3. Why Energy Storage?
• Energy Demand and Climate Change - World energy demand
expected to double by 2050
IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)].
Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
World Energy Technology Outlook – 2050. EUROPEAN COMMISSION
Directorate-General for Research
4. Investment in Renewable Energy
Consumption and production must be
exactly equal all the time.
‘. .
5. • The effective utilization of renewable energy
sources
• Improving the performance of consumer
products
The advancement of energy storage
technologies is essential for:
6. Existing and Emerging Energy Storage Technologies –
Comparison of theoretical energy densities
Figure obtained from: R. Padbury, X. Zhang. Journal of Power Sources 196 (2011) 4436–4444
8. What is a Lithium-Oxygen Battery?
Anode half cell reaction
Li2 + e- Li+
Cathode half cell reaction
O2+2Li++2e- Li2O2
Overall Reaction
2Li + O2 → Li2O2 - 3.1 v
OIL RIG
Figure obtained from: R. Padbury, X. Zhang / Journal of Power Sources 196 (2011) 4436–4444
9. What Limits the Li-O2 Battery?
Figure obtained from: R. Padbury, X. Zhang . Journal of Power Sources 196 (2011) 4436–4444
Reaction kinetics are related to internal resistance
10. • High porosity
• Large surface area to volume ratio
• Lighter material weight
How textiles can improve the performance of
the Li-O2 battery
11. • High Porosity – Facilitate O2 diffusion and reduction product
deposition during discharge
Figure obtained from: J.P. Zheng, P. Andrei, M. Hendrickson, E.J. Plichta, J. Electrochem. Soc. 158 (2011)
A43–A46
How textiles can improve the performance of
the Li-O2 battery
12. Electrospun carbon nanofibers (CNF’s)
SEM micrograph obtained from: Liwen Ji and Xiangwu Zhang. Nanotechnology 20 (2009) 155705 (7pp)
13. Research Objective
Maintain good electronic conductivity while
promoting ionic conductivity at the cathode:
• Increase reaction kinetics - achieve higher
discharge capacities
• Create a more uniform concentration of
reactants inside the cathode
14. Composite CNF’s
• Disperse inorganic particles in PAN
solution
• Electrospin to form non-woven mat
• heat treat to form carbon nanofiber
composites
SEM micrograph obtained from: Liwen Ji, Xiangwu
Zhang. Electrochemistry Communications 11 (2009)
1146–1149
16. Research and development of Li-O2
Battery
• Anode
– Stable to moisture
• Cathode
– Meso - porosity
– High oxygen diffusivity
– High Li+ conductivity
– High electrical conductivity
• Electrolyte
– High oxygen and Li+ solubility
– High oxygen and Li+ diffusivity
– Hydrophobic
• Catalyst
– Facilitate charge and discharge
reaction
High
Performance!
17. Acknowledgements
Principle Investigators:
Dr. Xiangwu Zhang
Dr Behnam Pourdeyhimi
Special Thanks:
Dr. Mataz Alcoutlabi, Dr. Zhan Lin, Dr. Quan Shi, Hun
Lee, Guanjie Xu, Yingfang Yao, Ozan Toprakci, Shuli
Li, Ying Li, Shu Zhang, Bohyung Kim, Narenden
Vitchuli, Michael Sieber, Sarah Hoit and Andrew
Hicks
18. Practical Energy Densities
Figure obtained from:J.S. Hummelshøj, J. Blomqvist, S. Datta, T. Vegge, J. Rossmeisl, K.S. Thygesen, A.C. Luntz, K.W. Jacobsen, J.K.
Norskov, J. Chem. Phys. 132 (2010) 071101
19. Practical Energy Densities
Lithium-Oxygen Battery The Internal Combustion Engine
Theoretical Energy Density ~ 13 kwh/kg Theoretical Energy Density ~ 13.2 kwh/kg
Energy efficiency ~ 50% Energy efficiency ~ 12%
Practical Energy Density ~ 6.5 kwh/kg Practical Energy Density ~ 1.5 kwh/kg
But, Li-O2 battery is further limited by bulky
components
Best approximation is 1.7 - 2.5 kwh/kg
Practical Energy Density = Efficiency x Theoretical Energy Density
