1,3,5-Trifluorobenzene endorsed EC-free electrolyte for high-voltage and wide-temperature lithium-ion batteries

Ethylene carbonate (EC) is susceptible to the aggressive chemistry of nickel-rich cathodes, making it undesirable for high-voltage lithium-ion batteries (LIBs). The arbitrary elimination of EC leads to better oxidative tolerance but always incurs interfacial degradation and electrolyte decomposition. Herein, an EC-free electrolyte is deliberately developed based on gradient solvation by pairing solvation-protection agent (1,3,5-trifluorobenzene, F 3 B) with propylene carbonate (PC)/methyl ethyl carbonate (EMC) formulation. F 3 B keeps out of inner coordination shell but decomposes preferentially to construct robust interphase, inhibiting solvent decomposition and electrode corrosion. Thereby, the optimized electrolyte (1.1 M) with wide liquid range (−70–77 °C) conveys decent interfacial compatibility and high-voltage stability (4.6 V for LiNi 0.6 Mn 0.2 Co 0.2 O 2 , NCM622), qualifying reliable operation of practical NCM/graphite pouch cell (81.1% capacity retention over 600 cycles at 0.5 C). The solvation preservation and interface protection from F 3 B blaze a new avenue for developing high-voltage electrolytes in next-generation LIBs.