JP2009064686A - Manufacturing method and device of wound electrode body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing device of a wound electrode body in which a sheet-like electrode is wound highly accurately. <P>SOLUTION: The manufacturing method of a wound electrode body comprises a process to insert a tip portion 85a of a sheet-like electrode 84b between two sheets of sheet-like separators 85a, 86b, and a process in which a roller 40 is pressed onto the winding core 20 from the outside of the outside separator 86b and the tip portion 85b of the sheet-like electrode 84b inserted is pinched between the roller 40 and the winding core 20. The outside separator 86b is supplied to the winding core 20 so that it may be wound to the winding core 20 at the further front part in winding core rotation direction than the pressing position 41 of the roller 40, and in the pinching process, the roller 40 presses the tip portion 85b of the sheet-like electrode 84b toward the rotation center C of the winding core 20 together with the sheet-like separators 85a, 86b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing an electrode body used for a battery. Specifically, the present invention relates to a manufacturing method and a manufacturing apparatus for a wound electrode body having a spiral structure.

  In recent years, lithium-ion batteries, nickel-metal hydride batteries, and other secondary batteries have become increasingly important as power sources for vehicles or as power sources for personal computers and portable terminals. In particular, a lithium ion battery that is lightweight and obtains a high energy density is expected to be preferably used as a high-output power source mounted on a vehicle.

  As one of this type of battery, a battery structure including a wound electrode body having a spiral structure is known. By making the electrode body spiral, the reaction area of the positive and negative electrodes can be increased, thereby increasing the energy density and enabling high output. The wound electrode body is composed of a sheet-like positive electrode, a negative electrode, and a separator, and is manufactured by stacking and winding each sheet. Various methods have been proposed as a method for manufacturing such a wound electrode body. A conventional construction method will be described with reference to FIGS. 6A to 6D.

  First, as shown in FIG. 6A, the two sheet-like separators 92a and 92b are inserted into the slit 91 of the core 90, and the core 90 is slightly rotated in this state to wind the sheet-like separators 92a and 92b.

  Next, as shown in FIG. 6B, between the wound outer separator 92a and the inner separator 92b, the tip of one of the positive and negative (for example, negative) sheet-like electrode 94 held by the chuck 96 and guided. Insert a part.

  Then, as shown in FIG. 6C, the roller 98 is pressed against the outer separator 92a from the outside of the outer separator 92a. Thereby, the front-end | tip part of the sheet-like electrode 94 can be pinched between the roller 98 and the core 90 with the sheet-like separators 92a and 92b.

  Subsequently, as shown in FIG. 6D, the chuck 96 that holds the sheet-like electrode 94 is opened, and tension is applied to the sheet 94. In addition, the other (for example, positive electrode) sheet-like electrode (not shown) is inserted and sandwiched between the core 90 and the inner separator 92b by the same operation. Then, by rotating the winding core 90 in this state, a wound electrode body formed by winding a pair of positive and negative (two) sheet-like electrodes and two sheet-like separators is formed (manufactured). According to such a method, since the sheet-like electrode is wound while tension is applied, it is possible to prevent winding deviation of the sheet-like electrode during winding.

As this type of prior art, for example, Patent Document 1 is cited. In Patent Document 1, when forming a wound body composed of an electrode and a separator, a wound electrode that suppresses the occurrence of loosening or winding deviation by applying a back tension (backward tension) to each sheet. A body manufacturing apparatus is described. Moreover, patent documents 2-4 are mentioned as a prior art regarding another winding apparatus.
JP 2000-182657 A JP-A-10-255812 JP-A-5-74446 JP 2003-68350 A

  However, with the conventional method described above, it is possible to prevent the winding deviation of the sheet-like electrode that occurs during winding, but it is difficult to prevent the winding deviation that occurs at the beginning of winding. That is, as shown in FIG. 6C, the sheet-like electrode 94 cannot be tensioned until its tip is nipped (clamped) between the roller 98 and the core 90, and is in a tension-free state. Therefore, if the roller 98 presses the tip of the tension-free sheet electrode 94, the sheet electrode 94 whose movement is restricted by the pressing force (clamping force) of the roller 98 may be loosened.

  The present invention was created to solve the problems in the initial operation (start of winding) of the conventional winding process, and the main object of the present invention is to provide a wound electrode body in which a sheet-like electrode is wound with high accuracy. It is to provide a manufacturing method. Moreover, the other object of this invention is to provide the manufacturing apparatus of the wound electrode body by which such a sheet-like electrode was wound with sufficient precision.

