JP3146758B2 - Solid polymer electrolyte fuel cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved structure of a solid polymer electrolyte fuel cell in which concentrated stress applied to a solid polymer electrolyte membrane is reduced.

[0002]

2. Description of the Related Art Various types of fuel cells, such as a solid polymer electrolyte type, a phosphoric acid type, a molten carbonate type, and a solid oxide type, are known as fuel cells depending on the type of electrolyte used therein. Of these, solid polymer electrolyte fuel cells exhibit low resistivity and function as proton conductive electrolytes when saturated with a polymer resin membrane having proton (hydrogen ion) exchange groups in the molecule. The fuel cell used.

FIG. 4 is a cross-sectional side view schematically showing a unit cell of a conventional solid polymer electrolyte fuel cell in a developed state. In FIG. 4, reference numeral 7 denotes a fuel cell composed of an electrolyte layer 7C, a fuel electrode (also an anode) 7A, and an oxidant electrode (also a cathode) 7B. The electrolyte layer 7C is a thin rectangular solid polymer electrolyte membrane (hereinafter sometimes abbreviated as a PE membrane).
Consists of The fuel electrode 7A is an electrode that is closely stacked on one main surface of the PE film 7C and receives supply of a fuel gas (for example, hydrogen or a gas containing hydrogen at a high concentration). The oxidant electrode 7B is made of a PE film 7C.
Is an electrode that is closely stacked on the other main surface of the first electrode and receives supply of an oxidizing gas (for example, air). The outer side of the fuel electrode 7A is one side 7a of the fuel cell 7
The outer surface of the oxidant electrode 7B is
Is the other side surface 7b. Each of the fuel electrode 7A and the oxidant electrode 7B has a respective catalyst layer 71 containing a catalyst active material.
A, 71B, and the catalyst layers 71A, 71B, respectively, while supplying and discharging a reaction gas (hereinafter, collectively referred to as a fuel gas and an oxidizing gas) as a current collector. It is composed of porous electrode base materials 72A and 72B having the function of (1). As shown in FIG. 4, the fuel electrode 7A and the oxidant electrode 7B have outer dimensions in the plane direction smaller than the outer dimensions in the plane direction of the PE film 7C.
A, between the end of the oxidant electrode 7B and the end of the PE film 7C, as shown in FIG.
Will be present. In the case shown in FIG. 4, both the fuel electrode 7A and the oxidant electrode 7B have the same outer dimensions in the plane direction.

The fuel cell 6A is made of a material that does not allow gas to permeate, and is disposed on one side 7a of the fuel cell 7 so that fuel gas (not shown) flows through one side of the fuel cell 7. A plurality of concave grooves (grooves for gas flow) 61A provided at the same interval for discharging the fuel gas containing hydrogen, and a convex partition 62A interposed between the gas flow grooves 61A are mutually separated. The separators are formed alternately. 6B is disposed on the other side surface 7b side of the fuel cell 7 and has the same interval for allowing an oxidizing gas (not shown) to flow through one surface thereof and discharging the oxidizing gas containing unconsumed oxygen. (A gas flow groove) 61B provided in plural by the
The convex partition walls 62B interposed between B are alternately formed with each other, and are made of a gas-impermeable material like the separator 6A.

The tops of the convex partitions 62A, 62B are formed so as to be flush with the side surfaces 6Aa, 6Ba of the separators 6A, 6B on the side facing the fuel cells. The separator 6A has the side surface 6Aa closely contacted with the side surface 7a of the fuel cell unit 7, and the separator 6B has the side surface 6Ba connected to the side surface 7a of the fuel cell unit 7.
b so as to sandwich the fuel cell 7 therebetween.

Reference numeral 73 denotes separators 6A, 6B
The reaction gas flowing through the gas flow grooves 61A and 61B of
A gas seal member having a function of preventing leakage from the outside of the flow passage, between the exposed surface portion having a dimension (W) which is a peripheral portion of each of the separators 6A and 6B, and a peripheral portion of the fuel cell 7. In the empty space. Further, as shown in FIG. 4, the separators 6A and 6B have outer dimensions in the plane direction that are larger than the outer dimensions in the plane direction of the fuel electrode 7A and the oxidant electrode 7B. In this case, the separators 6A and 6B are made of a PE film 7C.
Has the same outer dimension in the plane direction as the outer dimension in the plane direction.

