Steric Coordinated Electrolytes for Fast‐Charging and Low‐Temperature Energy‐Dense Lithium‐Ion Batteries

Abstract

AbstractElectrolytes are known as the dominant factors for fast‐charging affordability and low‐temperature capability of lithium‐ion batteries (LIBs). Unfortunately, the current electrolytes can hardly simultaneously satisfy all the required characteristics, including sufficient ion transport, high oxidation/reduction interfacial stability, and fast de‐solvation process over a wide‐temperature range. Here, we report a solution by designing electrolyte solvents that coordinate with Li+ in steric configuration. The steric coordinated electrolytes (SCEs) can overcome the dilemma of quasi‐planer coordinated ether electrolytes that has to be weakly coordinated with Li+ to avoid solvent co‐intercalation towards graphite (Gr) anode, therefore enabling the merits including sufficiently dissociation of Li‐salt with high ionic conductivity, low de‐solvation energy, and forming electrode‐electrolyte interphase with low energy barrier. As results, the SCEs with only single‐salt and single‐solvent (trimethoxymethane) achieve fast kinetics towards Gr anode and high oxidation stability. The LiNi0.8Co0.1Mn0.1O2 (NCM811)||Gr LIBs can reach 80% state of the charge in 6 min, and the Ah‐level energy‐dense pouch cells (4.5 V) retain 82.96% (500 cycles) and 85.94% (200 cycles) of initial capacities at room temperature and −20 °C, respectively. Our work deepens the fundamental understanding of Li‐ion solvation structures and affords an effective approach to design sustainable fluro‐free electrolytes for battery systems.