Shear Performance at Room and High Temperatures of Glass⁻Ceramic Sealants for Solid Oxide Electrolysis Cell Technology.

Hassan Javed,Milena Salvo,Enrico Bernardo,Martina Halasova,Antonio Sabato,Kai Herbrig,Ivo Dlouhy,Federico Smeacetto,Christian Walter

doi:10.3390/ma12020298

Abstract

To provide a reliable integration of components within a solid oxide electrolysis cell stack, it is fundamental to evaluate the mechanical properties of the glass–ceramic sealing materials, as well as the stability of the metal–glass–ceramic interface. In this work, the mechanical behavior of two previously developed glass–ceramic sealants joined to Crofer22APU steel is investigated at room temperature, 650 °C, and 850 °C under shear load. The mechanical properties of both the glass–ceramics showed temperature dependence. The shear strength of Crofer22APU/glass–ceramic/Crofer22APU joints ranged from 14.1 MPa (20 °C) to 1.8 MPa (850 °C). The elastic modulus of both glass–ceramics also reduced with temperature. The volume fraction of the crystalline phases in the glass–ceramics was the key factor for controlling the mechanical properties and fracture, especially above the glass-transition temperature.

Highlights

Solid oxide electrolysis cells (SOECs) are a promising technology to produce hydrogen through the electrolysis of water
Mechanical testing in shear conditions performed at room temperature, 650 ◦ C and 850 ◦ C enabled
Mechanical testing in shear conditions performed at room temperature, 650 °C and 850 °C

Summary

Introduction

Solid oxide electrolysis cells (SOECs) are a promising technology to produce hydrogen through the electrolysis of water. Among the various components of an SOEC stack, the stability and performance of the glass–ceramic sealants are key factors to determine and control the overall efficiency of the system [1,2]. Because of the operational thermal regime of the whole stack, the joined components are subjected to the change of the acting stress, from almost compressive and/or tensile to almost shear. In laminate structures, this means that the SOEC materials, and their interfaces often play a crucial role [3,4]. If the stresses increase to a critical level, either debonding at the Crofer22APU/glass–ceramic sealant interface or within the glass–ceramic can occur, causing gas leakage. Besides the thermal, chemical, thermomechanical and electrical stability of glass sealants, it is important to analyze their

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Conclusion