Class

Article

College

College of Engineering

Department

Mechanical and Aerospace Engineering Department

Faculty Mentor

Haoran Wang

Presentation Type

Poster Presentation

Abstract

Solid-state Li metal batteries have emerged as a promising way to enhance energy density and safety compared to the traditional Li-ion batteries. Even though numerous research studies are being conducted in this field, many unresolved issues have been hindering the commercialization of such batteries such as dendrite formation, loss of contact, battery failure in low cycles, etc. One of the reasons is the lack of knowledge on the deformation mechanisms (especially creep) at the atomistic level. In this study, Molecular Dynamics simulations have been performed and the creep behavior and superplasticity of pure Lithium was observed in nano scale. Grain rotation and grain boundary migration in Lithium polycrystals have been found to be a critical phenomena on the creep behavior and superplasticity of Lithium. We report that while the variation in loading direction has the most dominant effect on difference of deformation and grain rotation, availability of grain boundaries is crucial for significant creep behavior. It is found that in nano scale it is less likely for Lithium to maintain abundant grains which is needed for massive creep behavior, dislocation availability and continuous plastic deformation. It is even rarer to maintain stable grain boundaries parallel to the maximum shear planes under stack pressure of batteries. The findings provide insights into the mechanisms and shed light to the reasons of unexpected resilience of apparently soft Lithium in atomistic-nano scales.

Location

Logan, UT

Start Date

4-12-2023 2:30 PM

End Date

4-12-2023 3:30 PM

Included in

Engineering Commons

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Apr 12th, 2:30 PM Apr 12th, 3:30 PM

Nanoscale Mechanics of Li Anodes in Solid-State Li Batteries

Logan, UT

Solid-state Li metal batteries have emerged as a promising way to enhance energy density and safety compared to the traditional Li-ion batteries. Even though numerous research studies are being conducted in this field, many unresolved issues have been hindering the commercialization of such batteries such as dendrite formation, loss of contact, battery failure in low cycles, etc. One of the reasons is the lack of knowledge on the deformation mechanisms (especially creep) at the atomistic level. In this study, Molecular Dynamics simulations have been performed and the creep behavior and superplasticity of pure Lithium was observed in nano scale. Grain rotation and grain boundary migration in Lithium polycrystals have been found to be a critical phenomena on the creep behavior and superplasticity of Lithium. We report that while the variation in loading direction has the most dominant effect on difference of deformation and grain rotation, availability of grain boundaries is crucial for significant creep behavior. It is found that in nano scale it is less likely for Lithium to maintain abundant grains which is needed for massive creep behavior, dislocation availability and continuous plastic deformation. It is even rarer to maintain stable grain boundaries parallel to the maximum shear planes under stack pressure of batteries. The findings provide insights into the mechanisms and shed light to the reasons of unexpected resilience of apparently soft Lithium in atomistic-nano scales.