JP2009064687A - Method and apparatus for manufacturing wound electrode body - Google Patents

Abstract

A method and apparatus for manufacturing a wound electrode body in which a sheet-like electrode is wound with high accuracy are provided.
A step of inserting a leading end portion 85b of either positive or negative sheet-like electrode 84b between two sheet-like separators 86a and 86b wound around the outer periphery of a winding core 20, and an outer side of the outer separator 86b. Pressing the pressing member 40 against the winding core and sandwiching the leading end portion of the sheet inserted between the pressing member and the winding core, and the leading end portion of the sheet-like electrode in the direction opposite to the insertion direction of the sheet Applying a tension and stretching the leading end of the sheet; rotating the core to wind the leading end of the stretched sheet; and winding the leading end of the stretched sheet; A wound electrode body manufacturing method including a step of rotating and winding a sheet-shaped electrode together with two sheet-shaped separators.
[Selection] Figure 4B

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 method and apparatus for manufacturing 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. 7A to 7D.

  First, as shown in FIG. 7A, the two sheet-like separators 92a and 92b are inserted into the slit 91 of the winding core 90. In this state, the winding core 90 is slightly rotated to wind the sheet-like separators 92a and 92b.

  Next, as shown in FIG. 7B, between the wound outer separator 92a and the inner separator 92b, the leading end of either positive or negative (for example, negative electrode) sheet electrode 94 that is guided by being gripped by the chuck 96 Insert a part.

  Then, as shown in FIG. 7C, 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. 7D, the chuck 96 that holds the sheet-like electrode 94 is opened to apply tension 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 and 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. 7A, the sheet-like electrode 94 cannot be tensioned until its tip is pinched (clamped) between the roller 98 and the core 90, and is in a tension-free state. Therefore, when 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. .

  More specifically, in a typical wound electrode body forming apparatus, as shown in FIG. 7B, the center line C1 of the roller 98 and the winding core 90 are arranged so that the tip end portion of the sheet electrode 94 can be clamped by the roller 98. Although it is necessary to shift the center line C2, if the center line between the roller 98 and the core 90 is shifted in this way, as shown in FIG. 8A, when the leading end portion of the sheet is pressed (clamped), The pressing (clamping) force of the roller 98 acting on the tip portion acts in a direction to loosen the tip portion. Therefore, a large slack 95 is generated when the roller 98 is clamped. Then, as shown in FIG. 8B, when the sheet-like electrode 94 in which the large slack 95 is generated is wound as it is, a winding deviation is generated inside the wound electrode body in the initial operation (starting winding) stage of the winding process. It may be the main cause and is not preferable.

  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. Another object of the present invention is to provide an apparatus for suitably producing a wound electrode body in which such a sheet-like electrode is wound with high accuracy.

  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-like electrodes (that is, a pair of positive and negative strip-shaped electrodes before winding on a wound electrode body) and two sheet-like separators (that is, a strip-shaped separator before winding on a wound electrode body) are provided. It is a manufacturing method of the winding electrode body wound by the winding core.

  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 a leading end portion of any one of the sheet-like electrodes, and a pressing member pressed against the core from the outside of the outer separator disposed outside the two sheet-like separators; The step of sandwiching the tip portion of the inserted sheet-like electrode with the two separators between the core and a tension is applied to the tip portion of the sheet-like electrode in the direction opposite to the insertion direction of the sheet. A step of stretching the leading end portion of the sheet, a step of rotating the core while pressing by the pressing member, and winding the leading end portion of the stretched sheet, and the stretching After involving tip portion of the sheet, and further rotating the winding core, the sheet electrode and a step of winding together with the sheet-like separator two above.

  According to the above-described method for manufacturing a wound electrode body, in the initial operation (starting winding) stage of the winding process, the leading end portion of the sheet-like electrode that may occur when clamping with a pressing member (typically a roller) Can be removed by applying a back tension. Thereby, it can wind up in the state which tensioned the front-end | tip part of the sheet-like electrode, and can prevent winding deviation of the sheet-like electrode inside the wound electrode body in the winding start stage. Therefore, 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 a sheet-like electrode is wound with high accuracy.

  In a preferable aspect of the manufacturing method disclosed herein, the winding is performed while applying a tension larger than the reverse tension applied to the leading end portion of the sheet (stretching the leading end portion) to the sheet-like electrode. . Thereby, the generation | occurrence | production of the winding shift | offset | difference (typically winding shift | offset | difference in the width direction of a sheet | seat) of the sheet-like electrode during winding can be suppressed.