  The method for producing an electrode body provided by the present invention is a method for producing an electrode body having a spiral structure (hereinafter referred to as “winding electrode body”). Specifically, a pair of positive and negative sheet-shaped electrodes (that is, a pair of strip-shaped positive and negative electrodes before winding on a wound electrode body) and two sheet-shaped separators (that is, a strip-shaped separator before winding on a wound electrode body) It is a manufacturing method of the wound electrode body provided.

  The method for producing a wound electrode body according to the present invention includes the step of winding the two sheet-shaped separators around the outer periphery of the core, and the positive and negative between the two sheet-shaped separators wound around the outer periphery of the core. A step of inserting the tip portion of one of the sheet-like electrodes, and a pressing member (typically a roller) from the outside of the outer separator disposed outside the two sheet-like separators. The step of sandwiching the tip of the inserted sheet-like electrode between the pressing member and the core together with the two separators, and rotating the core while pressing with the pressing member, Winding the sheet electrode together with the sheet separator.

  Here, the outer separator is supplied to the core so as to be wound around the core ahead of the pressing position of the pressing member in the core rotation direction. In the nipping step, the pressing member is configured to press the tip portion of the inserted sheet-like electrode together with the sheet-like separator toward the rotation center of the core.

  According to the method of manufacturing the wound electrode body, in the initial operation (starting winding) stage of the winding process, the outer separator is wound around the core in the front of the pressing direction of the pressing member in the core rotation direction. Since it supplies, the clearance gap between two separators in the pressing position of this pressing member (in other words, the clearance gap for inserting the front-end | tip part of a sheet-like electrode) can fully be ensured. As a result, the sheet leading edge can be inserted and arranged up to a position where the gap between the two separators is deep (that is, ahead of the pressing position of the pressing member in the winding core rotation direction). It can be set as the structure which can be firmly pressed (clamped) with a member.

  In addition, since the tip portion is pressed together with the two separators toward the rotation center of the core, it can be avoided that the pressing force of the pressing member acts in the direction of loosening the sheet. That is, it is possible to suppress loosening of the sheet leading end portion that occurs when pressing (clamping) with the pressing member. Therefore, winding deviation inside the wound electrode body at the beginning of winding can be prevented. As a result, according to the manufacturing method of the present invention, it is possible to provide a battery including a highly reliable wound electrode body in which the sheet-like electrode is wound with high accuracy.

  In a preferable aspect of the manufacturing method disclosed herein, in the insertion step, the tip portion of the sheet-like electrode is located between the two sheet-like separators in front of the pressing position by the pressing member in the core rotation direction. It is inserted.

  According to the manufacturing method described above, the leading end portion of the sheet-like electrode can be inserted and arranged up to a position where the gap between the two separators is deep (that is, ahead of the pressing position of the pressing member in the winding core rotation direction). Therefore, it can be set as the structure which can press the said sheet | seat front-end | tip part firmly with a pressing member (clamp).

  In a preferred aspect of the manufacturing method disclosed herein, the pressing member is moved so as to pull the outer separator, which is in contact with the pressing member, together with the tip portion of the sheet-like electrode in the winding core rotation direction. And

  According to the above manufacturing method, when the leading end portion of the sheet-like electrode is pressed (clamped) by the pressing member, the leading end portion of the sheet is pulled by the pressing member in the core rotation direction (that is, the direction opposite to the direction in which the sheet is loosened). be able to. For this reason, it is possible to further suppress the loosening of the leading end of the sheet due to the pressing of the pressing member.

  In addition, it is preferable that the said winding process is performed in the state in which the said sheet-like electrode and the sheet-like separator were tensioned. Thereby, generation | occurrence | production of the winding shift | offset | difference (typically winding shift | offset | difference in the width direction of each sheet | seat) of the sheet-like separator and sheet-like electrode during winding can be suppressed.

  In addition, before performing the winding, the step of inserting the other sheet-like electrode of the positive and negative between the inner separator disposed inside the two sheet-like separators and the core including. In the winding step, the winding core is rotated while being pressed by the pressing member, and the pair of positive and negative sheet-like electrodes are wound together with the two separators, thereby preventing winding deviation at the beginning of winding. A wound electrode body wound with high accuracy can be manufactured.

  The present invention also provides an apparatus for producing a wound electrode body in which a pair of positive and negative sheet-like electrodes and two sheet-like separators are wound around a winding core.

