Electrolyte Design for Fast-Charging Li-Ion Batteries

Li-ion batteries with fast charging capabilities will push the adoption of electric vehicles (EVs). The United States Department of Energy has stated goals of achieving Extreme Fast Charging (XFC) - charging to 80% capacity in 15 minutes or under - by 2028. The liquid electrolyte plays an extremely important role in achieving this goal. This review considers recent progress made in electrolyte development for high-rate charge applications. Approaches such as using low-viscosity co solvents, highly concentrated electrolytes, and large polyanions are considered. New methods for measuring electrolyte transport properties are reviewed. The importance of electrolyte additives is also discussed. Finally, the importance of considering cell lifetime in the development of electrolytes for fast charge applications is stressed.