The thickness of the above-mentioned fuel cell 7 is 1 mm or less in many cases, and the larger the area, the more the manufacturing cost can be reduced. Therefore, the area of the fuel cell 7 is as large as possible, for example, 1 [mm]. m ² ]. In this case, the thickness of the fuel electrode 7A and the thickness of the oxidant electrode 7B constituting the fuel cell 7 are about 0.3 [mm] to 0.4 [mm], respectively. PE film 7
The thickness of C is 0.1 [mm] to 0.2 [m
m]. The PE film 7C, the fuel electrode 7A, and the oxidant electrode 7B are each manufactured in advance as a wide sheet-like intermediate material, and after cutting these sheet-like intermediate materials into the above-described dimensions, respectively, the catalyst layer 7 is formed.
The sides 1A and 71B are firmly adhered to each other by hot pressing the respective main surfaces of the PE film 7C.

[0008] The voltage generated by one fuel cell 7 is:
Since the value is as low as about 1 [V] or less, a large number of the unit cells 5 having the above-described configuration are connected in series to each other via each fuel cell 7 and the separators 6A and 6B interposed therebetween. In general, the fuel cell unit is configured as a fuel cell assembly (hereinafter, may be abbreviated as a stack), and is put to practical use with an increased voltage.

FIG. 5 is a schematic diagram showing the structure of a stack of a solid polymer electrolyte fuel cell. In FIG.
Reference numeral 8 denotes a plurality of unit cells 5 stacked on each other, and current collector plates 81a and 81b for taking out DC electricity generated in the fuel cells 7 of the plurality of unit cells 5 at both ends thereof; Electric insulating plates 82a and 82b for electrically insulating the electric plates 81a and 81b from the structure, and both sides of a stacked body in which the unit cells 5, the current collecting plates 81a and 81b, and the electric insulating plates 82a and 82b are stacked. Fastening plates 83a arranged at the ends,
A solid body comprising a tightening bolt 84 for applying an appropriate pressing force to the tightening plates 83a and 83b, and a cooling body 85 interposed every time a plurality of unit cells 5 are stacked. 3 is a stack of a polymer electrolyte fuel cell.

In the fuel cell 7, when DC power is generated as will be described later, a loss substantially equal to the generated power is generated. It is the role of the cooling body 85 to remove the heat due to this loss. A coolant (not shown) such as water or air for removing heat is passed through the cooling body 85 to maintain the fuel cell 7 at an appropriate temperature described later. Therefore,
In the stack 8 having the configuration shown in FIG. 5, the separators 6A and 6B prevent the permeation of the reaction gas, and the flow paths of the reaction gas supplied to the fuel cell 7 by the gas circulation grooves 61A and 61B. At the same time, the direct current generated by the fuel cell 7 and the heat generated by the loss in the fuel cell 7 are transmitted to the current collectors 81a, 81b and the cooling body 85 via the convex partitions 62A, 62B. It also plays the role of doing.

Further, in the stack 8, the fuel cells 7
To reduce the electrical resistance and thermal resistance between the current collector plates 81a and 81b and the cooling body 85 improves the characteristics of the fuel cell. In order to reduce the pressure, the pressure is applied by the tightening bolt 84 so that a constant pressure is always applied. Generally, this pressure is about several kg / cm ² .

In the stack 8 having the above configuration, the fuel gas is supplied to the fuel electrode 7A, the fuel gas is supplied to the fuel electrode 7A, and the fuel gas is supplied to the oxidant electrode 7B. By supplying the oxidant gas, the catalyst layers 71A, 71 of the respective electrodes 7A, 7B are supplied.
A three-phase interface is formed at the interface between B and the electrolyte layer 7C made of a PE film (the interface between the catalyst in the catalyst layers 71A and 71B, the PE film, and any one of the reaction gases). Then, direct current electricity is generated by causing an electrochemical reaction. The catalyst layers 71A and 71B are formed of a fine particulate platinum catalyst and a water-repellent fluororesin, and by forming a large number of pores, the efficiency of the reaction gas up to the three-layer interface. The structure is such that a three-layer interface having a sufficiently large area is formed while maintaining a proper diffusion.

