KR20140128744A - Method of testing of gasket for metal-biopolar plate of a fuel cell - Google Patents

Abstract

Disclosed is a method for testing adhesion of a gasket for a metal separation plate of a fuel cell by using a tangential force measuring device. The method of testing adhesion of a gasket for a metal separation plate of a fuel cell according to an embodiment of the present invention comprises (a) a step of preparing a metal separation plate having a gasket; (b) a step of pushing the gasket to the metal separation plate with an identical vertical load or at an identical height at a range of 0.5-2 mm with a tip for measuring adhesion of a tangential force measuring device; (c) a step of graphing by measuring the tangential force upon the moving distance of the pushed gasket; and (d) a step of determining the adhesion failure of the gasket by analyzing the slope of the graph.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method of evaluating the adhesion of a gasket for a fuel cell metal separator,

The present invention relates to a gasket for a fuel cell metal separator, and more particularly, to a method for evaluating the adhesion of a gasket for a fuel cell metal separator using a tangential force measuring instrument.

Fuel cell is a cell that converts the chemical energy generated by the oxidation of fuel directly into electric energy. In order to overcome problems such as depletion of fossil fuel, greenhouse effect by carbon dioxide generation, and global warming, A lot of research has been done together.

Fuel cells generally convert chemical energy into electrical energy using oxidation and reduction reactions of hydrogen and oxygen. At the anode, hydrogen is oxidized and separated into hydrogen ions and electrons, and hydrogen ions move to the cathode through the electrolyte. At this time, the electrons move to the anode through the circuit. A reduction reaction occurs in which hydrogen ions, electrons and oxygen react with each other in the anode.

Since a unit cell of a fuel cell is low in practicality due to a low voltage, generally several to several hundred unit cells are stacked and used. A separator is a separator that performs electrical connection between each unit cell and separates the reactant gas when the unit cells are stacked, and a plurality of units are connected to each other to form a fuel cell stack .

Conventional separators for fuel cells mainly use graphite, but they have recently been replaced by metal due to problems such as high cost and large volume.

In the case of a general metal separator, a reaction gas channel and a cooling water channel are formed in a central portion of a metal body provided in a rectangular shape, manifolds in which reaction gas flows in and out from both sides of each channel are formed, A gasket is formed so as to maintain the airtightness of the reaction gas in the periphery.

Due to the nature of fuel cells, operation and shutdown are frequently repeated. As a result, the metal separator is frequently exposed to high temperature and humidity, and depending on the position, it is exposed to a strong acidic atmosphere and a high polarization voltage.

For high durability even in prolonged use in a fuel cell operating environment, the gasket must maintain a constant airtightness. Conventionally, due to the lack of a method for measuring the adhesion of the gasket during the product production stage, the gas pressure supplied to the stack is measured to evaluate the adhesion of the gasket during visual inspection or assembly process of the fuel cell stack There was no.

Korean Patent Registration No. 0969065 (published on November 11, 2009) discloses a method of measuring gas pressure supplied to the gas and cooling water passages of the fuel cell stack after gas is injected into the stack during the assembling process of the fuel cell stack, A gas-tightness inspection apparatus and a method of a fuel cell stack are disclosed.

An object of the present invention is to provide a method for evaluating the adhesion of a gasket for a fuel cell metal separator which can evaluate the adhesion of the gasket quantitatively to form a gasket for a metal separator plate having excellent airtightness.

According to an aspect of the present invention, there is provided a method for evaluating the adhesion of a gasket for a fuel cell metal separator, the method comprising the steps of: (a) providing a metal separator having a gasket; (b) pushing the gasket to the metal separator with a tip for measuring the tangential force of the tangential force measuring device in the interval of 0.5 to 2 mm at the same vertical load or at the same height; (c) measuring the tangential force according to the moving distance of the pushed gasket and plotting the measured tangential force into a graph; And (d) determining a poor adhesion property of the gasket by analyzing the slope of the graph.

According to another aspect of the present invention, there is provided a method for evaluating the adhesion of a gasket for a fuel cell metal separator, the method comprising the steps of: (a) providing a metal separator having a gasket; (b) pushing the gasket at the same vertical load or at the same height in the elastic deformation section of the gasket with a tip for measuring the adhesion of the tangential force measuring device to the metal separator; (c) measuring the tangential force according to the moving distance of the pushed gasket and plotting the measured tangential force into a graph; And (d) determining a poor adhesion property of the gasket by analyzing the slope of the graph.

According to the present invention, it is possible to quantitatively evaluate the adhesion of the gasket by measuring the tangential force according to the travel distance of the gasket in a predetermined section by using the tangential force measuring device, thereby realizing a gasket capable of maintaining a constant airtightness, It is possible to secure long-term durability.

