JP2021099946A - Manufacturing method of membrane electrode assembly - Google Patents

Abstract

To provide a manufacturing method of a membrane electrode assembly capable of performing a slitting process under a common slit condition for both a formed portion and a non-formed portion of a negative electrode.SOLUTION: A manufacturing method of membrane electrode assembly according to the present invention includes a step (A) of forming a plurality of negative electrodes (102) on a strip-shaped base material (101) at intervals along the longitudinal direction of the base material (101), a step (B) of sequentially laminating a solid electrolyte membrane (103) and a plurality of positive electrodes (104) on individual negative electrodes (102), and a step (C) of slitting a laminate (LM1) including a base material (101), a negative electrode (102), a solid electrolyte membrane (103), and a plurality of positive electrodes (104), and a negative electrode non-forming portion (101N) of the base material into a plurality of rows, and further includes a step (X) of forming an insulating material (105) on at least cutting lines (L1 to L3) of the step (C) on the surface of the negative electrode non-forming portion (101N) of the base material before carrying out the step (C).SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for producing a membrane electrode assembly.

A solid-state battery such as a polymer electrolyte fuel cell includes a negative electrode, a solid electrolyte membrane, and a membrane electrode assembly (MEA) which is a laminate of positive electrodes.
See FIG. 1 for an example of a manufacturing apparatus and manufacturing method for a membrane electrode assembly by an intermittent coating method.

First, a plurality of negative electrodes are formed on a base material such as a strip-shaped metal foil at intervals along the longitudinal direction (transportation direction) of the base material (step (A)). In the base material, the portion between the negative electrodes adjacent to each other in the front-rear direction in the transport direction of the base material (the portion where the negative electrode is not formed) is referred to as a “negative electrode non-forming portion”.
Next, a solid electrolyte membrane and a plurality of positive electrodes are sequentially laminated on the individual negative electrodes (step (B)). The membrane electrode assembly, which is a laminate of the negative electrode, the solid electrolyte membrane, and the positive electrode, may be formed on both sides of a base material such as a metal foil.

Next, a plan-view line-shaped insulating material is formed next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode (step (X)). Next, the laminate including the base material, the negative electrode, the solid electrolyte membrane, and the positive electrode having a plurality of rows, and the negative electrode non-forming portion of the base material are slit into a plurality of rows (step (C), slit step).
Next, the membrane electrode assembly is pressed (step (D)).
Finally, a single-wafer cutting is performed to produce a membrane electrode assembly with a substrate in which a membrane electrode assembly is formed on at least one surface of the substrate (step (E)).

For example, in Patent Document 1, an active material is applied to a metal foil, and a base material used as a material for an electrode of a secondary battery is a slitter provided with a plurality of cut portions along the width direction of the base material. Discloses a cutting method for cutting into a plurality of strip-shaped sheet materials using the above (claim 3). In one aspect, the base material is one in which the active material is intermittently applied along the longitudinal direction (claim 4).

Japanese Unexamined Patent Publication No. 2019-018289

In the slitting process, the upper blade and the lower blade, which are rotary blades, are arranged above and below the slit object to slit. For example, in the horizontal direction, leave a space between the upper blade and the lower blade, and in the vertical direction, the upper blade and the lower blade overlap so that the height position of the lower end of the upper blade and the height position of the upper end of the lower blade overlap. Cutting can be performed by the gang slit method that sets the blade. The lateral distance between the upper and lower blades is called "clearance", and the vertical overlap between the upper and lower blades is called "wrap".

The clearance and wrap between the upper and lower blades are adjusted according to the thickness of the slit object. If the clearance between the upper blade and the lower blade and the lap are within an appropriate range, the crack formed by the upper blade and the crack formed by the lower blade are well connected, and good cutting can be performed.

Generally, the larger the thickness of the slit object, the larger the clearance and wrap between the upper and lower blades need to be set. The thickness of the negative electrode non-forming portion of the base material is, for example, about 15 μm, whereas the thickness of the laminated body in which the membrane electrode assembly is laminated on both sides of the base material is, for example, about 600 μm. There is a large difference in the thickness of the slit object between the negative electrode formed portion and the negative electrode non-formed portion, and these portions cannot be cut under the same slit conditions.
From the viewpoint of improving productivity, it is preferable that the slit process can be performed on both the formed portion and the non-formed portion of the negative electrode under common slit conditions.

The present invention has been made in view of the above circumstances, and is a method for producing a membrane electrode assembly capable of performing a slitting process on both a formed portion and a non-formed portion of a negative electrode under common slit conditions. The purpose is to provide.

