Study of Temperature Dependence of Electrode–Glass Ceramic Interface Using Impedance Spectroscopy

A commercially available glass-ceramic composition is applied on a ferritic stainless steel (FSS) substrate reproducing a type of interface present in solid oxide fuel cells (SOFCs) stacks. Electrochemical impedance spectroscopy (EIS) is used to study the electrical response of the assembly in the temperature range of 380–780 °C and during aging for 250 h at 780 °C. Post-experiment analyses, performed by means of X-ray diffraction (XRD), and along cross-sections by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis, highlight the microstructural changes promoted by aging conditions over time. In particular, progressive crystallization of the glass-ceramic, high temperature corrosion of the substrate and diffusion of Fe and Cr ions from the FSS substrate into the sealant influence the electrical response of the system under investigation. The electrical measurements show an increase in conductivity to 5 × 10−6 S∙cm−1, more than one order of magnitude below the maximum recommended value.

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ChemInform Abstract: PRESSURE AND TEMPERATURE DEPENDENCE OF THE ELASTIC MODULI OF A LOW-EXPANSION LITHIUM ALUMINIUM SILICATE GLASS-CERAMIC

Chemischer Informationsdienst ◽

10.1002/chin.197550017 ◽

1975 ◽

Vol 6 (50) ◽

Author(s):

KWANG YUL KIM ◽

ARTHUR L. RUOFF

Keyword(s):

Temperature Dependence ◽

Silicate Glass ◽

Glass Ceramic ◽

Elastic Moduli ◽

Lithium Aluminium ◽

Aluminium Silicate

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Temperature Dependence of the Pore Structure in Polyvinylidene Fluoride (PVDF)/Graphene Composite Membrane Probed by Electrochemical Impedance Spectroscopy

Polymers ◽

10.3390/polym10101123 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1123 ◽

Cited By ~ 7

Author(s):

Qizhao Luo ◽

Qing Huang ◽

Zhe Chen ◽

Lei Yao ◽

Qiuming Fu ◽

...

Keyword(s):

Thermal Stability ◽

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Pore Structure ◽

Temperature Dependence ◽

Composite Membrane ◽

Electrochemical Impedance ◽

Composite Membranes ◽

Graphene Composite ◽

Thermal Stability Of

In this paper, graphene was introduced in the PVDF to improve the thermal stability of the pore structure, which is the key feature for the membrane applied for the thermo-osmotic energy conversion (TOEC) process. The PVDF/graphene composite membranes were characterized by a scanning electron microscopy (SEM), a water contact angle measurement, and electrochemical impedance spectroscopy (EIS). It was found that the composite membranes exhibited improved surface hydrophobicity. Moreover, the pores in pure PVDF membrane would expand during the heat process while the existence of graphene in PVDF clearly suppressed the expansion, which implied better thermal stability of the pores in the composite membrane. According to the pore deformation time, the heat conductivities of the membranes were calculated and compared with each other. It confirmed that the composite membrane with higher graphene content exhibited enhanced heat conductivity. EIS can be used to monitor the temperature dependence of the pore structure in aqueous environments.

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