Nanotechnology for Energy Storage

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Nanotechnology for Energy Storage

• Dr. Scott Gold
• Asst. Prof. Chemical Engineering and Nanosystems
  Engineering
• Louisiana Tech University
• Building Energy Systems for Tomorrow
• Louisiana Tech Energy Systems Conference
• Nov. 5, 2009
• Research Group

Steven Bearden Eric Broaddus Stephen Brown Ben
Browning Joshua Hawthorne Ahmad Minhas Ravi
Sekhar Brittany Wilson
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Template Wetting Nanofabrication

• Process for making arrays of nanostructures
• We are one of 4 research groups in the world with
  expertise using this process! (The only one in
  the US)
• Porous template defines shape
• Nanostructures from many materials
• Ceramics and metal oxides
• Metals (platinum, palladium, gold)
• Piezoelectrics (Lead zirconium titanate or PZT,
  PVDF)
• Polymers

Surface tension draws the solution into the pores.
Solvent evaporates leaving behind solid precursor
this becomes our nanotubes , nanowires, or
other structure
Specially engineered wetting solution is applied
to the template.
Thats really nice.but what good is it???
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Energy Applications of Our Nanostructures

• Fuel Cells
• Proton Exchange Membranes
• Catalysis
• Piezoelectric energy scavenging devices
• Photovoltaics
• Supercapacitors
• Hydrogen Storage

Lets look at two of these
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Nanostructured Supercapacitors

• Low energy density compared to other power
  sources but high power density
• Rapid recharge/discharge rates
• Key component in power management systems
• Usually coupled with batteries and/or fuel cells
• First prototype device
• Gold electrodes, polystyrene dielectric
• Purely electrostatic
• Achieved 7 F/g active material
• Performance limited by high internal resistance

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Nanostructured Supercapacitors

• Future plans
• Continued nano-electrode characterization
• Optimize electrolyte deposition
• Improved prototypes

• Electrochemical supercapacitors
• Store charge within electrode material similar
  to batteries
• Best reported performance with expensive RuO2
• Polythiophenes
• Both n and p type doping can be achieved
• P3HT (poly-3-hexylthiophene)
• Achieved over 400F/g active material!

Charge-discharge curve for P3HT nano-electrode
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Hydrogen Storage

• Ammonia borane
• Stable solid in air
• Soluble in common solvents
• Can meet DOE goals
• Chemically regenerated

• Great challenge for fuel cell vehicles
• Goals
• High energy density
• DOE Targets
• 6 wt. by 2010
• 9 wt by 2015
• Safety
• Regeneration
• Compressed H2 gas
• Heavy tanks required
• Safety issues
• Metal hydrides
• Some promise
• Stability issues
• Difficulties recharging

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Hydrogen Storage

• Ammonia borane challenges
• Chemistry not well understood
• Catalyst required to lower hydrogen release
  temperature
• Without a catalyst
• Hydrogen released in 3 steps
• First step 100C
• Our thermolysis catalyst all steps below 100C

No catalyst
With our nanocatalyst
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Hydrogen Storage

• Ammonia borane challenges
• Our hydrolysis catalyst room temperature H2
• Prototype H2 generator under development
• Continuing chemical characterization

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Conclusions

• Unique nanotechnology being developed at
  Louisiana Tech
• Enabling advances in a variety of energy fields
• Super capacitors
• Hydrogen storage for Fuel cells
• Thank you!