Agro-waste ash and mineral oxides derived glass-ceramics and their interconnect study with Crofer 22 APU for SOFC application

摘要

In this study, silicate glass-ceramic is synthesized from wheat straw ash (WSA) using melt-quench technique. Xray diffraction is done to confirm the nature of the as-quenched samples. Inductive coupled plasma-mass spectroscopy (ICP-MS) and energy dispersive spectroscopy (EDS) are performed to evaluate the exact chemical composition of the as-prepared samples. Similar composition is also melted using conventional mineral oxides for comparison with WSA sample. The WSA sample shows good thermal stability in temperature range of 300-900 degrees C. The coefficient of thermal expansion (CTE) of WSA sample is more or less in the required range for solid oxide fuel cells (SOFC) application. The powder of WSA derived glass-ceramic is used to form the diffusion couple with the interconnect (Crofer 22 APU) for interfacial study. The excellent adhesion with the smooth and porosity-free interface is formed between glass-ceramic and Crofer 22 APU, when WSA is used as a sealant as compared to the mineral based glass-ceramics. Semi-coherent interface does not show any delimitation or separation even after five thermal cycles. The micro hardness (384 HV) of the interface is indicated good bonding between interconnect and glass-ceramic.