  That is, the manufacturing apparatus according to the present invention includes a first insertion unit that inserts a leading end portion of any one of the positive and negative sheet-like electrodes between two sheet-like separators wound around the outer periphery of the core. Pressing against the core from the outside of the outer separator disposed outside the two sheet-shaped separators, the leading end portion of the inserted sheet-shaped electrode between the two cores together with the two separators A pressing member (typically, a roller) that sandwiches and a winding means that rotates the winding core while pressing with the pressing member to wind the sheet electrode together with the sheet separator.

  Here, the outer separator is supplied to the core so as to be wound around the core ahead of the pressing position of the pressing member in the core rotation direction. And the said pressing member is comprised so that the front-end | tip part of the said sheet-like electrode may be pressed toward the rotation center of the said core with the said sheet-like separator.

  According to the above-described wound electrode body manufacturing apparatus, the outer separator is wound around the core in the core rotation direction in front of the pressing position of the pressing member in the initial operation (starting winding) stage of the winding process. Since it supplies, the clearance gap between two separators in the pressing position of this pressing member (in other words, the clearance gap for inserting the front-end | tip part of a sheet-like electrode) can fully be ensured. As a result, the sheet leading edge can be inserted and arranged up to a position where the gap between the two separators is deep (that is, ahead of the pressing position of the pressing member in the winding core rotation direction). It can be set as the structure which can be firmly pressed (clamped) with a member.

  In addition, since the tip portion is pressed together with the two separators toward the rotation center of the core, it can be avoided that the pressing force of the pressing member acts in the direction of loosening the sheet. That is, it is possible to suppress loosening of the sheet leading end portion that occurs when pressing (clamping) with the pressing member. Therefore, winding deviation inside the wound electrode body at the beginning of winding can be prevented. As a result, according to the manufacturing apparatus of the present invention, it is possible to provide a battery including a highly reliable wound electrode body in which the sheet-like electrode is wound with high accuracy.

  In a preferred aspect of the manufacturing apparatus disclosed herein, the first insertion means is configured such that the front end portion of the sheet-like electrode is positioned in front of the pressing position by the pressing member in the direction of rotation of the core, and the sheet-like electrode is positioned on the two sheets Is configured to be inserted between the separators.

  According to such a device configuration, the leading end portion of the sheet-like electrode can be inserted and arranged up to a position where the gap between the two separators is deep (that is, ahead of the pressing position by the pressing member in the core rotation direction). The sheet tip portion can be firmly pressed (clamped) by the pressing member.

  In a preferred aspect of the manufacturing apparatus disclosed herein, the pressing member is configured to move so as to pull the outer separator, which is in contact with the pressing member, together with the tip portion of the sheet-like electrode in the core rotation direction. Has been.

  According to the manufacturing apparatus, when pressing (clamping) the leading end portion of the sheet-like electrode, the pressing end member can pull the leading end portion of the sheet in the core rotation direction (that is, the direction opposite to the direction in which the sheet is loosened). For this reason, it is possible to further suppress the loosening of the leading end of the sheet due to the pressing force of the pressing member.

  In the manufacturing apparatus of the present invention, the other of the positive and negative sheet-like electrodes is inserted between the inner separator disposed inside the two sheet-like separators and the core. Insertion means. Then, by rotating the winding core by the winding means and winding the pair of positive and negative sheet-like electrodes together with the two separators, the winding is prevented from being generated at the beginning of winding and wound with high accuracy. A wound electrode body can be manufactured.

  The inventor of the present application has been working on the development of a manufacturing apparatus for a wound electrode body in which a sheet electrode and a sheet separator are wound. In particular, winding deviation is likely to occur at the beginning of winding of the wound electrode body. I found the phenomenon. Therefore, the inventor of the present application intensively studied the cause of the occurrence of many winding deviations at the beginning of winding in a typical wound electrode body manufacturing apparatus, and obtained the following knowledge.

  That is, as shown in FIG. 7A, in a typical wound electrode body manufacturing apparatus, the center line C1 of the pressing member (here, a roller) 98 and the center line C2 of the winding core 90 are not aligned with each other. Therefore, when the leading end portion of the sheet-like electrode 94 is sandwiched between the two, the pressing force “F0” of the roller 98 acting on the leading end portion of the sheet is in two directions, that is, in the direction of the rotation center of the core 90. It is broken down into a working force “F1” and a working force “F2” in the tangential direction of the core 90. The force “F2” acting in the tangential direction of the core 90 is opposite to the traveling direction of the sheet-like electrode 94 (that is, the rotational direction of the core 90). Works. At the initial operation (starting of winding) stage of the winding process, the leading end portion of the sheet-like electrode 94 is in a tension-free state, so that a large slack 95 occurs when it is held by the roller 98.

