Excellent Electrochemical Performance of La_0.3Sr_0.7Fe_0.9Ti_0.1O_3−δ as a Symmetric Electrode for Solid Oxide Cells

Abstract

Solid oxide cells (SOCs) can switch between fuel cell and electrolysis cell modes, which alleviate environmental and energy problems. In this study, the La0.3Sr0.7Fe0.9Ti0.1O3−δ (LSFTi 91) perovskite is innovatively used as a symmetric electrode for solid oxide electrolysis cells (SOECs) and solid oxide fuel cells (SOFCs). LSFTi 91 exhibits a pure perovskite phase in both oxidizing and reducing atmospheres, and the maximum conductivity in air and 5% H2/Ar is 150 and 1.1 S cm–1, respectively, which meets the requirement of the symmetric electrode. The polarization resistance (R p) at 1.5 V is as low as 0.09 Ω cm2 in the SOEC mode due to the excellent CO2 adsorption capacity. The current density can reach 1.9 A cm–2 at 1.5 V and 800 °C, which is the highest electrolytic performance in the reported single-phase electrodes. LSFTi 91 also exhibits eminent oxygen reduction reaction and hydrogen oxidation reaction (ORR and HOR) activities, with R p of 0.022 and 0.15 Ω cm2 in air and wet H2, respectively. The peak power density of SOFC could reach 847 mW cm–2 at 800 °C. In addition, good reversibility is confirmed in the cyclic operation of SOFC and SOEC.

Enhancing the oxygen reduction reaction activity and durability of a double-perovskite via an A-site tuning

“…2f) [4,29,30]. The peak at around 528.7 eV is assigned to the lattice oxygen (O lat ), and the peak at around 530.8 eV is corresponding to the surface adsorbed oxygen (O ads , including O 2− , O − , and OH − ), relating to the surface defect [31]. The peak at around 531.8 eV is attributed to hydroxyl groups or carbonate adsorbed on the surface.…”

“…The peaks of 779.7 and 795.0 eV are assigned to Ba 2+ in the perovskite or the surface carbonate [34]. Two sets of peaks belonging to Co 4+ (2p 3/2 at around 781.3 eV and 2p 1/2 at around 797.0 eV) and Co 3+ (2p 3/2 at around 777.8 eV and 2p 1/2 at around 793.0 eV) are obtained by deconvolution [31][32][33][34][35][36]. Two weak satellite peaks are attributed to Co 3 O 4 (a mixed state of Co 2+ and Co 3+ ), indicating a small amount of Co 2+ is on the surface of the BGPC sample [37,38].…”

Electrochemical Reduction of CO2 with Exsolved Metal–Oxide Interfaces in a Proton-Conducting Solid Oxide Electrolyzer

“…Solid oxide electrolytic cells (SOECs) have been widely investigated for the high efficiency in converting electrical energy to chemicals. Current research also focuses on promoting the key components of SOEC to accelerate wide practical implementation. , On the basis of this, SOECs focus on material developments, technical approaches, and improvement strategies, such as nanocomposite, surface/interface, and nanocomposites. The cathode material for the CO 2 reduction reaction is the porous metal material closely contacting the surface of the SOEC electrolyte .…”

Co-improving the electrocatalytic performance and H2S tolerance of a Sr2Fe1.5Mo0.5O6−δ based anode for solid oxide fuel cells

“…Mixed ionic electronic conductors (MIECs), with dual oxygen ion and electron conductivities, especially perovskite metal oxides, such as ABO 3 , A 2 BB′O 6− δ and AA′B 2 O 5+ δ , have received significant research attention in the past few decades. 6–8 The B-site of the perovskite oxide is usually occupied by one or more transition metals (Ti, Cr, Mn, Fe or Mo), such as La 1− x Sr x TiO 3+ δ , 9,10 La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3− δ , 11 PrBaMn 2 O 5+ δ , 12 Sr 2 MgMoO 6− δ (ref. 13) and Sr 2 Fe 1.5 Mo 0.5 O 6− δ .…”