PrBaCo2-xTaxO5+δ based composite materials as cathodes for proton-conducting solid oxide fuel cells with high CO2 resistance

Materials development and prospective for protonic ceramic fuel cells

“…Due to the challenges encountered with the use of BaCeO 3 -based oxides as electrolyte materials for protonconducting solid oxide fuel cells, efforts were channeled toward developing materials with excellent mixed conductivity and satisfactory stability against water and acidic atmospheres. 79,85,92,[117][118][119][120][121][122][123] Some of those strategies employed were (a) co-doping of BaCeO 3 using various suitable elements which could either be metallic or nonmetallic and (b) introduction of phases with high stability properties to the BaCeO 3 -based material in the form of composite material development. Based on the outcome of various research works, zirconium was found to be the most suitable element to improve the stability of BaCeO 3, 107 although at the expense of other electrical properties of the material as will be discussed in the next section.…”

Perspectives on Cathodes for Protonic Ceramic Fuel Cells

“…The optimal PBCO loading was ascertained at 36 wt % PBCO, leading to an MPD of 0.49 W•cm −2 at 750 • C [193]. Ta-doped PrBaCo 2 O 5+δ cathodes showed improved chemical stability and higher resistance to CO 2 [194]. In addition, composite cathodes of PrBa 0.9 Ca 0.1 Co 2-x Zn x O 5+δ and BCZYYB7111, as reported by Liu et al [195], showed a higher concentration of oxygen vacancies after Zn-doping of the double perovskite, which resulted in a higher power output of 0.87 W•cm −2 for the x = 0.15 composition at 750 • C in comparison to 0.33 W•cm −2 for the Zn-free composite.…”

Novel mixed H+/e−/O2− conducting cathode material PrBa0.9K0.1Fe1.9Zn0.1O5+δ for proton-conducting solid oxide fuel cells

“…The classical mixed ionic and electronic conductors (MIECs), such as Ba 0.5 Sr 0.4 Co 0.6 Fe 0.4 O 3Àd (BSCF), 29 La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3Àd (LSCF), 30 and PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+d (PBSCF), 31 were tested and veried for the uptake and transportation ability for proton, and PBSCF shows the best performance, while the single cell with PBSCF as the cathode presents a peak power density (PPD) of 0.8 W cm À2 at 600 C. 31 Besides, the TCOs could be obtained by element doping on MIECs. [32][33][34][35] Mo was doped on BSCF to decrease the hydration energy from À0.210 eV to À0.656 eV and the single cell with Ba 0.5 Sr 0.5 Co 0.7 Fe 0.2 Mo 0.1 O 3Àd as the cathode presents a PPD of 1.27 W cm À2 at 700 C, which is higher than that with the BSCF cathode. 33 In addition to the triple conductivity, the cathode materials require lower thermal expansion coefficients (TECs) and chemical compatibility with electrolytes.…”

“…31 Besides, the TCOs could be obtained by element doping on MIECs. 32–35 Mo was doped on BSCF to decrease the hydration energy from −0.210 eV to −0.656 eV and the single cell with Ba 0.5 Sr 0.5 Co 0.7 Fe 0.2 Mo 0.1 O 3− δ as the cathode presents a PPD of 1.27 W cm −2 at 700 °C, which is higher than that with the BSCF cathode. 33 In addition to the triple conductivity, the cathode materials require lower thermal expansion coefficients (TECs) and chemical compatibility with electrolytes.…”