By the way, P forming the electrolyte layer 7C
As described above, the E membrane is a polymer membrane having a proton (hydrogen ion) exchange group in the molecule, and exhibits a resistivity of 20 [Ω · cm] or less at room temperature when saturated with water, and exhibits a proton conductive electrolyte. It is a film that functions as The saturated water content of this PE film changes reversibly with temperature. In addition,
At present, as the PE film, a perfluorosulfonic acid resin film (for example, Nafion film manufactured by DuPont, USA) is known. The electrochemical reaction that occurs at the three-phase interface formed by the electrolyte layer 7C using such a PE film, the catalyst layer, and the reaction gas is as follows.

The reaction of the formula (1) takes place at the anode electrode 7A.

[0015]

(Equation 1)

The reaction of the formula (2) takes place at the cathode electrode 7B.

[0017]

(Equation 2)

That is, in the anode electrode 7A, hydrogen supplied from the outside generates protons and electrons. The generated protons pass through the PE film 7C through the cathode electrode 7C.
The electrons move toward B, and the electrons move to the cathode electrode 7B through an external electric circuit (not shown). On the other hand, in the cathode electrode 7B, oxygen supplied from the outside, the protons moving from the anode electrode 7A in the PE film 7C, and the electrons moving from the external electric circuit react to generate moisture. Thus, the fuel cell 7 generates hydrogen and oxygen to generate DC electricity. In such a solid polymer electrolyte fuel cell, in order to reduce the resistivity of the PE membrane 7C and obtain high power generation efficiency, a temperature condition of about 50 ° C. to 100 ° C. is usually used. Driven by Since the PE film 7C is a film through which the fuel gas and the oxidant gas as the reaction gas do not permeate, the PE film 7C also plays a role of preventing a so-called cross leak in which the reaction gases are mixed with each other.

In addition, as separators, apart from the separators 6A and 6B in which the grooves 61A or 61B are provided only on one side surface, grooves of separators adjacent to each other in a stack configuration are also integrally formed. In order to streamline the stack configuration, the gas flow grooves 6
There is also known a separator in which 1A and 61B are provided on both side surfaces thereof.

[0020]

The solid polymer electrolyte fuel cell using the separator according to the prior art described above sufficiently exhibits the function of DC power generation.
There are the following problems. That is, since the fuel cell 7 is manufactured by the above-described process, as shown in the case of the fuel electrode 7A in FIG. 6, the corners 74 of the rectangular fuel electrode 7A and the oxidant electrode 7B are formed. Is a right angle. By the way, the PE membrane 7C, which is an electrolyte membrane of a polymer electrolyte fuel cell, has the property that its dimensions expand or contract due to its wet state. That is, the dimension of the PE film 7C expands as the moisture content increases, and the dimension shrinks as the moisture content decreases. However, the PE film 7C and the electrode 7X
(Hereinafter, the fuel electrode 7A and the oxidant electrode 7B may be referred to as such when they are collectively referred to.) Since they are manufactured by the above-described process, they are extremely strongly joined. The shrinkage of the dimension of the PE film 7C is indicated by the exposed portion of the PE film 7C [dimension (W) in FIG. ], And no shrinkage occurs at the portion of the PE film 7C joined to the electrode 7X. As a result, in the PE film 7C at the boundary between the exposed portion of the PE film 7C and the electrode 7X, a large internal stress is generated due to the uneven contraction. In a portion that comes into contact with the corner portion 74 where the dimensional contraction in the horizontal direction in FIG. 6 and the dimensional contraction in the vertical direction in FIG.
In particular, when the corner portions 74 have a right angle, a large concentrated load acts.

For this reason, P near the corner 74 of the exposed portion
In some cases, the E film 7C was damaged. This PE film 7C
The exposed portion is a portion where a gas seal body 73 serving to prevent the reaction gas from leaking out of the flow passage is mounted. If the PE film 7C is damaged at this location, the flow of the reaction gas is prevented. Leakage to the outside of the flow path, and furthermore, so-called cross-leakage, causes a problem that the life of the electrode 7X is shortened, and finally, the operation of the fuel cell cannot be continued as illustrated in FIG. There are things that can happen.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a solid polymer electrolyte fuel cell, in which even if the PE membrane shrinks in size, the PE membrane is not damaged. An object of the present invention is to provide a solid polymer electrolyte fuel cell capable of reducing the degree of breakage.

