High-voltage lithium-ion battery with a wide operation-temperature range and fast-charging ability

Abstract

The slow desolvation process and the low ionic conductivity of lithium-ion batteries (LIBs) pose significant challenges, severely limiting their performance in extreme environments. Herein, we propose a weakly-solvated electrolyte system based on methyl difluoroacetate (MDFA) and isobutyronitrile (IBN) solvents to exert a synergistic effect, where the weak solvation affinity of MDFA facilitates the rapid desolvation process and the high-permittivity of IBN ensures the high ionic conductivity, setting solid foundation for smooth ions transport under fast-charging and wide-temperature operation. As-formulated electrolyte enables graphite (Gr) with a capacity of 192 mAh g -1 at 10 C and achieves a high reversible capacity retention of 91.7% at -40 °C. Benefitting from the high-voltage endurance of both solvents and the electrolyte, the LiNi 0.8 Co 0.1 Mn 0.1 O 2 ||Gr full cells can be stably operated at 4.5 V and displays a high capacity retention of 58.7% at 10 C. Moreover, the full cell exhibits an excellent reversible capacity of 101 mAh g -1 at -60 °C. What's more, the practical 1.2 Ah pouch cell performs a capacity retention of 75.3% at 3 C and 45.2% at -50 °C. Such an electrolyte design presents a promising strategy to develop electrolytes for LIBs that operate under harsh scenarios.