JP5865075B2 - Method and apparatus for manufacturing electrode laminate - Google Patents

Description

  The present invention relates to a method for manufacturing an electrode laminate of a large-sized secondary battery used for an electric vehicle and the like, and a manufacturing apparatus used in the manufacturing method.

  For large rechargeable batteries for power supply and power storage, the electrode laminate is housed in a square can container or square laminate because of its good heat dissipation to handle large currents and ease of external current extraction. (Flat laminate type) is often used. In the method where the positive electrode, the negative electrode, and the separator are wound in a roll shape instead of the flat laminated type, problems such as cracks due to elongation are likely to occur if the battery is large or if there is a large amount of current and large heat generation. . The electrode laminate is a laminate in which a separator is sandwiched between a positive electrode and a negative electrode, and a large number of separators and electrodes are laminated according to the storage capacity. In addition, as a secondary battery, a lithium ion secondary battery, in particular, is mainly used as a secondary battery mounted on an electric vehicle or the like because it is excellent in battery voltage, energy density, cycle characteristics, etc. and has little self-discharge. .

  Currently, the lamination method used for manufacturing the electrode laminate of the secondary battery is generally classified into three methods. Method 1 is a method in which electrode sheets and separators cut in advance to a predetermined size are stacked one by one using a transfer function of a robot arm or an actuator. Method 2 is a method of laminating a long sheet-like positive electrode, a negative electrode, and a separator by folding them into predetermined dimensions. Method 3 is a method in which method 1 and method 2 are combined.

  Among them, the method 1 has a problem that when the thickness is as thin as about 20 μm as in the case of a separator and the rigidity is insufficient, the gripping and positioning are not easy and it takes time to stack the electrodes. In addition, dust generated when cutting materials one by one into a predetermined size tends to be a quality problem due to contamination.

  Patent Document 1 is shown as an example of method 3. Patent Document 1 discloses an automatic laminating apparatus that shortens a laminating time by folding a separator (insulating film) that is particularly thin and difficult to be laminated in a long sheet without being cut in advance, and is folded by a folding arm. Yes. However, as with the method 1, the positive electrode and the negative electrode are not sufficient solutions since the work of cutting them one by one into a predetermined size remains.

  Patent Document 2 is shown as an example of Method 2. Patent Document 2 discloses a method of manufacturing a secondary battery electrode in which a collective electrode sheet in which a negative electrode, a separator, and a positive electrode are thermally welded is folded by a corrugated roll. In this method, the folding time can be shortened by folding, and the quality problem of Method 1 is solved by eliminating the pre-cutting of the material. However, this method guarantees the bending pitch dimensional accuracy by pressing (pinch) a corrugated roll having a predetermined shape on the collective electrode sheet, so that a new quality problem due to this is generated. There is. That is, when the collective electrode sheet passes between corrugated rolls, wrinkles are generated due to continuous pressure from the corrugated rolls, or the sheets meander and cannot be bent correctly. Due to such anxiety, the conveyance speed is kept low and the productivity is not high. Specifically, the conveyance speed is set to 2 to 3 m / min. Further, due to the difference in the peripheral speed between the convex portion and the concave portion on the roll circumference, there is a risk that the collective electrode sheet sandwiched between the convex portion and the concave portion may be rubbed and foreign matter generated by the convex portion and the concave portion.

  Patent Document 3 is shown as another example of Method 2. Patent Document 3 discloses a method for manufacturing a battery electrode in which a tooth shape of a gear is transferred to a collective electrode sheet by passing the collective electrode sheet through a meshing portion of two gears to form a continuous wedge shape. . However, even this method has the same problem as the corrugated roll of Patent Document 2. That is, the problem of wrinkles and bending quality caused by continuously applying the pressure necessary for transfer from the tooth surface to the collective electrode sheet, and rotation of the collective electrode sheet in contact with the addendum at the addendum There are problems such as the possibility of scraping scratches and foreign matter due to the difference in speed.

