A Durable Ruddlesden‐Popper Cathode for Protonic Ceramic Fuel Cells

Abstract

Protonic ceramic fuel cells (PCFCs) have been proved as an efficient energy converter at intermediate temperatures. To accelerate the kinetics of the proton-involved oxygen reduction reaction (p-ORR), developing efficient and durable cathodes is of great importance for improving PCFCs. In this work, a new triple-layered Ruddlesden-Popper (RÀ P) structure oxide, Sr 3 EuFe 2.5 Co 0.5 O 10À δ (3-SEFC 0.5), was developed as a potential single-phase cathode for PCFCs, showing high oxygen nonstoichiometry and desirable structural thermal stability. By employing this highly active and stable single-phase cathode, the PCFC demonstrated unprecedented low polarization resistances and exceptionally great peak power densities, which were approximately 0.030 Ω cm 2 and 900 mW cm À 2 measured at 700°C, respectively. These findings not only manifest the effectiveness of optimal doping in improving the structural stability and electrocatalytic activity in the multi-layered perovskite family, but also highlight the great potential of using multi-layered RÀ P series oxides as highly active and durable catalysts for PCFCs.

An Efficient Steam‐Induced Heterostructured Air Electrode for Protonic Ceramic Electrochemical Cells

“…Typical EIS of symmetrical cells with a configuration of PBCFN|BZCYYb|PBCFN a) in wet air and b) dry air, measured at 600–750 °C; c) temperature dependence of the area‐specific resistance (ASR or R p ) of symmetrical cells with PBCFN air electrode and several state‐of‐the‐art electrode materials tested in wet air (NBCF, Nd 0.5 Ba 0.5 FeO 3− δ ; [ 33 ] BCFZ, BaCo 0.4 Fe 0.4 Zr 0.2 O 3− δ ; [ 34 ] BSCF, Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3− δ ; [ 35 ] BSCF, Ba 0.5 Sr 0.5 Co 0.72 Fe 0.18 Ti 0.10 O 3− δ ; [ 35 ] BCFZY, BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3− δ ; [ 36 ] BSSC, Ba 5 SrSm 2 Co 4 O 15 [ 37 ] ; SEFC, Sr 3 EuFe 2.5 Co 0.5 O 10− δ [ 38 ] ); d) EIS and e) distribution of relaxation time (DRT)of PBCFN electrode as a function of p O2 measured at 650 °C; f) dependence of R p in the HF, IF, and LF as a function of p O2 .…”

High-performance protonic ceramic fuel cell cathode using protophilic mixed ion and electron conducting material

“…Note that the cell durability depends on not only the cathodeelectrolyte compositional combinations, but also anode, working gas, temperature and the applied voltage. [45][46][47] More detailed evaluation with longer tests is required. As shown in Fig.…”

Materials development and prospective for protonic ceramic fuel cells

“…89,118,164 The materials that are reported to be most suitable for achieving excellent triple conducting singlephase cathodes are either ABO 3Àδ perovskites, A 0 AB 2 O 5þδ double perovskites, and A nþ1 B n O 3nþ1 Ruddlesden-Popper with their A and B sites doped with elements such as Ba, Sr, Zr, Cu, Mn, Co, and Ni. 26,75,[165][166][167][168][169] It is best to consider materials with cubic structures and large lattice volumes because they enhance hydration and proton conduction. It is also essential when selecting dopants to consider transition metals with multiple oxidation states because that will significantly enhance redox capability and good electronic conductivity.…”