JP2007273460A - Activation method of fuel cell, fuel battery cell or membrane electrode assembly for fuel cell activated, cell stack or fuel cell having them, and fuel cell activation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an activation method of a fuel cell capable of obtaining a battery output of high performance promptly even immediately after assembly of the fuel cell or in the case of operating the cell after leaving standing unused for a long time, a cell or a membrane electrode assembly treated by this activation method, a cell stack or a fuel cell having the cell or the membrane electrode assembly treated by this activation method, and a fuel cell activation device to carry out the activation method. <P>SOLUTION: This is the activation method of the fuel cell 2 which generates power by supplying an oxidant including oxygen to a cathode C and supplying a fuel gas including hydrogen or an organic fuel to an anode A. Activation is carried out by supplying a reducing agent to at least the cathode C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for activating a fuel cell, a cell for a fuel cell or a membrane / electrode assembly for a fuel cell treated by the activation method, a cell stack or a fuel cell comprising the cell or membrane / electrode assembly, and The present invention relates to an activation device for a fuel cell for performing this activation method.

  A conventional polymer electrolyte fuel cell includes a cathode side gas diffusion layer and a cathode side catalyst diffusion layer of a cell in which a solid polymer electrolyte membrane is sandwiched between a cathode side catalyst layer and an anode side catalyst layer. And an anode-side gas diffusion layer sandwiching the membrane / electrode assembly comprising a cathode and an anode, supplying an oxidant to the cathode, and supplying a fuel gas or organic fuel containing hydrogen to the anode to generate electricity It has become.

FIG. 7 is an exploded explanatory view showing a basic configuration of a single cell of the polymer electrolyte fuel cell. Cathode-side electrode catalyst layer 42 and anode each carrying a sheet-like solid polymer electrolyte membrane 41 with carbon black particles supporting noble metal particles [mainly platinum (Pt) or platinum group metals (Ru, Rh, Pd, Os, Ir)]. The side electrode catalyst layer 43 is closely adhered and bonded by a heat treatment such as hot pressing to form a cell.
The cathode side electrode catalyst layer 42 and the anode side electrode catalyst layer 43 have a structure in which a mixture of carbon black and polytetrafluoroethylene (PTFE) is applied to carbon paper, carbon woven fabric, etc., respectively, and the cathode side gas diffusion layer 44 and anode side A membrane / electrode assembly 58 which is sandwiched between the gas diffusion layers 45 and constitutes the cathode 46 and the anode 47 is formed.
These cathode-side gas diffusion layer 44 and anode-side gas diffusion layer 45 are made of an oxidant gas (for example, air) and a fuel gas such as hydrogen, natural gas, city gas, LPG and butane, and an organic fuel such as methanol and ethanol. At the same time as supplying and discharging the battery, it functions as a current collector and transmits the current to the outside. An electrically conductive and gas-impermeable material having a gas flow channel 48 for reaction gas flow facing the membrane / electrode assembly 58 and a cooling water flow channel 49 for cooling water flow on the opposite main surface. A single cell 51 is configured by being sandwiched by a pair of separators 50 made of the same.

  As the solid polymer electrolyte membrane 41, a cation exchange membrane of polystyrene type having a sulfonic acid group is used as a cation conductive membrane, a mixed membrane of fluorocarbon sulfonic acid and polyvinylidene fluoride, and trifluoroethylene is used as a fluorocarbon matrix. Fluorine ion exchange resin membranes typified by grafted products and perfluorosulfonic acid resins (for example, trade name Nafion membrane manufactured by DuPont) are used. These solid polymer electrolyte membranes 41 have a proton exchange group in the molecule, and when the water content is saturated, the specific resistance becomes 20 Ωcm or less at room temperature, and functions as a proton conductive electrolyte.

When a reactive gas is supplied to each of the electrodes 46 and 47, the following electrochemical reaction occurs and DC power is generated.
Anode side: H ₂ → 2H ⁺ + 2e ⁻
Cathode side: 1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O
H ⁺ ions generated on the anode 47 side move toward the cathode 46 side in the solid polymer electrolyte membrane 41, and e ⁻ (electrons) move to the cathode 46 side through an external load. To do.
On the other hand, on the cathode 46 side, oxygen contained in the oxidant gas reacts with H ⁺ ions and e ⁻ that have moved from the anode 47 side to generate water. Thus, the polymer electrolyte fuel cell generates a direct current from hydrogen and oxygen to generate water.

  FIG. 8 is a cross-sectional view showing the basic configuration of a polymer electrolyte fuel cell stack (stacked body). In the polymer electrolyte fuel cell stack 60, a large number of single cells 51 for fuel cells are stacked, and a current collecting plate 52, an insulating plate 53 for electrical insulation and thermal insulation, and a load are applied to maintain the stacked state. Are clamped by bolts 55 and nuts 57, and a tightening load is applied by a disc spring 56.

However, there is a problem that a high-performance battery output cannot be obtained immediately when a solid polymer fuel cell is operated immediately after assembly or when a battery that is left unused for a long time is operated.
Therefore, the polymer electrolyte fuel cell is boiled with deionized water, warm water is introduced into the gas supply path, or alcohol is introduced into the gas supply path and then washed with deionized water, or the solid polymer There is a method for activating a polymer electrolyte fuel cell that can generate a high-performance battery output inherent in the battery in a short time by generating electricity at a high oxygen utilization rate and holding it at a low potential. It has been proposed (see Patent Document 1).
JP 2000-3718

The conventional activation method has a problem that the operation is complicated.
Conventionally, when the activation process is not performed immediately after the fuel cell is assembled or when the battery left unused for a long time is operated as it is, a high-performance battery output is required until about 10 to 20 hours have passed after the operation. There was a problem that could not be obtained.
A first object of the present invention is to obtain a high-performance battery output quickly by using a simpler method even when a fuel cell is operated immediately after assembly or when a battery left unused for a long time is operated. Providing a method for activating a fuel cell,
A second object of the present invention is to provide a cell or membrane / electrode assembly treated by this activation method,
The third object of the present invention is to provide a cell stack or fuel cell comprising a cell or membrane / electrode assembly treated by this activation method,
The fourth object of the present invention is to provide a fuel cell activation device for performing this activation method.

