ACTIVATION METHOD FOR FUEL CELL SYSTEM

• US 20110229782A1
• Filed: 05/31/2011
• Published: 09/22/2011
• Est. Priority Date: 07/11/2006
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamamoto, Jun
• Application Number:
  US13/118,797
• Publication Number:
  US 20110229782A1
• Time in Patent Office: Days
• US Class Current: 429/429
• CPC Class Codes: H01M 8/04126 Humidifying
• CPC Class Codes: H01M 8/04223 during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/241 with solid or matrix-supported electrolytes
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell system capable of performing activation for stabilizing electrical characteristics of a fuel cell with suppressing generation of polarity inversion associated with drying of a polymer electrolyte membrane and excess power consumption. An activation method for a fuel cell, the fuel cell system including a fuel cell having a fuel electrode and an oxidizer electrode that are provided on both sides of a polymer electrolyte membrane; a resistance detector for detecting an internal resistance of the fuel cell; a load connection portion having a mechanism for connecting a resistor between the fuel electrode and the oxidizer electrode; and a control unit for controlling the load connection portion. The control unit controls the operation of the load connection portion based on a value of the inner resistance of the fuel cell, which is detected by the resistance detector.

Claims

1. A method for performing an activation treatment of a fuel cell system, the fuel cell system comprising:

a fuel cell comprising a fuel electrode, an oxidizer electrode, and a polymer electrolyte membrane, where the fuel electrode and the oxidizer electrode are disposed on opposite sides of the polymer electrolyte membrane;

a resistance detector detecting an internal resistance of the fuel cell;

a resistor connected between the fuel electrode and the oxidizer electrode;

a load connection portion having a mechanism connecting the resistor; and

a control unit for controlling the load connection portion,

the method comprising;

forming a calibration curve based on a correlation between an internal resistance of the fuel cell and one of (i) a time period and (ii) an amount of charge required for displacement of current flowing through the resistor connected to the fuel cell to reach a saturation point;

storing the calibration curve in the control unit;

detecting an internal resistance of the fuel cell by the resistance detector;

calculating from the calibration curve one of a time period and an amount of charge based on the detected internal resistance; and

controlling an operation of the load connection portion based on the calculated one of the time period and the amount of charge.

2. The method according to claim 1, wherein:

the fuel cell comprises a fuel cell stack including a plurality of fuel cell units, where each fuel cell unit in the plurality of fuel cell units is provided with the load connection portion; and

the control unit controls the operation of the load connection portion for the each fuel cell unit based on an internal resistance of the each fuel cell unit detected by the resistance detector.

3. The method according to claim 2, wherein the internal resistance of the fuel cell is an average value of internal resistances of the plurality of fuel cell units and is calculated from the internal resistance of the entire fuel cell stack.

4. A method for performing an activation treatment of a fuel cell system, the fuel system comprising:

a fuel cell comprising a fuel electrode, an oxidizer electrode, and a polymer electrolyte membrane, where the fuel electrode and the oxidizer electrode are disposed on opposite sides of the polymer electrolyte membrane;

a resistance detector detecting an internal resistance of the fuel cell;

a resistor connected between the fuel electrode and the oxidizer electrode;

a load connection portion having a mechanism connecting the resistor; and

a control unit for controlling the load connection portion,

the method comprising;

forming a calibration curve based on a correlation between an internal resistance of the fuel cell and a minimum value of displacement of a current which flows when the fuel cell is short-circuited;

storing the calibration curve in the control unit;

detecting the internal resistance of the fuel cell by the resistance detector;

calculating from the calibration curve a minimum value of a current which flows when the fuel cell is short-circuited before the activation treatment based on the detected internal resistance; and

controlling an operation of the load connection portion when the minimum value is smaller than a predetermined current value.

5. The method according to claim 4, wherein the predetermined current value is a current value necessary for a rated operation.