  In addition, Patent Document 4 and Patent Document 5 are shown as methods for manufacturing a corrugated network (filter) used in drainage grooves, exhaust grooves, septic tanks, and the like in fields different from secondary batteries. In these patent documents, a method of folding a net-like body made of inorganic fibers or the like into a spell using a pair of rotating bodies consisting of a rotating shaft and a plurality of blades is disclosed. However, since this method is a method in which uncured resin is received by a blade and folded, many wrinkles or the like are generated. Further, the mesh body is folded while being in contact with the blades. For this reason, the strictness of the shape (no wrinkles and excellent bending quality) is required, and it is necessary to eliminate as much as possible the generation of scratches and foreign matter due to contact with other members during folding. It cannot be applied to the manufacture of

JP 2000-1261 A JP 2002-343342 A JP 2006-190531 A JP-A-6-192955 JP 7-310269 A

  As described above, the method for manufacturing an electrode laminate of a large-sized secondary battery disclosed in Patent Documents 1 to 3 and the like has a quality problem caused by the generation of foreign matters during bending and cutting, and continuous pressure on the material. The poor productivity resulting from the problem remains. In addition, the electrode laminate of the secondary battery is free from wrinkles due to its thinness and structure, has an excellent bending shape, and requires high quality as a whole without generating scratches or foreign matters as much as possible. It is also difficult to divert the manufacturing method of a folded laminate in other fields such as 5 and 5. In particular, due to the recent increase in demand for secondary batteries and the demand for quality improvement, development of methods and apparatuses capable of producing electrode stacks of higher quality secondary batteries with high productivity is desired.

  The present invention has been made to cope with such problems, and realizes high productivity in a manufacturing method of folding a long sheet-like positive electrode, negative electrode, and separator into predetermined dimensions. However, it aims at providing the manufacturing method of the electrode laminated body of a secondary battery which can eliminate a crack and a foreign material generation as much as possible, and the manufacturing apparatus used for this manufacturing method.

  The method for producing an electrode laminate according to the present invention is a method for producing an electrode laminate comprising a positive electrode, a negative electrode, and a separator used for a secondary battery. A material supply step for forming a collecting electrode sheet with the long sheet-shaped separator interposed therebetween, and a pair of independently rotating gear bodies X in which the tooth tip portion and the tooth bottom portion mesh with the collecting electrode sheet, and A bending and laminating step that is inserted between the gear bodies Y and that is alternately folded using the tooth tip portions of the gear body X and the tooth tip portions of the gear body Y, and in the bending laminating step, the collective electrode The distance between the tooth tip portion of the gear body X and the tooth tip portion of the gear body Y with which the collective electrode sheet is in contact is determined without contacting the sheet with the tooth tip portion and the tooth bottom portion of each gear body. Characteristic of sheet pitch and pitch To.

  The “gear body” is a gear-shaped rotating body having tooth top portions and tooth bottom portions alternately on the outer periphery. The “tooth tip portion” is a portion including the tooth tip and the vicinity of the tooth tip, and the “tooth base portion” is a portion including the tooth bottom and the vicinity of the tooth bottom. As described above, the gear body X and the gear body Y are (1) a pair of gear bodies in which the tooth tip portion and the tooth bottom portion mesh with each other, and (2) each rotate independently. Here, “the tooth tip portion and the tooth bottom portion mesh with each other” means that on the line connecting the rotation axis centers of the gear body X and the gear body Y, the tooth tip portion (tooth surface) of one gear body, The tooth bottom part (tooth bottom surface) of the other gear body is in contact with the sandwiched electrode sheet, and then the tooth tip part (tooth top surface) of the other gear body and the tooth of the one gear body The bottom (tooth bottom) is in contact with the sandwiched electrode sheet, and this is repeated with rotation. Further, “independently rotating” means that the gear body X and the gear body Y are controlled and rotated separately and independently. In this way, the gear body X and the gear body Y indirectly and alternately contact the tooth tip portion and the tooth bottom portion, but this does not transmit the motion, but transmits the motion by meshing the tooth surfaces. It is different from a normal pair of gears.

  Further, in the bending and laminating step, at least one of the gear bodies is configured to grip the collective electrode sheet at the tooth tip portion and the tooth bottom portion, and the gear body is provided on the tooth tip portion and the tooth tip portion. The distance from the adjacent tooth bottom portion is a bending pitch dimension value of the collective electrode sheet.

  Further, when the gear body X and the gear body Y are engaged with each other, the peripheral speeds of the meshing tooth tip portion and the tooth bottom portion are matched. Here, “when meshing” means an assembly in which a tooth tip portion of one gear body and a tooth bottom portion of the other gear body are sandwiched on a line connecting the rotation shaft centers of the gear body X and the gear body Y. When the contact is made through the electrode sheet, “peripheral speeds match” means that the peripheral speed of the tooth tip part and the peripheral speed of the tooth bottom part are in contact via the collective electrode sheet. , It means that the size and direction are the same.

