JPS6082683A - Manufacture of electrochemical apparatus using ion- exchange membrane - Google Patents

Abstract

PURPOSE:To improve the jointing state of both an ion-exchange membrane and a catalytic electrode layer and to obtain an electrochemical apparatus wherein an internal resistance has been diminished by performing a wet treatment, a fixation and a dry treatment for the ion-exchange membrane. CONSTITUTION:After an ion-exchange membrane 1 has been swelled to a hydrous state by such a method that the membrane 1 is immersed in boiling water, the circumference of the membrane is fixed by a frame or the like made of a resin, thereafter the membrane is dried under vacuum. A catalytic electrode layer incorporating an electrically-conductive catalyst powder such as platinium and a fluorine-contg. high molecular binder such as polytetrafluoroethylene is press- fixed and jointed onto both surfaces of said membrane 1 or the reverse surface to a surface on which a catalytic electrode has been jointed by an electroless plating and thereby a cathode 2 and anode 3 are formed. By said process, an electrochemical apparatus for water electrolysis or the like wherein the jointing strength of both the ion-exchange membrane and the catalytic electrode layer is large and the electric resistance of the jointing interface is small is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing various electrochemical devices and gases using an ion exchange membrane as an electrolyte. The purpose is that when joining the catalyst layer q and the ion exchange layer u, it absorbs water or swells and swells, then dries without shrinking in the two axial directions except for the ≠ longitudinal direction, and forms a 1 ion exchange model. The object of the present invention is to provide an electrochemical device that has two characteristics, such as high bond strength and low electrical resistance at the bond interface, depending on the application.

71 (t) for an electrochemical device using an ion exchange membrane as an electrolyte
14＠ equipment, halogenated alkali electrolysis equipment, oxygen separation equipment, droplet separation cultivation, fuel turtle pond, etc.These various electrochemical equipment include Although there are some methods and others that are not, the present invention relates to the previous method.j) Conventionally, methods for integrating ion exchange and electrodes can be roughly divided into
The electroless plating method described in No.-36873 and the ゛Ii+
There is a so-called press method in which a mixture of gas-conducting, gas-conducting catalyst powder and a binder is pressed onto an ion exchange membrane.

The electroless plating method is a method in which saponifying metal is deposited directly on the surface of the ion exchange membrane, and although it is simple, it cannot bond the catalyst in a state other than the metal state, such as in a metal state such as gold tetraoxide.

A major problem is that the catalyst cannot be freely selected.

On the other hand, in the press method, the powder is mixed with a binder and solidified, and then placed in an ion exchange press. For example, a ruthenium oxide catalyst, which has such properties as an anode in salt electrolysis, cannot be bonded by electroless plating, but it can be bonded easily by pressing.

In the JID press method, a polymer such as poly(tetrabutylene) as a binder is usually used as a binder because it has a chemically stable 11-position and is easily bonded.

Examples of ion exchange membranes include Nafion manufactured by Dubono, USA, which is made by introducing sulfone or carboxylic acid groups into fluorine-containing molecules (11).
It's okay.

Yl! During the EE bonding of the medium 'rtf I and the ion exchanger, it is heated to a temperature in the range of 50 to 800'C in order to increase the mechanical strength of the bond and reduce the contact resistance to the surface. At this time, if the catalyst layer (7 layers) and ion exchange layer contain water or are synthesized, a good bonding state cannot be obtained. , it is desirable to thoroughly dry these 7).

After drying, the ion-exchange membrane should be immersed in light to ensure the ionic conductivity of the ion-exchange membrane. Although it varies depending on the water content conditions, the standard is 10 to 20%, and the agent is added to the machine)
It swells more than the first. Therefore, it is clear that the dried product of the ion-exchange membrane and the medium has a raw material, and that the size of the hydrated IIO has changed significantly. As the contact resistance of the contact area increases, the result is a bond that has the same properties as the wet one when pressed with a water-containing material. To significantly reduce the dimensional change of the ion exchange H near q caused by drying (including drying), use the filtration method. It completely solves the problem and provides a substitute for the t+ i'U- function that is not present in the Ir tank (for chemical equipment. Namely, first, 94% of the ion exchange is done with water.

n mechanical medium or l mixture of these (?4 欣 or ``rin, salt shi (.

