Enhanced cathodic activity by tantalum inclusion at B-site of La0.6Sr0.4CO0.4Fe0.6O3 based on structural property tailored via camphor-assisted solid-state reaction

Abstract

Lanthanum strontium cobalt ferrite (LSCF) is an appreciable cathode material for solid oxide fuel cells (SOFCs), and it has been widely investigated, owing to its excellent thermal and chemical stability. However, its poor oxygen reduction reaction (ORR) activity, particularly at a temperature of ⩽ 800 °C, causes setbacks in achieving a peak power density of > 1.0 W·cm−2, limiting its application in the commercialization of SOFCs. To improve the ORR of LSCF, doping strategies have been found useful. Herein, the porous tantalum-doped LSCF materials (La0.6Sr0.4Co0.4Fe0.57Ta0.03O3 (LSCFT-0), La0.6Sr0.4Co0.4Fe0.54Ta0.06O3, and La0.6Sr0.4Co0.4Fe0.5Ta0.1O3) are prepared via camphor-assisted solid-state reaction (CSSR). The LSCFT-0 material exhibits promising ORR with area-specific resistance (ASR) of 1.260, 0.580, 0.260, 0.100, and 0.06 Ω·cm2 at 600, 650, 700, 750, and 800 C, respectively. The performance is about 2 times higher than that of undoped La0.6Sr0.4Co0.4Fe0.6O3 with the ASR of 2.515, 1.191, 0.596, 0.320, and 0.181 Ω·cm2 from the lowest to the highest temperature. Through material characterization, it was found that the incorporated Ta occupied the B-site of the material, leading to the enhancement of the ORR activity. With the use of LSCFT-0 as the cathode material for anode-supported single-cell, the power density of > 1.0 W·cm−2 was obtained at a temperature < 800 °C. The results indicate that the CSSR-derived LSCFT is a promising cathode material for SOFCs.

Revealing the detrimental CO2 reduction effect of La0.6Sr0.4FeO3-δ-derived heterostructure in solid oxide electrolysis cells

“…Compare with fresh samples the powders calcined at 1300°C just exhibited slightly different crystallinity and had no effect on the conductivity test. 41 The electrical conductivity of LSF and LSF8 samples in an oxidizing atmosphere and reducing atmosphere both reveal a transition from semiconductor-like to metal-like behavior 42 , 43 , 44 ( Figures 2 C and S7 ), i.e., the electrical conductivity first increases with increasing temperature until it reaches a maximum, then decreases with temperature subsequently. In addition, the electrical conductivity of RP-LSF is almost negligible compared to LSF.…”

Understanding the phase stability of yttria stabilized zirconia electrolyte under solid oxide electrolysis cell operation conditions

“…2,3 Among these methods, solid oxide electrolysis cells (SOECs) in water electrolysis technology operate at relatively high temperatures and have demonstrated potential for more efficient hydrogen production compared to alkaline and polymer electrolysis systems. [4][5][6][7] While numerous studies have reported the high performance of water electrolysis, ensuring the long-term stability of SOECs remains a challenge. 8 Efforts to mitigate degradation are crucial for developing highly efficient water electrolysis systems.…”

Superior Durability and Activity of a Benchmark Triple‐Conducting Cathode by Tuning Thermo‐Mechanical Compatibility for Protonic Ceramic Fuel Cells

“…[3][4][5][6][7][8][9][10] However, owing to the deficient protonconducting properties of MIEC cathode materials, the active site of cathodes is limited to a triple-phase boundary (TPB), which is the interface between cathodes and electrolytes. [11][12][13][14] Therefore, one of the basic requirements for highly active PCFC cathodes is the ability of conducting O 2− , H + , and e − at the same time, extending the active site to the entire cathode. [11,[15][16][17]18] Duan et al developed a new type of highly active triple conductive material, BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3−𝛿 (BCFZY), for PCFC cathodes, which showed excellent performance at medium temperatures (e.g., the area-specific resistance (ASR) was only 0.09 Ω cm 2 at 600 °C).…”

“…[ 3–10 ] However, owing to the deficient proton‐conducting properties of MIEC cathode materials, the active site of cathodes is limited to a triple‐phase boundary (TPB), which is the interface between cathodes and electrolytes. [ 11–14 ] Therefore, one of the basic requirements for highly active PCFC cathodes is the ability of conducting O 2− , H + , and e − at the same time, extending the active site to the entire cathode. [ 11,15–17,18 ]…”