  Moreover, typically, before performing the winding, the other sheet-like electrode of the positive and negative is connected to the inner separator disposed on the inner side of the two sheet-like separators and the core. Including a step of interposing. In the winding step, the winding core is rotated while being pressed by a pressing member (typically a roller), and a pair of positive and negative sheet-like electrodes are wound together with two separators, so that at the beginning of winding. It is possible to manufacture a wound electrode body that is wound with high accuracy while preventing the occurrence of winding deviation.

  Moreover, this invention provides the manufacturing apparatus of the wound electrode body provided with a pair of positive and negative sheet-like electrodes and two sheet-like separators.

  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 While pressing with the pressing member for holding, a first tension applying means for applying tension to the leading end portion of the sheet-like electrode in the direction opposite to the insertion direction of the sheet and extending the leading end portion of the sheet, Winding means for rotating the winding core to wind up the leading end portion of the stretched sheet-like electrode.

  According to the above wound electrode body manufacturing apparatus, in the initial operation (starting of winding) stage of the winding process, the slack of the leading end portion of the sheet-like electrode that may occur when pressing (clamping) with the pressing member is performed. It can be removed by applying a back tension (tension) by the tension applying means 1. Thereby, it can wind up in the state which tensioned the front-end | tip part of the sheet-like electrode, and can prevent winding deviation of the sheet-like electrode inside the wound electrode body in the winding start stage. Therefore, 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 a sheet-like electrode is wound with high accuracy.

  In a preferred aspect of the manufacturing apparatus disclosed herein, the winding means winds the leading end portion of the stretched sheet, and then further rotates the winding core so that the sheet-like electrode is attached to the two sheets. It is comprised so that it may wind with a sheet-like separator. Further, a second tension applying means for applying a tension larger than the tension by the first tension applying means to the sheet-like electrode at the time of winding is provided. Thereby, the generation | occurrence | production of the winding shift | offset | difference (typically winding shift | offset | difference in the width direction of a sheet | seat) of the sheet-like electrode during winding can be suppressed.

  Typically, the manufacturing apparatus of the present invention is configured such that the other of the positive and negative sheet-like electrodes is disposed between the inner separator disposed between the two sheet-like separators and the core. 2nd insertion means to insert in. 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.

  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 diagram 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 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 (second tension applying means) 64a, 64b, 66a, 66b, and is configured to apply tension (tension) to each sheet during winding. Yes.

  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). In this embodiment, the core support 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). In this embodiment, 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. In this embodiment, the center line C1 of the touch roller 40 and the center of the core 20 can be pressed (clamped) at the leading end portion 85b of the negative electrode sheet 84b in the initial operation (start of winding) stage of the winding process. The line C2 is displaced from the line C2.

  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.

  A servo cylinder (first tension applying means) 10 is attached to the negative electrode chuck 30b. The servo cylinder 10 is configured to apply a tension (tension) to the leading end portion of the sheet in a direction opposite to the insertion direction of the sheet and to stretch the leading end portion of the sheet at the beginning of winding of the negative electrode sheet 84b. . In this embodiment, the servo cylinder 10 includes an actuator (for example, an electric motor) (not shown) and a controller. The actuator controls the negative electrode chuck 30b (particularly, the gripping rollers 32 and 34 that grip the sheet leading end portion 85b) under the control of the controller. The sheet is configured to be retracted in a direction opposite to the sheet insertion direction at a predetermined timing. By controlling the position of the servo cylinder 10, back (reverse direction) tension can be applied to the tip portion of the negative electrode sheet at a predetermined timing.

  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).

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 1 N) / cm ² ) is added while rotating the core 20 (for example, one rotation). Thus, first, the separator sheets 86a and 86b are wound around the outer periphery of the core.

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 a tension roller (second tension applying unit) 64b, while the negative electrode sheet starts to be wound. It is gripped by the gripping rollers 32 and 34 of 30b. As a result, 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.

  Subsequently, as shown in FIG. 4A, the touch roller 40 is moved in a predetermined pressing direction (vertically upward in the figure), 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, the tension-free sheet leading end portion 85b is loosened as shown in the figure by the pressing (clamping) force of the touch roller 40.