Because of the salt water bath, it is immersed and used as a cell (C cell).
Add 1 shadow to the dimensions. Then, fix the swollen, 1, 1, 2, and 4 parts of the liq with a frame, and dry it in a square shape.

In this way, the ion exchange membrane will not shrink.

Dry in this way, dry on an ion exchange membrane, and melt.
A bonded body is made by observing ``11''. Even when this bonded body is used for the swelling treatment described above and immersed in the liquid, no reduction in size occurs and the contact resistance at the grain boundaries of the catalyst powder does not increase. Does not occur.

This book describes a method for joining a catalyst electrode to an ion exchange membrane.
F = 31i and 1i (press method is used for both returns −
It can be applied not only to the case where either one of the cathode and the metal plate is bonded by the method of bonding.In this case, the conventionally known t++C electrolytic plating method ), one catalytic electrode is bonded to one side of the ion exchange membrane.
After that, the guard fence operation as described above and the drying operation in 1 hole T-shaped shape, .
=r According to the Ki method, the ion exchange medium '11 temporary is joined, and another catalyst electrode 11 is joined to the opposite side of the ion exchange 11 by the Pre7 method. Bye.

Incidentally, ion exchange rj4 resin powder or ion exchange@+j'd fiber may be mixed into the medium Denso 1n.

An embodiment of the present invention will be described in detail below.

Example 1 Figure 1 shows a cross section of a Kagaro water electrolysis device according to an embodiment of the present invention.
An anode (3) consisting of an iQ base 14 of iridium oxide (Vi) powder and polytetrafluoroethylene is bonded to the other side of the cathode made of mixed IIIVI.

Immerse the ion exchange membrane in nB IJ ice water for 30 minutes to make it hydrated;
After inserting the IC, air-dry the area around the hole in the direction of the sea with a frame of mebushi sea bream, while the 7 nodes and the 1 node are respectively 1 and 2. 4' water of ethylene chloride (and 11
Mix the other two, sort them, and then dry them to make one. This is 100'C, 300kr
I/cA's press row f cow: long and 1 piece.

(4) is the anode collection C1f body, (5) is the cathode collection %i
It is the body.

(6) is the water supply port, (7) is the mouth of the shield element, (8)
) is the hydrogen outlet. (91, t91 is tun (cao and al.

When a direct current '1111E is applied to the water electrolysis cell with this arrangement, oxygen is generated from the 7' node and hydrogen is generated from the cathode, which are then discharged from the tl outlets (7) and (8).

In order to test the performance of this water-dissolved cell in comparison with a conventional example, we first tested an uninvented cell with -1- discharge (aluminum, heat treated and fixed). LAI,!: 141 ['s anode and cathode were treated under the same conditions without drying, and the r-cell (B) was treated with borosilicate after drying treatment. With the same anode and cathode as in (△) under the same conditions, we set the cell as T: C) and examined the laminar flow and submerged pressure characteristics of these cells at 30°C. 1,
Obtained the results shown in Figure 2.

Chis, (Comparing Al and +B1, (Ijl is ′i buried j King, and the difference becomes larger as lf′K1 degree becomes higher.) When we measured the internal resistance of the cell in (13), it was found to be approximately twice that of 4, indicating that the tactile resistance between the catalyst powder particles was 1 greater.

On the other hand, compare (to) and O) +! +! Then, 0 is 611 (sweat is higher than 1N and its internal resistance is 1J) as in ('3).
As a result of the ijl constant, it is found that the resistance at the bonding interface is large1
child.

Embodiment 2 FIG. 3 shows a cross-sectional structural diagram of an apparatus for separating oxygen from air according to an embodiment of the present invention.

In FIG. 3, (10) is an ion exchange membrane having a sulfonic acid group in perfluorocarbon, and (II) is a cathode made of jfR, a mixture of platinum black powder and a polymer binder made of polytetrafurinated ethylene. The other 1hi has no 1! The anode (12) made of platinum is bonded by the plating method.