  Then, as shown in FIG. 7B, by winding the sheet-like electrode 94 in which the slack 95 is generated as it is, this is a main cause of occurrence of winding deviation inside the wound electrode body at the beginning of winding. . The inventor of the present application can suppress the slack of the sheet-like electrode (and pulling the wound electrode body) by pressing the roller so that the force acts in a direction that does not loosen the tip of the sheet-like electrode. The present invention was found out and the present invention was achieved.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following drawings, members / parts having the same action are described with the same reference numerals. In addition, this invention is not limited to the following embodiment. In addition, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect actual dimensional relationships. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention (for example, a method for producing an electrode active material, a general technique relating to construction of a battery, etc.) It can be grasped as a design matter of those skilled in the art based on the prior art. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

  With reference to FIG. 1, the structure of the sheet-like electrode body 82 which comprises the winding electrode body of this embodiment is demonstrated easily. FIG. 1 is a diagram for explaining a configuration of a wound electrode body.

  The wound electrode body 80 of the present embodiment is formed by winding a sheet-like electrode body 82 (hereinafter referred to as “electrode body sheet”). The electrode body sheet 82 has a long (strip-shaped) sheet structure in the stage before assembling the wound electrode body 80. The electrode sheet 82 according to the present embodiment is a sheet-like electrode 84a, 84b (specifically, a sheet-like positive electrode 84a (hereinafter referred to as “positive electrode sheet”) and a sheet, similarly to a wound electrode body of a typical battery. The negative electrode 84b (hereinafter referred to as “negative electrode sheet”) is composed of a total of two sheet-like separators 86a and 86b (hereinafter referred to as “separator sheets”).

  Next, the configuration of the manufacturing apparatus 100 for the wound electrode body 80 will be described with reference to FIGS. 2A and 2B. FIG. 2A is a schematic view schematically showing the configuration of the manufacturing apparatus 100, and FIG. 2B is an enlarged view of a main part in which the periphery of the winding core 20 is enlarged at the stage of the initial operation (start of winding) of the winding process.

  As shown in FIG. 2A, in the wound electrode body manufacturing apparatus 100, the electrode body sheet 82 (that is, the positive and negative electrode sheets 84a and 84b and the two separator sheets 86a and 86b) are respectively rolled (54a, 54b, 56a, 56b), and is wound as a wound electrode body by the winding core 20 while being pressed by the touch roller 40. Each sheet line is provided with tension rollers 64a, 64b, 66a, 66b, respectively, so that tension (tension) is applied to each sheet during winding.

  The winding core 20 is configured to wind up the drawn electrode body sheet 82 and to be removed from the wound electrode body after the winding is completed. As shown in FIG. 2B, the core 20 is attached to a core support portion 22 (winding means). The core support part 22 is connected to a drive source (typically a motor) (not shown), and supports the core 20 so as to be rotatable in one direction. The core support portion 22 is configured to wind the electrode body sheet 82 (the positive and negative electrode sheets 84a and 84b and the two separator sheets 86a and 86b) by rotating the core 20. The core 20 is formed with a slit 21 that guides the separator sheets 86a and 86b.

  A touch roller 40 as a pressing member is disposed below the core 20. The touch roller 40 is configured to be pressed against the core 20 from the outside of the outer separator 86b (a separator disposed outside the two separator sheets 86a and 86b). Specifically, the touch roller 40 is rotatably attached to the roller support portion 42. The roller support portion 42 is connected to a pressing mechanism (not shown), and the pressing mechanism moves the roller support portion 42 in a predetermined direction (up and down linear direction in the illustrated example) to press the touch roller 40 against the core 20. It is configured. Here, the center line C1 of the touch roller 40 and the center line C2 of the winding core 20 are arranged so as to overlap each other.

  FIG. 2B shows an enlarged view of the periphery of the winding core 20 in the initial operation (starting winding) stage of the winding process. As shown in FIG. 2B, the negative electrode chuck 30b (first insertion means) is attached in the line of the negative electrode sheet 84b. The negative electrode chuck 30b is configured to insert a leading end portion 85b of the negative electrode sheet 84b (a part where the negative electrode sheet starts to be wound at the initial operation stage) into a predetermined position. Specifically, the negative electrode chuck 30b includes gripping rollers 32 and 34 that grip the sheet leading end portion 85b in the vicinity of the core 20, and a drive mechanism (not shown) that moves the negative electrode chuck 30b. The drive mechanism is configured to move the negative electrode chuck 30b in a predetermined direction (left direction in the drawing) and guide the sheet leading end portion 85b held by the holding rollers 32 and 34 between the separator sheets 86a and 86b.

