Reducing the reaction between boron-containing sealing glass-ceramics and lanthanum-containing cathode: Effect of La2O3

The volatile boron species from sealing glass-ceramics have a significant poisoning effect on the electrochemical activity of Solid Oxide Fuel Cell (SOFC) cathodes. The reaction between boron-containing sealing glass-ceramics and cathodes thus presents a challenge for the development of SOFC. Here we report for the first time that the addition of La2O3 can significantly reduce the boron volatility from sealing glass-ceramics and consequently the formation of LaBO3 in reaction couple between glass and (La,Sr)(Co,Fe)O3 (LSCF) cathode. In particular, the boron volatility can be reduced by about 6 times with the addition of 4 mol.% La2O3 (3.7 × 10−3 vs. 0.6 × 10−3%). The addition of La2O3 condenses the structure of glasses and glass-ceramics, contributing to the decrease in boron volatility from glass-ceramics. In addition, La2O3 dopant favors the formation of boron-containing phase (La5SiBO13) in glass-ceramics, which dramatically reduces the boron volatility. The reported results provide an effective approach for solving the sealing challenge.