1 is a flowchart illustrating a method of evaluating the adhesion of a gasket for a fuel cell metal separator according to an embodiment of the present invention.
2 is a view showing a section (a) of a method of evaluating the adhesion of a gasket for a metal separator using the tangential force measuring device according to the embodiment of the present invention.
FIG. 3 is a view showing a section (b) to a section (d) of a method of evaluating the adhesion of a gasket for a metal plate using the tangential force measuring device according to an embodiment of the present invention.
4 is an example of a graph showing a tangential force according to a moving distance of a gasket using a tangential force measuring device according to an embodiment of the present invention.
5 is a graph showing the adhesion of the gasket according to Examples 1 and 2, using the tangential force measuring device of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings.

It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a method for evaluating the adhesion of a gasket for a fuel cell metal separator using a tangential force measuring instrument according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a flowchart illustrating a method of evaluating the adhesion of a gasket for a fuel cell metal separator according to an embodiment of the present invention.

Referring to FIG. 1, a method of evaluating the adhesion of a gasket for a fuel cell metal separator according to an exemplary embodiment of the present invention includes a step S110 of forming a gasket, a step S120 of pushing a gasket, A tangential force measurement step S130 and a gasket adhesion failure determination step S140.

FIG. 2 is a view showing a section (a) of a method of evaluating the adhesion of a gasket for a metal plate using a tangential force measuring instrument according to an embodiment of the present invention. FIG. 3 is a cross- (B) and (d) of the method for evaluating the adhesion of a gasket for a metal separator using the same.

Referring to FIGS. 1 to 3, the metal separator plate 210 having the gasket 220 formed thereon is provided in the metal separator plate forming step S110 in which the gasket is formed.

The metal separator 210 may include manifolds in which a reaction gas channel and a cooling water channel are formed in a central portion of a metal body provided in a rectangular shape and in which reactant gas flows into and out from both sides of each channel, A gasket 220 may be formed around the folds.

The metal separator 210 may be made of stainless steel, titanium (Ti), aluminum (Al), or the like, for example, as long as it is rigid and has excellent electrical conductivity, thermal conductivity, gas tightness, , Nickel (Ni), or the like, in the form of a plate having a thickness of about 0.05 to 0.5 mm.

If the thickness of the metal separator 210 is less than 0.05 mm, it may not be easy to handle during the process. If the thickness of the metal separator 210 is more than 0.5 mm, the thickness of the fuel cell stack may become thick.

The metal separator 210 may be formed by forming a reaction gas channel or a cooling water channel on one side and the other side, respectively, through a normal stamping process.

The gasket 220 is used for securing the airtightness of the reaction gas and may be formed of a rubber material which is easy to mold. The rubber for forming the gasket 220 may be, for example, silicone rubber, but is not particularly limited thereto.

The gasket 220 may have a width of 1 to 4 mm. At this time, if the width of the gasket 220 is less than 1 mm, it may be difficult to secure the airtightness of the reaction gas and to support the compressive load in the lamination. On the other hand, if the width of the gasket 220 exceeds 4 mm, miniaturization of the fuel cell may be difficult.

The gasket 220 may be formed around the channel and the manifold on the metal separator plate 210 by an injection molding method or the like and provides airtightness to each of the channels and manifolds through the gasket 220.

In a fuel cell operating environment in which operation and stoppage are frequently repeated, the gasket 220 may be lifted or pushed as it is exposed to a high polarization voltage. In this case, the airtightness of the reaction gas can not be ensured, .

Therefore, it is necessary to quantitatively measure the initial adhesion force of the gasket 220 in order to realize the gasket 220 capable of maintaining the airtightness of the reaction gas for a long time in order to secure long-term durability in the fuel cell operating environment.

In the present invention, a new gasket adhesion evaluation method using a tangential force measuring instrument is presented, which will be described later.

In the gasket push step S120, the gasket 220 is pushed to the metal separating plate 210 with a tip 310 for measuring the adhesion force of the tangential force measuring device 300. [

In particular, the gasket pushing step (S120) of the present invention is characterized in that the tip 310 for measuring the adhesion is moved in the section of 0.5 to 2 mm or the elastic deforming section of the gasket 220 to push the gasket 220.

At this time, it is preferable that the push of the gasket is applied at the same vertical load or at the same height. However, there is a problem that the characteristics of the actual tangential force measuring device 300, the problem of maintaining the same height of the tip 310 for measuring the adhesion force, and the fact that the upper part of the metal separator 210 and the gasket 220 are horizontal, It is more preferable to push the gasket 220 by moving the tip 310 for measuring the adhesion force along the surface of the metal separator 210 by applying a vertical load of 0N.

As shown in Figs. 2 and 3, the gasket push process can be classified into four sections (a) to (d). (B) is a section showing the elastic deformation and adhesion of the gasket 220, (c) is a section showing the elastic deformation and adhesion of the gasket 220, The elastic unmodified section of the gasket 220, (d) section may be defined as a section of movement exceeding the width of the gasket 220.