  Although omitted in FIG. 2B, the positive electrode chuck 30a (second insertion means) is disposed in the line of the positive electrode sheet 84a. The positive electrode chuck 30a has the same structure as the negative electrode chuck 30b (that is, a gripping roller and a drive mechanism), and the tip portion of the positive electrode sheet 84a (the portion where the positive electrode sheet starts to be wound in the initial operation stage) It is configured to be inserted between the separator sheet 86a (a separator disposed inside the two separators 86a and 86b).

  Next, the operation of the manufacturing apparatus 100 of this embodiment and the winding process of the wound electrode body will be described in order with reference to FIGS. 3A to 3F. 3A to 3F, the positive electrode chuck 30a is omitted.

First, as shown in FIG. 3A, the two separator sheets 86 a and 86 b are wound around the core 20. Specifically, the two separator sheets 86a and 86b are pulled out from the roll states 56a and 56b, passed through the slit 21 provided in the core 20, and tensioned by the tension rollers 66a and 66b to the separator sheets 86a and 86b. (For example, 100 gf (about 0.98 N) / cm ² ) is added while rotating the core 20 while rotating (for example, one rotation). Thus, first, the separator sheets 86a and 86b are wound around the outer periphery of the core.

  At this time, the outer separator 86b is supplied to the core 20 so as to be wound around the core 20 in front of the pressing position 47 of the touch roller 40 described later in the core rotation direction. In other words, the supply position 89 of the outer separator 86b is arranged on the downstream side (that is, the front side) in the core rotation direction with respect to the pressing position 47 of the touch roller 40.

Next, preparation for winding the negative electrode sheet 84b around the core 20 is performed. That is, the negative electrode sheet 84b is pulled out from the roll state 54b, and tension (for example, 100 gf / cm ² ) is applied to the negative electrode sheet 84b with the tension roller 64b. Hold it. As a result, a tension (for example, 100 gf / cm ² ) is applied to the rear side of the sheet from the gripping position of the gripping rollers 32 and 34, but the tension roller is positioned to the front of the sheet from the gripping position of the gripping rollers 32 and 34. No tension is applied by 64b, and the tension becomes free.

  Next, as shown in FIG. 3B, the negative electrode chuck 30b is moved in a predetermined direction (left direction in the figure), and the sheet leading end portion 85b is inserted between the two separators 86a and 86b wound around the outer periphery of the winding core 20. To do.

  At this time, the sheet leading end portion 85b is inserted so as to be disposed between the two sheet-like separators in front of the pressing position 47 by the touch roller 40 described later in the winding core rotation direction. That is, the end side 87 of the sheet leading end portion 85 b is disposed downstream of the pressing position 47 of the touch roller 40 in the winding core rotation direction.

  Subsequently, the touch roller 40 is moved in a predetermined pressing direction (vertically upward in the drawing), and the touch roller 40 is pressed (clamped) from the outside of the outer separator sheet 86b to the core 20. By the pressing (clamping) of the touch roller, the leading end portion 85b of the negative electrode sheet 84b is held between the touch roller 40 and the core 20 together with the two separator sheets 86a and 86b.

  At this time, as indicated by an arrow “72”, the touch roller 40 presses the tension-free sheet leading end portion 85b toward the rotation center C of the core 20 together with the separator sheets 86a and 86b.

  Next, as shown in FIG. 3D, while pressing the touch roller 40 against the core 20, the core 20 is slightly rotated in the direction of the arrow “70”, and the leading end of the sheet is held between the touch roller 40 and the core 20. The part 85 b is wound around the core 20. The winding of the leading end portion 85b of the sheet can prevent the negative electrode sheet 85b from being easily detached from the core 20 even when a tension is applied to the negative electrode sheet 85b. Therefore, the gripping rollers 32 and 34 of the negative electrode chuck 30b are opened to open the negative electrode sheet. Apply tension to 84b. In this way, preparation for winding the negative electrode sheet 84b around the core 20 is completed.

Next, as shown in FIG. 3E, preparation is made to wind up the positive electrode sheet 84 a around the core 20. In the present embodiment, the positive electrode sheet 84a is pulled out from the roll state 54a, and the tip end portion 85a of the sheet is gripped by the gripping roller of the positive electrode chuck while applying tension (for example, 100 gf / cm ² ) to the positive electrode sheet 84a by the tension roller 64a. Then, the positive electrode chuck is moved while slowly rotating the winding core 20 in the arrow “70” direction, and the sheet leading end portion 85a is inserted between the winding core 20 and the inner separator sheet 86a. The sheet leading end portion 85 a is guided to the pressing position 47 of the touch roller 40 while being placed on the inner separator sheet 86 a and is wound on the core 20. Then, the gripping roller of the positive electrode chuck is opened to apply tension to the positive electrode sheet 84a. In this way, preparation for winding the positive electrode sheet 84a around the core 20 is completed.

