JP2015136675A - Coating apparatus, assembly method of coating apparatus, and manufacturing method of electrode for secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus capable of improving flatness of a coating layer formed on a coating object by a discharged coating liquid.SOLUTION: A coating apparatus includes: a first die 11 including a first surface 21 on which a lead-out port 15 for leading out a coating liquid is formed; a second die including a second surface 22 which faces the first surface 21 while spaced away from the first surface 21: a discharge portion 14 which forms a part of an outer peripheral edge of a gap between the first surface 21 and the second surface 22 and is used for discharging the coating liquid led out from the lead-out port 15 to a coating object; and a shim 13 sandwiched between the first surface 21 and the second surface 22. The shim 13 includes: an opening end 23a facing the discharge portion 14; and a communication part 23b communicating with the lead-out port 15. The shim 13 includes a taper shaped slit 23 where an opening width narrows from the communication part 23 to the opening end 23a. The opening end 23a of the slit 23 is positioned at the inner side relative to the discharge portion 14.

Description

  The present invention relates to a coating apparatus that discharges a coating liquid toward an object to be coated, a method for assembling the coating apparatus, and a method for manufacturing an electrode for a secondary battery using the coating apparatus.

  A secondary battery typified by a lithium ion battery has a known structure in which a laminate in which a positive electrode and a negative electrode are laminated via a separator is enclosed in an exterior material together with an electrolytic solution. A positive electrode and a negative electrode (hereinafter referred to as a secondary battery electrode) of a secondary battery having such a structure are generally composed of a current collector and an electrode active material layer laminated on the current collector. Yes. As a method for producing this secondary battery electrode, a method is known in which a coating liquid containing an electrode active material is discharged from a coating device toward a strip-shaped current collector sheet.

  FIG. 9 is a side view of the coating apparatus. A coating apparatus 100 illustrated in FIG. 9 includes a die 101, a die 102 that faces the die 101 at an interval, and a shim 103 that is sandwiched between the die 101 and the die 102.

  FIG. 10 is a plan view of the die 101 and shim 103 provided in the coating apparatus shown in FIG. As shown in FIG. 10, the die 101 is formed with a lead-out port 111 for leading out the coating liquid. On the other hand, a slit 113 is formed in the shim 103. The slit 113 has an opening end 113 a that becomes a discharge portion of the coating liquid and a communication portion 113 b that communicates with the outlet 111.

  In the coating apparatus 100, when the coating liquid containing the electrode active material is discharged from the discharge portion (open end 113a) toward the strip-shaped current collector sheet, as shown in FIG. An electrode active material layer 401 is formed.

  In the coating apparatus 100, the opening width W1 (see FIG. 10) of the slit 113 is constant. Therefore, when the coating liquid flows through the slit 113, the fluid pressure tends to gradually decrease from the center of the slit toward both ends. Therefore, as shown in FIG. 11, the electrode active material layer 401 has a convex shape with a raised central portion.

  In the manufacturing process of the secondary battery electrode, generally, the current collector sheet on which the electrode active material layer is formed is wound around a roller or the like. In order to smoothly wind the current collector sheet, it is desirable that the surface of the electrode active material layer be flat. However, when the surface is convex like the electrode active material layer 401 shown in FIG. 11, problems such as poor winding of the current collector sheet and damage to the electrode active material layer 401 are likely to occur.

  Therefore, a shim for solving the above problem is proposed and disclosed in Patent Document 1. FIG. 12 is a plan view of the shim disclosed in Patent Document 1. FIG. FIG. 13 is a cross-sectional view of an electrode active material layer formed using the shim 203 shown in FIG.

  A shim 203 shown in FIG. 12 is formed with a tapered slit 213 whose opening width W2 becomes narrower from the communicating portion 213b toward the opening end 213a. This taper shape can suppress a decrease in the flow pressure of the coating liquid at both ends of the slit 213. Therefore, as shown in FIG. 13, an electrode active material layer 501 having a flat central portion can be formed on the current collector sheet 301.