  Further, in the folding and laminating step, the distance between the tooth tip portion of the gear body X and the tooth tip portion of the gear body Y with which the collective electrode sheet is in contact is the folding pitch dimension value of the collective electrode sheet. Each gear body is rotated while managing the rotation angle of the gear body X and the gear body Y, respectively.

  An electrode laminate manufacturing apparatus of the present invention is an apparatus used in the manufacturing method of the present invention, and includes a material supply means for forming the aggregate electrode sheet and a bending means for folding the aggregate electrode sheet. The bending means comprises a pair of independently rotating gear body X and gear body Y in which the tooth tip portion and the tooth bottom portion mesh with each other, and each gear body can grip the collective electrode sheet at least at the tooth tip portion. The parts other than the tooth tip part and the tooth bottom part do not come into contact with the collective electrode sheet, and when bent, the gear body X and the gear body Y are teeth of the gear body X with which the collective electrode sheet is in contact. The distance between the tip portion and the tooth tip portion of the gear body Y is respectively rotated so as to be a fold pitch dimension value of the collective electrode sheet.

  As described above, the method for producing an electrode laminate of the present invention is a method for producing an electrode laminate by folding and laminating a collective electrode sheet composed of a long sheet-like positive electrode, a negative electrode, and a separator to a predetermined dimension. In this bending and laminating step, the collective electrode sheet is inserted between a pair of independently rotating gear body X and gear body Y in which the tooth tip portion and the tooth bottom portion mesh with each other, and the tooth tip portion of the gear body X The tooth tip portions of the gear body Y are alternately used to bend and folded. At that time, the collective electrode sheets are in contact with each other, without bringing the collective electrode sheets into contact with the portions other than the tooth tip portions and the tooth bottom portions of the gear bodies. Since the distance between the tooth tip portion of the gear body X and the tooth tip portion of the gear body Y is set to the folding pitch dimension value of the collective electrode sheet, the collective electrode sheet and the gear over the entire operation during the folding and laminating process. Body contact is limited to the tip or root Reluctant, it is possible to continuously meandering at a predetermined bending pitch dimension.

  In this way, by minimizing the contact of the gear body with the collective electrode sheet, the sheet can be folded without applying unnecessary stress (stress) to the sheet. Sheet meandering is suppressed, and high-quality folding is possible. In addition, since it is possible to bend continuously without using a gear body, it is possible to speed up the bending work compared to the method using a robot arm or actuator, and electrode stacking with high productivity. The body can be manufactured. In addition, the long sheet-like positive electrode, the negative electrode, and the separator are bent into a collective electrode sheet without cutting into a predetermined size in advance, so that compared to the case of the conventional method 1 The generation of foreign matter can be drastically reduced.

  Further, in at least one gear body of the above configuration, the collective electrode sheet is gripped by the tooth tip portion and the tooth bottom portion, and the distance between the tooth tip portion of the gear body and the tooth bottom portion adjacent to the tooth tip portion. By setting the bending pitch dimension value of the collective electrode sheet, even when gripping only at the tooth tip part is difficult, it can be easily gripped by providing an adsorption function or the like at the tooth bottom part, and gripping at the tooth bottom part is also used. Bending is possible.

  Further, when the gear body X and the gear body Y are engaged with each other, by causing the peripheral speeds of the tooth tip portion and the tooth bottom portion to mesh with each other to coincide with each other, scratches on the surface of the sheet and foreign matters are generated due to the difference in the peripheral speed. Can be prevented.

  Further, in the above configuration, the gear body X and the gear body X are arranged such that the distance between the tooth tip portion of the gear body X in contact with the collective electrode sheet and the tooth tip portion of the gear body Y becomes the folding pitch dimension value of the collective electrode sheet. While managing the rotation angle of the gear body Y according to a table of rotation angle values calculated in advance or the like, by rotating each gear body individually, the tooth tip part of the gear body X that is in contact with the collective electrode sheet and the gear always. It is possible to fold and feed the collective electrode sheet held between the tooth tips while securing the distance from the tooth tip portion of the body Y to the bending pitch dimension value.

  The electrode laminate manufacturing method and manufacturing apparatus according to the present invention belong to the above-described conventional method 2, but have a unique gear body that minimizes the contact area with the collective electrode sheet while solving the problems of the conventional method using a normal gear. It has been dramatically improved by using and controlling the rotation angle of the gear body, and can be folded at a speed that is at least twice as fast as that of the conventional method, eliminating scratches and foreign matter as much as possible while maintaining high productivity. A high-quality electrode laminate can be manufactured.

