Redox-stable symmetrical solid oxide fuel cells with exceptionally high performance enabled by electrode/electrolyte diffuse interface

Further optimization of the properties of Pr0.6Sr0.4Fe0.9W0.1O3-δ by Cu-doping as symmetric electrodes for solid oxide fuel cells

Superior electrochemical performance of non-precious Co-Ni-Mo alloy catalyst-impregnated Sr2FeMoO6-δ as an electrode material for symmetric solid oxide fuel cells

Mo-doped Pr0.6Sr0.4Fe0.8Ni0.2O3-δ as potential electrodes for intermediate-temperature symmetrical solid oxide fuel cells

Efficient and stable symmetrical solid oxide fuel cell via A-site non-stoichiometry

Enhanced redox-stable Sm0.5Sr0.5FeO3-δ electrode material for symmetric solid oxide fuel cells at reduced temperatures

In this work, La1−xSrxNi0.4Fe0.6O3-δ (0 ≤ x ≤ 0.2) oxides were synthesized and employed as the identical electrode of direct methane symmetrical solid oxide fuel cell (SSOFC). In addition, the phase structure, redox stability, electrical conductivity, chemical compatibility, and thermal expansion of La1−xSrxNi0.4Fe0.6O3-δ oxides were evaluated. The La2NiO4 phase occurs when the amount of doped Sr rises to 0.2. The composition of La0.9Sr0.1Ni0.4Fe0.6O3-δ (LSNF9146) boasts the highest conductivity of 463 S cm−1 with lowest activation energy of 0.066 eV as well as a relatively large thermal expansion coefficient. After treatment in methane for 10 h, the LSNF9146 oxide exhibits 33% lower carbon deposition than the LaNi0.4Fe0.6O3-δ (LNF46) oxide. Moreover, the impregnated LSNF9146 electrode demonstrates lower polarization resistance in both air and methane atmospheres. SSOFCs with impregnated LSNF9146 and LNF46 identical composite electrodes have the maximum power densities of 233 and 170 mW cm−2 at 850 °C in methane, respectively. These results prove that LSNF9146 is a promising symmetrical electrode with high catalytic activity, good redox stability, and coking resistance to direct methane SSOFCs.

Here, we report a new perovskite oxide with formula Sm0.8Sr0.2Fe0.8Ti0.15Ru0.05O3-δ (SSFTR), which exhibits a great potential as a symmetrical electrode material with satisfying stability in both reducing and oxidizing environments. Moreover, SSFTR exhibits good redox and thermal cycle stability. The electrolyte-supported (Sm0.2Ce0.8O1.9, SDC) symmetrical cell with SSFTR electrodes possesses a peak power density of 271 mW·cm-2 at 800 °C in wet H2. Moreover, the peak power density is remarkably improved to 417 mW·cm-2 when applying A-site-deficient perovskite oxide Sm0.7Sr0.2Fe0.8Ti0.15Ru0.05O3-δ as the symmetrical electrode, benifiting by the in situ-exsolved Ru nanoparticles with excellent electrocatalytic activity, since A-site deficiency can provide additional driving force for the exsolution of B-site cations upon reduction. As an ingenious approach, this exsolution of electrocatalytically active nanoparticles on the surface of electrode may be applicable to the development of other excellent performance electrodes for symmetrical SOFCs and other electrochemical systems.

Solid oxide fuel cells (SOFCs) offer a significant advantage over other fuel cells in terms of flexibility in the choice of fuel. Ammonia stands out as an excellent fuel choice for SOFCs due to its easy transportation and storage, carbon-free nature and mature synthesis technology. For direct-ammonia SOFCs (DA-SOFCs), the development of anode catalysts that have efficient catalytic activity for both NH3 decomposition and H2 oxidation reactions is of great significance. Herein, we develop a Mo-doped La0.6Sr0.4Fe0.8Ni0.2O3-δ (La0.6Sr0.4Fe0.7Ni0.2Mo0.1O3-δ, LSFNM) material, and explore its potential as a symmetrical electrode for DA-SOFCs. After reduction, the main cubic perovskite phase of LSFNM remained unchanged, but some FeNi3 alloy nanoparticles and a small amount of SrLaFeO4 oxide phase were generated. Such reduced LSFNM exhibits excellent catalytic activity for ammonia decomposition due to the presence of FeNi3 alloy nanoparticles, ensuring that it can be used as an anode for DA-SOFCs. In addition, LSFNM shows high oxygen reduction reactivity, indicating that it can also be a cathode for DA-SOFCs. Consequently, a direct-ammonia symmetrical SOFC (DA-SSOFC) with the LSFNM-infiltrated doped ceria (LSFNM-SDCi) electrode delivers a superior peak power density (PPD) of 487 mW cm-2 at 800 °C when NH3 fuel is utilised. More importantly, because Mo doping greatly enhances the reduction stability of the material, the DA-SSOFC with the LSFN-MSDCi electrode exhibits strong operational stability without significant degradation for over 400 h at 700 °C.

