Tailoring the Microstructure of a Solid Oxide Fuel Cell Anode Support by Calcination and Milling of YSZ.

Amir Reza Hanifi,Navjot Kaur Sandhu,Thomas H Etsell,Miguel A Laguna-Bercero,Partha Sarkar

doi:10.1038/srep27359

Amir Reza Hanifi, Navjot Kaur Sandhu + Show 3 more

Open Access

https://doi.org/10.1038/srep27359

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Journal: Scientific Reports	Publication Date: Jun 7, 2016
Citations: 39	License type: CC BY 4.0

Affiliation: University of Alberta, Alberta Innovates

Abstract

In this study, the effects of calcination and milling of 8YSZ (8 mol% yttria stabilized zirconia) used in the nickel-YSZ anode on the performance of anode supported tubular fuel cells were investigated. For this purpose, two different types of cells were prepared based on a Ni-YSZ/YSZ/Nd2NiO4+δ-YSZ configuration. For the anode preparation, a suspension was prepared by mixing NiO and YSZ in a ratio of 65:35 wt% (Ni:YSZ 50:50 vol.%) with 30 vol.% graphite as the pore former. As received Tosoh YSZ or its calcined form (heated at 1500 °C for 3 hours) was used in the anode support as the YSZ source. Electrochemical results showed that optimization of the fuel electrode microstructure is essential for the optimal distribution of gas within the support of the cell, especially under electrolysis operation where the performance for an optimized cell (calcined YSZ) was enhanced by a factor of two. In comparison with a standard cell (containing as received YSZ), at 1.5 V and 800 °C the measured current density was −1380 mA cm−2 and −690 mA cm−2 for the cells containing calcined and as received YSZ, respectively. The present study suggests that the anode porosity for improved cell performance under SOEC is more critical than SOFC mode due to more complex gas diffusion under electrolysis mode where large amount of steam needs to be transfered into the cell.

Highlights

Nickel-YSZ is the commonly used anode material in solid oxide fuel cells (SOFCs) due to its high performance at intermediate temperatures
Of particular interest is the distribution of channels along the fuel electrode, especially under solid oxide electrolysis cell (SOEC) mode, as high amounts of steam must be transported[9]
From the comparison of the anodes containing as received Tosoh YSZ or calcined YSZ, the following conclusions can be drawn: 1. The anode containing as received Tosoh YSZ had less porosity (33%) compared with the anode containing calcined-milled YSZ (46%)

Summary

Introduction

Nickel-YSZ is the commonly used anode material in solid oxide fuel cells (SOFCs) due to its high performance at intermediate temperatures. Ebbesen et al.[13] studied this effect in Ni-YSZ anode supported cells with different porosity (28% and 34%) They found that changing the porosity of the support structure results in a change in the Ni–YSZ TPB resistance and a significant change in the low frequency concentration related resistance at high current densities. They observed increased polarization in EC-mode while decreasing the porosity shows that diffusion limitations cannot be neglected for support structures with porosities below 30% (with a support thickness of 300 μm). The aim of the current study is to investigate the influence of Sample TY before reduction TY after reduction CY before reduction CY after reduction

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