[0023]

According to the present invention, there are provided the following objects: 1) a fuel cell for generating DC power by receiving a supply of a fuel gas and an oxidizing gas; and a fuel cell disposed on both sides of the fuel cell. And a separator having a plurality of gas flow grooves for supplying a fuel gas or an oxidizing gas to the fuel cell. The fuel cell has an electrolyte layer made of a PE film, and two main surfaces of the PE film. And an electrode having an outer dimension in the surface direction smaller than the outer dimension in the surface direction of the PE film, and the separator is provided on a side surface facing the fuel cell unit. In a solid polymer electrolyte fuel cell, a plurality of concave grooves for gas flow and convex partitions interposed between adjacent concave grooves are formed. The electrodes provided are And 2) a fuel cell for generating DC power by receiving a supply of fuel gas and oxidizing gas, and a fuel cell disposed on both sides of the fuel cell. And a separator having a plurality of gas flow grooves for supplying a fuel gas or an oxidizing gas to the fuel cell. The fuel cell has an electrolyte layer made of a PE film and two main members of the PE film. An electrode having an outer dimension in the plane direction smaller than the outer dimension in the plane direction of the PE film, and the separator is provided on the side surface on the side facing the fuel cell unit. A solid polymer electrolyte fuel cell, wherein a plurality of concave grooves for gas distribution and a convex partition wall interposed between adjacent concave grooves are formed. The electrodes provided by Is obtained by chamfering the corners.

[0024]

According to the present invention, the electrode provided in the fuel cell of the solid polymer electrolyte fuel cell has a structure in which the corners are formed in an arc shape, so that the dimensional shrinkage generated in the PE film is achieved. , P
The internal stress generated at the portion of the E film that contacts the corner of the electrode is
When the corners of the electrodes have a large curvature, the degree of concentration is reduced. Thereby, PE
It is possible to reduce the degree of breakage of the PE film that occurs near the corner of the exposed portion due to dimensional shrinkage of the film.
In addition, the electrode provided in the fuel cell of the solid polymer electrolyte fuel cell has a structure in which the corners are chamfered, so that in order to obtain the effect described in the above section, the processing is performed. This can be facilitated.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. Embodiment 1 FIG. 1 shows a fuel cell used in a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claim 1, wherein FIG. 1 (a) is viewed from the direction of arrow P in FIG. FIG. 1B is a plan view thereof, and FIG. 1B is a schematic side sectional view of FIG. 1A. In FIG. 1, FIGS.
The same reference numerals are given to the same parts as those of the fuel cell of the conventional polymer electrolyte fuel cell according to the conventional example shown in FIG. Note that, in FIG. 1, only the reference numerals shown in FIG.

In FIG. 1, reference numeral 1 designates a fuel cell 2 of the conventional solid polymer electrolyte fuel cell shown in FIG. 4 which has a fuel electrode 2A instead of a fuel electrode 7A and an oxidant electrode 7B. This is a fuel cell of a solid polymer electrolyte fuel cell using the agent electrode 2B. The fuel electrode 2A and the oxidant electrode 2B are connected to the fuel electrode 7 of the conventional example shown in FIG.
The only difference between A and the oxidant electrode 7B is that, as shown in FIG. 1, each corner 74 is formed in an arc shape having a radius of R. The fuel electrode 2A and the oxidant electrode 2B are connected to the catalyst layers 71A and 71B, respectively.
After cutting the sheet-shaped intermediate material composed of the side and the electrode base materials 72A, 72B into respective predetermined dimensions, the corner portion 74 is subjected to the above-mentioned arc processing, and thereafter, the PE film 7C is formed.
Are hot-pressed on their respective main surfaces to firmly adhere to each other.

Fuel cell 1 having the above configuration
Is used in place of the conventional fuel cell unit 7 in the unit cell 5 of the solid polymer electrolyte fuel cell illustrated in FIG. 4 to configure a unit cell of the solid polymer electrolyte fuel cell. In the present invention, since the above-described configuration is employed, the PE film 7C
Of the electrode 2 at the exposed portion of the PE film 7C due to the contraction of
The concentrated stress generated in the PE film 7C at the boundary with the X (hereinafter, when the fuel electrode 2A and the oxidant electrode 2B are collectively referred to), the corner 74 of the electrode 2X is It has an arc shape, and is reduced by its large radius of curvature.

