In situ, simultaneous thermal imaging and infrared molecular emission studies of solid oxide fuel cell electrodes

Abstract

Various in situ probes of solid oxide fuel cells (SOFCs) have advanced recently to provide detailed, real time data regarding materials and chemical processes that relate to device performance and degradation. These techniques offer insights into complex fuel chemistry at the anode in particular, especially in the context of model predications. However, cell-to-cell variations can hinder mechanistic interpretations of measurements from separate, independent techniques. The present study describes an in situ technique that for the first time simultaneously measures surface temperature changes using near infrared thermal imaging and gas species using Fourier-transform infrared emission spectra at the anodes of operating SOFCs. Electrolytesupported SOFCs with Ni-based anodes are operated at 700 °C with internal, dry-reformed methane at 75% maximum current and at open circuit voltage (OCV) while electrochemical and optical measurements are collected. At OCV, more cooling is observed coincident with more CO reforming products. Under load, CO is depleted while the anode cools less, especially near the current collectors. The extent of cooling is more sensitive to polarization for electrolytesupported cells because their anodes are thinner relative to anode-supported cells. This study exemplifies how this duplex technique can be a useful probe of electrochemical processes in SOFCs.

Tailoring SOFC Electrode Microstructures for Improved Performance

“…[51] To obtain chemical information about SOFC electrodes in operando, spectroscopic methods are needed to collect data from a distance due to the high temperature and need for gas environment. [51] To obtain chemical information about SOFC electrodes in operando, spectroscopic methods are needed to collect data from a distance due to the high temperature and need for gas environment.…”

“…The various microscopy and spectroscopic methods that have been used to study conventional SOFC electrodes in situ or in operando are covered elsewhere . To obtain chemical information about SOFC electrodes in operando, spectroscopic methods are needed to collect data from a distance due to the high temperature and need for gas environment.…”

In situ construction of hetero-structured perovskite composites with exsolved Fe and Cu metallic nanoparticles as efficient CO2 reduction electrocatalysts for high performance solid oxide electrolysis cells

“…39,40 The segregated Sr cations on the perovskite surface are also important for the chemical adsorption of CO 2 molecules. 41,42 A-site alkali and/or alkaline earth oxides such as SrO 41 or CaO 43 on the perovskite surface has been revealed to improve CO 2 adsorption at elevated temperatures, as these metal oxides are alkaline in nature and can adsorb CO 2 , 44 resulting in a highly active surface for CO 2 reduction.…”

Chlorine-Induced Degradation in Solid Oxide Fuel Cells Identified by Operando Optical Methods

“…The same type of commercially available, electrolyte-supported SOFCs were tested using an alumina tube assembly at the Naval Research Laboratory (NRL) designed for operando infrared measurements. , Experimental details for the NIRTI and FTIRES are similar to those in the previous studies using these methods including the recent modification to perform these measurements simultaneously. − Briefly, a calcium fluoride or sapphire window provided optical access to the anode chamber, through which infrared light emitting from the furnace and anode surface passed to a duplex Fourier transform infrared spectrometer and NIR thermal imaging camera. The FTIRES data provide insight into gas composition at the anode by measuring molecularly resolved mid-infrared spectra, while temperature-calibrated NIR thermal images spatially resolve temperature changes at the anode.…”