JP2018153837A - Press device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press device which can disperse force applied on a support roll.SOLUTION: A press device includes a press roll 53, a first work roll 54, and a second work roll 55. The second work roll 55 is arranged on a downstream side in a conveyance direction of an electrode 20 from the first work roll 54. A displacement device displaces the first work roll 54 and the second work roll 55 from a first position P1 to a second position P2 before a first state in which an active material layer 19c and the press roll 53 are not in contact with each other is changed to a second state in which the active material layer 19c and the press roll 53 are in contact with each other in conjunction with conveyance of the electrode 20. The second position P2 is on a downstream side from the first position P1 in the conveyance direction D.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a press apparatus.

  Conventionally, power storage devices are mounted on vehicles such as EV (Electric Vehicle) and PHV (Plug in Hybrid Vehicle). For example, a lithium ion secondary battery, which is a type of power storage device, includes an electrode assembly housed in a case. Generally, the electrode assembly is formed by stacking a plurality of electrodes each having a current collector foil and an active material layer.

  By the way, in the electrode manufacturing process, it is preferable to press the active material layer using a pressing device in order to improve the output density of the power storage device. For example, Patent Document 1 discloses a press apparatus configured to support a small-diameter press roll using a plurality of support rolls.

JP 62-166006 A

  However, when the press device disclosed in Patent Document 1 is applied to an active material layer pressing step in an electrode in which an active material layer is intermittently provided on the surface of a current collector foil, the following problems occur: Occurs. That is, as the electrodes are transported, the portion where the active material layer is provided and the portion where the active material layer is not provided alternately pass through the press roll. And when an active material layer and a press roll contact, ie, when a press roll runs on an active material layer, there exists a possibility that the force produced by this may concentrate on a one part support roll.

  An object of the present invention is to provide a press device that can disperse the force applied to a support roll.

  A pressing device that solves the above problems is a pressing mechanism for pressing an electrode having a long current collecting foil and an active material layer that is arranged at intervals along the length direction of the current collecting foil. The press mechanism includes a press roll, a first support roll that extends along the press roll and supports the press roll, and extends along the press roll. A second support roll that supports the press roll; and a displacement mechanism that displaces the first support roll and the second support roll along an outer peripheral surface of the press roll, and the second support roll includes: In the relative movement direction of the electrode with respect to the press roll, the displacement mechanism is located downstream of the first support roll, and the displacement mechanism is configured to move the electrode along with the relative movement of the electrode with respect to the press roll. From the first state where the active material layer and the press roll are not in contact to the second state where the active material layer of the electrode and the press roll are in contact, the first support roll and the second roll The support roll is displaced from the first position to the second position, and the second position is located downstream of the first position in the relative movement direction of the electrode with respect to the press roll. To do.

  According to this, the first support roll and the second support roll move relative to the press roll relative to the press roll before reaching the second state where the active material layer and the press roll are in contact with each other. It is displaced to the second position on the direction side. For this reason, it is suppressed that the force produced when an active material layer and a press roll contact is concentrated on the 2nd support roll in the relative moving direction side of the electrode with respect to a press roll. Therefore, the force applied to the support roll can be dispersed.

In the press apparatus, the second position is a position rotated from the first position to the relative movement direction side of the electrode with respect to the press roll, with a center line of the press roll as a rotation axis. , The rotation angle of the electrode relative to the press roll in the direction of movement is θ, the diameter of the press roll is r, and the thickness of the portion of the electrode where there is an active material layer before pressing Where d0 is the thickness of the portion of the electrode where the active material layer after pressing is d, and the following relational expression:
L = r (d0−d) / (1/2)
cos θ = r / (1 / 2L)
Should be established.

According to this, it is further suppressed that the force generated when the active material layer and the press roll come into contact with each other is concentrated on the second support roll.
In the press apparatus, the first support roll and the second support roll include a first portion and a plurality of second portions protruding in a diametrical direction from the first portion. The second part of the one support roll and the second part of the second support roll may be in contact with the press roll.

