Nano-structured composite cathode by infiltration process for solid oxide fuel cells
【摘要】：Solid oxide fuel cells(SOFCs) are one of the cleanest and most efficient energy conversion technologies from chemical energy to electricity. The resistance minimization of cathode for oxygen reduction reaction(ORR) is a key issue which contributes the main performance degradation in SOFCs at low temperature. Surface modification of the electrode through nano technology is a promising method for SOFCs performance improvement. Herein,we reported a novel solution-based infiltration process to decorate La Ni0.6Fe0.4O3(LNF) cathode surface. The phase composition,chemical compatibility,microstructure and electrochemical performance of the materials were investigated by X-ray diffractometry(XRD),scanning electron microscopy(SEM) and electrochemical impedance spectra(EIS). The introduction of the BSC nano particles and coating resulted in an electro-catalytic performance enhancement of the LNF cathode. The composite cathode with an infiltration ratio of 10wt% BSC demonstrated a polarization resistance of 0.13Ω·cm2 at 700 oC,which is 3 times lower than that of pure LNF. A short-run test of 80 h was carried out at 750 oC using symmetrical cells,and the BSC@LNF cathode shows a more stale electrochemical performance than Pr6O11@LNF. The improved stability could be attributed to the BSC film coated on the cathode surface,which may prevent the electrochemical performance degradation.