Combined Thermal Imaging and X-ray
Diffraction of Solid Oxide Fuel Cells at
Operating Temperature with Thermal
Gradients
James B. Robinson, Dr. Dan Brett, Dr. Paul Shearing
james.robinson.11@ucl.ac.uk
Electrochemical Innovation Laboratory
Department of Chemical Engineering
The Hydrogen & Fuel Cell Researcher Conference – UoB, 16th December 2013
Overview
• Introduction
– Thermal Imaging
– Solid Oxide Fuel Cells
• Experimental Design
– Furnace Design
– Obtaining Thermal Gradients & X-ray Diffraction
• Effect of Thermal Gradients on Ni/YSZ Anodes
1
What is Thermal Imaging?
• Measurement of Heat or a Property of Heat
• Everything above 0K emits infrared
• Quantity of Infrared Incident is Calibrated to Give a
Temperature
• Enables non-contact measurement
• Heavily property dependent
• Emissivity
• Transmittivity
• Reflectivity
2
Where is Thermal Imaging Used?
Quality Control
Fire Fighting
Law
Enforcement
Energy Efficiency
Medicine
Border Security
All images from FLIR ATS
Sport
3
Emissivity…The Major Challenge
4
Combined Infrared & X-Ray Diffraction of
SOFC Anodes with Thermal Gradients
• SOFC’s considered promising Future Energy Source
• High Electrical Efficiency
• ‘Zero’ Emissions
• Composed of 3 Layers
• Cathode – LSCF, LSM….
• Electrolyte – YSZ, CGO
• Anode – Cermet (Ni/YSZ)
• Thermal Management Amongst Most Important Factors
• Degradation Avoidance
• Efficient Operation
• Failure Avoidance
5
Combined Infrared & X-Ray Diffraction of
SOFC Anodes with Thermal Gradients
• SOFC’s High Temperature Operation May Result in Large Gradients
• Associated with Cracking & Failure of Cells
• Gradients Greater than 104 K m-1 Reported1
• Creep Observed in Ni/YSZ Anodes Due to 8YSZ Matrix
• Deformed Ni due to the Constraints of YSZ
• Limited in-Situ Work Performed on Synchrotron
• Redox Cycling2
• Residual Stresses3
• Microstructural Characterisations4
1
Severson & Assadi, Jour. Fuel Cell Sci. & Tech., 10 (6) (2013)
Sumi et al., Jour. Fuel Cell Sci. & Tech., 3 (1) (2005)
3 Vilanova et al., Jour. Appl. Crystallography, 45 (5) (2012)
4 Shearing et al., Electrochem. Comms. 12 (8) (2010)
2
6
Combined Infrared & X-Ray Diffraction of
SOFC Anodes with Thermal Gradients
Furnace Base
Furnace Top
7
IR & XRD of SOFC Anodes – Furnace Design
8
XRD of SOFC Anodes – Thermal Gradients
• Temperatures Averaged Over Full Scan Duration (30 mins)
• Isothermal in Beam Path (90° Direction), Enabling Analysis at Constant
Temperature
9
Acknowledgments
•
•
•
•
•
Dami Taiwo
Rhodri Jervis
Leon Brown
Sam Cooper
Toby Neville
•
•
•
•
•
Dr. David Eastwood
Dr. Christina Reinhard
Dr. Jay Millichamp
Dr. Tom Mason
Prof. Peter Lee
Thanks For Listening…
Any Questions?