Thermoelectrics Capabilities
CSIRO Materials Science and Engineering (CMSE)
Dr. Nick Savvides, Dr. Karl Müller, Dr. Haiyan Chen,
Jack Ling, Dr. Dong Chen, Sarah Miller, and Dr.
Howard Lovatt

Motivation
α 2σ
• Figure of merit for thermoelectrics ZT = T
κ
• Current best materials have ZT ~1
• Typical system efficiency 5 - 12%
• ZT ~ 2 would give up to 25% efficiency
• (For reference, current combustion engine efficiency ~25%!)
1.0
ZT: figure of merit
Bi2Te3
0.8 PbTe
0.6
BiSb Si1 xGex
0.4
0.2
0.0 Room temperature
0 200 400 600 800 1000 1200
Temperature (K)
CSIRO. Thermoelectric Capabilities

Materials Research
• Aims of present work
• Prepare fine Mg2Si, Mg2Ge, Mg2Sn and their solid solutions
• Characterize the microstructure, TE prop: α, σ, κ
• Optimize ZT by nanostructuring …..
• Processing
• Ingots & single-crystals
• direct-melting, Bridgman method, zone-melting…
• Dense compacts:
• Reduction to nano-powders, mechanical alloying, hot pressing…
• Characterization
• Microstructure & composition: XRD, SEM, TEM, EDX…
• TE properties: Seebeck, resistivity, thermal conductivity ….
• Device assembly & testing…..
CSIRO. Thermoelectric Capabilities

Seebeck Coefficient
Compound Literature CSIRO
Mg2Si 200 – 500 µV/K 330 – 350 µV/K
Mg2Ge 200 – 700 220 – 360
Mg2Sn 20 – 115 135 – 188
αy Isotropy
Mg2Sn
αx
CSIRO. Thermoelectric Capabilities

Electrical Conductivity
Dramatic increase in electrical conductivity with control of eutectic composition
CSIRO. Thermoelectric Capabilities

Theoretical Materials
Motivation
• No theoretical limit to performance
• Recent reports of experimental
materials with high ZT
CSIRO. Thermoelectric Capabilities

Theoretical Materials
Result
• CSIRO has a provisional patent on a novel material
- offers high ZT ~10
Nanoparticle
Electron Reservoir
~100 nm
Molecular
Quantum Dot
0D ~1 nm
CSIRO. Thermoelectric Capabilities

Genset Waste Heat Recovery
• 30 kW natural gas Genset
• Waste heat from exhaust 18kW
• Target electricity 500W
• FY 07/08: Demonstration unit
Electric Output Expander
+17kW
Condenser
Water Heater
Boiler
Thermoelectric 95°C
-34kW +34kW -30kW
90°C
520°C 150°C 85°C
+17kW
Pump
5.4 L/min
CSIRO. Thermoelectric Capabilities

TEG System in Construction
CSIRO. Thermoelectric Capabilities

Solar Thermoelectric Design and Analysis
• Motivation: To design and evaluate solar thermoelectric
systems suitable for urban, rural and remote locations
• Facilities and Capabilities:
• The National Solar Energy Centre in Newcastle has tracking solar
collector systems including parabolic troughs and heliostat array. A
solar dish is located at Lucas Heights
• The National Solar Energy Centre continuously records accurate
local weather data for system analysis
• Design and analysis of solar thermal systems using the latest tools
and techniques developed by, and in collaboration with, the
international solar thermal community
• Multidisciplinary team of physicists, electrical, electronic,
mechanical and chemical engineers with expertise in optics, fluid
dynamics and thermodynamics
CSIRO. Thermoelectric Capabilities

Concentrating Solar Facilities
CSIRO. Thermoelectric Capabilities

DET Thermoelectric Activities
• Engaging with major engineering company on feasibility of
harnessing energy from the environment, including a low
temperature, non-concentrating, solar powered thermoelectric
device ($70k)
• Performing an techno-economic appraisal of a solar
thermoelectric trough concept
• Evaluating technologies for harnessing energy from the
environment to power sensors. Literature review in progress
CSIRO. Thermoelectric Capabilities

Power Conditioning and Control
Power generation
• Convert/invert voltage
• Need to find maximum power point and convert/invert voltages
CSIRO. Thermoelectric Capabilities

Applications
• Medical hyperthermia/hypothermia
• Energy conservation
• Waste heat energy recovery
• Sensing
• Refrigeration
• Solar thermal power generation
CSIRO. Thermoelectric Capabilities

CSIRO Material Science and Engineering (CMSE)
Dr. Howard C Lovatt
Stream Leader - Energy Conversion Devices
Phone: +61 2 9413 7412
Email: howard.lovatt@csiro.au
Web: www.csiro.au
Thank You
Contact Us
Phone: 1300 363 400 or +61 3 9545 2176
Email: Enquiries@csiro.au Web: www.csiro.au