The method for producing a membrane electrode assembly of the present invention is:
A method for manufacturing a membrane electrode assembly including a negative electrode, a solid electrolyte membrane, and a positive electrode.
A step (A) of forming a plurality of negative electrodes at intervals along the longitudinal direction of the base material on the strip-shaped base material, and
A step (B) of sequentially laminating a solid electrolyte membrane and a plurality of positive electrodes on each of the negative electrodes.
It has a step (C) of slitting a laminate containing the base material, the negative electrode, the solid electrolyte membrane, and the positive electrode of the plurality of rows into a plurality of rows of a non-negative electrode forming portion of the base material.
Further, before carrying out the step (C), there is a step (X) of forming an insulating material on the surface of the negative electrode non-forming portion of the base material at least on the cutting line of the step (C).

According to the present invention, it is possible to provide a method for manufacturing a membrane electrode assembly capable of performing a slitting step under common slit conditions for both a formed portion and a non-formed portion of the negative electrode.

It is a schematic diagram which shows an example of the manufacturing apparatus and manufacturing method of the membrane electrode assembly by the intermittent coating method. It is a schematic plan view which shows the state of the work before the slit process. It is a partial schematic cross-sectional view parallel to the transport direction of the base material of FIG. FIG. 2 is a schematic cross-sectional view taken along the line IV-IV of FIG. FIG. 2 is a schematic cross-sectional view taken along the line VV of FIG. It is a schematic cross-sectional view which shows the design modification example of FIG. It is a schematic cross-sectional view which shows the other design modification example of FIG.

The present invention relates to a method for producing a membrane electrode assembly including a negative electrode, a solid electrolyte membrane, and a positive electrode. A method for manufacturing a membrane electrode assembly according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an example of a manufacturing apparatus and a manufacturing method of a membrane electrode assembly by an intermittent coating method. FIG. 2 is a schematic plan view showing a state of the work before the slit process. FIG. 3 is a schematic cross-sectional view of a portion parallel to the transport direction of the base material of FIG. FIG. 4 is a sectional view taken along line IV-IV of FIG. FIG. 5 is a sectional view taken along line VV of FIG. In order to make it easier to see, the scale of each member is appropriately different for each drawing.

First, as shown in FIG. 1, a plurality of negative electrodes 102 are formed at intervals on a base material 101 such as a strip-shaped metal foil unwound from a base material roll such as a metal foil roll by a known method (. Step (A). Specifically, the negative electrode material is intermittently applied along the longitudinal direction (transportation direction) of the base material 101, pressed by using the roll unit PR1 composed of a pair of press rolls, and a plurality of sheets are spaced apart from each other. Negative electrode 102 is formed. In the base material 101, a portion between the negative electrodes 102 adjacent to the front and back in the transport direction of the base material 101 (a portion where the negative electrode 102 is not formed) is referred to as a “negative electrode non-forming portion 101N”. The negative electrode non-forming portion 101N is a portion used as a portion for taking out a drawer tab for electrically connecting to an external terminal.

Next, as shown in FIG. 1, the solid electrolyte membrane 103 and the plurality of positive electrodes 104 are sequentially laminated on the individual negative electrodes 102 by a known method (step (B)). Specifically, the material of the solid electrolyte membrane is coated on each negative electrode 102 and pressed by the roll unit PR2 composed of a pair of press rolls to form the solid electrolyte membrane 103, and further, this solid. A positive electrode material is applied onto the electrolyte membrane 103 to form a positive electrode 104. In this step, a plurality of positive electrodes 104 are formed for one negative electrode 102. The number of positive electrodes formed on one negative electrode 102 is not particularly limited, and in the illustrated example, two positive electrodes 104 are formed on one negative electrode 102.
The membrane electrode assembly 100, which is a laminate of the negative electrode 102, the solid electrolyte membrane 103, and the positive electrode 104, may be formed on both surfaces of the base material 101 such as a metal foil.

Next, as shown in FIGS. 1 and 2, a plan-viewing line-shaped insulating material 105 is formed next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104 by a known method ( Step (X)). In the illustrated example, a total of three insulating materials 105 are formed between and outside the two positive electrodes 104 along the three cutting lines L1 to L3 in the subsequent slitting process.

It is preferable that the width of the forming region of the plurality of positive electrodes 104 is designed to be smaller than the width of the forming region of the negative electrode 102.
If both the negative electrode 102 and the positive electrode 104 are on the cutting line in the subsequent slitting step, these electrodes may come into contact with each other and cause a short circuit. Therefore, as shown in FIG. 4, the width W4 of the forming region of the positive electrode 104 of the plurality of rows is smaller than the width W2 of the forming region of the negative electrode 102 so that the positive electrode 104 does not exist on the cutting lines L1 to L3 in the slit process. It is preferable to design.

