ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Xiaoxin Zhang,Yanping Zheng,Zhenfa Ding,Guangming Yang,Xiao Xiao,Meilan Peng,Mengjie Wu,Jianhui Li,Jun Liu,Abdullah Alodhayb,Xianzhu Fu,Zongping Shao,Yifei Sun
The poor temperature activity and durability due to surface Sr segregation are two main challenges restricting the practicability of state-of-the-art La1–xSrxCo1–yFeyO3 (LSCF) air electrodes for solid oxide electrochemical cells (SOCs). This article reports the recent discovery to unleash the constraints of performance and stability by constructing a novel nanofiber air electrode consisting of a LSCF host and GDC guest in nanoscale intertwined moiety (LSCF/GDC NF). The electrical conductivity relaxation and distribution of relaxation time results collectively disclosed the boosted surface oxygen exchange rate by two orders of magnitude at moderate SOC operation conditions (600 °C), as compared to commercial LSCF (1.01 × 10–3 cm s–1 vs 4.1 × 10–5 cm s–1). As a result, the electrochemical performance was synchronically promoted by over 5-fold (0.12 Ω·cm2 vs 0.64 Ω·cm2). Moreover, the interval stability test over 200 h in switching atmospheres (air/H2O/CO2) buttresses the superb robustness of LSCF/GDC NF with an extremely slow deactivation rate of 1.79 × 10–6 Ω·cm2 h–1 and nondetectable top-surface Sr segregation, collectively affirmed by X-ray photoelectron spectroscopy and low-energy ion scattering spectra. At atomic scale, the operando X-ray diffraction results preliminarily unravel that the formation of intertwined moiety employs the compressive strain on LSCF, which maintains the length of Sr–O against thermoinduced elongation. In addition, systemically, XPS and density functional theory simulation results prove the thermodynamically favored formation of oxygen vacancies at the biphase boundary in LSCF/GDC NF and raised the energy barrier for the formation of an intrinsic vacant Sr site. This study provides a practical and facile strategy to engineer the air electrode with enhanced performance and durability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
IONICS
·
2024
·
IF 2.4
Wang Lei,Tian Yanting,Li Zhanfeng,Zhu Jiping,Bian Tianlong
La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (LSCF) perovskite with good stability and high oxygen diffusion coefficient has been extensively studied as oxygen electrode in reversible solid oxide cells (RSOCs). Significant promotion of oxygen reaction kinetics of the LSCF oxygen electrode was achieved by the addition of Ca x Co 4 O 9+δ (CCOx, x = 3, 1.5) nano-catalysts in the present study. The La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ -Ca 1.5 Co 4 O 9+δ (LSCF-CCO1.5) electrode exhibited the optimal electrochemical property among the LSCF-based electrodes and the lowest polarization resistance ( R p ) of 0.039 Ω·cm 2 was attained at 800 °C, which was ~ 97% lower than that of the LSFM electrode. Furthermore, the LSCF-CCO1.5 oxygen electrode also manifested excellent thermal cycling stability and alternating polarization durability. The hydrogen production rate of the LSCF-CCO1.5 electrolytic cell was 946 mL·cm −2 ·h −1 at 1.5 V at 800 °C, which was 2.6 times higher than that of the LSCF cell (362 mL·cm −2 ·h −1 ). The results certified the enhancement of electrochemical properties for LSCF oxygen electrode by the addition of CCOx nano-catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2022
·
IF 4.632
Rui Yang,Yunfeng Tian,Yun Liu,Jian Pu,Bo Chi
To promote the electrocatalytic activity and stability of traditional La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3– δ (LSCF) oxygen electrodes in reversible solid oxide cells (RSOCs), conventional physical mixed method was used to prepare the Pd-LSCF composite oxygen electrode. The cell with Pd-LSCF|GDC|YSZ|Ni-YSZ configuration shows perfect electrochemical performance in both solid oxide fuel cell (SOFC) mode and solid oxide electrolysis cell (SOEC) mode. In the SOFC mode, the cell achieves a power density of 1.73 W/cm 2 at 800 °C, higher than that of the LSCF oxygen electrode with 1.38 W/cm 2 . In the SOEC mode, the current density at 1.5 V is 1.67 A/cm 2 at 800 °C under 50 vol% steam concentration. Moreover, the reversibility and stability of the RSOCs were tested during 192 h long-term reversible operation. The degradation rate of the cell is only 2.2%/100 h and 2.5%/100 h in the SOEC and the SOFC modes, respectively. These results confirm that compositing Pd with the LSCF oxygen electrode can considerably boost the electrochemical performance of LSCF electrode in RSOCs field.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2021