It is a schematic diagram which shows the manufacturing process of the electrode laminated body of this invention. It is a bending operation | movement figure of the collective electrode sheet which concerns on 1st Embodiment. It is a bending operation | movement figure of the collective electrode sheet which concerns on 2nd Embodiment.

  The manufacturing method of the electrode laminated body of this invention is a method for manufacturing the electrode laminated body (flat laminated type) which consists of a positive electrode, a negative electrode, and a separator used for secondary batteries, such as a lithium ion secondary battery. is there. The manufacturing method of the electrode laminated body of this invention is demonstrated based on FIG. FIG. 1 is a schematic view illustrating a manufacturing process of an electrode laminate of a secondary battery. In addition, the black arrow in a figure has shown the feed direction.

  First, as a material supply process, a positive electrode sheet 1, a separator sheet 2, and a negative electrode sheet 3, which are long sheets, are supplied from roll-coiled uncoiler devices 4 a to 4 c, respectively. Are integrated to form a long assembly electrode sheet 10. The collective electrode sheet 10 has a configuration in which the separator sheet 2 is sandwiched between the positive electrode sheet 1 and the negative electrode sheet 3. Next, as a folding and laminating step, the collective electrode sheet 10 is further conveyed and inserted into the bending portion 7 composed of the gear body X and the gear body Y by the feeding roller portion 6 so as to have a predetermined folding pitch dimension value. Spells are folded. Then, as a cutting process, the collective electrode sheet 10 that has passed through the bent portion 7 is conveyed to the cutting portion 8 by the conveyor 8a, and the number of peaks is measured by the peak number measuring device 8c, and the number of peaks necessary for the electrode laminate is determined. Is cut by the cutting blade 8b. Finally, as a post-processing step, the compressed portion 9 composed of the contracted claw 9a and the contracted stopper 9b is compressed in the stacking direction and discharged in the form of the electrode stack 11. Tabs are welded to both ends of the electrode laminate 11 in the width direction, and the tabs are accommodated in a rectangular can container or the like and immersed in an electrolyte solution to form a secondary battery.

  The manufacturing method of the present invention essentially includes the material supplying step and the folding and laminating step, and is particularly characterized by the folding and laminating step in the bent portion 7. More specifically, in this bending lamination step, the supplied collective electrode sheet 10 is inserted between a pair of independently rotating gear bodies X and Y that engage with the tooth tip portion and the tooth bottom portion. It is a step of alternately folding the tooth tip part of the body X and the tooth tip part of the gear body Y, and without bringing the collective electrode sheet 10 into contact with the parts other than the tooth tip part and the tooth bottom part of each gear body, A characteristic is that the distance between the tooth tip portion of the gear body X and the tooth tip portion of the gear body Y with which the collective electrode sheet 10 is in contact is set as a bending pitch dimension value of the collective electrode sheet 10.

  As the material supply step, the cutting step, and the post-treatment step, if a desired treatment can be performed, a known device / method used in the manufacturing process of the electrode laminate of the secondary battery can be adopted. it can. However, it is necessary to operate the sheet conveyance timing by the feeding roller unit 6 and the conveyor 8a while having a close relationship with the operation in the folding and stacking process. The stacking speed in this apparatus is assumed to be 30 to 200 m / min in terms of sheet conveying speed.

  A first embodiment of the folding and laminating step in the present invention will be described in detail with reference to FIG. FIG. 2 is a diagram showing a bending operation in the bending lamination step of this embodiment. As shown in FIG. 2, the collective electrode sheet is folded in a zigzag manner by effectively using the tooth tip portion of each gear body. The gripping of the collective electrode sheet at each tooth tip portion is based on the tension of the sheet and the frictional force between the sheet and the tooth tip portion due to bending. In addition, gripping of the collective electrode sheet at each tooth bottom portion is performed by providing an adsorption mechanism such as a vacuum function at the tooth bottom portion. In addition, when the gripping force at each tooth tip portion is insufficient, an adsorption mechanism similar to the tooth bottom portion may be provided at the tooth tip portion. In addition, in the bending lamination process, since tension is applied to the collective electrode sheet, it does not bend or loosen except at the portion that is in contact with or gripped by the tooth tip portion or the tooth bottom portion. Hereinafter, the tooth tip portion, the tooth bottom portion, the pitch dimension value, and the like are also expressed only by symbols in the drawing.