From this state, as shown in FIG. 4B, tension is applied to the leading end portion 85b of the sheet in the direction opposite to the insertion direction of the sheet, and the leading end portion 85b of the sheet is stretched. In this embodiment, the actuator of the servo cylinder 10 is operated, and the negative electrode chuck 30b is moved backward together with the gripping rollers 32 and 34 by a predetermined amount (here, about 5 mm). As a result, the leading end portion 85b of the sheet in which the slack has occurred is stretched and is in a taut state. The tension is such that the looseness of the leading end portion 85b of the sheet can be eliminated, and the clamp by the touch roller 40 is not released (that is, the sheet portion sandwiched between the touch roller 40 and the core 20). (In this embodiment, less than 30 gf (about 0.3 N) / cm ² , for example, 0.1 to 0.3 N / cm ² ), and the manufacturing conditions of the wound electrode body It can be appropriately adjusted according to the above. The timing for retracting the negative electrode chuck 30b can be controlled by the controller of the servo cylinder 10. That is, the controller operates the actuator of the servo cylinder 10 to retract the negative electrode chuck 30b based on a signal or the like generated when the touch roller 40 is pressed (clamped) against the core 20.

Next, as shown in FIG. 5A, while the touch roller 40 is pressed against the core 20, the core 20 is slightly rotated in the direction of the arrow "70" (for example, 1/4 rotation) to wind the stretched sheet leading end portion 85b. Wind around the wick 20. The leading end portion 85b can be firmly attached to the core 20 by winding the leading end portion 85b of the sheet. Then, the gripping rollers 32 and 34 of the negative electrode chuck 30b are opened. By opening the gripping rollers 32 and 34, a tension (for example, 100 gf / cm ² ) applied to the rear side of the sheet from the gripping position is transmitted to the leading end portion 85b of the sheet. Therefore, a tension (for example, 1 to 1.5 N / cm) larger than the tension applied to the leading end portion 85b of the sheet shown in FIG. 4B (that is, the tension required to stretch the leading end portion, in this example, less than 30 gf / cm ² ). cm ^2, for example, 100 gf / cm ² ) can be applied to the entire negative electrode sheet 84b. In this way, preparation for winding the negative electrode sheet 84b around the core 20 is completed.

Next, as shown in FIG. 5B, preparation for winding the positive electrode sheet 84 a around the core 20 is performed. In the present embodiment, the positive electrode sheet 84a is pulled out from the roll state 54a, and a tension (for example, 100 gf (about 0.98 N) / cm ² ) is applied to the positive electrode sheet 84a by the tension roller 64a, and the leading end portion 85a of the sheet is moved to Grip with the gripping roller. 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 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.

  In this way, 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, the core 20 is then pushed with the arrow “70 while being pressed by the touch roller 40 as shown in FIG. 5C. ”Further 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 as to have a predetermined length (for example, 4 m50 cm) at the end of winding, respectively. 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 method for manufacturing a wound electrode body of the present embodiment, as shown in FIG. 4B, the negative electrode sheet 84 b that can be generated when clamping with the touch roller 40 in the initial operation (starting winding) stage of the winding process. The slack of the tip end portion 85b of the head can be removed by applying a back tension. As a result, as shown in FIG. 5A, the leading end portion 85b of the negative electrode sheet 84b can be wound tightly, and the winding of the negative electrode sheet 84b inside the wound electrode body at the start of winding is prevented. can do. Therefore, according to the manufacturing method and manufacturing apparatus of the present invention, it is possible to provide a battery including a highly reliable wound electrode body in which the negative electrode sheet 84b is wound with high accuracy.

  Further, the winding process is performed 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, in the configuration of the present invention, the looseness of the leading end portion of the sheet can be suppressed regardless of whether it is positive or negative. For example, the arrangement may be such that the tip portion of the positive electrode sheet 84a is clamped by the touch roller 40 with the positive and negative positions reversed.

  In this embodiment, by retracting the negative electrode chuck 30b while gripping the leading end portion 85b of the negative electrode sheet 84b, a back tension can be applied to the leading end portion 85b with a very simple configuration. Further, the retraction of the negative electrode chuck 30b can be easily and reliably executed by the position control of the servo cylinder 10.

  In this embodiment, the servo cylinder 10 is used as the first tension applying means. However, the negative electrode chuck 30b (particularly, the gripping rollers 32 and 34 for gripping the leading end portion of the sheet) is retracted at a predetermined timing. If it is possible, back tension can be applied to the leading end portion 85b of the sheet, and therefore the first tension applying means is not limited to the servo cylinder 10.

