Ethylene carbonate-free electrolytes toward better lithium-ion batteries

Better lithium-ion batteries with high-safety, high-voltage, wide-temperature, and fast-charging performances are urgently demanded for diverse applications, such as electric vehicles, large-scale grid systems, and special defense/polar/aerospace/seabed purposes. The electrolyte engineering is widely recognized as the simplest and most powerful strategy. Although the ethylene carbonate (EC) solvent has dominated the electrolyte market for more than 30 years, the issues of serious side reactions at high temperature/voltage, sluggish desolvation kinetics, and formation of high Li⁺ diffusion resistance interphase greatly hinder further development. Given the urgency for EC-free electrolytes and the notable progress, a comprehensive and timely review is imperative. This review presents the advances of EC-free electrolytes with enhanced performance. Additionally, we emphasize future directions and perspectives on EC-free electrolyte design for better lithium-ion batteries toward practical applications.