TY - JOUR
T1 - Electrochemical studies of Ruddlesden-Popper layered perovskite-type La0.6Sr1.4Co0.2Fe0.8O4+δ cathode for solid oxide fuel cells and associated electrical loss phenomena
AU - Baral, Ashok Kumar
AU - Tsur, Yoed
AU - Thangadurai, Venkataraman
N1 - Publisher Copyright:
© 2018 Elsevier Ltd and Techna Group S.r.l.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - The electrochemical performance of solid oxide fuel cell (SOFC) depends on functional properties of the anode, the cathode and the electrolyte that are being employed. There is a need for better cathode catalyst to decrease operating temperature of SOFCs. Here, we report a layered perovskite-type Ruddlesden-Popper structure La0.6Sr1.4Co0.2Fe0.8O4+δ (RP-LSCF) as cathode for SOFCs. The structural stability, thermal expansion, electrical, and fundamental electrochemical properties of RP-LSCF were investigated. The O2 reduction reaction (ORR) and O2 surface exchange properties of RP-LSCF and Gd-doped CeO2 (GDC)-RP-LSCF composite were studied using symmetrical cells. Area normalized resistances for charge transfer (Ri) and surface exchange processes (Rs), and total polarization are found to be 0.14, 0.28 and 0.42 Ω cm2 at 800 °C, respectively. The exchange current density and oxygen surface exchange co-efficient for RP-LSCF are 54.53 mA cm−2 and 1.15 × 10−6 cm s−1 at 800 °C, respectively. Addition of nano-GDC with RP-LSCF leads to increase of polarization resistances, while the activation energies for charge transfer and surface exchange processes are reduced significantly. For the first time, we report a dielectric loss tangent analysis corresponding to the electrode phenomena in RP-LSCF and GDC-RP-LSCF to understand the electrical losses associated with SOFC cathode (ORR) processes.
AB - The electrochemical performance of solid oxide fuel cell (SOFC) depends on functional properties of the anode, the cathode and the electrolyte that are being employed. There is a need for better cathode catalyst to decrease operating temperature of SOFCs. Here, we report a layered perovskite-type Ruddlesden-Popper structure La0.6Sr1.4Co0.2Fe0.8O4+δ (RP-LSCF) as cathode for SOFCs. The structural stability, thermal expansion, electrical, and fundamental electrochemical properties of RP-LSCF were investigated. The O2 reduction reaction (ORR) and O2 surface exchange properties of RP-LSCF and Gd-doped CeO2 (GDC)-RP-LSCF composite were studied using symmetrical cells. Area normalized resistances for charge transfer (Ri) and surface exchange processes (Rs), and total polarization are found to be 0.14, 0.28 and 0.42 Ω cm2 at 800 °C, respectively. The exchange current density and oxygen surface exchange co-efficient for RP-LSCF are 54.53 mA cm−2 and 1.15 × 10−6 cm s−1 at 800 °C, respectively. Addition of nano-GDC with RP-LSCF leads to increase of polarization resistances, while the activation energies for charge transfer and surface exchange processes are reduced significantly. For the first time, we report a dielectric loss tangent analysis corresponding to the electrode phenomena in RP-LSCF and GDC-RP-LSCF to understand the electrical losses associated with SOFC cathode (ORR) processes.
KW - Dielectric loss tangent
KW - Layered perovskite
KW - Oxygen reduction reaction
KW - SOFC cathode
U2 - 10.1016/j.ceramint.2018.10.041
DO - 10.1016/j.ceramint.2018.10.041
M3 - Article
AN - SCOPUS:85055151407
SN - 0272-8842
VL - 45
SP - 1641
EP - 1650
JO - Ceramics International
JF - Ceramics International
IS - 2
ER -