According to this, the first support roll and the second support roll are reduced in weight, and the maintenance of these support rolls can be easily performed.
In the pressing apparatus, the electrode has a first surface and a second surface opposite to the first surface, and the active material layer includes the first surface, the second surface, and the second surface. The press mechanism includes a first press mechanism, and a second press mechanism on the opposite side of the electrode from the first press mechanism, and the press roll of the first press mechanism includes: The press roll of the second press mechanism may be in contact with the active material layer on the second surface while in contact with the active material layer on the first surface.

  According to this, the active material layers on the first surface and the second surface of the electrode can be pressed by the first press mechanism and the second press mechanism. And even if it is such a structure, in the 1st press mechanism and the 2nd press mechanism, the force added to a support roll can be disperse | distributed.

  In the press apparatus, the outer diameter of the press roll may be smaller than the outer diameter of the first support roll and the outer diameter of the second support roll. According to this, by reducing the diameter of the press roll, the weight is reduced and the maintenance of the press roll can be easily performed.

  According to the present invention, the force applied to the support roll can be dispersed.

The perspective view of a secondary battery. The perspective view of an electrode. The schematic diagram of the manufacturing apparatus of an electrode. The perspective view of a press mechanism. The top view of a press mechanism. (A) And (b) is a schematic diagram which shows operation | movement of a press mechanism. The timing chart which shows the operation timing of a press mechanism.

Hereinafter, an embodiment embodying the press apparatus will be described.
First, a secondary battery as a power storage device manufactured using a press device will be described.
As shown in FIG. 1, for example, the secondary battery 10 is a lithium ion secondary battery or a nickel hydride secondary battery. The secondary battery 10 includes a case 11 and an electrode assembly 12 accommodated in the case 11. The electrode assembly 12 includes a positive electrode 13 and a negative electrode 13. In the electrode assembly 12, the positive electrode 13 and the negative electrode 13 are alternately stacked with an insulating separator interposed therebetween.

  As shown in FIG. 2, the electrode 13 includes a metal foil 15 as a current collector foil. The electrode 13 includes an active material layer 16 that covers a part of the metal foil 15. The electrode 13 includes a tab 17 for collecting current.

Next, the manufacturing apparatus 30 for the electrode 13 and the manufacturing method for the electrode 13 will be described. The manufacturing apparatus 30 manufactures the long electrode 20, which is a stage before forming the electrode 13.
As shown in FIG. 3, the manufacturing apparatus 30 includes a supply device 31 that supplies a metal foil 18 as a long (band-shaped) current collector foil. The metal foil 18 (electrode 20) includes a first surface 18a and a second surface 18b opposite to the first surface 18a. The supply device 31 performs a supply process for supplying the metal foil 18. The metal foil 18 is made of metal suitable for the polarity of the electrode to be manufactured.

  The manufacturing apparatus 30 includes a conveyance device (not shown). The metal foil 18 is transported along the length direction by the transport device. In the following description, the “transport direction D” means the transport direction of the metal foil 18 (electrode 20).

  The manufacturing apparatus 30 includes a coating apparatus 32 that intermittently applies the pasty active material mixture 19 containing an active material to both surfaces 18a and 18b of the metal foil 18 with a predetermined time interval. The coating device 32 may be a die method or a transfer method. For the active material mixture 19, an active material suitable for the polarity of the electrode to be manufactured is used.

  For this reason, on both surfaces 18a and 18b of the metal foil 18, a coated portion 19a to which the active material mixture 19 is applied and an uncoated portion 19b to which the active material mixture 19 is not applied are conveyed in the transport direction D. They are formed alternately along the length direction of the electrodes 20. Since the coating part 19a is an area where the active material layer 19c is formed, it can be said that the electrode 20 has the active material layer 19c arranged in a line along the length direction of the metal foil 18. Thus, the coating device 32 performs a coating process in which the active material mixture 19 is intermittently applied to the metal foil 18.

  The coating device 32 is activated so that the boundary between the coated part 19a and the uncoated part 19b preferably extends along a direction intersecting the transport direction D, more preferably along a direction orthogonal to the conveying direction D. The material mixture 19 is applied to the metal foil 18.

  The manufacturing apparatus 30 includes a drying device 33. The drying device 33 dries the active material mixture 19 applied to the metal foil 18. The drying device 33 performs a drying process for drying the active material layer 19c.

