摘要
One of the key tasks in solid oxide fuel cell research is to develop cost-competitive electrodes that work efficiently in wide range of air and fuel utilizations.Herein,we promote our study to a series of Cobalt and Titanium substituted La_(0.4)Sr_(0.6)Fe_(0.7)Ti_(0.3-x)Co_(x)O_(3-δ)(LSFTC,x=0,0.05,0.1,0.2)perovskite oxides.It is shown that Cobalt doping effectively improves the electrical conductivity and oxygen electrochemical reduction activity,yielding decreased cathode polarization resistance and lower dependence of pO_(2) change.For example,σ_(600℃)=81 S/cm and R_(p,C750℃)=0.1 Ω cm^(2) for LSFTC-5 are obtained in pO_(2)=0.21 atm.In anode conditions of wet H2,the LSFTC cubic perovskites are partially reduced to hybrid structure of ABO_(3)-A_(2)BO_(4)-metal with Cobalt doping amount less than 10% and are fully decomposed to A_(2)BO_(4)-metal with 20% doping.The higher Cobalt substitution generates more nano particles exsolution,which promotes anode processes at low temperatures.However,the generated AO-rich compositions are shown detrimental to anode performance in both conducting property and anode catalytic activity under low H_(2) partial pressures.In current study,the electrodes are evaluated under practical working conditions with broad pO_(2) and pH_(2),which provides guidelines for industrial-applicable SrFeO_(3) based symmetrical electrode development.
基金
the financial support from National Natural Science Foundation of China(51702163)
Ministry of Science and Technology of China(2018YFB1502203)
Jiangsu Province(BK20170847,BE2017098)
Top-notch Academic Programs Project of Jiangsu Higher Education Institutions.