  In this embodiment, preparation for winding the negative electrode sheet is first performed, and then preparation for winding the positive electrode sheet is performed. However, such preparation may be performed simultaneously. That is, it is possible to insert the leading end portion 85b of the negative electrode sheet between the two separators 86a and 86b while inserting the leading end portion 85a of the positive electrode sheet between the core 20 and the inner separator 86a.

  When the preparation for winding up the positive and negative electrode sheets 84a and 84b and the two separator sheets 86a and 86b is completed in this way, the core 20 is then pushed with the arrow “70 while being pressed by the touch roller 40 as shown in FIG. 3F. ”In the direction. Thereby, the positive electrode sheet 84 a, the negative electrode sheet 84 b and the two separator sheets 86 a and 86 b are wound around the core 20 while being tightened by the touch roller 40. Then, the positive electrode sheet 84a, the negative electrode sheet 84b, and the two separator sheets 86a and 86b are cut at the end position so that each of the separator sheets 86a and 86b has a predetermined length (for example, 4 m50 cm) at the end of winding. A wound electrode body is manufactured (formed) by winding the end portion. In this way, the winding process of the wound electrode body is completed.

  According to the manufacturing method and the manufacturing apparatus of the wound electrode body of the present embodiment, the outer separator 86b is moved more in the core rotation direction than the pressing position 47 of the touch roller 40 in the initial operation (starting winding) stage of the winding process. Since it is supplied so as to be wound around the core 20 in the front, the gap between the two separators 86a and 86b at the pressing position 47 of the touch roller 40 (in other words, to insert the leading end portion 85a of the negative electrode sheet 84b). Can be sufficiently secured. Accordingly, the sheet leading end portion 85b can be inserted and arranged up to a position where the gap between the two separators 86a and 86b is deep (that is, ahead of the pressing position 47 of the touch roller in the core rotation direction). The sheet leading end portion 85b can be configured to be firmly pressed (clamped) by the touch roller 40.

  In addition, since the tip end portion 85b is pressed together with the two separators 86a and 86b toward the rotation center of the core 20, it can be avoided that the pressing force of the touch roller acts in the direction of loosening the sheet. . That is, it is possible to prevent the sheet leading end portion 85b from being loosened when pressed (clamped) by the touch roller. Therefore, winding deviation inside the wound electrode body at the beginning of winding can be prevented. As a result, a battery including a highly reliable wound electrode body in which the negative electrode sheet 84b is wound with high accuracy can be provided.

  Further, the winding process is executed in a state where tension is applied to the positive and negative electrode sheets 84a and 84b and the two separators 86a and 86b, respectively. Generation of winding misalignment in the width direction of the sheet can be suppressed.

  In this embodiment, an example in which the leading end portion 85b of the negative electrode sheet 84b is clamped by the touch roller 40 has been described. However, if the touch roller 40 is pressed in the direction of the rotation center C of the core 20, the sheet is positive or negative. The looseness of the tip portion can be suppressed. Therefore, for example, the tip portion of the positive electrode sheet 84a may be clamped by the touch roller 40 with the positive and negative positions reversed.

  Further, in this embodiment, as shown in FIG. 3B, an example in which the touch roller 40 is moved in a vertically upward linear direction is shown, but the leading end portion of the sheet is placed on the core 20 regardless of the pressing direction of the touch roller 40. If the sheet is configured to be pressed toward the rotation center C of the sheet, it is possible to suppress the looseness of the leading end portion of the sheet. Therefore, for example, as illustrated in FIGS. 4A and 4B, the pressing of the touch roller 40 You may arrange | position an apparatus structural member so that a direction may become a diagonally upward direction instead of a vertically upward direction.

  Further, the direction in which the touch roller 40 is moved is not limited to the linear direction. For example, as shown in FIGS. 5A and 5B, the touch roller 40 can be moved around the fulcrum 75 so as to draw an arc. According to such a configuration, the touch roller 40 can be moved so as to pull the outer separator 86b that comes into contact with the sheet, together with the sheet leading end portion 85b, in the core rotation direction (that is, the direction opposite to the direction in which the sheet is loosened). . For this reason, it is possible to further suppress the loosening of the leading edge of the sheet due to the pressing (clamping) of the touch roller 40.

