Inexpensive, Efficient Approaches for Energy Production and Storage
We are interested in developing new synthetic methods for nanoscale materials with applications in energy conversion and storage. We work in three general areas: photovoltaics, hydrogen storage, and Li-ion rechargeable batteries. For this talk, I will focus first on using photovoltaic devices to produce energy, and second on developing new architectures for rechargeable Li-ion batteries for storing that energy.
Colloidal inorganic nanocrystals offer many advantages for use in photovoltaic devices: controllable synthesis, processability, and tunable band gap energies. Ideal materials for photovoltaics would contain earth abundant, nontoxic elements and would possess ideal band gaps. Copper and iron chalcogenides exhibit these properties. I’ll discuss the synthesis and characterization of Cu2ZnSnS4 nanoparticles, as well as structure-property relationships for these particles as the metal and chalcogen stoichiometries are tuned. Finally, preliminary results on the effects of ligand exchanges on the surface of the particles on overall device efficiency will be presented.
The second part of the talk will focus on batteries. There are two main limitations to the rate of charging Li-ion batteries: slow diffusion of Li+ into the electrodes and slow diffusion between them. The synthesis of high surface area electrodes has been shown to dramatically enhance performance because reducing the particle size of the electrode material reduces the distance the Li+ ions have to diffuse. The problem of decreasing the Li+ diffusion length between electrodes has not yet been solved. We are working to incorporate high surface area structures of a novel anode material into a new battery architecture wherein the current collector is conformally coated with an electrolyte made by electrochemical deposition, then surrounded by the cathode electrode. The significant advantage is that the diffusion length for Li+ between the cathode and anode will be dramatically reduced, which should lead to much faster charging rates.
About the Speaker
Dr. Prieto is an Associate Professor in the Department of Chemistry at CSU. In addition to her research in Li-ion batteries, she has active projects developing nanoparticles inks for photovoltaics, light metal nanoparticles for hydrogen storage, and novel nanowire structures. She earned a Ph.D. in Inorganic Chemistry from the University of California, Berkeley, where she was a Cooperative Research Fellow supported by Bell Labs, Lucent Technologies. Her postdoctoral work was performed at Harvard University, where she measured the electronic properties of single molecules and nanoparticles. While at Harvard she was named one of the first L’Oréal USA for Women in Science Fellows. Prof. Prieto founded Prieto Battery, Inc. in 2009 with the goal of commercializing a novel three dimensional high power density lithium-ion battery made from aqueous based electroplating baths. In 2011 she was named the ExxonMobil Solid State Chemistry Faculty Fellow (and ACS award), a Presidential Early Career Awardee for Scientists and Engineers (PECASE) and won the Excellence in Storage Technology Commercialization Award from the Colorado Cleantech Industry Association. In 2012 she was awarded the Margaret B. Hazaleus Award at Colorado State University in recognition of her mentoring efforts, and in 2014 she received the Agnes Fay Morgan Research Award from Iota Sigma Pi. She is an Associate Editor for ChemicalCommunications, and has recently been inducted as a Fellow of the Royal Society of Chemistry. Her batteries are currently on display at the Smithsonian Institute, Lemelson Center in the “Places of Invention” exhibit.