Associate professor Arndt Remhof, Hydrogen and Energy, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland

Novel Ionic Conductors

Lithium ion batteries enabled the success of portable electronics and dominate the global battery market.  The demand for high energy density batteries will further increase with the market trend towards electric vehicles and grid leveling applications. Further improvements in energy density and reduction in cost are key to enable a large scale deployment of batteries for these applications.

At high energy densities and large scale, absolute operational safety becomes a stringent requirement. Batteries using a solid state electrolyte instead of the conventional liquid electrolytes have a great potential to overcome the well-known safety challenges of traditional lithium ion batteries. However, the development of next-generation solid-state electrolytes with high ionic conductivity nearing the conductivity of liquid electrolytes represents a major scientific challenge.

We report the discovery of a superionic phase near room temperature in the class of lithium amide-borohydrides, enabling ionic conductivities of up to 8 mS cm^-1 at 40 °C, comparable to values of common organic liquid electrolytes. DFT calculations in conjunction with ab-initio MD simulations suggest an anion-assisted lithium-ion conduction mechanism for the highly conductive phase. A Li₄Ti₅O₁₂ half-cell incorporating a lithium amide-borohydride electrolyte exhibits good rate performance and stable cycling over 400 cycles. The results confirm the high conductivity of the solid-state electrolyte and indicate high bulk and interfacial stability. Our results demonstrate the potential of lithium amide-borohydrides as solid-state electrolytes for high-power lithium ion batteries.

Host: Deputy director & associate professor Trolle René Linderoth, iNANO & Dept. of Physics and Astronomy, Aarhus University

Coffee, tea and bread will be served from 10:00 am in front of iNANO AUD