Fast Charging of Lithium-Ion Batteries by the Effective Formulation of Nonaqueous Liquid Electrolytes

The state-of-the-art lithium-ion batteries (LIBs) with graphitic anode and lithium transition metal oxide cathode activated by a nonaqueous liquid electrolyte are unable to achieve fast-charging ability without adversely affecting the electrochemical performance and safety issues. The realization of extremely fast charging with a goal of 15 min recharging time is expected to accelerate the adoption of lithium-ion batteries in electric vehicles. Nevertheless, the utilization of such a goal requires further research and development with advanced materials at multiple levels. Reformulation of nonaqueous liquid electrolytes has been identified as an effective strategy to conquer these challenges. Herein, lithium difluoro oxalaborate (LiDFOB) and bis(2,2,2-trifluoroethyl) ether (BTFE) were added as electrolyte additives in the routinely employed electrolytes, and their charge–discharge performances were evaluated with the LiFePO₄ cathode at different C rates. Further, the experimental results are correlated to the LUMO and HOMO values. The cathode/electrolyte interfacial properties were investigated by XPS and FT-IR. Results confirmed that the incorporation of electrolyte additives not only facilitated the formation of a robust and stable cathode/electrolyte interface but also appreciably minimized the self-extinguishing time and corrosion of the aluminum current collector.