Mitigation of Atmospheric Carbon Dioxide on Two Fronts: Improving Efficiency of the Vanadium Diboride Anode Material for Primary Batteries and Direct Electrolysis of CO2 into Carbon Nanotubes
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GW Chemistry Department presents our seminar speaker, M. Jake Lefler, Graduate Student, Licht Lab, Department of Chemistry.
Today’s approaches to greenhouse gas mitigation often focus on carbon sequestration, i.e. removing carbon dioxide from the atmosphere or from the flue gas of major industries. But while this method reduces immediate atmospheric exposure, it is simply a Band-Aid over a larger issue and is insufficient to resolve the CO2 problem.
The first approach that we take for the mitigation of atmospheric CO2 is indirect: through the development of a high capacity, energy dense anode material for batteries. Improvements in battery technologies will allow for diminished dependence on other, carbon emitting energy sources. Currently, zinc is the most widely used anode material in primary air cells, but the capacity of zinc is limited by an oxidative discharge that releases only two electrons per zinc, leading to an intrinsic capacity of 820 mAh/g. Vanadium diboride (VB2), on the other hand, undergoes an eleven-electron oxidative discharge, which provides it with an intrinsic capacity of 4,060 mAh/g in alkaline electrolyte, approximately five times that of zinc. However, the depth of discharge is impeded by the discharge products; we probe pathways to alleviate this issue, enabling the fabrication of larger capacity batteries.
Secondly, a more direct method of atmospheric CO2 mitigation involves the transformation of CO2 into useful products (carbon utilization, rather than carbon sequestration). This approach incentivizes mitigation when the CO2 products are valuable. We accomplish this removal of CO2 from the atmosphere via direct reduction in molten carbonate melts. Until now, CO2 has been viewed as a molecule that is too stable to be of use, allowing it to accumulate in the atmosphere. Utilizing the benefits of a thermally energetic (high temperature) system, CO2 can be split in molten carbonate electrolyte at low voltages, producing solid carbon at the cathode and a pure oxygen product at the anode. Not only does this process absorb and reduce atmospheric CO2, it also generates a valuable nanostructured carbon product, specifically carbon nanotubes (CNTs). Advances in the CO2 to CNT process in molten lithium carbonate have led to the ability to produce CNTs at high yield with morphological control.
Jake Lefler received his B.S. in Biochemistry from the University of Delaware. His undergraduate research consisted of synthesizing analogues of proline, as well as synthesizing oligopeptides to coordinate with various transition metal centers. It was during his undergraduate research experience that he realized he wanted to use his double minor in Electrical Engineering and Sustainable Energy Technology to move into the field of inorganic chemistry. He joined Dr. Stuart Licht’s research group to pursue his interest in the field of energy storage, where the research has aligned with another of his interests, climate change mitigation strategies.