The invention according to claim 1 of the present invention for solving the above-mentioned problems is the activation of a fuel cell for generating electricity by supplying an oxidant containing oxygen to the cathode and supplying a fuel gas or organic fuel containing hydrogen to the anode. A method,
An activation method for a fuel cell, wherein activation is performed by supplying a reducing agent to at least a cathode.

The invention according to claim 2 of the present invention is a method for activating a fuel cell in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electric power,
An activation method for a fuel cell is characterized in that activation is performed by supplying a reducing agent to an anode and supplying an inert gas to a cathode.

The invention according to claim 3 of the present invention is a method for activating a fuel cell in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electric power,
While supplying a reducing agent to the anode, a fixed resistor or conductor is disposed between the cathode and the anode, and the cell or membrane / electrode assembly is activated by controlling the potential difference between the cathode potential and the anode potential to 100 mV or less. This is a method for activating a fuel cell.

The invention according to claim 4 of the present invention is a method for activating a fuel cell in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electric power,
By supplying a reducing agent to the anode, supplying an inert gas to the cathode, and providing a fixed resistor or conductor between the cathode and the anode, the potential difference between the cathode potential and the anode potential is controlled to 100 mV or less. A method for activating a fuel cell, comprising activating a cell or a membrane / electrode assembly.

  The invention according to claim 5 of the present invention is the method for activating a fuel cell according to any one of claims 1 to 4, wherein the reducing agent or the inert gas is a humidified gas having a relative humidity of 90% or more. It is characterized by being.

  A sixth aspect of the present invention is the fuel cell activation method according to any one of the first to fourth aspects, wherein the reducing agent is a humidified hydrogen gas.

According to the seventh aspect of the present invention, the activity of a cell or membrane / electrode assembly of a fuel cell for generating electricity by supplying an oxidant containing oxygen to the cathode and supplying a fuel gas or organic fuel containing hydrogen to the anode A method of
Cell or membrane / electrode assembly produced by heat treatment is treated at a temperature of 50 to 200 ° C. in a reducing atmosphere containing a reducing agent. It is a conversion method.

  The invention according to claim 8 of the present invention is the method of activating a fuel cell or membrane / electrode assembly of the fuel cell according to claim 7, wherein the reducing agent is humidified hydrogen gas. .

  According to a ninth aspect of the present invention, there is provided a cell or membrane / electrode assembly activated by the activation method according to any one of the first to eighth aspects, and the activated cell or membrane / electrode. It is a stack or a fuel cell provided with a joined body.

A tenth aspect of the present invention is an activation device for a fuel cell for performing the fuel cell activation method according to any one of the first to eighth aspects,
Reducing agent supply means for supplying a reducing agent to the anode or cathode;
An inert gas supply means for supplying an inert gas to the cathode;
Control means for controlling these,
An activation device for a fuel cell comprising:

The invention according to claim 11 of the present invention is a fuel cell activation device for activating a cell or membrane / electrode assembly of a fuel cell,
A processing vessel for processing a cell or membrane / electrode assembly produced by heat treatment,
Supply means for supplying a reducing agent to the processing vessel;
Heating means for heating the processing vessel;
Control means for controlling these,
An activation device for a fuel cell comprising:

The invention according to claim 1 of the present invention is a method for activating a fuel cell in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electric power,
An activation method for a fuel cell, characterized in that activation is performed by supplying a reducing agent to at least the cathode,
Since the fuel cell can be easily activated, a high-performance battery output can be easily and quickly obtained even immediately after assembly of the fuel cell or when operating a battery that has been left unused for a long time. There is an effect.

The invention according to claim 2 of the present invention is a method for activating a fuel cell in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electric power,
Along with the anode, the cathode can be activated, and the fuel cell can be easily activated.As a result, a high-performance battery output can be achieved quickly even when the fuel cell is assembled or when a battery that has not been used for a long time is operated. There is a remarkable effect that it can be easily obtained.

The invention according to claim 3 of the present invention is a method for activating a fuel cell in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electric power,
While supplying a reducing agent to the anode, a fixed resistor or conductor is disposed between the cathode and the anode, and the cell or membrane / electrode assembly is activated by controlling the potential difference between the cathode potential and the anode potential to 100 mV or less. A method for activating a fuel cell, characterized in that:
In this way, the reducing agent is supplied to the anode and a fixed resistor or conductor is disposed between the cathode and the anode, and the potential difference between the cathode potential and the anode potential is controlled to 100 mV or less, preferably as close to 0 mV as possible. The cell or membrane / electrode assembly can be quickly and easily activated economically without impairing the performance of the catalyst, etc., so that the battery that has been left unused for a long time can be operated immediately after assembly of the fuel cell. Even in the case, there is a remarkable effect that a high-performance battery output can be easily obtained earlier.

The invention according to claim 4 of the present invention is a method for activating a fuel cell in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electric power,
By supplying a reducing agent to the anode, supplying an inert gas to the cathode, and providing a fixed resistor or conductor between the cathode and the anode, the potential difference between the cathode potential and the anode potential is controlled to 100 mV or less. A method for activating a fuel cell, characterized by activating a cell or a membrane / electrode assembly,
In this way, a reducing agent is supplied to the anode, an inert gas is supplied to the cathode, a fixed resistor or a conductor is disposed between the cathode and the anode, and the potential difference between the cathode potential and the anode potential is 100 mV or less, preferably as much as possible. By controlling to a value close to 0 mV, the cell or membrane / electrode assembly can be activated more quickly and reliably without impairing the performance of the catalyst, etc., so that the fuel cell can be left immediately after assembly or left unused for a long time. Even when the battery is operated, a remarkable effect is obtained that a high-performance battery output can be easily obtained earlier.

The invention according to claim 5 of the present invention is the method for activating a fuel cell according to any one of claims 1 to 4, wherein the reducing agent or the inert gas is a humidified gas having a relative humidity of 90% or more. It is characterized by being,
By using the humidified gas, there is a further remarkable effect that the fuel cell can be activated more quickly.