  In FIG. 2 (1), the collective electrode sheet 10 fed from the sheet feeding point O is sandwiched between the tooth tip E of the gear body X and the tooth bottom part e of the gear body Y, and is inserted into the tooth tip A of the gear body Y. Shows the bent state. The rotation angle β1 of the gear body X is based on the rotation angle α1 of the gear body Y. The distance between the tooth tip portion E of the gear body X and the tooth tip portion A of the gear body Y that the collective electrode sheet is in contact with It can be calculated by matching the bending pitch dimension value P of the electrode sheet 10 (the calculation method is omitted). The rotation direction of each gear body for feeding the collective electrode sheet is as shown in the figure, and the gear body X and the gear body Y are reversely rotated.

  2 (1), after a short time has elapsed, the gear body Y is adjusted so that the distance between the tooth tip portions A and O is increased by the length of the collective electrode sheet 10 flowing from the sheet insertion point O. The rotation angle α1 is increased. Further, the rotation angle β1 of the gear body X is increased so that the distance between tooth tips AE = P. When the time further elapses, the state shown in FIG. In this state, the tooth tip A of the gear body Y is in a position corresponding to the length of the collective electrode sheet 10 that has flowed in (increased to the rotation angle α2), and the tooth tip E of the gear body X is Corresponding to the position of the tooth tip portion A, it is a position where the distance between tooth tip portions AE = P with which the collective electrode sheet is in contact (increased to the rotation angle β2).

  FIG. 2 (3) shows a state in which the gear body X and the gear body Y are rotated by 90 degrees relative to FIG. 2 (1). The collective electrode sheet 10 fed from the sheet feeding point O is sandwiched between the tooth tip portion A of the gear body Y and the tooth bottom portion a of the gear body X and bent at the tooth tip portion F of the gear body X. Here, contrary to FIG. 2 (1), the rotation angle α1 of the gear body Y is calculated based on the rotation angle β3 of the gear body X. The calculation is performed by matching the distance between the tooth tip portion A of the gear body Y and the tooth tip portion F of the gear body X with which the collective electrode sheet is in contact with the bending pitch dimension value P.

  When the time further elapses, the state shown in FIG. In this state, the tooth tip portion F of the gear body X is in a position corresponding to the length of the collective electrode sheet 10 that has flowed (increased to the rotation angle β4), and the tooth tip portion A of the gear body Y is Corresponding to the position of the tooth tip F, the tooth tip portion distance FA with which the collective electrode sheet is in contact is FA = P (increase to the rotation angle α4).

  From this point, when the time further elapses, the positional relationship shown in FIG. 2 (1) is restored and the movements shown in FIGS. 2 (1) to (4) are repeated. When these operations are repeated four times, the gear rotates once, and thereafter, by continuously controlling and rotating the gear, it is possible to perform continuous spell folding.

  In this embodiment, the gear body X and the gear body Y are rotated by instructing the respective rotation angles to two independent servo motors and a control device capable of position control (not shown). Further, the increase angle of each of the rotation angles (α1 to 4, β1 to 4) is calculated in advance and held in a table as rotation angle values of the gear body X and the gear body Y in time series, and the control device described above Is instructed. The rotation angle value is calculated so that the distance between the tooth tip portion of the gear body X in contact with the collective electrode sheet and the tooth tip portion of the gear body Y is always the folding pitch dimension value of the sheet. Further, if necessary, the rotation angle value is calculated so that the peripheral speeds of the tooth tip portion and the tooth bottom portion that mesh with each other when the gear body X and the gear body Y are engaged with each other.

  A second embodiment of the folding and laminating step in the present invention will be described in detail with reference to FIG. FIG. 3 is a diagram showing a bending operation in the bending lamination step of this embodiment. This embodiment is a form in which the collective electrode sheet is gripped at the tooth bottom portion of the gear body Y as compared with the first embodiment. Other configurations (such as control of the gear body) other than those described below are the same as those in the first embodiment.

  In this embodiment, at least for the gear body Y (which is gripped by the tooth bottom portion), the distance between the tooth tip portion and the tooth bottom portion adjacent to the tooth tip portion is set to the folding pitch dimension value P of the collective electrode sheet. This is a precondition. 2 and 3, for each of the gear body X and the gear body Y, the distance (Ae and the like) between the tooth tip portion and the tooth bottom portion adjacent to the tooth tip portion is set to the collective electrode sheet. The bending pitch dimension value P is set as follows.

  In FIG. 3 (1), the collective electrode sheet 10 fed from the sheet feeding point O is sandwiched between the tooth tip E of the gear body X and the tooth bottom part e of the gear body Y, and is inserted into the tooth tip A of the gear body Y. Shows the bent state. Here, the collective electrode sheet 10 is gripped by the above-described means also at the tooth bottom part e.

