Tailoring of ni: 8ysz cermet via solution-based syntheses

Abstract

Major challenges of Ni: 8YSZ cermet anode material in solid oxide fuel cell (SOFC) application are (i) the reduction of operating temperature,(ii) minimization of Ni concentration and (iii) optimization of porosity, without sacrificing electrical conductivity, thermal expansion compatibility and overall cell performance. Lowering of operating temperature is possible by increasing the density of triple phase boundary (TPB) by developing a suitable microstructure, containing fine grained Ni and 8YSZ. Decreasing grain size of Ni may minimize percolation threshold, and better Ni-Ni connectivity is possible via tailoring the microstructure of Ni: 8YSZ cermet. The porosity of cermet forms by the reduction of NiO to Ni and
proper microstructure of NiO: 8YSZ composites may be developed by optimizing the fabrication parameters
such as binder concentration, compaction pressure and sintering temperature. Above motivations led to work
on tailoring the microstructural parameters such as size and distribution of NiO/Ni particles in NiO/Ni: 8YSZ composites, which strongly depends on the initial size and forms of Ni such as NiO, Ni(OH)2 and Ni. These forms of Ni may evolve during different solution-based syntheses and varying synthesis conditions may develop different size and distribution of NiO in NiO: 8YSZ composites, which may result in different types of microstructure of Ni: 8YSZ cermet.