A sixth aspect of the present invention is the fuel cell activation method according to any one of the first to fourth aspects, wherein the reducing agent is a humidified hydrogen gas. ,
By using a humidified hydrogen gas humidified gas as the reducing agent, the fuel cell can be activated more easily.

According to the seventh aspect of the present invention, the activity of a cell or membrane / electrode assembly of a fuel cell for generating electricity by supplying an oxidant containing oxygen to the cathode and supplying a fuel gas or organic fuel containing hydrogen to the anode A method of
Cell or membrane / electrode assembly produced by heat treatment is treated at a temperature of 50 to 200 ° C. in a reducing atmosphere containing a reducing agent. Method,
An electrolyte membrane having a high glass transition temperature (Tg) is used to increase the operating temperature and durability of the fuel cell, and when the Tg of the electrolyte membrane is high, the activation time usually tends to be long. However, as long as this electrolyte membrane is not damaged, the activation time can be significantly shortened by treating at a high temperature selected from temperatures of 50 to 200 ° C. in a reducing atmosphere containing a reducing agent. There is an effect.

The invention according to claim 8 of the present invention is the method of activating a fuel cell or membrane / electrode assembly of the fuel cell according to claim 7, wherein the reducing agent is humidified hydrogen gas. Is,
By using a humidified hydrogen gas humidified gas as the reducing agent, the fuel cell can be activated more easily.

According to a ninth aspect of the present invention, there is provided a cell or membrane / electrode assembly activated by the activation method according to any one of the first to eighth aspects, and the activated cell or membrane / electrode. A stack or fuel cell comprising a joined body,
A fuel cell equipped with an activated cell or membrane / electrode assembly can easily obtain high-performance battery output immediately even after assembly or when operating a battery that has been left unused for a long time. There is a remarkable effect of being able to.

A tenth aspect of the present invention is an activation device for a fuel cell for performing the fuel cell activation method according to any one of the first to eighth aspects,
Reducing agent supply means for supplying a reducing agent to the anode or cathode;
An inert gas supply means for supplying an inert gas to the cathode;
Control means for controlling these,
An activation device for a fuel cell, comprising:
Using the fuel cell activation device, the cell stack or the fuel cell can be easily and easily activated with a remarkable effect.

The invention according to claim 11 of the present invention is a fuel cell activation device for activating a cell or membrane / electrode assembly of a fuel cell,
A processing vessel for processing a cell or membrane / electrode assembly produced by heat treatment,
Supply means for supplying a reducing agent to the processing vessel;
Heating means for heating the processing vessel;
Control means for controlling these,
An activation device for a fuel cell, comprising:
Using this fuel cell activation device, a cell or membrane / electrode assembly is treated, and the treated cell or membrane / electrode assembly is attached to the cell stack or fuel cell when the cell stack or fuel cell is assembled. When used, a cell stack or fuel cell that is easily activated can be obtained. Thus, immediately after the cell stack or fuel cell is assembled, a high-performance battery output can be obtained easily and quickly. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory view illustrating an example of an activation device for a fuel cell according to the present invention.
In FIG. 1, reference numeral 1 denotes a fuel cell activation device of the present invention. The activation device 1 for a fuel cell according to the present invention has at least one reducing agent selected from hydrogen or other reducing agent on the anode A and cathode C of a fuel cell (or cell stack, hereinafter referred to as fuel cell) 2. Reducing agent supply means 3 (hereinafter referred to as means 3) for supplying humidified hydrogen gas (hereinafter referred to as hydrogen) at a predetermined temperature for a predetermined time is provided. The means 3 includes a hydrogen supply source 4 such as a hydrogen cylinder for supplying hydrogen to the anode A and the cathode C of the fuel cell 2, a hydrogen supply line 5 for transferring hydrogen from the hydrogen supply source 4, and a hydrogen supply line 5. Humidifying means 6 installed on the way and open / close valves 7, 8, 9.

  The fuel cell activation device 1 of the present invention uses at least one inert gas (hereinafter referred to as nitrogen) selected from nitrogen, argon or other inert gas instead of supplying hydrogen to the cathode C. An inert gas supply means 10 (hereinafter referred to as means 10) that can be supplied at a predetermined temperature for a predetermined time is provided. This means 10 includes a nitrogen supply source 11 such as a nitrogen cylinder for supplying nitrogen to the cathode C of the fuel cell 2, a nitrogen supply line 12 for transferring nitrogen from the nitrogen supply source 11, and a nitrogen supply line 12. An on-off valve 13 is provided.

Although not shown, in order to humidify the nitrogen supply line 12 for supplying nitrogen to the cathode C of the fuel cell 2 as necessary, a humidifying means 6 or an on-off valve 7 installed in the middle of the hydrogen supply line 5. , 8 can be provided with a humidifying means and an on-off valve.
Further, the fuel cell activation device 1 of the present invention includes a control means 14 for controlling them.

(Example 1 of activating the fuel cell 2 using the fuel cell activation device 1)
In this example 1, hydrogen is supplied to the anode A and the cathode C to activate the fuel cell 2.
The on-off valves 7 and 13 are closed, the on-off valves 8 and 9 are opened, and hydrogen is supplied from the hydrogen supply source 4 of the means 3 to the anode A and the cathode C of the fuel cell 2 through the hydrogen supply line 5 to purge the inside. The purge gas is discharged from a purge line (not shown). The hydrogen is supplied from the hydrogen supply source 4 to a predetermined temperature and pressure by a temperature / pressure adjusting device (not shown) and supplied to the anode A and the cathode C of the fuel cell 2 through the hydrogen supply line 5 for a predetermined time. The fuel cell 2 is activated. The control means 14 controls temperature, pressure, time, valve opening / closing, and the like.
After the purge is completed, the purge line (not shown) is closed, and the anode A and the cathode C of the hydrogen fuel cell 2 are activated at a predetermined temperature, pressure, and time in a hydrogen atmosphere without supplying hydrogen through the hydrogen supply line 5. You can also.

