TECHNICAL FIELD

The present invention relates to an electrochemical cell.

BACKGROUND ART

In recent years, fuel cells that are a type of electrochemical cell have attracted attention in light of environmental problems and their effective use as an energy source.

A fuel cell generally includes an anode, a cathode, and a solid electrolyte layer disposed between the anode and the cathode.

The cathode for example is configured with a perovskite oxide such as (La, Sr) (Co, Fe) O3: (lanthanum strontium cobalt ferrite) or the like (for example, reference is made to Japanese Patent Application Laid-Open No. 2006-32132).

SUMMARY OF INVENTION

However, fuel cell output may be reduced by repetitive power generation. The present inventors have gained the new insight that one cause of a reduction in output is deterioration of the cathode, and that such deterioration of the cathode is related to the total proportion of SrSO4and (Co, Fe)3O4that is introduced into the cathode.

The present invention is proposed based on the new insight above, and has the object of providing an electrochemical cell that is configured to inhibit a reduction in the fuel cell output.

The electrochemical cell according to the present invention has an anode, a cathode, and a solid electrolyte layer disposed between the anode and the cathode. The cathode contains a main phase and a second phase. The main phase is configured with a perovskite oxide which is expressed by the general formula ABO3and includes at least one of Sr and La at the A site. The second phase is configured with SrSO4and (Co, Fe)3O4. An occupied surface area ratio of the second phase in a cross section of the cathode is less than or equal to 10.5%.

The present invention provides an electrochemical cell that is configured to inhibit a reduction in the fuel cell output.