Here, when nothing is formed next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104, the positive electrode 104 is formed in a plan view in the subsequent step of pressing the membrane electrode assembly. Press pressure is not applied well to both ends of the negative electrode located outside the region, and the rolling cannot be followed, so that cracks may occur. Therefore, as shown in FIG. 4, it is preferable to form the insulating material 105 having a plan view line shape next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104.

In the conventional manufacturing method, in the step (X) of forming the insulating material 105 having a plan view line shape next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104, the negative electrode non-forming portion 101N is formed. Does not form anything in particular. In the present embodiment, in this step (X), the insulating material 105 is formed on the surface of the negative electrode non-forming portion 101N of the base material 101 at least on the cutting lines (L1 to L3 in the illustrated example) of the later slit step. ..
That is, in the manufacturing method of the present embodiment, in the step (X) of forming the insulating material 105 in a plan view line shape next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104, FIG. , 3 and 5, the plan-view line-shaped insulating material 105 is stretched as it is, and the plan-view line-shaped insulating material 105 is also formed on the negative electrode non-forming portion 101N of the base material 101.
In FIG. 1, the plan view line-shaped insulating material 105 formed on the negative electrode non-forming portion 101N is not shown.

Next, as shown in FIG. 1, the work is slit into a plurality of rows by a known method (step (C), slit step). Specifically, the first lamination shown in FIG. 4 including a base material 101, a negative electrode 102, a solid electrolyte membrane 103, a plurality of positive electrodes 104, and a plurality of plan-view line-shaped insulating materials 105 using a slitter SL. The body LM1 and the second laminated body LM2 shown in FIG. 5, which includes the negative electrode non-forming portion 101N of the base material and the plurality of plan-view line-shaped insulating materials 105, are slit into a plurality of rows.
In this step, both the first laminated body LM1 and the second laminated body LM2 are cut so that the pair of rotary blades of the slitter SL pass through the insulating material 105 in a plan view line (cutting line L1). See ~ L3.).

Next, as shown in FIG. 1, the membrane electrode assembly 100 is pressed using the roll unit PR3 composed of a pair of press rolls by a known method (step (D)).
Finally, single-wafer cutting is carried out by a known method to produce a membrane electrode assembly with a substrate in which the membrane electrode assembly 100 is formed on at least one surface of the substrate 101 (step (E)). ).

In the manufacturing method of the present embodiment, in the step (X) of forming the insulating material 105 in a plan view line shape next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104, FIGS. As shown in 5, the insulating material 105 having a plan view line shape is stretched as it is. As a result, on the surface of the negative electrode non-forming portion 101N of the base material 101, the insulating material 105 having a plan view line shape is formed at least on the cutting lines (L1 to L3 in the illustrated example) of the slit process.

In the manufacturing method of the present embodiment, as shown in FIG. 3, the difference in thickness of the slit target between the formed portion and the non-formed portion of the negative electrode can be made smaller than before, so these regions are cut under the same slit conditions. Can improve productivity.
In the manufacturing method of the present embodiment, as shown in FIG. 3, the thickness of the slit object between the formed portion and the non-formed portion of the negative electrode can be changed more slowly than before, so that the impact on the blade is alleviated and the work is deformed. And the electrode collapse can be suppressed.

In the manufacturing method of the present embodiment, as shown in FIG. 3, the end portion of the front first laminated body LM1 and the start end portion of the rear first laminated body LM1 are interposed via an insulating material 105 in a plan view line shape. Is connected. In this case, the insulating material 105 acts like a fixing material to suppress bending of the first laminated body LM1 and collapse and / or peeling of the electrodes contained in the first laminated body LM1 in the slit step. it can.
Since the insulating material 105 formed on the negative electrode non-forming portion 101N is cut off when the membrane electrode assembly 100 is processed to the electrode size, there is no effect on the performance of the finally manufactured battery.

(Example of design change)
6 and 7 are schematic cross-sectional views showing an example of design modification of FIG.
In the cross-sectional view shown in FIG. 4, the insulating material 105 may be formed at least next to both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104.