  Hereinafter, returning to FIG. 1, the material constituting the wound electrode body 80 will be described in detail. The wound electrode body 80 according to the present embodiment is a wound electrode body 80 produced by winding the positive electrode sheet 84a and the negative electrode sheet 84b while slightly shifting the same as the wound electrode body of a normal lithium ion battery. .

  As shown in FIG. 1, the positive electrode sheet 84a can be formed by attaching a positive electrode active material layer 81a for a battery to both surfaces of a sheet-like positive electrode current collector. However, the positive electrode active material layer 81a is not attached to one side edge (the lower side edge in the figure) along the longitudinal direction of the positive electrode sheet 84a, and the positive electrode current collector is exposed with a certain width. An active material layer non-forming portion 83a is formed. The negative electrode sheet 84b has the same configuration as the positive electrode sheet 84a, and can be formed by attaching the negative electrode active material layer 81b to both surfaces of a sheet-like negative electrode current collector. A negative electrode active material layer non-forming portion 83b in which the negative electrode current collector is exposed can be formed on one side edge (upper side edge in the drawing) of the negative electrode sheet 84b.

In addition, the material and member itself which comprise this winding electrode body 80 may be the same as that of the electrode body of the conventional lithium ion battery, and there is no restriction | limiting in particular. For example, an aluminum foil (this embodiment) or other metal foil suitable for the positive electrode is preferably used for the positive electrode current collector. As the positive electrode active material, one or more of materials conventionally used in lithium ion batteries can be used without any particular limitation. Preferable examples include LiMn ₂ O ₄ , LiCoO ₂ , LiNiO _{2 and the} like.

  On the other hand, for the negative electrode current collector, a copper foil (this embodiment) or other metal foil suitable for the negative electrode is preferably used. As the negative electrode active material, one or more of materials conventionally used in lithium ion batteries can be used without any particular limitation. Preferable examples include carbon-based materials such as graphite carbon and amorphous carbon, lithium-containing transition metal oxides and transition metal nitrides.

  Examples of the separator sheets 86a and 86b include those made of a porous polyolefin resin. For example, a porous separator sheet made of synthetic resin (for example, made of polyolefin such as polyethylene) can be suitably used. When a solid electrolyte or a gel electrolyte is used as the electrolyte, there may be a case where a separator is unnecessary (that is, in this case, the electrolyte itself can function as a separator).

  In addition, a battery can be manufactured by accommodating the wound electrode body 80 thus formed in a container together with an electrolyte. The configuration of such a battery is not particularly limited. A nickel-metal hydride battery, an electric double layer capacitor, etc. are mentioned as a suitable battery structure. A battery configuration particularly suitable for the implementation of the present invention is a lithium ion secondary battery. Since the lithium ion secondary battery is a battery that can achieve a high output with a high energy density, it is possible to construct a high-performance power source, particularly a power source for mounting on a vehicle.

In this case, the electrolyte is a lithium salt such as LiPF ₆ . An appropriate amount (for example, concentration 1M) of lithium salt such as LiPF ₆ is dissolved in a non-aqueous electrolyte such as a mixed solvent of diethyl carbonate and ethylene carbonate (for example, a mass ratio of 1: 1) and used as an electrolyte. it can. Further, the material of the container is not particularly limited as long as it is the same as that used in a typical battery, but a relatively light material can be used. For example, a metal container whose surface is preferably coated with an insulating resin coating, a polyolefin resin such as polypropylene, and other synthetic resin containers are suitable. The battery is constructed by housing the wound electrode body 80 in a container and injecting and sealing the electrolyte.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

The figure for demonstrating the structure of a wound electrode body. Schematic which shows typically the structure of the manufacturing apparatus of a wound electrode body. The principal part enlarged view which expanded the periphery of the winding core in the stage of the initial stage operation of the winding process. Process drawing explaining the winding process of a wound electrode body. Process drawing explaining the winding process of a wound electrode body. Process drawing explaining the winding process of a wound electrode body. Process drawing explaining the winding process of a wound electrode body. Process drawing explaining the winding process of a wound electrode body. Process drawing explaining the winding process of a wound electrode body. Process drawing explaining the winding process of the modification of this embodiment. Process drawing explaining the winding process of the modification of this embodiment. Process drawing explaining the winding process of the modification of this embodiment. Process drawing explaining the winding process of the modification of this embodiment. Process drawing explaining the winding process of the conventional winding electrode body. Process drawing explaining the winding process of the conventional winding electrode body. Process drawing explaining the winding process of the conventional winding electrode body. Process drawing explaining the winding process of the conventional winding electrode body. Process drawing explaining the winding process of the conventional winding electrode body. Process drawing explaining the winding process of the conventional winding electrode body.

