Investigation On Preperation, Characterization And Conductivity For Perovskite-type Proton Conductors

The phnomenon that SrCeO3 doped oxides showed protonic conduction had been reported in 1981. Then Nowick decovered a new class of complex perovskites of the form A2(B'B")O6, A3(B'B")O9. After high temperature perovskite-type proton conductor became one of research top, however, the structure of the performance proton conductor and the theory of the preparation process are not yet perfect.In this study, powders of perovskite-type proton conductors BaCe0.85Y0.15O3-α, CaZr0.9In0.1O3-αand complex perovskites Ba3Ca1.25Nb1.75O9-δ, Ba3Ca1.18Nb1.82O9-δ, Ba3Ca1.1Nb1.9O9-δwere prepared after calcining at 1400℃for 10h by high temperature solid state reaction. The proton conductor tubes and disks were formed by the methods of cold isostatic pressuring and hot injection moulding. After sintering in the condition of 1550℃for 10h, obtain BaCe0.85Y0.15O3-α, CaZr0.9In0.1O3-αproton conductor tubes and BaCe0.85Y0.15O3-α, Ba3Ca1.25Nb1.75O9-δ, Ba3Ca1.18Nb1.82O9-δand Ba3Ca1.1Nb1.9O9-δproton conductor disks.Series of performance determinations about the raw material of proton conductors, proton conductors powders after calcining, and proton conductors tubes disks after sintering were also carried on. XRD result showed that those powders consisted of the expected BaCe0.85Y0.15O3-α, CaZr0.9ln0.1O3-α, Ba3Ca1.25Nb1.75O9-δ, Ba3Ca1.18Nb1.82O9-δ, Ba3Ca1.1Nb1.9O9-δfive perovskite-type proton conductors.Laser diffraction particle size analysis and DTA and TG results indicated that the proper milling time could make particle refine,decrease the sgnthe-size temperature and increase the density of sample.The calcination has not caused the particle size of the powders to increase. Analysis displayed the calcining temperature of BaCe0.85Y0.85O3-α, CaZro.9In0.1O3-α, Ba3Ca1.25Nb1.75O9-δ, Ba3Ca1.18Nb1.82O9-δand Ba3Ca1.1Nb1.9O9-δ.The analysis of density, porosity, intensity and tightness showed that proton conductor tubes had good compactness. The relative density of CaZr0.9In0.1O3-αtubes formed by hot injection moulding is 94.4% and BaCeo.85Yo.1503-a tubes'is 96.96%. The relative density of CaZro.9lno.103-αtubes formed by cold isostatic pressuring is 96.0%, yet the relative of BaCeo.85Yo.1503-αtubes is 95.48%. The measurement of BaCeo.85Y0.1503-α, Ba3Ca1.18Nb1.82O9-δand Ba3Ca1.1Nb1.9O9-δdisks by electrochemical impedance spectroscopy displayed protonic conductivity of those proton conductors.