EAGER: New Lithium Oxy-ThioBorate Solid State Electrolytes

Iowa State University, Ames IA

Investigators

Abstract

This EAGER project is conducting fundamental high-risk research on new polycrystalline solid electrolytes that can be used in the development of new all solid-state batteries that are safer and more energy dense. While lithium-ion batteries are powerful, they present a potential dangerous fire hazard in some demanding applications. In this new project, new solid electrolytes are being prepared and studied that will help create a new type of all solid-state battery that is more durable and resistant to decay and can hold 10 times more energy than traditional lithium batteries. This research project trains graduate students in state-of-the-art solid electrolyte and materials synthesis, materials characterization, and solid-state electrochemistry of solid electrolytes and as such broadens the cadre of new knowledge workers in the critical field of energy storage. Further, the graduate students supported by this project will conduct informal science education using the Gaffers Guild Glass Blowing Studio at Iowa State University. At the very core of every lithium battery is a potentially flammable organic liquid electrolyte. If a lithium battery is overcharged, overheated, or draws too much current too rapidly, the organic liquid electrolyte can react and cause damage. In this new project, fundamental research is being conducted to study new kinds of lithium thioborate (LBS) and oxygen-doped lithium oxy-thioborate (LBSO) solid electrolytes. The project will examine the underlying structural chemistry of mixing boron, oxygen, and sulfur to explore three hypotheses: (1) That these new LBS and LBSO solid electrolytes will have among the highest ever reported Li ion conductivities combined with low density and high voltage stability. (2) That adding oxygen will improve the chemical durability and electrochemical stability of the solid electrolytes by forming bridging oxygens between the boron atoms. (3) That adding sulfur will increase the lithium ion conductivity by forming low basicity BS4-1 anion sites of low binding energy. 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.