In-situ strategy to suppress chromium poisoning on La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes of solid oxide fuel cells

The surface segregation of strontium in the La0.6Sr0.4Co0.8Fe0.2O3-δ (LSCF) electrode interacts with volatile contaminants such as chromium in the solid oxide fuel cell (SOFC) interconnect, causing deterioration in cell performance. A simple in-situ reaction strategy has been exploited to synergistically improve oxygen reduction reaction (ORR) activity in air and anti-chromium stability of LSCF electrode via infiltration and calcination of nickel nitrate and ferrite nitrate (NF) precursor on the LSCF backbone. The chemical compatibility, electrochemical performance, interfacial element distribution and stability in chromium-containing atmosphere of the as-prepared hybrid electrodes were systematically investigated. At a calcination temperature of 1100 °C, Sr(Co,Ni)O3-δ layer was formed owing to Co diffusion and Sr precipitation from LSCF and the reaction with Ni atoms at the surface of LSCF. This will promote anti-chromium ability for the hybrid LSCF@NF cathode material. After the symmetrical cells were operated at 750 °C for 400 h under Cr contamination, the polarization resistance of LSCF@NF was only half of that of blank LSCF electrode with much less Cr species. This strategy via in-situ reaction may be extended to other high temperature energy conversion systems such as anti-sulfur and anti-carbon deposition of SOFC anodes and CO2 resistance of cathodes.