Evaluating Of LaCo_0.6Ni_0.4O_3-δ Cathode Contact Material For Intermediate Temperature Solid Oxide Fuel Cells

LaCo0.6Ni0.4O3-(LCN) as cathode contact material (CCM) for application in solidoxide fuel cell (SOFC) is studied in this paper. LCN is prepared through the polymericsteric entrapment precursor route with polyvinyl alcohol (PVA) as the entrapment agentand then calcined at800°C and1100°C for3h respectively. XRD analysis has proved thepurity of the ascalcined LCN. The physical and electrochemical properties of LCN istested later. The conductivity of LCN reaches the highest value of1420S cm-1at400°Cand remains1300S cm-1at800°C，which is much higher than those conventionalperovskite contact materials like LSM and LNF. Polished SUS430pellets heated at800°Cfor6days as well as the untreated ones are used as interconnect. Testing the area specifiresistance(ASR) of all the assemblys of different LCN and SUS430.The assembly of LCNcalcined at800°C with pretreated SUS430at800°C for6days exhibit the bestperformance of a low and stable area specific resisstance(ASR) value about112mΩ cm2at the end of the200h test. The calcination temperature and the pretreatment of theinterconnect are considered to be crucial factors affecting the ASR property of LCN CCMfor application in stack.Single cells with LCN calcined at800°C and1100°C are tested under praticalsituations, both of the cells exhibit good performances with a power density higher than530mW cm-2at a current density of937.5mA cm-2.The composite of10wt%glass and1100°C calcined LCN are proposed as new CCM.The reaction in the composite is very small and ASR test has shown that the adding ofglass in the LCN can release stress during operation conditions, thus reducing the contactresistance between the LCN particles and the interconnect. The assembly with compositeas CCM and untreated SUS430as interconnect present the best performance with an ASRvalue of93mΩ cm2, the adding of glass showes a promising prospect and further effortsshould be paied on the study in this area.