  The manufacturing apparatus 30 includes a pressing device 50 that presses the dried active material layer 19c. Details of the press device 50 will be described later. The pressing device 50 performs a pressing process of pressing the dried active material layer 19c. The manufacturing apparatus 30 includes a scraping device 35 that scrapes the long electrode 20 in a roll shape. The scraping device 35 performs a scraping process for scraping the long electrode 20.

  The long electrode 20 manufactured using the manufacturing apparatus 30 is subjected to a forming process for forming the electrode 20 into the electrode 13. The electrode 13 is subjected to a lamination process. In the stacking step, the electrodes 13 having different polarities are alternately stacked with the separator interposed therebetween to form the electrode assembly 12. The electrode assembly 12 is subjected to a housing process of housing in the case 11 together with the electrolyte. The secondary battery 10 is completed by the completion | finish of an accommodation process.

Next, details of the press device 50 will be described.
The press device 50 includes a first press mechanism 51 and a second press mechanism 52 as press mechanisms for pressing the long electrode 20. The second press mechanism 52 is on the opposite side of the first press mechanism 51 across the electrode 20.

  In the present embodiment, the first press mechanism 51 and the second press mechanism 52 are configured symmetrically with the metal foil 18 in between. Therefore, while the first press mechanism 51 will be described in detail, the description of the second press mechanism 52 is omitted or simplified by giving the same reference numerals to the same configuration as the first press mechanism 51.

  As shown in FIGS. 4 and 5, the first press mechanism 51 includes a press roll 53 that presses the active material layer 19 c. The press roll 53 extends in a direction along the surface direction of the electrode 20 and in a direction orthogonal to the transport direction D. The press roll 53 is a solid cylindrical member made of metal. For example, the press roll 53 may be surface hardened by hard chrome plating or the like.

  The first press mechanism 51 includes a first work roll 54 as a first support roll that extends along the press roll 53 and supports the press roll 53. The first work roll 54 is a solid and metal member. The first work roll 54 includes a cylindrical shaft portion 54a. The first work roll 54 includes a plurality of support portions 54b having a larger diameter than the shaft portion 54a and a flat cylindrical shape. The plurality of support portions 54b have their center lines aligned with the center line 54c of the shaft portion 54a, and are arranged at a predetermined interval along the length direction of the shaft portion 54a.

  The first press mechanism 51 includes a second work roll 55 as a second support roll that extends along the press roll 53 and instructs the press roll 53. The second work roll 55 is a solid and metal member. The second work roll 55 includes a cylindrical shaft portion 55a. The second work roll 55 includes a plurality of support portions 55b having a larger diameter than the shaft portion 55a and a flat cylindrical shape. The plurality of support portions 55b have their respective center lines aligned with the center line 55c of the shaft portion 55a, and are arranged at equal intervals along the length direction of the shaft portion 55a.

  As described above, the work rolls 54 and 55 have a shape in which the disk-like support portion is skewered at the shaft portion as a whole. The shaft portion 54a and the shaft portion 55a have the same outer diameter. The plurality of support portions 54b and the plurality of support portions 55b have the same outer diameter.

  The outer diameter of the press roll 53 is smaller than the outer diameter of the first work roll 54 (support part 54b) and the outer diameter of the second work roll 55 (support part 55b). The outer peripheral surface of the support portion 54 b of the first work roll 54 and the outer peripheral surface of the support portion 55 b of the second work roll 55 are in contact with the outer peripheral surface of the press roll 53. When viewed from the direction in which the center lines 53c to 55c extend, the center lines 53c to 55c form an equilateral triangle or an isosceles triangle having the center line 53c of the press roll 53 as a vertex.

  The shaft portions 54a and 55a correspond to the first portion. Since the plurality of support portions 54b protrude in the diameter direction from the shaft portion 54a, and the plurality of support portions 55b protrude in the diameter direction from the shaft portion 55a, the plurality of support portions 54b and 55b are formed in the second portion. Equivalent to. The plurality of support parts 54b and 55b are alternately arranged in a staggered manner so that the support part 55b is inserted between the support part 54b and the support part 54b.

  The second work roll 55 is on the downstream side of the first work roll 54 in the transport direction D. In the present embodiment, the transport direction D is a relative movement direction of the electrode 20 with respect to the press roll 53.

