TDA RESEARCH, INC. — Department of Defense STTR Phase II: A21C-T016

Description

5.0 volt lithium batteries could provide higher power and greater energy density than existing 4.2 volt batteries, but there is currently not a known combination of electrodes and electrolytes that are stable under repeated charge/discharge cycles. Individual components such as the anode, new olivine cathodes and ionic liquid electrolyte are individually stable at these voltages, but they fail at the solid electrolyte interphase (SEI) in a fully assembled cell. If the battery’s SEI could tolerate cycling between 4.6 and 5 volts this would increase the energy density and power. The goal of this project is to develop a 5.0 volt tolerant electrolyte based on the combination of a non-flammable ionic liquid solvent and a novel artificial SEI material, and demonstrate it with existing anode and cathode materials in a full lithium ion battery cell with less than 20% capacity fade after 80 cycles and an energy density of more than 350 Wh/kg to meet the Army’s future battery needs.