JP 2010-51953 A

  In the shim 203 shown in FIG. 12, since the slit 213 is formed in a tapered shape (tapered shape), the flow pressure of the coating liquid at both ends of the slit 213 is particularly high. And since the opening end 213a is a discharge part of a coating liquid, the flow pressure of the coating liquid in the both ends becomes especially high in the discharge part. As a result, as shown in FIG. 13, the electrode active material layer 501 has a shape in which both end portions protrude, and it cannot be said that the flatness is sufficiently secured.

  Accordingly, the present invention provides a coating apparatus capable of improving the flatness of a coating layer formed on a coating object by discharging a coating liquid, a method for assembling the coating apparatus, and manufacturing a secondary battery electrode. It aims to provide a method.

  In order to achieve the above object, a coating apparatus according to the present invention includes a first die having a first surface on which a lead-out port for leading a coating liquid is formed, and a distance from the first surface. And a part of an outer peripheral edge of a gap between the first die and the second surface, the coating being led out from the outlet A discharge portion for discharging the liquid toward the coating object, and a shim sandwiched between the first surface and the second surface, the shim on the discharge portion A slit having a taper shape having an opening end facing each other and a communicating portion communicating with the outlet port, the opening width of which narrows from the communicating portion toward the opening end; It is located inside the part.

  In order to achieve the above object, a method for assembling a coating apparatus according to the present invention includes a first die having a first surface on which a lead-out port for leading a coating solution is formed, and a second surface. A coating apparatus assembly method comprising: a second die provided; and a shim provided with a tapered slit having an open end, wherein the first surface and the second surface are spaced apart from each other. Disposing the first die, the shim, and the second die so that the shims face each other and the shim is sandwiched between the first surface and the second surface. A part of the slit is communicated with the outlet, and the opening width of the slit becomes narrower from the communicating part toward the opening end, and the opening end is connected to the first surface and the second surface. Located on the inner side of the outer peripheral edge of the gap, and the slot of the outer peripheral edge of the gap. It said open end portion opposite to bet comprises the step of placing the said first die so that the discharge portion for discharging said shim and said second die said coating liquid.

  In order to achieve the above object, a method for manufacturing an electrode for a secondary battery according to the present invention includes a first die having a first surface on which a lead-out port is formed, and a distance from the first surface. A second die having an opposing second surface; and a part of an outer peripheral edge of a gap between the first surface and the second surface, wherein the coating liquid led out from the outlet is A discharge portion for discharging toward the coating object; a shim sandwiched between the first surface and the second surface; an open end facing the discharge portion; An electrode for a secondary battery using a coating device having a communicating portion that communicates with an outlet, and a shim having a tapered slit whose opening width narrows from the communicating portion toward the opening end. A method of manufacturing a coating liquid containing an electrode active material led out from the outlet port, wherein the discharge portion of the coating device From the open end of the slit which is located remote interior, through the discharge portion, comprising the step for ejecting the strip of the current collector sheet.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to improve the flatness of the coating layer formed in a coating target object by discharge of a coating liquid.

It is a perspective view which shows the coating apparatus of 1st Embodiment. It is a side view of the coating apparatus shown in FIG. It is a top view of the 1st die | dye and shim which were provided in the coating apparatus shown in FIG. It is sectional drawing of the electrode active material layer formed with the coating apparatus shown in FIG. It is a perspective view which shows the coating apparatus of 2nd Embodiment. FIG. 6 is a plan view of a first die and a second die provided in the coating apparatus shown in FIG. 5. It is a top view of the shim provided in the coating apparatus shown in FIG. It is a side view for demonstrating the assembly method of the coating apparatus shown in FIG. It is a side view of a coating device. It is a top view of the die | dye and shim which were provided in the coating apparatus shown in FIG. It is sectional drawing of the electrode active material layer formed with the coating apparatus shown in FIG. 6 is a plan view of a shim disclosed in Patent Document 1. FIG. It is sectional drawing of the electrode active material layer formed using the shim shown in FIG.

  An embodiment of the present invention will be described. Hereinafter, an embodiment in which the coating apparatus of the present invention is applied to a secondary battery electrode manufacturing apparatus will be described.

(First embodiment)
FIG. 1 is a perspective view showing a coating apparatus according to the first embodiment. FIG. 2 is a side view of the coating apparatus shown in FIG.