The degree of reduction of the concentrated stress generated in the PE film 7C depends on the radius (R) of the circular arc.
Depends on the value of That is, as the radial dimension (R) increases, the degree of reduction of the concentrated stress increases. However, as the radius dimension (R) increases, the area of the fuel cell 1 that contributes to the electrochemical reaction decreases, so that the output characteristics of the power generation device decrease. Therefore, the radius dimension (R) of the fuel cell 1 is 10 [mm], 3 [mm] and 1 [mm].
Were manufactured and assembled into a unit cell to perform operation operation. The unit cell using the fuel cell 1 having the radius dimension (R) of 10 [mm] was able to operate stably for the longest time, but the radius dimension (R) was 3 [m
m], a practically sufficient continuous operation time could be obtained for the unit cell using the fuel cell 1 as shown in the continuous operation data illustrated in FIG. However, in the unit cell using the fuel cell 1 having the radius dimension (R) of 1 [mm], although the improvement was made as compared with the conventional example shown in FIG. 6, a desired continuous operation time could not be obtained. In addition,
Under this condition of the value of the radius dimension (R), there was hardly any significant difference in the power generation characteristics. From these facts, it can be said that the value of the radius dimension (R) is preferably set to about 3 mm or more.

Embodiment 2 FIG. 3 shows a fuel cell used in a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claim 2, wherein FIG. It is the top view seen from the arrow direction, (b) is the side surface sectional drawing which showed typically of FIG. 3a. 3, the same parts as those of the fuel cell of the conventional solid polymer electrolyte fuel cell shown in FIGS. 4 and 6 are denoted by the same reference numerals, and description thereof will be omitted. Note that, in FIG. 3, only the reference numerals shown in FIG.

In FIG. 3, reference numeral 3 designates a fuel electrode 4A and an oxidizing agent, instead of the fuel electrode 7A and the oxidizing agent electrode 7B, for the fuel cell 7 of the conventional solid polymer electrolyte fuel cell shown in FIG. This is a fuel cell of a solid polymer electrolyte fuel cell using the agent electrode 4B. The fuel electrode 4A and the oxidant electrode 4B are connected to the fuel electrode 7 of the conventional example shown in FIG.
As shown in FIG. 3, the only difference between A and the oxidant electrode 7B is that each corner 74 is chamfered by the dimension of one side; S. The fuel electrode 4A and the oxidant electrode 4B are respectively connected to the catalyst layer 71.
After cutting the sheet-shaped intermediate material composed of the A and 71B sides and the electrode base materials 72A and 72B into respective predetermined dimensions, the corners 74 are subjected to the above-described chamfering processing. Are hot-pressed on the main surface of each of them to firmly adhere to each other.

The fuel cell 3 having the above configuration
Is used in place of the conventional fuel cell unit 7 in the unit cell 5 of the solid polymer electrolyte fuel cell illustrated in FIG. 4 to configure a unit cell of the solid polymer electrolyte fuel cell. In the present invention, since the above-described configuration is employed, the PE film 7C
Of the electrode 4 at the exposed portion of the PE film 7C due to the contraction of
The concentrated stress generated in the PE film 7 </ b> C at the boundary with X (hereinafter, when the fuel electrode 4 </ b> A and the oxidant electrode 4 </ b> B are collectively referred to) is applied to the corner 74 of the electrode 4 </ b> X. This is reduced by chamfering and increasing the equivalent radius of curvature. In addition, there is an advantage that the machining is easier than the case of the arc-shaped machining of the first embodiment in obtaining the increased radius of curvature.

