High-Performance Electrolyte With Improved Voltage and Thermal Stability For Lithium Metal Batteries

Widespread adoption of electric vehicles is hindered by the weight, size, and cost of battery technology. Lithium-ion battery technology is plateauing in performance, and next-generation solutions are required to deliver step change improvements. Lithium metal batteries promise greatly reduced weight compared to lithium-ion, but they suffer from serious performance, cycle stability, and safety issues because of incompatibility with conventional organic electrolytes. This project proposes a lithium metal rechargeable battery based on a non-flammable and chemically stable electrolyte that has demonstrated enhanced compatibility with lithium metal anodes and high-voltage cathodes. The objective of the project is to improve the rate capability of the electrolyte with the use of different co-solvents that improve physical properties while maintaining oxidative stability at high voltage and cycling stability with lithium metal. This work will bring the cycling performance and rate capability of the lithium metal battery chemistry much closer to commercial viability for electric vehicle applications. The proposed project will identify and screen the most promising and commercially viable co- solvents for use in a high-voltage lithium metal chemistry. Based on the electrochemical data collected in the screening process, the most promising candidates will be down-selected for an expanded experimental study. That work will focus on further optimization of the co-solvent content as well as assessing the benefits of combining multiple co-solvents. The most promising electrolyte compositions will be assessed in rate and cycle life tests in commercially representative coin cells, and the best-performing electrolytes will finally be cycled and studied in single-layer pouch cells.