Explanation of symbols

20 Core 21 Slit 22 Core support 30a Positive chuck 30b Negative chuck 32 Holding roller 40 Touch roller 42 Roller support 47 Pressing position 54a Rolled positive sheet 54b Rolled negative sheet 56a, 56b Rolled separator sheet 64a , 64b, 66a, 66b Tension roller 70 Rotating direction 80 Winding electrode body 81a Positive electrode active material layer 81b Negative electrode active material layer 82 Electrode body sheet 83a Positive electrode active material layer non-formed part 83b Negative electrode active material layer non-formed part 84a Positive electrode sheet 84b Negative electrode sheet 85a Positive electrode sheet front end portion 85b Negative electrode sheet front end portion 86a Inner separator sheet 86b Outer separator sheet 87 End side 89 Supply position 90 Core 91 Slit 92a Sheet-shaped separator 92a Outer separator 92b Inner separator 94 sheet electrode 96 chuck 98 roller 100 manufacturing apparatus center line of the center line C2 core of C rotation center C1 rollers

Claims (9)

A method for producing a wound electrode body comprising a pair of positive and negative sheet-like electrodes and two sheet-like separators,
Winding the two sheet-shaped separators around the outer periphery of the core;
Inserting a tip portion of either positive or negative sheet-like electrode between two sheet-like separators wound around the outer periphery of the core;
A pressing member is pressed against the winding core from the outside of the outer separator disposed between the two sheet-like separators, and a tip portion of the inserted sheet-like electrode between the pressing member and the winding core Sandwiching the two separators together,
Rotating the core while being pressed by the pressing member, and winding the sheet-shaped electrode together with the sheet-shaped separator,
Here, the outer separator is supplied to the core so as to be wound around the core in front of the pressing position of the pressing member in the core rotation direction,
In the nipping step, the pressing member is configured to press the distal end portion of the inserted sheet-shaped electrode together with the sheet-shaped separator toward the rotation center of the winding core. Manufacturing method of electrode body.   In the insertion step, the leading end portion of the sheet-like electrode is inserted so as to be disposed between the two sheet-like separators in front of the pressing position by the pressing member in the core rotation direction. The manufacturing method according to claim 1.   In the holding step, the pressing member is moved so as to pull the outer separator, which is in contact with the pressing member, together with the tip portion of the sheet-like electrode in the core rotation direction. 2. The production method according to 2.   The said winding process is performed in the state in which the said sheet-like electrode and the sheet-like separator were tensioned, The manufacturing method as described in any one of Claims 1-3 characterized by the above-mentioned.   Before performing the winding, the other sheet-like electrode of the positive and negative is inserted between the inner separator disposed inside the two sheet-like separators and the core. The manufacturing method according to any one of claims 1 to 4. An apparatus for producing a wound electrode body comprising a pair of positive and negative sheet-like electrodes and two sheet-like separators,
A first insertion means for inserting a tip portion of one of the positive and negative sheet-like electrodes between two sheet-like separators wound around the outer periphery of the core;
One of the two sheet-like separators is pressed against the core from the outside of the outer separator, and the tip of the sheet-like electrode inserted between the two cores is inserted into the two separators. A pressing member to be held between,
A winding means for rotating the core while pressing with the pressing member, and winding the sheet-like electrode together with the sheet-like separator;
Here, the outer separator is supplied to the core so as to be wound around the core in front of the pressing position of the pressing member in the core rotation direction,
The said pressing member is a manufacturing apparatus comprised so that the front-end | tip part of the said sheet-like electrode may be pressed toward the rotation center of the said core with the said sheet-like separator.   The first insertion means is configured to insert the leading end portion of the sheet-like electrode between the two sheet-like separators in front of the pressing position by the pressing member in the core rotation direction. The manufacturing apparatus according to claim 6.   The manufacturing method according to claim 6, wherein the pressing member is configured to move the outer separator, which is in contact with the pressing member, so as to pull the outer separator together with a tip portion of the sheet-like electrode in a winding core rotating direction. apparatus.   2. A second insertion means for inserting the other of the positive and negative sheet-like electrodes between an inner separator disposed on the inner side of the two sheet-like separators and the core. Item 9. The manufacturing apparatus according to any one of Items 6 to 8.

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