Incidentally, the degree of reduction of the concentrated stress generated in the PE film 7C depends on the value of the chamfer dimension (S) as in the case of the first embodiment. That is, as the chamfer dimension (S) increases, the degree to which the concentrated stress is reduced increases. However, as the chamfer dimension (S) increases, the area of the fuel cell 3 that contributes to the electrochemical reaction decreases, so that the output characteristics of the power generation device decrease. Therefore, as the fuel cell 3, the chamfer dimensions (S) are 10 [mm] and 3 [m
m] and 1 [mm] were fabricated, assembled into a unit cell, and operated. Chamfer dimension (S) is 1
Although the unit cell using the fuel cell 3 of 0 [mm] was able to operate stably for the longest period, the unit cell using the fuel cell 3 with the chamfer dimension (S) of 3 [mm] was used. The battery was able to obtain a continuous operation time almost equivalent to that of the fuel cell 1 of Example 1 having the radius dimension (R) of 3 [mm]. However, in the unit cell using the fuel cell 3 having the chamfer dimension (S) of 1 [mm], although the improvement was made as compared with the conventional example shown in FIG. 6, a desired continuous operation time could not be obtained. This chamfer dimension (S)
Under the condition of the value of, no significant difference was recognized in the power generation characteristics. From these facts, it can be said that the value of the chamfer dimension (S) is preferably about 3 [mm] or more.

[0033]

According to the present invention, by employing the above-described structure, even if the PE film shrinks in size, the concentrated stress generated in the PE film at the boundary between the exposed portion of the PE film and the electrode is reduced. With the reduction, the degree of occurrence of breakage of the PE film can be reduced. As a result, as exemplified in FIG. 2, the solid polymer electrolyte fuel cell has an effect that stable operation can be performed for a long period of time.

[Brief description of the drawings]

FIG. 1 shows a fuel cell used for a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claim 1, wherein FIG. 1 (a) is a plan view of the fuel cell seen from the direction of arrow P in FIG. FIG. 1B is a side sectional view schematically showing FIG. 1A.

FIG. 2 is a graph showing an example of continuous operation data of a unit cell of a solid polymer electrolyte fuel cell using a fuel cell according to the present invention;

3A and 3B show a fuel cell used in a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claim 2, wherein FIG. 3A is a plan view seen from the direction of arrow P in FIG. FIG. 3B is a side cross-sectional view schematically showing FIG.

FIG. 4 is a cross-sectional side view schematically showing a unit cell of a conventional solid polymer electrolyte fuel cell in a developed state.

FIG. 5 is a configuration diagram schematically showing a stack of a solid polymer electrolyte fuel cell;

FIG. 6 is a plan view seen from the direction of arrow P in FIG. 4;

FIG. 7 is a graph showing an example of continuous operation data of a unit cell of a solid polymer electrolyte fuel cell using a conventional fuel cell unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell 2A Fuel electrode 2B Oxidant electrode 3 Fuel cell 4A Fuel electrode 4B Oxidant electrode 5 Single cell (of solid polymer electrolyte type fuel cell) 6A Separator 6B Separator 7C Electrolyte layer (PE film) 74 Corner

Claims (2)

(57) [Claims] 1. A fuel cell which receives a supply of a fuel gas and an oxidant gas to generate DC power, and is disposed on both sides of the fuel cell to supply the fuel cell or the oxidant gas to the fuel cell. And a separator having a plurality of gas flow grooves for the fuel cell. The fuel cell is disposed in close contact with each of the two main surfaces of the electrolyte layer made of a solid polymer electrolyte membrane and the electrolyte. An electrode having an outer dimension in the plane direction smaller than the outer dimension in the plane direction of the layer.The separator has a plurality of concave grooves for gas flow on the side surface on the side facing the fuel cell unit. In a solid polymer electrolyte fuel cell, an electrode provided in the fuel cell has an arc-shaped corner portion. What formed A solid polymer electrolyte fuel cell. 2. A fuel cell for receiving a supply of a fuel gas and an oxidant gas to generate DC power, and disposed on both sides of the fuel cell to supply the fuel cell or the oxidant gas to the fuel cell. And a separator having a plurality of gas flow grooves for the fuel cell. The fuel cell is disposed in close contact with each of the two main surfaces of the electrolyte layer made of a solid polymer electrolyte membrane and the electrolyte. An electrode having an outer dimension in the plane direction smaller than the outer dimension in the plane direction of the layer.The separator has a plurality of concave grooves for gas flow on the side surface on the side facing the fuel cell unit. In the polymer electrolyte fuel cell, an electrode provided in the fuel cell has a chamfer at a corner thereof. It was given A solid polymer electrolyte fuel cell.