The connection between the ion exchange ('At1A (10) and the cathode (IIJ) is done as shown in 77 (r).The anode is connected to one side using the 1! solution plating method, and the ion exchange dλ is placed in water. After soaking and swelling with water, the area around the tube is fixed with a synthetic resin frame and dried under vacuum.Meanwhile, the cathode is made of platinum black powder and poly(4)I-containing ethylene water (rW). Mix M and make it into a shape of I. After that, dry it under vacuum and apply 1" L of the prepared powder to an untreated platinum plate of an ion exchange membrane at 100°C and 300 A: q/cd. (18) is the anode current collector, (14 is the cathode current collector. (15) is the water supply port, (16) is the water and l!ill element kawaguchi (17) is the air inlet, (18J
is the air outlet. (19 people (L92 is electric R arm and Chiru.

When DC IF pressure is applied to a cell with such a structure that separates oxygen from air, the degree of reduction of oxygen at the cathode decreases.

A reaction occurs and the elements in the electricity are consumed. On the other hand, anode C
is consumed at the cathode, and the same amount of oxygen is produced as gas, which is discharged from the outlet +71.

Next, let's test the performance of this device 4 by comparing it with a conventional example.

First, the above-mentioned uninvented cell was used as fDl, and one piece was bonded with platinum by electroless plating without being subjected to swelling treatment, fixation or drying treatment, and was then attached to an ion exchange membrane (lO).
) Same as 1 (A soft cathode was crimped under the same conditions and one cell was made (E).

- Swelling place 411! A cathode similar to fDl is used with a similar row FF until the soil is slightly water-containing.
iF] and 25-CKJ of these cells to obtain the results shown in Figure 4. First of all, if we compare p) and (El), (141 has a better electric power.

This means that the internal resistance of (υ) is about twice as large as that of (Al).On the other hand, when tDl and (Fl) are compared by one degree, (Fl has a higher voltage than (D), and the catalyst particles It can be seen that the resistance at the interface has increased.'As mentioned above, by subjecting the ion exchange membrane to swelling treatment and 11 constant drying treatment before pressure bonding, the ion exchange membrane and the feed electrode layer can be bonded. By improving the shape of the ion exchange membrane and reducing the internal resistance, it is possible to create an electrochemical cell with unprecedented high performance.
The industrial value of this method is extremely great because it will lead to the creation of an electrochemical device as described in d.

[Brief explanation of the drawing]

FIG. 1 shows an example of the present invention [((671) (cross-sectional structural diagram of an electrolytic cell), and FIG. 2 shows an example of the present invention (671). i6 (
13, U) is a diagram showing the current-voltage characteristics of the current-voltage characteristics. y, Fig. 3 is a cross-sectional structural diagram of a cell separating the q base from the air according to the second embodiment of the present invention, and Fig. 4 is according to the second embodiment of the present invention! Figure 1 shows a comparison of current-voltage characteristics between a cell that partially condenses oxygen from 2 air and a conventional cell (E, F). ■・・・Ion exchange a lament, 21 cathode. 3...Anode, 4...Anode collection α body. 5 Cathode collection 'if body, 6...Water supply port. 7... Exhaust port for water and @element, 8... Exhaust port for curved hydrogen. 9.9...Battery container, 10...Ion exchange. 11. Cathode, 12. Song anode. 13...Anode iA 7M body, 14-...-
Cathode current collector, 15...1 water supply, 16...
... Water and oxygen outlet, 17... Air supply port, [8... Air wandering 1130, 19.19.
Song 1il tank. 1 mouth 2 mouths

Claims (1)

[Claims] An ion-exchange membrane that becomes an rfl dissolution stomach, or an ion-exchange membrane with a carrier current bonded to one side by the electroless 1T gemmel method, is coated with water, bath additives, or these muddy substances). The ion exchange membrane is immersed in a concentrated solution of acids, bases, and salts, and after swelling, the area around the ion exchange membrane is 1.!if 1.
After drying and drying at 15, electrically conductive catalyst powder and poly(tetrafluoroethylene), etc. 1 including a basic polymer binder! A method for producing an ion exchange membrane characterized by pressure-bonding an R1 medium electrode layer: a gas chemical device method.