  In the press device 50, the minimum distance between the press roll 53 of the first press mechanism 51 and the press roll 53 of the second press mechanism 52 in the direction orthogonal to the surface direction of the electrode 20 is the active material layer 19c. The distance is set equal to the thickness of the electrode 20 when compressed to the target thickness. This distance is larger than the thickness of the metal foil 18 and smaller than the entire thickness of the electrode 20 in the portion where the active material layer 19c before pressing is present.

  The press device 50 includes a force device (not shown). The pressing device presses the press roll 53 toward the electrode 20 with a predetermined force via the work rolls 54 and 55 in each of the press mechanisms 51 and 52.

  In the present embodiment, the press roll 53 of the first press mechanism 51 is in contact with the active material layer 19c on the first surface 18a. On the other hand, the press roll 53 of the second press mechanism 52 is in contact with the active material layer 19c on the second surface 18b.

  As shown in FIG. 3, the press device 50 includes a displacement device 60 as a displacement mechanism that displaces the work rolls 54 and 55 along the outer peripheral surface of the press roll 53. For example, the displacement device 60 can be configured using one or more of an air cylinder, a hydraulic cylinder, a rotary motor, and a stepping motor.

Here, the first position P1 and the second position P2 of the work rolls 54 and 55 will be described.
As shown in FIG. 6A, the first position P1 presses the active material layers 19c and 19c between the press roll 53 of the first press mechanism 51 and the press roll 53 of the second press mechanism 52. It is the position for.

  The first position P1 is orthogonal to the surface direction of the electrode 20, and when the plane S1 including the center line 53c of the press roll 53 is assumed, the work rolls 54 and 55 are along the conveyance direction D across the plane S1. It is a position that is lined up symmetrically.

  In FIG. 6B, as indicated by the arrow A1, the second position P2 has the same separation distance between the rolls 53 to 55 (center lines 53c to 55c), but the work rolls 54 and 55 are pressed. It is a position displaced along the outer peripheral surface of the roll 53 to the downstream side in the transport direction D from the first position P1. That is, the second position P2 is a position rotated from the first position P1 to the transport direction D side with the center line 53c of the press roll 53 as a rotation axis.

  The angle of rotation in the transport direction D side is θ, the diameter of the press roll 53 is r, the thickness of the portion of the electrode 20 where the active material layer 19c is before pressing is d0, When the thickness of the portion where the active material layer 19c after pressing is d is d, the following relational expressions 1 and 2 are established.

L = r (d0-d) / (1/2) ... Relational expression 1
cos θ = r / (1 / 2L)... Relational expression 2
The press device 50 includes a control device 61. The control device 61 includes a microprocessor and controls the operation of the displacement device 60 by executing a predetermined program. The control device 61 is configured to be able to displace the work rolls 54 and 55 by controlling the operation of the displacement device 60.

  As shown in FIG. 7, the coated portions 19 a and the uncoated portions 19 b alternately pass between the two press rolls 53, 53 as the electrode 20 is conveyed. For this reason, the thickness of the portion of the electrode 20 passing between the press rolls 53, 53 is between the thickness d in the coated part 19a and the thickness d0 in the uncoated part 19b. It changes periodically alternately.

Next, the control procedure of the displacement device 60 by the control device 61 and its operation will be described.
As shown in FIG. 7, the controller 61 moves the electrode 20 before the portion passing between the press rolls 53, 53 changes from the uncoated portion 19 b to the coated portion 19 a. The displacement device 60 is controlled so as to be displaced from the first position P1 to the second position P2. That is, the control device 61 performs a first displacement process for displacing the work rolls 54 and 55 of the press mechanisms 51 and 52 to the second position P2.

  For example, the control device 61 presses the press mechanism at the time point T1 between the time points T0 to T2 when the uncoated portion 19b passes between the press rolls 53 and 53 and the time point T6 between the time points T4 to T7. The work rolls 54 and 55 of 51 and 52 are displaced from the first position P1 to the second position P2, respectively.

  As described above, in the displacement device 60, the active material layer 19c and the press roll 53 are in contact with each other from the first state where the active material layer 19c and the press roll 53 are not in contact with the conveyance of the electrode 20. Before entering the state, the work rolls 54 and 55 are displaced from the first position P1 to the second position P2.

