Guest Speaker
Title: |
Can Chemo-Mechanical Couplings Enable Solid-State Batteries? Insights from Mesoscale Simulation |
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Speaker: |
Dr. Scott Monismith |
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Affiliation: |
Sandia National Laboratories |
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When: |
Friday, February 21, 2025 at 12:00:00 PM |
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Where: |
Boggs Building, Room 03-47 |
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Host: |
Chaitanya Deo | |
Abstract Li-metal based batteries with a solid electrolyte are often considered the holy grail of energy storage solutions in that they are higher energy density and safer than their liquid electrolyte counterparts. However, one prominent failure mechanism is the growth of lithium filaments through the solid electrolytes, leading to short-circuits and failure early in life. Microstructural characteristics (i.e. cracks and grain-boundaries) may drive this failure mode by orchestrating brittle fracture of the electrolyte, providing new surfaces along which the Li filaments may grow. To better understand this failure mechanism, we develop a coupled multiphysics phase-field model which simulates the growth of li metal filaments through solid electrolytes using Li7La3Zr2O12 (LLZO) as a pedagogical example. Using this framework, we can estimate critical potentials/current densities at which cracks propagate and short-circuits form. We further confirm earlier experimental results which showed dendrite deflection via the application of applied external stress, leading to the aversion of short circuits. We attribute this to the superposition of mode II loading onto the latent mode I stress intensity due to Li metal deposition and demonstrate that a similar effect can be achieved by spatially tuning the toughness of the material. These results, together, demonstrate that the mechanical behavior of solid electrolytes may hold the key to enabling their use in Li metal battery cells. |
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Biography Scott is a postdoctoral scientist at Sandia National Labs. He did his Ph.D at Tufts University and prior to that he was a battery cell engineer at an electric car company. |
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