Title :

Fundamental Understanding and Catalyst Development of Rechargeable Li-Air Batteries

Speaker :

Ms. Yi-Chun LU

PhD Candidate, Department of Materials Science and Engineering

Massachusetts Institute of Technology, USA

Venue :

Room 215, William M. W. Mong Engineering Building, CUHK

Date :

Apr 3, 2012, Tuesday
2:00 PM - 3:00 PM

Abstract :

Rechargeable Li-air batteries have the potential to provide 3-4 times gravimetric energy density than that of conventional Li-ion batteries. Li-air batteries generate energy by electrochemically reduce O2 from the air forming solid lithium (per)oxides (i.e., oxygen reduction reaction, ORR). During charge, these oxides are electrochemically decomposed to regenerate lithium and oxygen (i.e., oxygen evolution reaction, OER). Critical challenges limiting the practical use of this technology include low electrolyte stability, poor round-trip efficiency, rate capability, and cycle life. Catalyst development is crucial to address these challenges as it directly influences the rates of the discharge and charge reactions. We developed electrochemical model systems coupled with advanced spectroscopic techniques to probe the intrinsic catalytic activity of catalyst and the underlying physical origins of catalyst effects. We established nonaqueous rotating disk electrode and Li2O2-filled composite electrode techniques to investigate the intrinsic ORR and OER activity of catalysts, respectively. We demonstrate that the application of catalyst can significantly alter the discharge and charge voltages as well as the rate capability of Li-air batteries. Reaction mechanisms and physical parameters that govern the catalytic activities of ORR and OER will be discussed.

Biography :

Yi-Chun Lu received her B.S. in Materials Science and Engineering from National Tsing Hua University, Taiwan in June of 2007, and is currently a Ph.D. candidate in Materials Science and Engineering at Massachusetts Institute of Technology (MIT), USA and expected to receive her Ph.D. in June of 2012. Ms. Lu’s research interest centers on developing rational material design principles for clean energy conversion and storage. She was awarded as a Martin Fellow, an MIT fellowship from the Martin Family Society of Fellows for Sustainability. Ms. Lu was the recipient of Electrochemical Society (ECS) Battery Division Student Research Award in 2010 and European Materials Research Society (E-MRS) Graduate Student Award in 2011.

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Enquiries: Ms. Winnie Wong, Department of Mechanical and Automation Engineering, CUHK at 3943 8337. *MAE Series (2011-12) is contained in the World-Wide Web home page at http://www3.mae.cuhk.edu.hk/maeseminars.php#mae.