Comparison of in-situ Raman studies of SOFC with thick single-crystal and thin-film magnetron sputtered membranes

In current work, we conducted comparative studies of electrolyte-supported and anode-supported solid oxide fuel cells by means of electrochemical techniques (studies of I-V curves and impedance spectroscopy) as well as using Raman spectroscopy from the inner interface of the anode electrode and solid electrolyte. Electrolyte-supported (ESC) SOFCs were based on thick single-crystalline 8YSZ anion conductor membrane and had multilayered composite electrodes. Anode-supported cells (ASC) were based on thick two-layered commercially available anode supports, the thin-film electrolyte was deposited using a magnetron sputtering technique. Comparative studies showed a significant dependence of 460 cm−1 Raman peak both on fuel mixture composition and current load applied to the cell. Linear dependences of OCV on normalized peak area gave an opportunity to estimate local anodic overpotential on the current load applied for both SOFC structures. Application of ASC model cells gave an opportunity to significantly extend a range of current loads applied. Analysis of impedance spectra gave the opportunity to study the structure of complex resistance as well as the structure of local anodic overpotential obtained. •Comparative studies ESC/ASC SOFCs via electrochemical techniques and Raman spectroscopy.•Significant dependence of 460 cm−1 peak (GDC sublayer) on fuel composition and current load was shown.•Local anodic overpotential was estimated using dependences of OCV on Raman peak area.•Application of model ASC gave an opportunity to significantly extend a range of current loads.•Impedance spectra showed Raman estimated anode overpotential to be contribution of the fuel oxidation anode reaction.