Ta-doped PrBaFe2O5+δ double perovskite as a high-performance electrode material for symmetrical solid oxide fuel cells

Symmetrical solid oxide fuel cells (SSOFCs) represent a promising path towards energy conversion and storage solutions characterized by reduced material costs, simplified manufacturing, and improved operational stability.

Composite electrodes of Ti-doped SrFeO3-δ and LSGMZ electrolytes as both the anode and cathode in symmetric solid oxide fuel cells

The structure stability, conductivity and electrochemical properties of Cr-substituted La0.3Sr0.7FeO3-δ SOFC electrode materials were investigated in this work, primarily for application in symmetrical solid oxide fuel cells. Cr substitution, giving La0.3Sr0.7Fe1-xCrxO3-δ (LSFC, x = 0, 0.2, 0.3), remarkably improves the phase stability of La0.3Sr0.7FeO3-δ materials in reducing atmospheres and their redox tolerance in varying atmospheres. Symmetrical half-cells employing La0.3Sr0.7Fe0.8Cr0.2O3-δ on La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) electrolyte supports exhibit electrode polarization resistances (RP) of as low as 0.25 Ω•cm2 in air and 0.45 Ω•cm2 in humidified H2 at 750oC. Maximum power densities of 0.30 W/cm2 (800oC) and 0.22 W/cm2 (750oC) were obtained for a symmetrical single cell using humidified H2/air. The excellent anodic and cathodic electrochemical performance of LSFC is thought to be due to its high electrical conductivity (180 and 0.43 S•cm-1 at 700oC in air and 10%H2+N2, respectively) and good ionic conductivity.

Today, the development of active and stable catalysts still represents a challenge to be overcome in the research field of low-temperature fuel cells.[...]

If the necessary infrastructure can be provided, a practical future electric vehicle will be an efficient hydrogen-powered hybrid operating on a polymer fuel cell. Light weight, lowest cost and high efficiency imply an atmospheric pressure, rather than a pressurized, system. Polymer fuel cells require humidification for ionic conductivity, which means that product water is normally rejected as liquid. Atmospheric pressure systems of this type are difficult to operate. A self-humidified atmospheric pressure system operating at higher temperature (about 75-80 °C) on oxygen-enriched air rejecting product water in the vapour phase is described. It combines the advantages of unpressurized operation with the higher power density of a pressurized system, but with much lower parasitic power requirements.

In this study, the electrochemical performance of a single phase, mixed ion and electron conducting (MIEC) Ce0.8Y0.1Mn0.1O2-δ (10CYMO) anode was evaluated using symmetrical half-cell and full-cell configurations under humidified H2, 10 ppm H2S/H2, and CH4. An yttria-stabilized zirconia (YSZ) electrolyte support layer was used in this work, as ac impedance spectroscopy revealed that the 10CYMO/YSZ/10CYMO cell gave the lowest area specific polarization resistance (ASR) of 0.23 Ωcm2 at 800°C in wet H2, compared to La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) and Zr0.89Sc0.1Ce0.01O2-δ (ScSZ). Exposure of the 10CYMO anodes to 10 ppm H2S/H2, either in a half-cell or full cell configuration, showed slight enhancement on the electrochemical performance, which was explained using a concept describing the sulfur and ceria interaction. The performance of a 10CYMO/YSZ/La0.8Sr0.2MnO3-δ _ YSZ full cell was evaluated under 90%H2-N2/3%H2O, giving a power density of 75 mW/cm2 at 800°C and is better than seen for other fluorite-based anodes reported in the literature.