(Another example 2 of activating the fuel cell 2 using the fuel cell activation device 1)
In Example 2, the fuel cell 2 is activated by supplying humidified hydrogen to the anode A and the cathode C.
First, the on-off valves 8 and 13 are closed, the on-off valves 7 and 9 are opened, hydrogen is introduced from the hydrogen supply source 4 of the means 3 to the humidifying means 6 through the hydrogen supply line 5, and predetermined heating and humidification are performed. Humidified hydrogen is supplied to the anode A and cathode C of the fuel cell 2 through the hydrogen supply line 5 to purge the inside, and the purge gas is discharged from a purge line (not shown). After purging, the humidified hydrogen is controlled by a temperature / pressure adjusting device (not shown) so as to have a predetermined temperature / pressure, and supplied to the anode A and the cathode C of the fuel cell 2 through the hydrogen supply line 5 for a predetermined time. The fuel cell 2 is activated. The control means 14 controls humidity, temperature, pressure, time, valve opening / closing, and the like.
After the purge is completed, the purge line (not shown) is closed, and the anode A and the cathode C of the hydrogen fuel cell 2 are connected at a predetermined temperature, pressure, and time in a humidified hydrogen atmosphere without supplying humidified hydrogen via the hydrogen supply line 5. It can also be activated.

(Another example 3 of activating the fuel cell 2 using the fuel cell activation device 1)
In this example 3, humidified hydrogen is supplied to the anode A, and nitrogen is supplied to the cathode C to activate the fuel cell 2.
The on-off valves 8 and 9 are closed, the on-off valves 7 and 13 are opened, and hydrogen is introduced from the hydrogen supply source 4 of the means 3 to the humidifying means 6 through the hydrogen supply line 5 to perform predetermined heating and humidification. The hydrogen thus supplied is supplied to the anode A of the fuel cell 2 through the hydrogen supply line 5 to purge the inside, and the purge gas is discharged from a purge line (not shown). On the other hand, nitrogen is supplied from the nitrogen supply source 11 of the means 10 to the cathode C of the fuel cell 2 through the nitrogen supply line 12 to purge the inside, and the purge gas is discharged from a purge line (not shown). After purging, the humidified hydrogen is controlled by a temperature / pressure adjusting device (not shown) so as to have a predetermined temperature / pressure, and supplied to the anode A of the fuel cell 2 through the hydrogen supply line 5 for a predetermined time. 10 is supplied from a nitrogen supply source 11 to a cathode C of the fuel cell 2 through a nitrogen supply line 12 and controlled by a temperature / pressure adjusting device (not shown) so as to have a predetermined temperature / pressure. Activate. The control means 14 controls humidity, temperature, pressure, time, valve opening / closing, and the like.
After the purge is completed, the purge line (not shown) is closed, and the anode A and cathode C of the hydrogen fuel cell 2 are activated at a predetermined temperature, pressure, and time in a humidified hydrogen and nitrogen atmosphere without supplying humidified hydrogen and nitrogen. You can also

FIG. 2 is an explanatory view for explaining another example of the fuel cell activation device of the present invention.
In FIG. 2, reference numeral 20 denotes another fuel cell activation device of the present invention.
The fuel cell activation device 20 of the present invention includes an openable / closable lid 22 for processing a cell or a membrane / electrode assembly (hereinafter referred to as MEA) 21 produced by heat treatment. A processing vessel 24 provided with a heating means 23 that uses a heater or steam for heating to a predetermined temperature, and a supply means 25 that supplies hydrogen to the processing vessel 24 at a predetermined temperature and pressure for a predetermined time (hereinafter referred to as means 25). ). The means 25 includes a hydrogen supply source 26 such as a hydrogen cylinder for supplying hydrogen to the processing vessel 24, a hydrogen supply line 27 for transferring hydrogen from the hydrogen supply source 26, and a hydrogen supply line 27 in the middle. An installed humidifying means 28 and on-off valves 29, 30, 31 are provided. A control means 32 provided in the processing container 24 controls temperature, pressure, time, valve opening and closing, and the like.

(Example 1 of activating the MEA 21 using the fuel cell activation device 20)
In Example 1, a case will be described in which the MEA 21 is placed in the processing container 24 and the MEA 21 is activated using hydrogen.
First, the lid 22 is opened, the MEA 21 is placed in the processing container 24, and the lid 22 is sealed and closed. The on-off valve 29 is closed, the on-off valves 30 and 31 are opened, the hydrogen is supplied from the hydrogen supply source 26 of the means 25 through the hydrogen supply line 27 into the processing vessel 24 to purge the inside, and the purge gas is not shown in the figure. Drain from line. After the purge is completed, the purge line (not shown) is closed. The processing container 24 is heated by the heating means 23. The processing container 24 is controlled by a temperature / pressure adjusting device (not shown) so as to have a predetermined temperature / pressure. After the purge is completed, the MEA 21 is activated for a predetermined time by hydrogen in the processing container 24. The control means 32 controls temperature, pressure, time, valve opening / closing, and the like.
Note that the MEA 21 can be activated while supplying hydrogen into the processing vessel 24 without closing the purge line (not shown) after the purge is completed.

(Example 2 of activating the MEA 21 using the fuel cell activation device 20)
In Example 2, a case will be described in which the MEA 21 is activated using hydrogen humidified by putting the MEA 21 in the processing container 24.
The on-off valve 30 is closed, the on-off valves 29 and 31 are opened, hydrogen is introduced from the hydrogen supply source 26 of the means 25 to the humidifying means 28 through the hydrogen supply line 27, and is heated and humidified in a predetermined manner, so that the humidified hydrogen Is sent into the processing vessel 24 through the hydrogen supply line 27 to purge the inside, and the purge gas is discharged from a purge line (not shown). After the purge is completed, the purge line (not shown) is closed. On the other hand, the processing container 24 is heated by the heating means 23. The processing container 24 is controlled by a temperature / pressure adjusting device (not shown) so as to have a predetermined temperature / pressure. After completion of the purge, the MEA 21 is activated for a predetermined time by the humidified hydrogen in the processing container 24. The control means 32 controls temperature, pressure, time, valve opening / closing, and the like.
Note that the MEA 21 can be activated while supplying humidified hydrogen into the processing vessel 24 without closing a purge line (not shown) after the purge is completed.

