Inhibition of Dendrites in Rechargeable Lithium Metal Batteries
Dr. Asghar Aryanfar, California Institute of Technology
Date: Monday, September 7, 2015
Place: EA 409
Portable electronics and intermittent renewables demand high-capacity, reliable and sustainable energy storage systems. Batteries are the most common energy storage devices for clean source of electrical energy and the underlying technologies presumably has potential to satisfy the Moore’s law. Pure lithium is the lightest and most electropositive metal, and it could be the optimal anode material for rechargeable batteries, making them comparable to fossil fuels. However, Li-metal batteries unexpectedly fail due to short circuiting via formation of dendrites and dead lithium. This phenomenon poses a major safety issue since it triggers a series of adverse events that start with overheating, followed by the thermal decomposition and ultimately the ignition of the organic solvents used in such devices.
We developed an experimental platform for understanding, tracking and quantifying the amorphous crystals grown in Li battery upon charging under various conditions. Simultaneously, we have established a computational framework for predicting the dynamics of dendritic propagation. The coarse-grained Monte Carlo model assisted us in the interpretation of pulsing experiments, whereas MD calculations provided insights into the mechanism of dendrites thermal relaxation. Furthermore, the underlying algorithms empower us to quantify the battery capacity loss from detached dead lithium crystals.
Asghar Aryanfar received the B.S. in Civil and Mechanical Engineering (double major with distinction) from Sharif University of Technology in 2009 and the M.S. and Ph.D. degrees in Mechanical Engineering from California Institute of Technology, in 2010 and 2015, respectively. He is currently Postdoctoral Fellow at University of California, Los Angeles and Visiting Associate at Caltech. Aryanfar’s research has been in the application of experimental electrochemistry and computational multiphysics modeling to energy systems. Current projects include analysis and design of sustainable rechargeable lithium metal batteries and characterization of corrosion in extreme heterogeneous environments.