Enhanced Electrochemical Performance of Cu-Doped La2NiO4+delta Cathode for Solid Oxide Fuel Cells

摘要

To illustrate the effect of Cu-doping in Ruddlesden-Popper-type La2NiO4+delta oxides, the crystal structure, interstitial oxygen formation, electrical conductivity, catalytic activity and chromium tolerance of La2NiO4+delta(LNO)and La2Ni0.9Cu0.1O4+delta(LNCO) are analyzed. XRD Rietveld and HT-TEM results confirm that both can be identified as Ruddlesden-Popper-type structures with tetragonal symmetry. Compared with non-doped LNO, LNCO has less interstitial oxygen, and its electrical conductivity decreases owing to the reduction of the carrier concentration. The effects on electrode performance are analyzed using symmetric cells, and interface polarization resistance at 800 degrees C is reduced from 2.20 Omega cm(2) to 0.54 Omega cm(2) after Cu-doping. Experimental results together with the excellent chromium tolerance confirmed by HT-XRD results demonstrate that Cu-doped LNO can work as a promising chromium-tolerant cathode.