When activating the fuel cell 2 or the MEA 21, a gas for activation is flowed to purge air and the like inside, and the gas is discharged to the outside. The purge gas is activated even after the purge gas flow rate or purging is completed. The flow rate of the gas when activated while flowing as a gas for use is not particularly limited, but is 1 ml / min. Per 1 cm ^{2 of} MEA 21. ~ 5 ml / min. Of 1 ml / min. Per 1 cm ^{2 of} MEA21. ~ 4 ml / min. The range of is particularly preferable.

  When the purging is completed, the purging is stopped, and the fuel cell 2 and the MEA 21 are activated with the on-off valve (not shown) closed so that the gas for activating the fuel cell 2 and the processing container 24 is not discharged. It can also be done.

  When the Tg of the solid polymer electrolyte membrane 41 is about 120 ° C., the temperature at which the fuel cell 2 and MEA 21 are activated may be 20 ° C. to Tg of the solid polymer electrolyte membrane. preferable. Even within this range, it is preferable to perform at a temperature as high as possible because activation can be performed in a short time. That is, the range of 50 to 100 ° C. is more preferable because the solid polymer electrolyte membrane does not deteriorate and the activation reaction proceeds well. Further, it is particularly preferable to carry out the reaction at 80 to 90 ° C. because the solid polymer electrolyte membrane does not deteriorate and the activation reaction proceeds well in a shorter time. If it is less than 20 ° C., the activation reaction may be slow and may not proceed, and if it exceeds the Tg of the solid polymer electrolyte membrane, MEA may be deteriorated.

In the present invention, when the Tg of the electrolyte membrane is as high as 180 ° C., for example, the activation time is usually long, so the temperature at the time of activation is increased. That is, the activation time can be significantly shortened by treating the cell or membrane / electrode assembly produced by heat treatment at a temperature of 50 to 200 ° C. in a reducing atmosphere containing a reducing agent.
If it exceeds 200 ° C., the electrolyte membrane may be damaged, and if it is less than 50 ° C., the activation time may not be significantly shortened, which is not preferable. Therefore, when Tg of an electrolyte membrane is high, 60-190 degreeC is preferable, More preferably, it is 80-150 degreeC.

  The pressure when activating the fuel cell 2 and the MEA 21 is preferably within the range of atmospheric pressure to the allowable pressure of the cell. Even within this range, it is preferable to carry out at a pressure as high as possible since activation can be achieved in a short time. It is more preferable to carry out at atmospheric pressure to a pressure at the time of steady operation of the fuel cell 2, and it is particularly preferable to carry out at a pressure at the time of steady operation of the fuel cell 2. Since the cell breaks when the allowable pressure of the cell is exceeded, there is a certain value in the design. For example, it can be up to atmospheric pressure for home use and about 3 atm for automobile use.

  The time for activating the fuel cell 2 and the MEA 21 is preferably 1 minute or longer. Less than 1 minute is not preferable because the activation effect is extremely small. 30 minutes to 2 hours are more preferable because of a high activation effect. Although activation proceeds even after 2 hours, cost and time are required for the effect. Considering activation and cost, about 1 hour is particularly preferable.

  The anode A is supplied with hydrogen or a gas containing hydrogen such as nitrogen gas containing at least one reducing agent selected from a reducing agent such as aqueous hydrogen peroxide, aqueous hydrazine, aqueous ascorbic acid, and aqueous citric acid. Of these, hydrogen is preferably used.

  Hydrogen may be dry, dry to 100% RH, or over-humidified at 100 to 120% RH. However, since the activation reaction does not proceed easily at low humidification, it is preferable to use hydrogen humidified to 90 to 120% RH, and particularly preferable to use hydrogen humidified to 100% RH or more and 110% RH. For example, water permeation is easily performed by using 110% RH over-humidified hydrogen, so that the activation time can be further shortened.

The cathode C is selected from at least one reducing agent selected from hydrogen or other reducing agents, a gas containing hydrogen such as nitrogen gas containing hydrogen, humidified hydrogen, nitrogen, argon or other inert gas. Supplying at least one inert gas. Among these, hydrogen can be particularly preferably used.
When using a gas containing hydrogen, such as nitrogen gas containing hydrogen, the lower limit of the hydrogen concentration is 1% in consideration of safety. On the other hand, the higher the hydrogen concentration, the faster the activation reaction, so 1% hydrogen. It is preferable to contain more than 10%, and more preferably 10% or more hydrogen because the activation reaction can be promoted and the activation time can be shortened.

  The inert gas may be dry, may be dry to 100% RH, and may be used even in an excessive humidification of 100 to 120% RH. However, since the activation reaction is difficult to proceed at low humidification, it is preferable to use an inert gas humidified to 90 to 120% RH, and it is particularly preferable to use an inert gas humidified to 100% RH or more and 110% RH. For example, water is easily precipitated by using an overhumid inert gas of 110% RH, so that the activation time can be further shortened.

FIG. 3 is an explanatory diagram for explaining an example in which the fuel cell activation device of the present invention shown in FIG. 1 is used to activate by providing a specific resistance between the cathode and the anode.
In these drawings, parts having the same reference numerals are parts having the same function.
The fuel cell activation device 1A of the present invention shown in FIG. 3 is short-circuited by providing a fixed resistor R between the cathode C and the anode A, and controls the potential difference between the cathode potential and the anode potential to 100 mV or less. Except for the above, the fuel cell activation device 1 of the present invention shown in FIG.

  The reducing agent is supplied to the anode A of the fuel cell activation device 1A of the present invention shown in FIG. 3, and the inert gas is supplied to the cathode C, so that the potential difference between the cathode potential and the anode potential is controlled to 100 mV or less. Thus, the cell or the membrane / electrode assembly can be activated more quickly without impairing the performance of the catalyst.

