quest for materials for renewable energy...
TRANSCRIPT
Quest for Materials for Renewable Energy Applications
Stefan Stefanoski, Ph.D.
Department of Electrical and Renewable Energy EngineeringOregon Institute of Technology, Wilsonville, OR
May 6, 2016
TECHTalks2016
Quest for Materials for Renewable Energy Applications S. Stefanoski
Background
St. Cyril and Methodius UniversityNatural Sciences and Mathematics
Skopje, MacedoniaBS in Applied Physics (2005)
University of South FloridaDepartment of Physics
Tampa, FL, USAMS (2010) and PhD (2012)
in Applied Physics
Oregon Institute of TechnologyDepartment of EREE, Wilsonville, OR, USAMS in REE (2017)Adjunct Professor
Carnegie Institution for ScienceGeophysical LaboratoryWashington, D.C. USA
Postdoctoral Fellow (2013-2015)
Max Planck InstituteInstitute for Chemical Physics of Solids
Dresden, GermanyVisiting Scientist (2011)
Quest for Materials for Renewable Energy Applications
Why Are Materials Important?
www.inhabitat.com
S. Stefanoski
Quest for Materials for Renewable Energy Applications
New Allotrope of Silicon, Si24
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1000 ton Multianvil Press
D. Y Kim, S. Stefanoski et al. Nature Materials, 14, 169-173, (2015)
Temperature: 800 0CPressure: 8 GPa
Zr2O3 insulation
Ta heater and capsule
MgO
Mixture of Na-Si in 1:6 ratio inside Ta capsule
Si24
Quest for Materials for Renewable Energy Applications
400 KRT
New Allotrope of Silicon, Si24
Radiative limit with potential fluctuations
AM1.5 radiative limit
D. Y Kim, S. Stefanoski et al. Nature Materials, 14, 169-173, (2015)
S. Stefanoski
5 mm
= 1.3 eV
Quest for Materials for Renewable Energy Applications
Thermoelectric Effect - Thermoelectricity
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-+
T∇
E
+-
Quest for Materials for Renewable Energy Applications
Thermoelectric Generator
S = Seebeck coefficient (DV/DT)s= electrical conductivityk= thermal conductivity (lattice
+ electrons)
TSZTκσ2
=
o High S ® generate the largest DVfor a given DT (S = DV/DT);
o High s® device carries the largest current possible for a given DV;
o Low k® heat is not conducted through the legs, and DT is easily maintained.
S. Stefanoski
SeebeckEffect
PeltierEffect
Quest for Materials for Renewable Energy Applications
Thermoelectric Materials for Automotive Applications
Automotive Energy Flow Diagram www.GM.com
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Quest for Materials for Renewable Energy Applications
Radioisotope Thermoelectric Generator (RTG)
CassiniVoyager
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Quest for Materials for Renewable Energy Applications
Thermoelectric Materials
Skutterudites
Yb14MnSb11Clathrates
Half-Heuslers Alloys
Pb
Te
Chalcogenides
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Quest for Materials for Renewable Energy Applications
Synthesis and Properties of Clathrates
100 μm 200 μm
Na24Si136Na8Si46
585 oC 665 oC
Na4Si4
NaClgraphite
flake
graphite foil
X (Na-content)
[1] S. Stefanoski et al. Chem. Matter. 23, 1491, (2011)[2] S. Stefanoski et al. in The Physics and Chemistry
of Inorganic Clathrates, ed. G. S. Nolas, (2014)
S. Stefanoski
Quest for Materials for Renewable Energy Applications
Summary, Projections, Recommendations
o Materials relevant for Renewable Energy applications are in the focus of scientificR&D: heavy funding of Universities and National Labs; multiple openings forMS/PhD positions are available.
o “Frontiers in Crystalline Matter: From Discovery to Technology”, NationalAcademies Press, 2009: “ The U.S. has an urgent need for increased research anddiscovery and crystal growth of materials”
o Every technologically-relevant application starts with the synthesis and characterization (crystal structure, electrical, thermal, optical, and other properties) of materials.
o Global solar installations will grow to 64.7GW in 2016. The top countries are China, U.S.and Japan. IF materials with higher solar-absorption potential are available, industry willgrow even further.
Global Solar Forecast
o Si24 is a promising candidate to replaceconventional silicon for PV applications. Scaling-up is needed before commercialization.
S. Stefanoski
Quest for Materials for Renewable Energy Applications
Thank you!
S. Stefanoski