Michael Womble, Graduate Student, Wagner Lab, GW Department of Chemistry
Improved Capacity and Stability of Li-O2 Batteries using Nanostructured Composite Cathodes and Super Concentrated Electrolytes
Mon, 10 July, 2023
2:00pm - 3:00pm
Michael Womble, Graduate Student, Wagner Lab, GW Department of Chemistry
The Department of Chemistry Presents: Michael Womble, Graduate Student, Wagner Lab, GW Department of Chemistry
The transportation sector currently contributes to roughly 30% of the CO2 emissions in the United States. Electrification of this sector is a crucial step in decarbonization. However, the current rate of adoption of electric vehicles (EVs) is too slow to be able to meet current targets for CO2 emission reduction. There are a couple of impediments to increasing the adoption rate of EVs. First, the energy and power densities of current Li-ion batteries, which while approaching their theoretical limits, are too low to match the driving range of vehicles powered by internal combustion engines (ICE). Second, EVs cost more compared to ICE vehicles. This is in large part due to the price of the Li-ion battery. Therefore, advancement of alternative battery chemistries could significantly increase the EV adoption rate.
Li-O2 battery chemistry is a promising alternative battery chemistry due to its high theoretical energy density, an order of magnitude higher than that of Li-ion batteries, and potentially dramatically lower cost. However, there are several problems standing in the way of Li-O2 batteries including unoptimized cathode pore structures and electrolyte degradation which result in short cycling lifetimes. By understanding and controlling the mass transport of oxygen in the cathode and electrolyte we look to improve the capacity and cycling lifetimes of Li-O2 batteries. Here we present the synthesis of carbon nanochains and their application as cathode material, alone and in combination with multi-walled carbon nanotubes (MWCNTs), to improve the capacity and cycling lifetimes of Li-O2 cells. We also report the study of the mass transport of oxygen in highly concentrated electrolytes with the goal of reducing electrolyte degradation to improve Li-O2 cell service lifetimes.
BIO
Michael Womble was born and raised in Albuquerque, New Mexico. He received his B.S. in chemistry from The University of Tulsa in 2015, where he worked as an undergraduate researcher for Dr. Justin Chalker, as well as interned at Sandia National Labs working for Dr. David Wheeler. He then attended The University of the Texas at Dallas where he received his M.S. in materials science and engineering under the guidance of Dr. Julia Hsu. He then joined the chemistry department at The George Washington University in 2018 and is working towards his PhD under the guidance of Dr. Michael Wagner.
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