  Preferably, a conductor is provided instead of the fixed resistor R shown in FIG. 3 and short-circuited, and the potential difference between the cathode potential and the anode potential is controlled to a value as close to 0 mV as possible without impairing the performance of the catalyst or the like. The cell or membrane / electrode assembly can be activated even more quickly.

The method of disposing the fixed resistor R or the conductor between the cathode C and the anode A is not particularly limited to the method shown in FIG.
As the fixed resistor R used in the present invention, an auxiliary machine or an electronic load in the system can be used in addition to a commonly used resistor.

  If the upper limit value of the potential difference exceeds 100 mV, the activation time may be a little longer, and the lower limit value is preferably 0 mV, but it is not practical, and in practice, the lower limit value is 10 to 50 mV.

  FIG. 6 shows a cathode potential (for example, 0.7 V) and an anode potential (0 V) with respect to a hydrogen standard electrode (NHE) when activation is performed by supplying nitrogen to the cathode C and supplying hydrogen to the anode A. It is a graph explaining that a cathode potential changes when a fixed resistor R or a conductor is disposed between a cathode C and an anode A and short-circuited.

  As shown in FIG. 6, when a fixed resistor R or a conductor is disposed between the cathode C and the anode A and short-circuited, the cathode potential varies and approaches the anode potential.

Immediately after assembling the fuel cell, or if the fuel cell is left unused for a long period of time, oxides are generated on the surface of the noble metal particles [mainly platinum (Pt), etc.] that are the cathode side electrode catalyst and the anode side electrode catalyst. It is considered that it takes a long time to obtain a high-performance battery output when the fuel cell is operated as it is without performing the activation treatment because the activity is impaired by the oxide.
According to the activation method of the present invention, the oxide can be easily removed by reduction, and the catalyst surface can be wetted. Therefore, it can be activated, and a high-performance battery output can be obtained quickly. .

When a reducing agent such as hydrogen is supplied to the anode A, an inert gas is supplied to the cathode C, and a fixed resistor or a conductor is disposed between the anode A and the cathode C, the anode A is activated. When the supplied reducing agent such as hydrogen is activated by supplying an inert gas to the cathode C via the electrolyte membrane, the reducing agent such as hydrogen supplied to the anode A moves to the cathode C via the electrolyte membrane. Since the transferred reducing agent such as hydrogen can be easily removed by reducing the oxide on the surface of the catalyst of the cathode C, and the surface of the catalyst can be wetted, it can be activated, and the cathode can be activated by an electrochemical reaction. This is thought to be due to the reduction of the oxide on the C catalyst surface.
The cathode C can be activated by supplying a reducing agent such as hydrogen to the anode A and supplying a fixed resistor or a conductor between the anode A and the cathode C without supplying an inert gas to the cathode C. and the fixed resistor or conductor between the anode a shorted by disposing the oxygen concentration of the cathode is reduced cathode C potential is varied. It is considered that the cathode C as well as the anode A can be activated by controlling the potential difference between the cathode potential and the anode potential to 100 mV or less, preferably as close to 0 mV as possible.

  Of course, the reason why the activation method of the present invention can be easily activated in a short time and can quickly obtain a high-performance battery output is not limited to the above idea.

Examples The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples without departing from the gist of the present invention.
Example 1
A solid polymer fuel cell for automobiles was produced by a known method (the method described in JP-A-2006-278038).
Using the fuel cell activation device 1 shown in FIG. 1, before generating electricity, the cell temperature is set to 80 ° C., hydrogen gas humidified at 80 ° C. is supplied to both the anode and the cathode and purged for 1 hour. Activation was performed by supplying hydrogen gas (100% RH) humidified at 80 ° C. to the anode and the cathode. Thereafter, the temperature was lowered to 30 ° C. while supplying hydrogen gas, and power generation was started. The relationship between time (h) (horizontal axis) and voltage (V) (vertical axis) after the start of power generation is shown in FIGS.

(Comparative Example 1)
The results of power generation performed in the same manner as in Example 1 except that the activation was not performed are shown in FIGS.

  From FIG. 4, the fuel cell of Comparative Example 1 cannot obtain a high-performance battery output until about 10 to 20 hours have passed after the operation, whereas the fuel cell of Example 1 is activated and operated. It turns out that high-performance battery output could be obtained soon.

(Example 2)
A household polymer electrolyte fuel cell was produced by a known method (the method described in JP-A-2006-278038).
Using the fuel cell activation device 1 shown in FIG. 1, before generating electricity, the cell temperature is set to 80 ° C., hydrogen gas humidified at 80 ° C. is supplied to both the anode and the cathode and purged for 1 hour. Activation was performed by supplying hydrogen gas (100% RH) humidified at 80 ° C. to the anode and the cathode. Thereafter, the temperature was lowered to 30 ° C. while supplying hydrogen gas to the anode, and then air was supplied to the cathode to start power generation. As with the fuel cell of Example 1, high performance battery output could be obtained as soon as possible after operation.

(Example 3)
A portable direct methanol solid polymer fuel cell was produced by a known method (the method described in JP-A-2006-338932).
Using the fuel cell activation device 1 shown in FIG. 1, before generating electricity, the cell temperature is set to 80 ° C., hydrogen gas humidified at 80 ° C. is supplied to the anode and the cathode, and purge is continued for 1 hour. Activation was performed by supplying hydrogen gas (100% RH) humidified at 80 ° C. to the anode and the cathode. Thereafter, the temperature was lowered to 30 ° C., methanol was supplied to the anode, and air was supplied to the cathode to start power generation. The fuel cell of Example 3 was activated in the same manner as the fuel cell of Example 1, and a high-performance battery output could be obtained immediately after operation.