  When time elapses from the state of FIG. 3A, the state of FIG. 3B is obtained. In this state, the tooth tip portion A of the gear body Y is at a position corresponding to the length of the inflowing collective electrode sheet 10 (increases to the rotation angle α2) and is adjacent to the tooth tip portion A in the same gear body Y. The collective electrode sheet 10 is also gripped by the tooth bottom portion e. In this state, the gear body X does not contribute to the bending of the collective electrode sheet 10, but in order to avoid contact with the gear body Y and the non-bent portion of the collective electrode sheet, the gear body X is similar to the case of FIG. The tooth tip E of the body X is rotated to a position where the distance between tooth tips AE = P (increase to the rotation angle β2).

  FIG. 3 (3) shows a state in which the gear body X and the gear body Y are rotated by 90 degrees relative to FIG. 3 (1). The collective electrode sheet 10 fed from the sheet feeding point O is sandwiched between the tooth tip portion A of the gear body Y and the tooth bottom portion a of the gear body X and bent at the tooth tip portion F of the gear body X. In this state, the gripping of the collective electrode sheet 10 is continued at the tooth bottom part e adjacent to the tooth tip part A.

  When the time further elapses, the state shown in FIG. In this state, the tooth tip portion F of the gear body X is in a position corresponding to the length of the collective electrode sheet 10 that has flowed (increased to the rotation angle β4), and the tooth tip portion A of the gear body Y is Corresponding to the position of the tooth tip F, the tooth tip portion distance FA with which the collective electrode sheet is in contact is FA = P (increase to the rotation angle α4). Further, the collective electrode sheet 10 is released from the tooth bottom portion e of the gear body Y. The release timing of the collective electrode sheet 10 is not particularly limited to the time shown in FIG. 3 (4), and may be any time when the released sheet does not interfere with each gear body and is not caught in the rotating body.

  If the time further elapses from here, the positional relationship of FIG. 3 (1) is returned and the above-described movements of FIGS. 3 (1) to (4) are repeated. When these operations are repeated four times, the gear rotates once, and thereafter, by continuously controlling and rotating the gear, it is possible to perform continuous spell folding.

  In this embodiment, the tooth bottom portion for gripping the collective electrode sheet may be at least one gear body. In addition to the form gripped by the tooth bottom portion of the rotating body Y shown in FIG. It is good also as a form to hold | grip. As shown in this embodiment, even when it is difficult to grip only the tooth tip, it is possible to easily grip the tooth bottom by providing the above-mentioned suction function and the like, and grip at the tooth bottom. It is possible to bend using

  As shown in FIG. 2 and FIG. 3, in these embodiments, the collective electrode sheet is folded by using the tooth tip portions of the gear body X and the tooth tip portions of the gear body Y alternately. The gripping is performed only at the tooth tip portion or the tooth bottom portion. Further, as shown in FIG. 2 (1) and the like, the gear body X and the gear body Y have a structure in which the tooth tip portion and the tooth bottom portion mesh with each other, and the tooth tip portion of one gear body and the tooth of the other gear body. In a state where the bottom portion is in indirect contact with each other, the collective electrode sheet is sandwiched and held therebetween. As described above, the contact portion between the collective electrode sheet and the gear body is limited to the tooth tip portion or the tooth bottom portion over the entire operation during the folding and laminating process. Can be prevented.

  Further, each gear body is rotated according to the input amount of the collective electrode sheet from the sheet input point O, and the tooth tip portion of the gear body X and the tooth tip portion of the gear body Y in contact with the collective electrode sheet Since the distance is maintained at a constant value P, the tooth tip portion that has once contacted the collective electrode sheet continues to contact the same location of the collective electrode sheet until it is separated.

  In these embodiments, when the gear body X and the gear body Y are engaged with each other as shown in FIG. 2 (1), the collective electrode sheet is obtained by matching the peripheral speeds of the tooth tip portion and the tooth bottom portion that mesh with each other. It is possible to prevent scratches on the surface of the sheet and foreign matter generation due to the difference in peripheral speed when the gears are engaged with each other.

  The electrode laminate manufacturing apparatus of the present invention is an apparatus used for carrying out the above-described manufacturing method of the present invention, and includes a material supply means for forming the collective electrode sheet and a bending means for folding the collective electrode sheet. It becomes. Further, if necessary, it is provided with cutting means or the like for cutting the assembly electrode sheet that is folded and stacked for each predetermined number of peaks. Referring to FIG. 1, the uncoiler devices 4 a to 4 c, the aligning roller unit 5, and the charging roller unit 6 are material supply units, the folding unit 7 is a folding unit, and the cutting unit 8 is a cutting unit. As described above, as the material supply means and the cutting means, a known device used in the manufacturing process of the electrode stack of the secondary battery can be adopted on the assumption that the material supplying means and the cutting means are closely linked with the bending means. .

