A study for improving performance of solid oxide fuel cell using GDC interlayer

Abstract

A solid oxide fuel cell using ceramic electrolyte has a problem of deterioration of materials due to operation at high temperatures (>800℃), and researches are under way on SOFC which can operate at low temperatures (400~450℃) to solve the problem. However, Yttria Stabilized Zirconia(YSZ), the representative electrolyte of SOFC, reduces SOFC cell performance due to insufficient ionic conductivity at low operation temperatures. To solve such a problem, we conducted researches on SOFC cell which improves decreased performance using the materials that avoid performance drop or reduce resistance. As the adopted methods; we made an SOFC cell which gives high performance even at low temperatures by inserting GDC interlayer between YSZ electrolyte and electrode and conducted performance evaluation and analysis of the concerned cell. At 450℃, GDC 50nm cell showed 37% more performance than only YSZ cell, and GDC 100nm cell showed 56% more performance than only YSZ. We did EIS measurement to find out the reason for the performance increase, and as a result confirmed that the electrode interface resistance was reduced. Judging from such results, the improvement in the performance of GDC interlayer SOFC cell came from the decrease in electrode interface resistance by the surface exchange coefficient of GDC.