Example 4
A solid polymer fuel cell for automobiles was produced by a known method (the method described in JP-A-2006-278038).
Before performing power generation using the fuel cell activation device 1 shown in FIG. 1, the cell temperature is set to 80 ° C., hydrogen gas humidified at 80 ° C. is supplied to the anode, and nitrogen humidified at 80 ° C. is supplied to the cathode. After supplying and purging, activation was performed by supplying humidified hydrogen gas (100% RH) and humidified nitrogen (100% RH) respectively for 1 hour for both the anode and the cathode. Thereafter, the temperature was lowered to 30 ° C. while supplying hydrogen gas to the anode, and then power was generated by supplying air to the cathode. The fuel cell of Example 4 was activated in the same manner as the fuel cell of Example 1, and a high-performance battery output could be obtained quickly after operation.

(Example 5)
A household polymer electrolyte fuel cell was produced by a known method (the method described in JP-A-2006-278038).
Before performing power generation using the fuel cell activation device 1 shown in FIG. 1, the cell temperature is set to 80 ° C., hydrogen gas humidified at 80 ° C. is supplied to the anode, and nitrogen humidified at 80 ° C. is supplied to the cathode. After supplying and purging, activation was performed by supplying humidified hydrogen gas (100% RH) and humidified nitrogen (100% RH) respectively for 1 hour for both the anode and the cathode. Thereafter, the temperature was lowered to 30 ° C. while supplying hydrogen gas to the anode, and then power was generated by supplying air to the cathode. The fuel cell of Example 5 was activated in the same manner as the fuel cell of Example 1, and a high-performance battery output could be obtained immediately after operation.

(Example 6)
A portable direct methanol solid polymer fuel cell was produced by a known method (the method described in JP-A-2006-338932).
Before power generation using the fuel cell activation device 1 shown in FIG. 1, the cell temperature is set to 80 ° C., hydrogen gas humidified at 80 ° C. is supplied to the anode, and nitrogen humidified at 80 ° C. is supplied to the cathode. After purging, hydrogen gas (100% RH) humidified at 80 ° C. and nitrogen (100% RH) humidified at 80 ° C. were supplied for activation for 1 hour. Thereafter, the temperature was lowered to 30 ° C., methanol was supplied to the anode, and air was supplied to the cathode to start power generation. The fuel cell of Example 6 was activated in the same manner as the fuel cell of Example 1, and was able to obtain a high-performance battery output as soon as possible after operation.

(Example 7)
MEA was produced by a known method (the method described in JP-A-2006-278037).
Using the fuel cell activation device 20 shown in FIG. 2, the MEA 21 was placed in the processing vessel 24 and activated.
That is, the lid 22 is opened, the MEA 21 is placed in the processing container 24, and the lid 22 is sealed and closed. The on-off valve 29 is closed, the on-off valves 30 and 31 are opened, the hydrogen is supplied from the hydrogen supply source 26 of the means 25 through the hydrogen supply line 27 into the processing vessel 24 to purge the inside, and the purge gas is not shown in the figure. Discharged from the line. After the purge was completed, the purge line (not shown) was closed. The processing vessel 24 was heated to 80 ° C. by the heating means 23 and activated the MEA 21 in a hydrogen atmosphere for 1 hour.
The fuel cell produced using this activated MEA 21 was activated in the same manner as the fuel cell of Example 1 and was able to obtain a high-performance battery output as soon as possible after operation.

(Example 8)
Using the fuel cell activation device 1A of the present invention shown in FIG. 3, a specific resistance of 100 mΩ is provided between the cathode C and the anode A, and the potential difference between the cathode potential and the anode potential is controlled to 50 mV for activation. In the same manner as in Example 4 before performing power generation, the cell temperature was set to 80 ° C., hydrogen gas humidified at 80 ° C. was supplied to the anode, and nitrogen humidified at 80 ° C. was supplied to the cathode and purged. Then, both the anode and the cathode were directly activated for 1 hour by supplying humidified hydrogen gas (100% RH) and humidified nitrogen (100% RH), respectively. Thereafter, the temperature was lowered to 30 ° C. while supplying hydrogen gas to the anode, and then power was generated by supplying air to the cathode. FIG. 5 shows the relationship between time (h) (horizontal axis) and voltage (V) (vertical axis) after the start of power generation.

  From FIG. 5, it can be seen that the fuel cell of Example 8 was able to obtain a high-performance battery output earlier than after the operation as compared with the fuel cells of Example 1 and Example 4.

Example 9
Using the fuel cell activation device 1A of the present invention shown in FIG. 3, a conductor is disposed between the cathode C and the anode A to short-circuit, and the potential difference between the cathode potential and the anode potential is controlled to 10 mV for activation. In the same manner as in Example 4 before performing power generation, the cell temperature was set to 80 ° C., hydrogen gas humidified at 80 ° C. was supplied to the anode, and nitrogen humidified at 80 ° C. was supplied to the cathode and purged. Then, both the anode and the cathode were directly activated for 1 hour by supplying humidified hydrogen gas (100% RH) and humidified nitrogen (100% RH), respectively. Thereafter, the temperature was lowered to 30 ° C. while supplying hydrogen gas to the anode, and then power was generated by supplying air to the cathode. FIG. 5 shows the relationship between time (h) (horizontal axis) and voltage (V) (vertical axis) after the start of power generation.

  From FIG. 5, it can be seen that the fuel cell of Example 9 was able to obtain a high-performance battery output earlier than after the operation as compared with the fuel cell of Example 8.

(Example 10)
Using the fuel cell activation device 1A of the present invention shown in FIG. 3, a conductor is disposed between the cathode C and the anode A to short-circuit, and the potential difference between the cathode potential and the anode potential is controlled to 10 mV for activation. In the same manner as in Example 4 before performing power generation, the cell temperature was set to 80 ° C., hydrogen gas humidified at 90 ° C. was supplied to the anode, and nitrogen humidified at 90 ° C. was supplied to the cathode and purged. Then, both the anode and the cathode were activated for 1 hour by supplying humidified hydrogen gas (110% RH) and humidified nitrogen (110% RH), respectively. Thereafter, the temperature was lowered to 30 ° C. while supplying hydrogen gas to the anode, and then power was generated by supplying air to the cathode. FIG. 5 shows the relationship between time (h) (horizontal axis) and voltage (V) (vertical axis) after the start of power generation.