  As shown in FIGS. 1-3, the bending part 7 which is a bending means consists of a pair of gear body X and gear body Y which rotate independently and a tooth tip part and a tooth base part mesh. In addition, each gear body can hold the collective electrode sheet 10 at least at the tooth tip portion, and the portions other than the tooth tip portion and the tooth bottom portion do not contact the collective electrode sheet 10. Further, when the gear body X and the gear body Y are bent, the distance between the tooth tip portion of the gear body X in contact with the collective electrode sheet 10 and the tooth tip portion of the gear body Y is the folding pitch dimension of the collective electrode sheet. Each rotates so as to have a value P.

  Each of the gear body X and the gear body Y has a gear shape having a tooth tip portion and a tooth bottom portion, as shown in the drawings, in a vertical cross-sectional shape with respect to the rotation axis. The gear body X and the gear body Y are columnar bodies in which the above vertical cross-sectional shape is continuous in the width direction (rotational axis direction). As a whole, the shape is such that a total of four substantially triangular columnar bodies are combined on each surface of the quadrangular columnar body including the axis. In addition, the four parts (each square vertex position) that are closest to the shaft center on the outer periphery of the gear body are the tooth bottom parts, and the four parts that are the farthest distance (substantially triangular vertexes) are the tooth tip parts. It is. The “distance between the tooth tip portion and the tooth tip portion or the distance between the tooth tip portion and the tooth bottom portion” in the present invention is a distance obtained by connecting the two portions with a straight line in the vertical cross-sectional shape.

  Further, in the vertical cross section, the shape from the adjacent tooth tip portion to the tooth bottom portion is a concave arc shape with respect to a straight line connecting the tooth tip portion and the tooth bottom portion. In this way, by setting the shape from the adjacent tooth tip portion to the tooth bottom portion in the vertical cross-sectional shape to be a shape that is beaten inside the straight line connecting the tooth tip portion and the tooth bottom portion, one of the gears In the body, even when the collective electrode sheet is gripped between the adjacent tooth tip portion and the tooth bottom portion, the sheet does not contact a portion between the tooth tip portion and the tooth bottom portion. In addition to this shape, by controlling the rotation angle, each gear body is configured such that portions other than the tooth tip portion and the tooth bottom portion do not contact the collective electrode sheet.

  In each figure, the number of teeth of each gear body is four, but the number of teeth is not limited to this, and may be five, for example. Moreover, if it is an aspect which can fully suppress generation | occurrence | production of wrinkles etc., it is good also as a shape which is not partly continuous in the width direction.

  The length of the long width direction of the collective electrode sheet is the width of one electrode stack, and is a continuous shape in a strip shape in the long direction. Further, the bending pitch dimension value P is the height of one electrode laminate. The dimension of each gear body in the width direction is equal to or greater than the width dimension of the collective electrode sheet.

  The structure of the collective electrode sheet will be described. The collective electrode sheet is configured such that a separator sheet is sandwiched between a positive electrode sheet and a negative electrode sheet. The positive electrode sheet and the negative electrode sheet are long sheets in which an active material layer is formed on a metal foil current collector. Each sheet is prepared by kneading an active material, a conductive material, a binder, and a dispersion solvent to prepare a slurry, and applying the obtained slurry to a uniform thickness on a metal foil current collector, followed by drying. In the case of forming on both sides, after applying and drying on the other side, it is obtained by pressing the active material with a pressure that does not destroy the shape of the active material.

  In addition, the collective electrode sheet is configured by using any number of sheets, for example, a three-layer structure including one positive electrode sheet, one negative electrode sheet, and one separator sheet, two positive electrode sheets, There is a five-layer structure including one negative electrode sheet and two separator sheets. Regardless of the number of layers of the assembly electrode sheet, it is possible to produce a laminate using the production method and production apparatus of the present invention.

  In the positive electrode sheet, when an aluminum foil is used as the metal foil current collector, the thickness is about 10 to 30 μm, and the thickness excluding the metal foil current collector is about 30 to 120 μm. Moreover, in a negative electrode sheet, when using copper foil for a metal foil collector, the thickness is about 5-20 micrometers, and the thickness except this metal foil collector is about 30-100 micrometers. The separator sheet interposed between the positive electrode sheet and the negative electrode sheet has a thickness of about 10 to 30 μm.