  The coating apparatus 1 according to this embodiment shown in FIGS. 1 and 2 includes a first die 11, a second die 12, and a shim 13. In this embodiment, the material of each die 11, 12 and shim 13 is SUS (Stainless Steel). The material of each die 11, 12 and shim 13 is not limited to SUS as long as it does not corrode against the coating solution.

  The first die 11 has a first surface 21 (see FIG. 2). On the other hand, the second die 12 has a second surface 22 (see FIG. 2). The first surface 21 and the second surface 22 face each other with a space therebetween. A part of the outer peripheral edge of the gap between the first surface 21 and the second surface 22 is a discharge portion 14 for discharging the coating liquid.

  FIG. 3 is a plan view of the first die 11 and the shim 13 provided in the coating apparatus shown in FIG. As shown in FIG. 3, the first face 21 of the first die 11 is formed with a lead-out port 15 and a manifold 16 surrounding the lead-out port 15. The outlet 15 is an opening for leading a coating liquid containing an electrode active material. On the other hand, the manifold 16 is a recess for temporarily storing the coating liquid derived from the coating liquid outlet 15 in order to secure the amount of the coating liquid necessary for ejection from the ejection portion 14.

  The shim 13 is a plate-like member for adjusting the distance between the first die 11 and the second die 21 and the flow pressure of the coating liquid discharged from the discharge portion 14. As shown in FIG. 3, a slit 23 is formed in the shim 13. The slit 23 has an open end 23 a that faces the discharge portion 14 and a communication portion 23 that communicates with the outlet 15 via the manifold 16. The slit 23 is formed in a tapered shape whose opening width W0 (see FIG. 3) becomes narrower from the communicating portion 23b toward the opening end 23a. Further, the opening end 23 a of the slit 23 is located inside the discharge portion 14.

  Hereinafter, the assembly method of the coating apparatus 1 of this embodiment is demonstrated concisely. In the present embodiment, the first surface 21 and the second surface 22 are opposed to each other at an interval, and the shim 13 is sandwiched between the first surface 21 and the second surface 22. One die 11, shim 13 and second die 12 are arranged. At this time, the first die 11 and the shim 13 are connected so that the communicating portion 23 b of the slit 23 communicates with the outlet 15 via the manifold 16 and the opening end 23 a of the slit 23 is located inside the discharge portion 14. A second die 12 is placed. In the present embodiment, the first die 11, the shim 13, and the second die 11 are set so that the distance d (see FIG. 3) from the opening end 23 a to the discharge portion 14 is within an allowable range (for example, 0.1 to 2 mm). Each position of the die 12 is adjusted.

  Since the coating apparatus 1 of this embodiment is used for manufacturing the electrode of the secondary battery described above, a coating liquid containing an electrode active material is supplied into the manifold 16 from the outlet 15. When the supply of the coating liquid is continued, the coating liquid stored in the manifold 16 starts to flow along the slit 23 and is finally discharged from the discharge portion 14. The discharged coating liquid adheres to a strip-shaped current collector sheet that is an object to be coated. As a result, an electrode active material layer 41 is formed on the current collector sheet 31 as shown in FIG.

  In the shim 203 shown in FIG. 12, since the opening end 213a of the tapered slit 213 is a coating liquid discharge portion, the flow pressure of the coating liquid at both ends of the discharge portion is particularly high. As a result, as shown in FIG. 13, the electrode active material layer has a shape in which both end portions thereof protrude, and the flatness is not sufficiently ensured.

  On the other hand, in the coating apparatus 1 of the present embodiment, as shown in FIG. 3, the shim 13 has the opening end 23 a of the tapered slit 23 positioned on the inner side of the discharge portion 14. Therefore, the flow of the coating liquid spreads outward until the coating liquid flowing out from the opening end 23a reaches the discharge portion 14 (see the arrow in FIG. 3). That is, the coating liquid spreads in the width direction perpendicular to the opposing direction of the first surface 21 and the second surface 22 and the discharging direction of the coating liquid in the space between the opening end 23a and the discharge portion 14. Proceed without being regulated. Thereby, since the flow pressure of the coating liquid at both ends (both ends in the width direction) of the discharge portion 14 is suppressed, the height of both ends of the electrode active material layer is suppressed. As a result, the flatness of the surface of the electrode active material layer 41 is improved.

