GOALI: Engineering Mechanically Stable Interfaces Through Short-Range Molecular Rearrangement Driven by Inhomogeneous Li Ion Transfer Kinetics

Michigan Technological University, Houghton MI

Investigators

Abstract

This fundamental research project aims to fill critical knowledge gaps required to enable the engineering of next generation high energy density solid state batteries. Specifically, the project will address how the chemistry, composition and physical arrangement of atoms, ions, molecules, and defects in both the atomic structure and interface morphologies collectively control the development of localized pressure known to causes catastrophic failure such as cracking or short circuiting in a battery. This new knowledge will directly inform robust strategies to engineer the safest and highest performance batteries for consumer electronics and electric vehicles. The interdisciplinary and integrative research approach will train and educate students in state-of-art experimental mechanics, analytical modelling, electrochemistry and materials processing. Moreover, these tools and techniques will be taught from unique perspectives in academia, industry and a US national lab. In this way, the students will be well equipped to contribute to a world-class materials science and engineering workforce prepared to accelerate the discovery, development, and deployment of advanced materials. The research goal of this proposal is to perform targeted nanoindentation studies designed to fill critical knowledge gaps that will directly inform strategies to optimize the chemistry, composition and processing of solid-state electrolytes designed to stabilize critical interfaces and maximize device performance. These outcomes will be achieved by engineering solid-state electrolytes to provide stress directed, short range molecular rearrangement that mitigates the deleterious strains and commensurate stresses caused by inhomogeneous lithium-ion transfer kinetics. Moreover, this capability will be engineered to operate as efficiently as possible over a wide range of battery relevant operating conditions. Statistical analysis of experimentally observed transitions in stress relaxation mechanisms will enable the construction of novel small-scale deformation mechanism maps expressed as a function of key operational variables, electrochemical cycling, and temperature. These unique maps will provide much needed insight into the physical dimensions of interface defects capable of producing catastrophic device failure by fracture of the solid-state electrolyte. In this way, the maps will directly inform strategies and guidelines for engineering stable interfaces capable of supporting stress-free, planar deposition of a pure, metallic lithium anode. 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.