  6B, when the active material layer 19c and the press roll 53 come into contact with each other in a state where the work rolls 54 and 55 are at the second position P2, as shown by using an arrow A2, it occurs at the moment of the contact. The force is distributed and applied to the work rolls 54 and 55. If the active material layer 19c and the press roll 53 come into contact with each other in the state where the work rolls 54 and 55 are at the first position P1, as shown by phantom lines in FIG. The force is concentrated on the work roll 55 and applied.

  Further, as shown in FIG. 7, the controller 61 is configured so that the portion passing between the press rolls 53, 53 is changed from the coated portion 19 a to the uncoated portion 19 b as the electrode 20 is conveyed. The displacement device 60 is controlled so as to be displaced from the second position P2 to the first position P1. That is, the control device 61 performs a second displacement process for displacing the work rolls 54 and 55 of the press mechanisms 51 and 52 to the first position P1.

  For example, the controller 61 presses the press mechanism 51 at a time point T3 between the time points T2 and T4 when the coating unit 19a passes between the press rolls 53 and 53 and a time point T8 between the time points T7 and T9. , 52 are displaced from the second position P2 to the first position P1, respectively.

  Thus, when the displacement device 60 enters the second state in which the active material layer 19c and the press roll 53 are in contact with the conveyance of the electrode 20, the work rolls 54 and 55 are moved from the second position P2 to the first position. Displace to position P1.

  In FIG. 6A, as indicated by the arrow A3, the active material layer 19c is pressed in a state where the work rolls 54 and 55 are in the first position P1, so that the force generated by the pressing is the work roll. 54 and 55 are added in a distributed manner.

  The timing at which the coating part 19a or the uncoated part 19b passes between the press rolls 53, 53 is the application interval in the application device 32, the distance from the application device 32 to the press device 50, and the conveyance of the electrode 20. It can be identified from the speed.

Therefore, in this embodiment, the following effects can be obtained.
(1) According to the present embodiment, the force generated when the active material layer 19c and the press roll 53 come into contact with each other is suppressed from being concentrated on the second work roll 55 on the conveyance direction D side. Therefore, the force applied to the work roll can be dispersed.

  (2) According to the present embodiment, when the relational expression 1 and the relational expression 2 are established, the force generated when the active material layer 19c and the press roll 53 come into contact concentrates on the second work roll 55. Is further suppressed.

  Specifically, when pressing the coated portion 19a from the uncoated portion 19b in the pressing step in the electrode 20 in which the active material mixture 19 is intermittently applied at a predetermined time, the density of the active material layer 19c Even if the press roll 53 is hardened by, for example, hard chrome plating, the high press linear pressure is biased toward the second work roll 55 by the reaction force from the small-diameter press roll 53 that increases the press linear pressure. The momentary application and suppression of dents and scratches on the surface of the second work roll 55 are suppressed.

  (3) According to the present embodiment, the work rolls 54 and 55 can be reduced in weight by making the disk-shaped support part skewered at the shaft part, and maintenance of these work rolls can be facilitated. become.

(4) According to the present embodiment, the active material layer 19 c on both surfaces 18 a and 18 b of the electrode 20 can be pressed by the press mechanisms 51 and 52.
(5) According to the present embodiment, the diameter of the press roll 53 is reduced to reduce the weight, and maintenance such as replacing the press roll 53 can be facilitated.

The above embodiment may be modified as follows.
The press device 50 may not include one of the first press mechanism 51 and the second press mechanism 52. In this case, the coating device 32 may form the active material layer 19 c on one side of the metal foil 18.

The press device 50 may include a plurality of first press mechanisms 51. The press device 50 may include a plurality of second press mechanisms 52.
One or both of the work rolls 54 and 55 may be a cylindrical roll.

O Support parts 54b and 55b do not need to be alternately arranged in a staggered pattern.
The press mechanisms 51 and 52 may include three or more work rolls. However, from the viewpoint of dispersing the force generated when the active material layer 19c and the press roll 53 come into contact with each other, an even number is preferable.

The work rolls 54 and 55 may have different diameters.
The press mechanisms 51 and 52 may include one or a plurality of backup rolls that support the work rolls 54 and 55.