·Vol. 15
·期 4
·3264-3272
·
IF 8.897
Cai Changkun,Xie Manyi,Xue Ke,Shi Yu,Li Shuting,Liu Yuanyuan,An Shengli,Yang Hong
La 06 Sr 04 Co 02 Fe 08 O 3− δ (LSCF) is recognized as one of the most promising cathode materials for the highly-desired intermediate-temperature solid oxide fuel cell (IT-SOFC) technology. However, it is still challenged by polarization losses due to reduced operation temperatures. In this work, a series of Ba 2+ -doped La 0.6− x Ba x Sr 0.4 Co 0.2 Fe 0.8 O 3− δ (LBSCF x, x = 0.05, 0.10, 0.15, and 0.20) materials are successfully synthesized and their electrochemical performances are evaluated as a cathode for IT-SOFC technology. The study shows that, compared to the un-doped LSCF, the Ba 2+ -doped LBSCF possess higher electrical conductivities at 500–800 °C and display lower polarization resistances to oxygen adsorption/dissociation. As a result, the Ni-SDC|SDC|LBSCF0.20 cell (SDC = samarium-doped cerium, Sm 0.2 Ce 0.8 O 1.9 ) delivers a high maximum power density of 0.704 W/cm 2 at 750 °C, which is > 30% higher than the Ni-SDC|SDC|LSCF cell. This work reveals that Ba 2+ -doping is effective in enhancing oxygen catalytic activity of LSCF-based cathode materials, demonstrating a new and commercial-feasible strategy in developing high performance cathode materials for the IT-SOFC technology.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2026
·
IF 8.3
Jinjun Hu,Wei Meng,Shuang Qi,Ling Wang,Weiwei Meng,Yuehua Li,Lei Dai
Conventional sensing of nitrogen oxide (NO) is based on charge transfer reactions that occur exclusively at the triple-phase boundaries (solid electrolyte/sensing electrode/NO, TPBs). Here, an interface-engineered strategy is proposed to overcome this limitation by constructing a bidirectional mixed ionic-electronic conducting (MIEC) architecture. By modifying a porous YSZ scaffold with NiO to introduce an electron-conducting phase, a mixed conductive heterogeneous porous framework, NiO-YSZ, was formed. Subsequently, La 0.8 Sr 0.2 Co 0.2 Fe 0.8 O 3-δ (LSCF) active sensing phase was incorporated into this framework via an impregnation method, ultimately resulting in a 3D composite sensing electrode (LSCF-NiO-YSZ) that possesses both ionic and electronic conductivity. This design expands the active site region beyond TPBs and enables more efficient charge transfer. The influence of YSZ/NiO mass ratios was systematically examined, and sensors based on NiO-modified YSZ exhibited markedly higher response values and improved sensitivity compared to pristine YSZ. The optimal composition (YSZ/NiO = 5:5) delivered a sensitivity of 10.29 °·decade −1 with excellent reproducibility and selectivity at 500°C and 0.1 Hz. These results highlight interface conduction engineering as an effective route for achieving high-performance impedancemetric NO sensors.
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Jin Li,Xin Zhou,Congcong Wu,Li Zhao,Binghai Dong,Shimin Wang,Bo Chi
Challenged by the surface strontium (Sr) enrichment, long-term stability of the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) cathode remains to be the most intractable problem hindering its further development and application in solid oxide fuel cells (SOFCs). To enhance the durability and performance of LSCF-based electrodes, we propose a novel approach by introducing a highly active A-site deficient La 0.95 CoO 3-δ (LC95) thin film onto the surface of the porous LSCF scaffold, simultaneously working as the accepter for Sr diffusion and conformal collector for electrons conduction. Besides the inhibiting effect from the dense coating, the A-site deficiencies reserved in coating lattice enable promising stabilization for Sr diffusion and segregation. At 700 °C, the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ @La 0.95 CoO 3-δ (LSCF@LC95) hybrid cathode shows a polarization resistance of 0.28 Ωcm 2 , much lower than that for pristine LSCF cathode (0.36 Ωcm 2 ). In addition to the higher electrochemical activity, single cell with LSCF@LC95 cathode exhibits remarkable long-term stability without detectable degradation over 120 h.
研究领域:
材料科学
·
电化学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）