Collaborative Research: Harnessing Mechanics for the Design of All-Solid-State Lithium Batteries

University Of Utah, Salt Lake City UT

Investigators

Abstract

This grant will support fundamental research on the mechanics of lithium anodes in all-solid-state lithium batteries. All-solid-state lithium batteries are a promising candidate for next-generation, high-capacity rechargeable batteries. Lithium anodes can provide the highest energy density among all known anode materials. Solid-state electrolytes improve battery safety by eliminating flammable liquid electrolytes. However, new problems emerge. During charging, non-uniform lithium plating occurs at the anode, which can cause fracture of the current collector. During discharging, non-uniform lithium stripping leads to void formation, dead lithium, and capacity drop. Cracking and dendrite growth also occur in solid electrolytes, causing short-circuits. This research will investigate how mechanics can be used to achieve uniform and stable plating and stripping in lithium anodes. This research will advance next-generation battery technology for electric vehicles, contributing to the national economy and sustainability. This project will integrate the research capabilities of two Utah universities, and train next-generation engineers and scientists for research in renewable energy. Moreover, this grant will enhance the diversity of STEM fields by recruiting and training under-represented minorities. This research hypothesizes that mechanics can be harnessed as a control parameter to program electrochemical processes in all-solid-state lithium batteries and achieve “plasticity-assisted” uniform plating and stripping of lithium. Four research tasks are researched to test this hypothesis: (1) lithium plating and stripping are investigated using correlated mechanical-(electro)chemical-morphological characterization and residual stress measurements; (2) density functional theory and molecular dynamics simulations of lithium-solid electrolyte interfaces are used to quantify the stress and geometric effects on lithium plating/stripping at the atomic scale; (3) informed by the atomic simulations in Task 2, a continuum model is built to account for the interplay of stresses, interfacial geometries and chemical reactions; (4) integrated experiments and computations are leveraged in a mechanics-driven design approach for anode interfaces in all-solid-state lithium batteries to engineer plasticity-assisted uniform lithium plating/stripping. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.