PROPERTY EVALUATION METHOD OF FUEL BATTERY CELL, FUEL BATTERY DEVICE, AND MANUFACTURING METHOD OF FUEL BATTERY CELL

摘要

PROBLEM TO BE SOLVED: To provide a property evaluation method of a fuel battery capable of separating a component caused by ion transport number reduction according to a simple method from reduction from a theoretical open circuit voltage in an open circuit voltage of a fuel battery cell.SOLUTION: A fuel battery cell includes a fuel electrode, an air electrode and an electrolyte that is held between the fuel electrode and the air electrode. The property evaluation method includes a measuring step of measuring a relation between a voltage and a current value while performing power generation on the fuel battery cell. A range to vary the voltage in the measuring step includes at least a range exceeding the open circuit voltage of the fuel battery cell. A range to vary the current includes at least a range below zero. When voltages are applied in positive and negative directions from the open circuit voltage, an IV curve can be obtained. An inclination of a tangent of a certain voltage value on the obtained curve becomes total resistance of the cell at that point. The total resistance is plotted to voltage+open circuit voltage value and a voltage value where the total resistance becomes maximum is a reduction voltage (E) caused by the ion transport number.