Imidazolium-based ionanofluid electrolytes with viscosity decoupled ion transport properties for lithium-ion batteries

A series of LiTFSI salt-doped ionanofluid electrolytes based on imidazolium ionic liquid that includes ionic liquid functionalized SnO2 nanoparticles were prepared through a simple solution-chemistry method. The obtained ionanofluid electrolytes exhibit high thermal stability, fragility, and substantially lower crystallinity than the original ionic liquid electrolytes. The temperature-dependent ion conductivity study indicates that in contrast to ionic liquid-based electrolytes, ionanofluid electrolytes are apparent to have viscosity-decoupled ion transport properties. The Li/LiFePO4 cell assembled with 15 wt% LiTFSI salt-doped ionanofluid electrolyte, having the highest Li+ ion transport ability with moderate ion conduc-tivity, demonstrates appreciable cycling performance with excellent rate capability. The cell delivers a room temperature discharge capacity of about similar to 141.2 mAhg(-1) (-88% of theoretical capacity (CTheo) of LiFePO4) at C/5 rate and is able to retain more than 96 % of the same with nearly 99 % coulombic efficiency after 50 charge-discharge cycles. The potentio-electrochemical impedance study reveal that the ionano-fluid electrolyte able to form a stable passivation layer within the cell. The study establishes the enor-mous potential of ionanofluid electrolytes for practical applications in next-generation lithium-ion batteries. (c) 2023 Elsevier B.V. All rights reserved.