagram at the start of winding of the negative electrode plate in Example 1, (e) State diagram at the time of winding in Example 1, (f) At the end of winding in Example 1 State diagram State diagram of operation start of roller guide in embodiment 2 of the present invention State diagram of operation start of movable roller in embodiment 3 of the present invention (A) State diagram at the start of winding in Example 4 of the present invention, (b) State diagram at the time of winding the separator and positive electrode plate in Example 4, (c) Start of air blow in Example 4 (D) State diagram at the beginning of winding of the negative electrode plate in Example 4, (e) State diagram at the time of winding in Example 4, (f) At the end of winding in Example 4 State diagram (A) State diagram at the beginning of winding in the conventional method of manufacturing an electrode group, (b) State diagram at the time of cutting the separator in the same method, (c) State diagram at the time of winding the separator and the positive electrode plate in the same method, d) State diagram at the beginning of winding of the negative electrode plate in the method, (e) State diagram at the time of winding of the method, (f) State diagram at the end of winding of the method Schematic perspective view showing an electrode group for a lithium ion secondary battery

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Negative electrode plate 3 Separator 3a Separator 3b Separator 4 Electrode terminal for positive electrode plates 5 Electrode terminal for negative electrode plates 6 Electrode group 7 Core 7a Core auxiliary pin 7b Core pin 8 Main nip roller 8a Movable main nip roller 8b Fixed main nip roller DESCRIPTION OF SYMBOLS 9 Sub nip roller 9a Fixed sub nip roller 9b Movable sub nip roller 10 Spraying part 11 Roller guide 12 Movable guide 13 Positive electrode unwinding part 14 Negative electrode unwinding part 15 Separator unwinding part 16 Separator unwinding part 17 Traveling roller 18 Dancer roller for positive plate 19 Dancer roller for negative plate 20 Dancer roller for separator 21 Dancer roller for separator 22 Chuck 23 Cutter for electrode plate 24 Cutter for separator 25 Turret 26 Front / rear drive cylinder 27 Vertical drive Linda 28 compressed air on-off valve 29 the compressed air generator

Claims (9)

  A strip-shaped positive electrode plate coated with a positive electrode mixture containing at least a positive electrode active material on the positive electrode current collector and a strip-shaped negative electrode plate coated with a negative electrode mixture serving as an active material capable of holding lithium on the negative electrode current collector. An electrode group manufacturing method for forming an electrode group wound in a spiral shape with a separator interposed therebetween, wherein the separator is disposed on both sides of the positive electrode plate and then disposed via the separator A method of manufacturing an electrode group, wherein the negative electrode plate and the separator are wound so as to be forced along the positive electrode plate when the plate is wound.   The method for producing an electrode group according to claim 1, wherein compressed air is blown to cause the negative electrode plate and the separator to follow the positive electrode plate.   2. The method for producing an electrode group according to claim 1, wherein a contact member synchronized with the movement of the separator or the negative electrode plate is pressed against the separator or the negative electrode plate to place the negative electrode plate and the separator along the positive electrode plate. .   An electrode group manufacturing apparatus for forming an electrode group formed by winding a strip-shaped positive electrode plate and a strip-shaped negative electrode plate in a spiral manner with a separator interposed therebetween, the two separators and the tip of the positive electrode plate A pair of mains sandwiching the positive electrode plate, the two separators, and the negative electrode plate, and a sub nip roller sandwiching the one separator and the negative electrode plate interposed between the positive electrode plate and the negative electrode plate An apparatus for manufacturing an electrode group, comprising: a nip roller; a winding core that winds in a spiral; and an auxiliary mechanism that forces the negative electrode plate and the separator along the positive electrode plate.   5. The electrode group manufacturing apparatus according to claim 4, wherein the auxiliary mechanism is configured to blow air blow onto a separator or a negative electrode plate.   The apparatus for manufacturing an electrode group according to claim 4, wherein the auxiliary mechanism is configured to press a roller-type guide against a separator or a negative electrode plate.   5. The electrode group manufacturing apparatus according to claim 4, wherein the auxiliary mechanism is configured to press the movable guide against the separator or the negative electrode plate.   The electrode group according to claim 4, wherein the sub nip roller is pressed against one of the pair of main nip rollers to sandwich the negative electrode plate between the separator interposed between the positive electrode plate and the negative electrode plate. apparatus. 5. The electrode group manufacturing apparatus according to claim 4, wherein a pair of independent subnip rollers sandwiches the negative electrode plate and the separator interposed between the positive electrode plate and the negative electrode plate.