The mechanical and electrical properties of Ni/YSZ anode support for solid oxide fuel cells

The most commonly used solid oxide fuel cell (SOFC) anode material is a two phase nickel and yttria stabilized zirconia (Ni/YSZ) cermet. And the mechanical stability of anode support layer, in anode-supported electrolyte designs, is very important for large scale applications. During the assembly of stack and normal operation, the cermet anode should withstand enough mechanical loading to prevent the cell from cracking caused by various stresses. The electrical conductivity at ambient temperature as a function of Nickel content has a typical ‘S’ shape curve increasing from 0.06 S.cm to 1178.78 S.cm. The open porosity increased from 13 % to 42% with the Ni content changing from 26 wt% to 55 wt%. The open porosity as a function of Ni vol% could be expressed by equation P=0.694X+P0, where P is open porosity, P0 is initial porosity and X is Ni vol%. The density decreased with Ni content increasing both before and after reduction. The flexural strength increased with the decreasing content of Ni and has an inflexion between 60 wt% and 65 wt% of nickel before reduction. When the nickel content more than 50 wt%, the flexural strength decreased more than 25% after reduction. A0520 – Abstract 242 – Poster Presentation – Section A05 – Anodes – Wednesday, July 2, 2008 – 16:00 h