  In addition, as shown in FIG. 4, the height of the both ends of the electrode active material layer 41 may become low, and the whole surface may not become flat. However, even in such a case, when the current collector sheet on which the electrode active material layer is formed is wound around a roller (not shown), the central portion is flat and both ends are low. The electrode active material layer 41 of the form is less likely to be damaged than the electrode active material layer 501 (see FIG. 13) whose both ends protrude. Therefore, a high quality secondary battery electrode can be manufactured.

(Second Embodiment)
A second embodiment of the present invention will be described. Hereinafter, it demonstrates centering on a different point from the coating device 1 of 1st Embodiment. The same components as those in the coating apparatus 1 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 5 is a perspective view showing a coating apparatus according to the second embodiment. FIG. 6A is a plan view of the first die 11 provided in the coating apparatus shown in FIG. FIG. 6B is a plan view of the second die 12 provided in the coating apparatus shown in FIG. FIG. 7 is a plan view of the shim 13 provided in the coating apparatus shown in FIG.

  As shown in FIGS. 5-7, the coating apparatus 2 of this embodiment is implemented by the point provided with the 1st through-hole 51a, the 2nd through-hole 51b, and the 3rd through-hole 51c. It differs from the coating apparatus 1 of the form 1. Each through hole is a hole for positioning the first die 11, the second die 12, and the shim 13, and communicates with each other.

  The first through hole 51a linearly penetrates the first die 11 at a position away from the outlet 15 and the manifold 16 (see FIGS. 5 and 6A). The second through hole 51b linearly penetrates the second die 12 (see FIGS. 5 and 6B). The third through hole 51c linearly penetrates the shim 13 at a position away from the slit 23 (see FIGS. 5 and 7). In this embodiment, the diameter of each through hole is about 30 mm, and two each through hole is formed. However, each through hole only needs to be formed at a position away from the flow path of the coating liquid, and the diameter and number of the through holes are not particularly limited.

  FIG. 8 is a side view for explaining an assembling method of the coating apparatus of the present embodiment.

  First, as shown in FIG. 8A, the first through hole 51 a formed in the first die 11, the second through hole 51 b formed in the second die 12, and the shim 13 are formed. The rod member 52 is inserted into each through hole so that the formed through holes 51c communicate with each other. Thereby, the 1st die | dye 11, the 2nd die | dye 12, and the shim 13 can be positioned easily so that the opening end 23a of the slit 23 may be located inside the discharge part 14. FIG.

  When the first die 11, the second die 12, and the shim 13 are arranged as described above, the bar member 52 is extracted from the through hole 51 (see FIG. 8B). Thereafter, the first die 11 and the second second die 12 are fixed by a fixing member (not shown) (for example, a screw). In the present embodiment, the gap between the outer peripheral surface of the bar member 52 and the inner peripheral surface of the through hole 51 is about 40 μm so that the bar member 52 can be removed from the through hole 51.

  As a method for arranging the die and shim, in addition to the above-described method, a method in which a concave portion is provided on one of the die and the shim and a convex portion that engages with the concave portion is provided on the other side can be considered. However, in this method, it is necessary to perform different processing on the die and the shim, which is troublesome. Further, in this method, since the shim is firmly fixed to the die, there is a possibility that it takes time to disassemble the apparatus when performing maintenance of the apparatus.

  On the other hand, in the coating apparatus 2 of the present embodiment, the first die 11, the second die 12, and the shim 13 are each subjected to hole processing for forming a through hole having the same diameter, so that it takes time for processing. The first die 11, the second 12 and the shim 13 can be arranged with high accuracy and without any trouble. Moreover, in the coating apparatus 2 of this embodiment, after arrangement | positioning of the 1st die | dye 11, the 2nd die | dye 12, and the shim 13, the bar member 52 is extracted. For this reason, when disassembling the completed device, there is no need to remove the bar member 52, and there is no work to disengage the concave and convex portions. Accordingly, since the disassembling work is facilitated, it is possible to reduce the time required for maintenance of the apparatus.

