A novel electrode with multifunction and regeneration for highly efficient and stable symmetrical solid oxide cell

Abstract

Symmetrical solid oxide cells (SSOCs) have been extensively recognized due to their simple cell configuration, low cost and reliability. High performance electrode is the key determinant of SSOCs. Herein, a multifunctional perovskite oxide La0.6Ca0.4Fe0.8Ni0.2O3-δ (LCaFN) is investigated as electrode for SSOCs. The results confirm that LCaFN shows excellent oxygen reduction reaction (ORR), oxygen evolution reaction (OER), carbon dioxide reduction reaction (CO2-RR) and hydrogen oxidation reaction (HOR) catalytic activity. In SOFC mode, the SSOCs with LCaFN achieve good electrochemical performance with maximum power density of 300 mW cm -2 at 800 °C. For pure CO2 electrolysis in SOEC mode, polarization resistance of 0.055 Ω cm 2 and current density of 1.5 A cm -2 are achieved at 2.0 V at 800 °C. Besides, the cell shows excellent stability both in SOFC mode and SOEC mode.Most importantly, SSOCs with symmetrical LCaFN electrodes show robust and regenerative performance under anodic or cathodic process during the switching gas, showing the great reliability of the SSOCs. The results show that this novel electrode offers a promising strategy for operation of SSOCs.

Electrochemical Reduction of CO2 using Solid Oxide Electrolysis Cells: Insights into Catalysis by Nonstoichiometric Mixed Metal Oxides

“…Simple perovskites (ABO 3 ) are the most commonly investigated nonstoichiometric mixed ionic and electronic conducting oxides for electrochemical CO 2 reduction. ,,− It is well established that the B-site transition-metal cations in these oxides are responsible for the catalytic activity and electron transfer. − B-site cations are highly hybridized with the surrounding oxygen anions in BO 6 octahedra . Due to B-site hybridization with lattice oxygen, oxygen vacancies interact with the B-site to promote the adsorption and activation of CO 2 on the surface.…”

“…Alternatives have been proposed to lower the SOEC operating temperatures, such as Sc 2 O 3 -stabilized ZrO 2 (SSZ), Sr- and Mg-doped LaGaO 3 (La 1– x Sr x Ga 1– y Mg y O 3 , LSGM), which exhibit much higher ionic conductivities between 400 and 800 °C as compared to YSZ. However, these oxides present different challenges related to their instability and cost. , Buffer/protecting layers have been added between the electrode and these electrolytes to minimize their instability. − …”

Phase transition with in situ exsolution nanoparticles in the reduced Pr0.5Ba0.5Fe0.8Ni0.2O3−δ electrode for symmetric solid oxide cells

“…Therefore, these devices can be used to rapidly switch between SOFC and SOEC modes. 12 Because of this enormous potential, SSOCs have captured increasing interest in research and development. Electrodes need to be electrochemically active towards several reactions.…”

Enhanced Electrochemical Performance of the Fe-Based Layered Perovskite Oxygen Electrode for Reversible Solid Oxide Cells

“…Because the iron ion has many similar physicochemical properties to the cobalt ion, Fe-based perovskites have been extensively investigated. These materials are supposed to be more stable than cobalt-based oxides and more adaptive to the widely used electrolyte due to matching TEC (12–18 × 10 –6 K –1 ) . Among these, Fe-based A-site ordered double perovskites LnBaFe 2 O 5+δ (LnBFO, Ln = La, Pr, Nd, Sm, and Gd) stand out greatly and attract extensive attention owing to their special structure, regarded as a stacking sequence of −[BaO]–[FeO 2 ]–[LnO δ ]–[FeO 2 ]–[BaO]– along the c -axis.…”

“…These materials are supposed to be more stable than cobalt-based oxides and more adaptive to the widely used electrolyte due to matching TEC (12−18 × 10 −6 K −1 ). 19 Among these, Fe-based A-site ordered double perovskites LnBaFe 2 O 5+δ (LnBFO, Ln = La, Pr, Nd, Sm, and Gd) stand out greatly and attract extensive attention owing to their special structure, regarded as a stacking sequence of…”