  Since the collective electrode sheet is obtained by superimposing the sheets having the above thicknesses, the thickness thereof is about 90 to 250 μm (in the case of a three-layer structure), and is thin as a whole. Further, when the collective electrode sheet is cut, foreign materials such as active materials and metal foils that are constituent materials are generated from the cut surface, and when these are mixed between the stacked layers, the battery quality may be deteriorated due to a short circuit or the like. The same problem occurs when the active material layer on the surface is damaged by contact with other members and these foreign substances are generated. As described above, the electrode laminate of the secondary battery is required to have a high quality as a whole by eliminating scratches and foreign matters as much as possible from its thinness and structure.

  On the other hand, in the manufacturing method and manufacturing apparatus of the electrode laminate of the present invention, the long sheet-like positive electrode, the negative electrode, and the separator are contacted with the above-described collective electrode sheet by folding the electrode into predetermined dimensions. By using a unique gear body with a minimized area, it is possible to manufacture a high-quality secondary battery electrode stack while realizing high productivity and eliminating scratches and foreign matters as much as possible.

  As described above, the method and apparatus for producing an electrode laminate of the present invention can be suitably used for producing an electrode laminate of a secondary battery because it can eliminate generation of scratches and foreign matters as much as possible while realizing high productivity. . In particular, it can be suitably used for producing an electrode laminate of a large-sized lithium ion secondary battery for use in a power source or power storage.

DESCRIPTION OF SYMBOLS 1 Positive electrode sheet 2 Separator sheet 3 Negative electrode sheet 4a-4c Uncoiler device 5 Matching roller part 6 Input roller part 7 Bending part 8 Cutting part 9 Contracting part 10 Collective electrode sheet 11 Electrode laminated body

Claims (4)

A method for producing an electrode laminate comprising a positive electrode, a negative electrode, and a separator used in a secondary battery,
A material supply step of forming a collective electrode sheet with the long sheet-shaped separator sandwiched between the long sheet-like positive electrode and the negative electrode, and the collective electrode sheet comprises a tooth tip portion and a tooth bottom portion. Folding stack that is inserted between a pair of gear bodies X and Y that rotate independently and meshes and uses the tooth tip portions of the gear body X and the tooth tip portions of the gear body Y alternately. A process,
In the bending and laminating step, the collective electrode sheet is not brought into contact with the portions other than the tooth tip portion and the tooth bottom portion of each gear body, and the tooth tip portion of the gear body X and the tooth of the gear body Y in contact with the collective electrode sheet. The distance from the tip is the bending pitch dimension value of the collective electrode sheet ,
A method for manufacturing an electrode laminate, wherein the peripheral speeds of the tooth tip portion and the tooth bottom portion that mesh with each other when the gear body X and the gear body Y are engaged with each other.   In the bending and laminating step, at least one of the gear bodies is configured to grip the collective electrode sheet at a tooth tip portion and a tooth bottom portion, and the gear body is adjacent to the tooth tip portion and the tooth tip portion. The method for producing an electrode laminate according to claim 1, wherein the distance from the tooth bottom portion is a bending pitch dimension value of the collective electrode sheet. In the bending and laminating step, the gear body is set such that the distance between the tooth tip portion of the gear body X and the tooth tip portion of the gear body Y, which is in contact with the collective electrode sheet, becomes the folding pitch dimension value of the collective electrode sheet. 3. The method for manufacturing an electrode laminate according to claim 1, wherein each gear body is rotated while managing a rotation angle between X and the gear body Y. 4. An electrode laminate manufacturing apparatus used in the manufacturing method according to any one of claims 1 to 3 ,
A material supply means for forming the collective electrode sheet; and a folding means for folding the collective electrode sheet.
The bending means comprises a pair of independently rotating gear body X and gear body Y in which the tooth tip portion and the tooth bottom portion mesh with each other, and each gear body can grip the collective electrode sheet at least at the tooth tip portion, A portion other than the tooth tip portion and the tooth bottom portion is configured not to contact the collective electrode sheet,
When the gear body X and the gear body Y are bent, the distance between the tooth tip portion of the gear body X in contact with the collective electrode sheet and the tooth tip portion of the gear body Y is the folding pitch dimension of the collective electrode sheet. Rotate to each value ,
An apparatus for manufacturing an electrode laminate, wherein when the gear body X and the gear body Y are engaged, the peripheral speeds of the tooth tip portion and the tooth bottom portion that mesh with each other coincide .

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