  From FIG. 5, it can be seen that the fuel cell of Example 10 was able to obtain a high-performance battery output earlier than after the operation as compared with the fuel cell of Example 9.

Since the fuel cell can be easily activated by the fuel cell activation method of the present invention, a high-performance battery output can be quickly produced even when the fuel cell is assembled or immediately after being left unused for a long time. Can be easily obtained.
The fuel cell or the fuel cell membrane / electrode assembly treated by the fuel cell activation method of the present invention can be easily used by being mounted on the fuel cell when the cell stack or the fuel cell is assembled. Since an activated cell stack or fuel cell is obtained, a high-performance battery output can be easily obtained immediately after the cell stack or fuel cell is assembled.
The cell stack or fuel cell can be easily and reliably activated using the fuel cell activation device of the present invention, and the cell or membrane / electrode assembly produced by heat treatment can be easily and reliably activated. .
Since the present invention has the remarkable effects as described above, the industrial utility value is high.

It is explanatory drawing explaining an example of the activation apparatus for fuel cells of this invention. It is explanatory drawing explaining the other example of the activation apparatus for fuel cells of this invention. It is explanatory drawing explaining an example which arrange | positions and activates the specific resistance between a cathode and an anode using the activation apparatus for fuel cells of this invention shown in FIG. It is a graph which shows the relationship between time (h) (horizontal axis) and voltage (V) (vertical axis) after the power generation start of Example 1 and Comparative Example 1. The relationship between the time (h) (horizontal axis) and the voltage (V) (vertical axis) after the start of power generation in Example 1, Examples 8 to 10 and Comparative Example 1 is enlarged in the portion X shown in FIG. It is a graph shown. The cathode potential (0.7V) and anode potential (0V) with respect to the hydrogen standard electrode (NHE) and the cathode C and anode when nitrogen is supplied to the cathode C and hydrogen is supplied to the anode A for activation. It is a graph explaining that a cathode potential changes when a fixed resistor R or a conductor is disposed between A and short-circuited. It is a decomposition explanatory view showing the basic composition of the single cell of a polymer electrolyte fuel cell. It is sectional drawing which shows the basic composition of a polymer electrolyte fuel cell stack (laminated body).

Explanation of symbols

1, 1A, 20 Fuel cell activation device 2 Fuel cell 3 Reducing agent supply means 4, 26 Hydrogen supply source 5, 27 Hydrogen supply line 6, 28 Humidification means 7, 8, 9, 13, 29, 30, 31 Open / close Valve 10 Inert gas supply means 11 Nitrogen supply source 12 Nitrogen supply lines 14, 32 Control means 21, 58, MEA membrane / electrode assembly 22 Lid 23 Heating means 25 Supply means A, 47 Anode C, 46 Cathode R Fixed resistance 41 Solid polymer electrolyte membrane 42 Cathode side electrode catalyst layer 43 Anode side electrode catalyst layer 44 Cathode side gas diffusion layer 45 Anode side gas diffusion layer 50 Separator 51 Single cell 60 Solid polymer fuel cell stack (laminated body)

Claims (11)

A method for activating a fuel cell that supplies an oxidant containing oxygen to a cathode and supplies a fuel gas or organic fuel containing hydrogen to an anode to generate electricity,
A method for activating a fuel cell, wherein the activation is performed by supplying a reducing agent to at least the cathode. A method for activating a fuel cell that supplies an oxidant containing oxygen to a cathode and supplies a fuel gas or organic fuel containing hydrogen to an anode to generate electricity,
A method for activating a fuel cell, wherein activation is performed by supplying a reducing agent to an anode and supplying an inert gas to a cathode. A method for activating a fuel cell that supplies an oxidant containing oxygen to a cathode and supplies a fuel gas or organic fuel containing hydrogen to an anode to generate electricity,
While supplying a reducing agent to the anode, a fixed resistor or conductor is disposed between the cathode and the anode, and the cell or membrane / electrode assembly is activated by controlling the potential difference between the cathode potential and the anode potential to 100 mV or less. A method for activating a fuel cell, comprising: A method for activating a fuel cell that supplies an oxidant containing oxygen to a cathode and supplies a fuel gas or organic fuel containing hydrogen to an anode to generate electricity,
By supplying a reducing agent to the anode, supplying an inert gas to the cathode, and providing a fixed resistor or conductor between the cathode and the anode, the potential difference between the cathode potential and the anode potential is controlled to 100 mV or less. A method for activating a fuel cell, comprising activating a cell or a membrane / electrode assembly.   The method for activating a fuel cell according to any one of claims 1 to 4, wherein the reducing agent or the inert gas is a humidified gas having a relative humidity of 90% or more.   The method for activating a fuel cell according to any one of claims 1 to 4, wherein the reducing agent is humidified hydrogen gas. A method of activating a fuel cell or membrane / electrode assembly in which an oxidant containing oxygen is supplied to a cathode and a fuel gas or organic fuel containing hydrogen is supplied to an anode to generate electricity,
Cell or membrane / electrode assembly produced by heat treatment is treated at a temperature of 50 to 200 ° C. in a reducing atmosphere containing a reducing agent. Method.   8. The method of activating a fuel cell or membrane / electrode assembly according to claim 7, wherein the reducing agent is a humidified hydrogen gas.   A cell or a membrane / electrode assembly activated by the activation method according to any one of claims 1 to 8, and a stack or a fuel cell comprising the activated cell or membrane / electrode assembly. A fuel cell activation device for performing the fuel cell activation method according to any one of claims 1 to 8,
Reducing agent supply means for supplying a reducing agent to the anode or cathode;
An inert gas supply means for supplying an inert gas to the cathode;
Control means for controlling these,
An activation device for a fuel cell comprising: An activation device for a fuel cell for activating a cell of a fuel cell or a membrane / electrode assembly,
A processing vessel for processing a cell or membrane / electrode assembly produced by heat treatment,
Supply means for supplying a reducing agent to the processing vessel;
Heating means for heating the processing vessel;
Control means for controlling these,
An activation device for a fuel cell comprising:

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