The gasket pushing step S120 of the present invention does not move the tip 310 for measuring the adhesion from the section (a) to the section (c) of the sections (a) to (d) And is characterized in moving the measuring tip 310. This is because the contact strength between the gasket 220 and the metal separator 210 can be measured by measuring the tangential force of the initial section of the section (b).

In the tangential force measurement step S130, the tangential force according to the moving distance of the pushed gasket 220 is measured and plotted in a graph.

4 is an example of a graph showing a tangential force according to a moving distance of a gasket using a tangential force measuring device according to an embodiment of the present invention.

FIG. 4 is a graph showing the tangential force according to the moving distance of the gasket 220 in the sections (a) to (d). In the present invention, the gaskets 220 It is required to measure the tangential force according to the moving distance of the tangential force.

At this time, the slope of the specific section can be measured from the tangential force-indentation depth curve showing the tangential force obtained through the adhesion tester and the depression depth of the gasket.

In the gasket adhesion failure determination step S140, the slope of the graph showing the tangential force according to the movement distance of the gasket 220 in the predetermined period and in the period (b) is analyzed to determine the poor adhesion of the gasket 220.

At this time, the slope of the graph is expressed by [Equation 1]. Under the assumption that the elastic force of the gasket is constant, the slope becomes a function of the adhesion strength and the gasket movement (or the tip travel distance). At this time, if the value of the slope is less than 2.5, the adhesion of the gasket 220 is judged to be defective.

[Formula 1]

Graph slope = (adhesion strength between gasket and metal separating plate + elastic force of gasket) × moving distance of gasket

As described above, according to the present invention, it is possible to implement a gasket 220 that can maintain a constant airtightness by evaluating the adhesion of the gasket 220 quantitatively using the tangential force measuring device 300. Therefore, it is possible to prevent the generation capacity of the fuel cell from deteriorating through ensuring long-term durability in the operating environment of the fuel cell.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to embodiments of the present invention. It should be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

Example 1

A gasket having a width of 1 mm was formed of a rubber material on a metal separator made of stainless steel. Then, the molded gasket was heat-treated at 1000 占 폚.

Example 2

The remaining constitution was carried out in the same manner as in Example 1, except that the molded gasket was heat-treated at 1200 ° C.

≪ Evaluation of adhesion &

The tangential force measuring device of FIG. 2 was placed on the metal separating plates of Examples 1 and 2, and a vertical load of 0 N was applied to the metal separator with a tip for measuring the adhesion force to push the gasket by a distance of 0.6 mm. Then, the tangential force according to the travel distance of the gasket is measured and is shown graphically in FIG. The moving distance of the gasket is described as a pressing mark in Fig.

5 is a graph showing the adhesion of the gasket according to Examples 1 and 2, using the tangential force measuring device of the present invention.

Referring to FIG. 5, in the case of Example 1 using a gasket made of a rubber material heat-treated at 1000 ° C, the slope of the graph was larger than that of Example 2 using a rubber material gasket heat-treated at 1200 ° C. At this time, the slope of the graph represents [Expression 1].

[Formula 1]

Graph slope = (adhesion strength between gasket and metal separating plate + elastic force of gasket) × moving distance of gasket

Therefore, assuming that the elasticity of the gaskets of Examples 1 and 2 is the same, the adhesion strength of Example 1 is superior to that of Example 2, because the difference in adhesion strength is regarded as the slope difference of the graph.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. These changes and modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

210: metal separator 220: gasket
300: Tangential force measuring device 310: Tip for measuring adhesion

Claims (5)

(a) providing a metal separator having a gasket formed thereon;
(b) pushing the gasket to the metal separator with a tip for measuring the tangential force of the tangential force measuring instrument at 0.5 to 2 mm intervals at the same vertical load or at the same height;
(c) measuring the tangential force according to the moving distance of the pushed gasket and plotting the measured tangential force into a graph; And
(d) analyzing the slope of the graph to determine whether the gasket is poorly adhered to the gasket.
(a) providing a metal separator having a gasket formed thereon;
(b) pushing the gasket at the same vertical load or at the same height in the elastic deformation section of the gasket with a tip for measuring the adhesion of the tangential force measuring device to the metal separator;
(c) measuring the tangential force according to the moving distance of the pushed gasket and plotting the measured tangential force into a graph; And
(d) analyzing the slope of the graph to determine whether the gasket is poorly adhered to the gasket.
3. The method according to claim 1 or 2,
The slope of the graph
A method for evaluating the adhesion of a gasket for a fuel cell metal separating plate, which is represented by the following formula (1).
[Formula 1]
Graph slope = (adhesion strength between gasket and metal separating plate + elastic force of gasket) × moving distance of gasket
The method of claim 3, wherein
The step (d)
Wherein the adhesion of the gasket is judged to be defective if the slope of the graph is less than 2.5.
3. The method according to claim 1 or 2,
The step (c)
Wherein the slope of the specific section is measured from a tangential force-indentation depth curve showing the tangential force and the depression depth of the gasket.

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