  For example, as shown in FIGS. 6A and 6B, the pair of gripping rollers 32 and 34 can be moved backward by the urging force of the compressed elastic members 12 and 14. The elastic member is, for example, the springs 12 and 14. As shown in FIG. 6A, the springs 12 and 14 are attached to a pair of gripping rollers 32 and 34, respectively, and are fixed in a compressed state by the first brake plates 16 and 17. 6A shows the state in which the leading end portion 85b of the negative electrode sheet 84b in FIG. 4A is clamped by the touch roller 40. FIG.

  Then, as shown in FIG. 6B, when the first brake plates 16 and 17 are released from this state, the pair of gripping rollers 32 and 34 are pushed back by the biasing force of the compressed springs 12 and 14, and the second brake plates 32 and 34 are pushed back. Retreat to the position of the brake plates 18 and 19. In this manner, the slack of the tip end portion 85b of the negative electrode sheet 84b can be eliminated by moving the pair of gripping rollers 32 and 34 backward. According to this configuration, the device configuration can be simplified and the device cost can be reduced as compared with the position control by the servo cylinder described above. The gripping rollers 32 and 34 pushed back to the position of the second brake plates 18 and 19 can be easily pushed into the positions of the first brake plates 16 and 17 using air, for example.

  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 (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-formation 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 a lithium ion secondary battery is a battery that can achieve high output at high energy density, a high-performance power source, particularly a vehicle-mounted power source, can be constructed.

In this case, the electrolyte is a lithium salt such as LiPF ₆ . An appropriate amount (for example, concentration 1M) of a lithium salt such as LiPF ₆ may be dissolved in a nonaqueous electrolytic solution such as a mixed solvent of diethyl carbonate and ethylene carbonate (for example, a mass ratio of 1: 1) and used as the electrolytic solution. 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 winding electrode body. Schematic which shows typically the structure of the formation apparatus of a wound electrode body. The principal part enlarged view which expanded the periphery of the core of FIG. 2A. 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 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 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

10 Servo cylinder 12 Spring 16, 18 Brake plate 20 Core 21 Slit 22 Core support 30a Positive chuck 30b Negative chuck 32, 34 Grip roller 40 Touch roller 42 Roller support 64a, 64b, 66a, 66b Tension roller 80 Winding Electrode 81a Positive electrode active material layer 81b Negative electrode active material layer 82 Sheet-like electrode body 83a Positive electrode active material layer non-formed part 83b Negative electrode active material layer non-formed part 84a Sheet-like positive electrode 84b Sheet-like negative electrode 85a Positive electrode sheet tip part 85b Negative electrode sheet Tip portion 86a inner separator sheet 86b outer separator sheet 90 core 91 slit 92a outer separator 92b inner separator 94 sheet 96 chuck 98 roller 100 manufacturing device C rotation center C1 center line C2 center line

Claims (7)

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 the positive or negative sheet-like electrode between two sheet-like separators wound around the outer periphery of the core; and
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 sheet-like separators together,
Applying tension to the leading end portion of the sandwiched sheet-like electrode in a direction opposite to the insertion direction of the sheet, and stretching the leading end portion of the sheet;
A step of rotating the core while being pressed by the pressing member, and winding the leading end portion of the stretched sheet;
A step of winding the leading end portion of the stretched sheet and then further rotating the core to wind the sheet-like electrode together with the two sheet-like separators;
A method for producing a wound electrode body, comprising:   2. The manufacturing method according to claim 1, wherein the winding step is executed while applying a tension larger than the reverse tension applied to a leading end portion of the sheet to the sheet-like electrode.   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 claim 1 or 2. 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 placed between the two separators. A pressing member to be held between,
A first tension applying means for applying tension to the leading end portion of the sheet-like electrode in a direction opposite to the insertion direction of the sheet and extending the leading end portion of the sheet;
A manufacturing apparatus comprising winding means for rotating the winding core while being pressed by the pressing member and winding the leading end portion of the stretched sheet-like electrode.   The winding means is configured to wind the sheet-shaped electrode together with the two sheet-shaped separators by further rotating the winding core after winding the leading end portion of the stretched sheet. The manufacturing apparatus according to claim 4, wherein:   6. The manufacturing apparatus according to claim 4, further comprising a second tension applying unit configured to apply a tension larger than a tension applied by the first tension applying unit to the sheet-like electrode during the winding.   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 7. The manufacturing apparatus according to any one of Items 4 to 6.

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