| dc.description.abstract | In this study, the perovskite structure La0.6-xSr0.4Co0.2Fe0.8O3 cathode material made by the combustion synthesis method was doped with bismuth to form La0.6-xSr0.4BixCo0.2Fe0.8O3-δ(X=0 , 0.1, 0.2, 0.3, 0.4, 0.5; respectively marked as LSB1CF, LSB2CF, LSB3CF, LSB4CF) to explore its feasibility as a proton-conducting solid fuel cell cathode material. During the combustion process, the pH value (pH value: 1, 2, 3, 4) and the ratio of glycine-nitrate (G/N ratio: 0.75, 1.00, 1.25, 1.50) of the LSCF precursor nitrate aqueous solution were adjusted to observe After sintering at 1000°C for 2h, the crystalline structure of the powder is then synthesized with the best combustion method synthesis parameters (G/N ratio, pH value), and its electrochemical properties are analyzed. According to the LSCF experimental results, in the samples of LSCF 1.25/3, LSCF 1.25/4, LSCF 1.50/3 and LSCF 1.50/4, LSCF 1.50/3 is the most crystalline structure among all the combustion synthesis parameters. It conforms to the result of SOFC cathode, so this parameter is used as the combustion parameter for subsequent LSBxCF synthesis. Through X-ray crystal diffraction analysis of LSBxCF cathode powder, it can be found that the 2θ of the overall characteristic peak tends to become larger due to the smaller Bi3+ doped ion radius entering the A-site, and there are some minor miscellaneous items in LSB4CF and LSB5CF. The other parameter connections did not appear miscellaneous. The conductivity is measured by the four-point direct current electric quantity, LSCF will cause the electronic conductivity to decrease with the doping of Bi, but at the same time, the proton conductivity will never be able to conduct protons, and will slightly increase with the increase of the doping amount.. The LSB3CF single cell has the highest power density of 358.4 mW cm-2 at 800°C, which is 155% higher than the LSCF single cell 140.6 mW cm-2, and the lowest polarization impedance of 0.09 Ω cm2, which is 25% lower than the LSCF single cell; And it has the highest power density of 183.5 mW cm-2 and 134.3 mW cm-2 at 700°C and 600°C, respectively. The results of this study show that the LSB3CF cathode material can effectively enhance the conduction of protons in the cathode, and the electrochemical performance is good at the operating temperature of 800 ℃. It has the highest power density of 358.4 mW/cm2, and it has the highest power density at 700°C and 600°C. The best electrochemical performance. | en_US |