1, 2 coating device 11 first die 12 second die 13 shim 14 discharge portion 15 outlet 16 manifold 21 first surface 22 second surface 23 slit 31 current collector sheet 41 electrode active material layer 51a first 1 through hole 51b 2nd through hole 51c 3rd through hole 52 Bar member 100 Coating device 101, 102 Die 103, 203 Shim 104, 204 Discharge portion 105 Outlet 113, 213 Slit 301 Current collector sheet 401, 501 Electrode active material layer

Claims (8)

A first die having a first surface formed with a lead-out port for leading out the coating liquid;
A second die having a second surface facing the first surface at an interval;
A part of the outer periphery of the gap between the first surface and the second surface, and a discharge portion for discharging the coating liquid led out from the outlet to the coating object;
A shim sandwiched between the first surface and the second surface,
The shim includes an opening end facing the discharge portion and a communication portion communicating with the outlet, and includes a tapered slit whose opening width narrows from the communication portion toward the opening end, The coating apparatus, wherein the opening end of the slit is positioned on the inner side of the discharge portion.   A first through hole that linearly penetrates the first die at a position away from the outlet for positioning the first die, the second die, and the shim; and the second die A second through hole that linearly passes through the first shim and a third through hole that linearly penetrates the shim at a position away from the slit, and the first through hole and the second through hole. The coating device according to claim 1, wherein the through hole and the third through hole communicate with each other.   The coating apparatus of Claim 1 or 2 which apply | coats the said coating liquid containing an electrode active material to the said coating target object which is a strip | belt-shaped collector sheet.   The coating apparatus of any one of Claim 1 to 3 whose distance from the said opening end to the said discharge part exists in the range of 0.1-2 mm. A first die having a first surface formed with a lead-out port for leading out the coating liquid;
A second die having a second surface;
A shim having a tapered slit having an open end, and an assembling method of a coating apparatus,
The first die and the second surface such that the first surface and the second surface face each other with a space therebetween, and the shim is sandwiched between the first surface and the second surface; A step of arranging the shim and the second die, wherein a part of the slit is communicated with the outlet, and the opening width of the slit becomes narrower from the communicating part toward the opening end; The opening end is located inside the outer peripheral edge of the gap between the first surface and the second surface, and the portion of the outer peripheral edge of the gap facing the opening end of the slit is A method for assembling a coating apparatus, including the step of arranging the first die, the shim, and the second die so as to be a discharge portion for discharging a coating liquid.   A first through hole that linearly penetrates the first die at a position away from the outlet, a second through hole that linearly penetrates the second die, and a position away from the slit When the first die, the shim, and the second die are disposed in advance, a third through hole that linearly penetrates the shim is formed in advance. Positioning the first die, the shim and the second die with respect to each other by inserting a rod member into each through hole in order to connect the through hole and the third through hole to each other; The method for assembling a coating apparatus according to claim 5, wherein the bar member is extracted. A first die having a first surface formed with an outlet port;
A second die having a second surface facing the first surface at an interval;
A part of the outer periphery of the gap between the first surface and the second surface, and a discharge portion for discharging the coating liquid led out from the outlet to the coating object;
A shim sandwiched between the first surface and the second surface, having an open end facing the discharge portion, and a communicating portion communicating with the outlet, and from the communicating portion A method of manufacturing an electrode for a secondary battery using a coating device having a shim with a tapered slit whose opening width becomes narrower toward the opening end,
A coating liquid containing the electrode active material led out from the outlet is formed into a band-like shape from the opening end of the slit located inside the ejection part of the coating apparatus via the ejection part. The manufacturing method of the electrode for secondary batteries including the process discharged toward a collector sheet.   In the step of discharging the coating liquid, the coating liquid forms a space between the opening end and the discharge portion in the facing direction of the first surface and the second surface and the discharging direction of the coating liquid. The manufacturing method of the electrode for secondary batteries of Claim 7 which advances, without the expansion to the width direction orthogonal to each other being controlled.

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