elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Investigation of Plasma Sprayed and Constrained-Sintered Zirconia Based Electrolytes

Christenn, Claudia and Ansar, Asif (2009) Investigation of Plasma Sprayed and Constrained-Sintered Zirconia Based Electrolytes. International Thermal Spray Conference and Exposition 2009 (ITSC 2009), 04.-07. Mai 2009, USA.

Full text not available from this repository.

Abstract

Solid oxide fuel cells (SOFCs) electrochemically convert chemical energy into electrictrical power. A SOFC consists of a porous cathode, a gas tight oxygen ion conductive electrolyte, and a porous anode. The ionic conductivity of usually used yttria-stabilized zirconia (YSZ) electrolyte shows a strong dependency on layer thickness and cell operating temperature. Usually SOFCs operate in a temperature range of 900 to 1000 °C. The current development in SOFCs is focused on reducing the operating temperature below 800 °C. Reduction of cell temperature leads to decrease of ionic conductivity of electrolytes following Arrhenius law. To solve this problem two different ways are possible: a) reducing the thickness of the conventionally used yttria-stabilized zirconia (YSZ) electrolyte by using nanostructured particles as feedstock or b) by using an electrolyte with improved ionic conductivity for IT-SOFCs. Conventional and nanostructured YSZ electrolyte layers were prepared by plasma spraying. As all thermal sprayed coatings contain some porosity, which influences the cell performance, sprayed electrolyte layers were sintered in a second step. Conventional sintering of electrolytes is performed over several hours at temperatures above 1400 °C. Thin sprayed layers were sintered in the temperature range of 800 to 1520 °C. Nanostructured YSZ particles after spraying maintained nanostructure. Nanostructure material assisted in enhancing the kinetics for sintering and grain growth. Coatings of both materials were under compressive stresses. However, it was observed that sintering of free-standing coatings differed from that of coatings on substrates which was explained by theory of constrained sintering. A detailed comparison of sintering behaviour under constrained and non-constrained conditions for conventional and nanostructured YSZ was developed. All constrained sintering measurements were performed in a dilatometer. Sintering properties, microstructure, and conductivity of sprayed and sintered YSZ electrolyte layers were investigated by Scanning electron microscopy, 4-point dc method, and mercury intrusion porosimetry and image analysis.

Item URL in elib:https://elib.dlr.de/61240/
Document Type:Conference or Workshop Item (Speech)
Title:Investigation of Plasma Sprayed and Constrained-Sintered Zirconia Based Electrolytes
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Christenn, ClaudiaTTUNSPECIFIED
Ansar, AsifTTUNSPECIFIED
Date:May 2009
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:Plasma spraying, Solid oxide fuel cell, Electrolyte, YSZ, Sintering
Event Title:International Thermal Spray Conference and Exposition 2009 (ITSC 2009)
Event Location:USA
Event Type:international Conference
Event Dates:04.-07. Mai 2009
Organizer:German Welding Society (DVS), ASM Thermal Spray Society (TSS), and the International Institute of Welding (IIW)
HGF - Research field:Energy
HGF - Program:Efficient Energy Conversion (old)
HGF - Program Themes:E BZ - Fuel cells (old)
DLR - Research area:Energy
DLR - Program:E BZ - Fuel cells
DLR - Research theme (Project):E - Hochtemperatur-Brennstoffzellen (old)
Location: Stuttgart
Institutes and Institutions:Institute of Engineering Thermodynamics > Electrochemical Energy Technology
Deposited By: Christenn, Claudia
Deposited On:03 Dec 2009 14:02
Last Modified:03 Dec 2009 14:02

Repository Staff Only: item control page

Browse
Search
Help & Contact
Information
electronic library is running on EPrints 3.3.12
Copyright © 2008-2017 German Aerospace Center (DLR). All rights reserved.