(Circle) the press apparatus 50 does not need to be provided with the control apparatus 61. FIG. For example, the work rolls 54 and 55 may be displaced by an operator operating the displacement device 60.
(Circle) the press apparatus 50 may be provided with the detection means which detects the position of the active material layer 19c. For example, when a CCD camera is employed as the detection means, the control device 61 may analyze an image photographed by the CCD camera and specify the timing at which the work rolls 54 and 55 are displaced. The detection means may be a sensor that detects a change in capacitance, or may be a sensor that detects a magnetic change such as X-rays, β radiation, or NMR (nuclear magnetic resonance). And the control apparatus 61 is good to specify the timing which displaces the work rolls 54 and 55 based on the detection result by a detection means.

  (Circle) the apparatus integrated in the manufacturing apparatus 30 may be changed suitably. For example, the manufacturing apparatus 30 may include a forming apparatus that forms the long electrode 20 into the electrode 13. The forming apparatus performs a forming process of forming the long electrode 20 into the electrode 13. The manufacturing apparatus 30 may include a stacking apparatus that stacks the electrodes 13 with a separator interposed therebetween to form the electrode assembly 12. The stacking apparatus performs a stacking process in which the electrodes 13 are stacked and the electrode assembly 12 is formed. The manufacturing apparatus 30 may include a storage device that stores the electrode assembly 12 in the case 11. The housing device performs a housing process of housing the electrode assembly 12 in the case 11. For example, the manufacturing apparatus 30 may not include some or all of the supply device 31, the coating device 32, the drying device 33, and the scraping device 35.

Hereinafter, a technical idea that can be grasped from the above embodiment and another example will be additionally described.
(A) The electrode has a first surface and a second surface opposite to the first surface, and the active material layer includes the first surface and the second surface. The press mechanism includes a first press mechanism and a second press mechanism on the opposite side of the electrode from the first press mechanism, and the press roll of the first press mechanism includes the first press mechanism. While being in contact with the active material layer on one surface, the press roll of the second press mechanism is in contact with the active material layer on the second surface.

(B) The outer diameter of the press roll is smaller than the outer diameter of the first support roll and the outer diameter of the second support roll.
(C) The first support roll and the second support roll have a first portion and a plurality of second portions projecting in a diametric direction from the first portion, and the first support roll The second part of the roll and the second part of the second support roll are in contact with the press roll.

  (D) A method for manufacturing an electrode using the pressing device.

  D: transport direction, P1: first position, P2: second position, 18: metal foil, 18a ... first surface, 18b ... second surface, 19c ... active material layer, 20 ... electrode, 50 ... pressing device, 51 ... 1st press mechanism, 52 ... 2nd press mechanism, 53 ... Press roll, 53c ... Center line, 54 ... 1st work roll, 54a ... Shaft part, 54b ... Support part, 55 ... 2nd work roll, 55a ... Shaft Part, 55b ... support part, 60 ... displacement device, 61 ... control device.

Claims (2)

A pressing device comprising a pressing mechanism for pressing an electrode having a long current collecting foil and an active material layer arranged with a gap along the length direction of the current collecting foil,
The press mechanism is
A press roll,
A first support roll extending along the press roll and supporting the press roll;
A second support roll that extends along the press roll and supports the press roll;
A displacement mechanism for displacing the first support roll and the second support roll along an outer peripheral surface of the press roll,
The second support roll is downstream of the first support roll in the relative movement direction of the electrode with respect to the press roll,
The displacement mechanism moves from the first state where the active material layer of the electrode and the press roll are not in contact with each other as the electrode moves relative to the press roll. Before the second state is in contact, the first support roll and the second support roll are displaced from the first position to the second position,
The press apparatus according to claim 2, wherein the second position is located downstream of the first position in the relative movement direction of the electrode with respect to the press roll. The second position is a position rotated from the first position to the relative movement direction side of the electrode with respect to the press roll, with the center line of the press roll as a rotation axis,
The rotation angle of the electrode relative to the press roll toward the moving direction is θ,
The diameter of the press roll is r,
Of the electrodes, the thickness of the portion with the active material layer before pressing is d0,
Of the electrodes, when the thickness of the portion where the active material layer is pressed is d, the following relational expression:
L = r (d0−d) / (1/2)
cos θ = r / (1 / 2L)
The press device according to claim 1, wherein