As in the design modification example shown in FIG. 6, the insulating material 105 extends from the surface of the base material 101 to the side of both ends parallel to the longitudinal direction (transportation direction of the base material) of each positive electrode 104. It may be formed. The insulating material 105 can be formed by coating or filling.
In this design modification example, the insulating material 105 can cover and protect both end faces of the negative electrode 102, the solid electrolyte membrane 103, and the positive electrode 104. In this design modification example, in the slitting process, only the base material 101 and the insulating material 105 can be cut without cutting the multilayer layers of the negative electrode 102, the solid electrolyte membrane 103, and the insulating material 105 (cutting lines L1 to L3). Please refer to.). When there is a material with low hardness under the material with high hardness in multi-layer cutting, the shearing force is not transmitted well to the material with low hardness, and the material with low hardness may not be cut well. In the method of cutting only the base material 101 and the insulating material 105, the shearing force is satisfactorily transmitted to the bottom, so that the cutting can be performed smoothly, and delamination and falling of foreign matter in the electrode slit can be suppressed.

The timing of the forming step of the insulating material 105 is not particularly limited as long as it is before the slit step. As in the design change example shown in FIG. 7, first, the insulating material 105 having a plan view line shape is formed on each of the plurality of cutting lines (L1 to L3 in the illustrated example) of the slit process, and these plurality of plan view line shapes are formed. The insulating material 105 of the above may be used as a partition wall, and the negative electrode 102, the solid electrolyte film 103, and the positive electrode 104 may be sequentially laminated between the plurality of insulating materials 105.

In the design modification example shown in FIG. 7, it is possible to suppress the spread of the electrode material and the solid electrolyte material, and to suppress the short circuit between the negative electrode and the positive electrode during material coating. By forming the negative electrode 102, the solid electrolyte membrane 103, and the positive electrode 104 with the same size, it is possible to expand the effective power generation area when the negative electrode area is the same. In this embodiment, since there is no step in the lamination of the negative electrode 102, the solid electrolyte film 103, and the positive electrode 104, the negative electrode 102, the solid electrolyte film 103, and the positive electrode 104 are pressed in the step (D) of pressing the membrane electrode assembly 100. It can be pressed uniformly and well as a whole.

In the design change example shown in FIG. 7, similarly to the design change example shown in FIG. 6, in the slitting step, the negative electrode 102, the solid electrolyte membrane 103, and the insulating material 105 are not cut in layers, and the base material 101 is formed. Only the insulating material 105 can be cut (see cutting lines L1 to L3). In this method, similar to the design modification example shown in FIG. 6, the shearing force is satisfactorily transmitted to the bottom, so that cutting can be performed smoothly, and delamination and falling of foreign matter in the electrode slit can be suppressed.

As described above, according to the present invention, there is provided a method for manufacturing a membrane electrode assembly capable of performing a slit process under common slit conditions for both a formed portion and a non-formed portion of the negative electrode. can do.
In the production method of the present invention, since the insulating material is formed on a part of the negative electrode non-forming portion of the base material, the exposure of the base material is less than before, and it is possible to suppress the generation of foreign matter from the base material.
In the manufacturing method of the present invention, in the step (X) of forming a plan view line-shaped insulating material next to both ends parallel to the longitudinal direction of each positive electrode (base material transport direction), the plan view line-shaped insulating material is formed. Is stretched to the non-negative electrode forming portion of the base material. In this method, it is possible to suppress the biting of the work into the blade or the press roll, and to suppress the decrease in the rotation speed of the blade or the press roll and the resulting quality defect. In this method, the impact of the press roll entering and exiting the membrane electrode assembly can be moderated, compression of the membrane electrode assembly can be suppressed, and bending, wrinkles, and press cracking of the membrane electrode assembly can be suppressed.

The present invention is not limited to the above-described embodiment, and the design can be appropriately changed as long as the gist of the present invention is not deviated.

100 Membrane electrode assembly 101 Base material 101N Negative electrode non-forming part 102 Negative electrode 103 Solid electrolyte film 104 Positive electrode 105 Insulation material LM1 First laminate LM2 Second laminate

Claims (1)

A method for manufacturing a membrane electrode assembly including a negative electrode, a solid electrolyte membrane, and a positive electrode.
A step (A) of forming a plurality of negative electrodes at intervals along the longitudinal direction of the base material on the strip-shaped base material, and
A step (B) of sequentially laminating a solid electrolyte membrane and a plurality of positive electrodes on each of the negative electrodes.
It has a step (C) of slitting a laminate containing the base material, the negative electrode, the solid electrolyte membrane, and the positive electrode of the plurality of rows into a plurality of rows of a non-negative electrode forming portion of the base material.
Further, a membrane electrode assembly having a step (X) of forming an insulating material on the surface of the negative electrode non-forming portion of the base material at least on the cutting line of the step (C) before carrying out the step (C). Manufacturing method.

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