Electrochemical and mechanical properties of solid oxide fuel cell Ni/YSZ anode fabricated from NiO/YSZ composite powder

Abstract

The electrochemical and mechanical properties were investigated on Ni/Yttria-stabilized zirconia (YSZ) solid oxide fuel cells (SOFCs) anode fabricated from a NiO/YSZ composite powder. The composite powder was fabricated by dry milling of NiO and YSZ nanoparticles using attrition type apparatus without media balls for 30 min. The composite powder suppresses the microscopic as well as macroscopic segregation of the component during tape casting and subsequent sintering, resulting fine as well as the highly uniform anode microstructure. The anode supported SOFC made from the composite powder showed the maximum power density of 0.25 and 0.75 W·cm ¹2 at 700 and 800°C, respectively, which is significantly higher than that fabricated from the conventional powder mixture. Better performance can be attributed to the lower interfacial resistance due to the formation of huge amount of triple phase boundary consisting of Ni, YSZ and pore phases. The higher electrical conductivity would also contributed to the high performance. The equibiaxial flexural strength of NiO/YSZ fabricated from the composite powder was higher than that from the powder mixture.

Development of Ni-doped Yttria stabilized Zirconia composite for SOFC applications as Anodic material

“…A low electrical conductivity in the sample may be due to high grain boundary density [29]. It may be noted that there are three basic properties [3,11,[32][33][34] of an anode for SOFC's applications. These are (i) it oxidizes the fuel, (ii) it acts as catalyst for reforming the fuel, and (iii) it helps electrons to conduct in the external circuit.…”

Microstructure and mechanical properties of Ni/10mol% Sc2O3–1mol% CeO2–ZrO2 cermet anode for solid oxide fuel cells

“…The mechanical properties of Ni/YSZ anodes have been reported in several publications. [2][3][4][5][6] Recently, scandia and ceria stabilized zirconia (SCSZ) ceramics emerged as new, promising electrolyte materials exhibiting much higher ionic conductivity at a lower temperature range in contrast to traditional YSZ electrolytes. 7,8 As SCSZ electrolytes become a more feasible option in single cells, the Ni/YSZ cermets may also need to be modified to replace YSZ with a SCSZ matrix.…”