Ionic liquid based nanofluid electrolytes with higher lithium salt concentration for high-efficiency, safer, lithium metal batteries

Incorporation of ionic liquid functionalized TiO2 nanoparticles in low conducting, 0.6 M lithium salt doped N- methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)limide (Pyr(14)TFSI) ionic liquid electrolyte is found to not only suppress crystallinity but also significantly improve both ionic conductivity and lithium transference number in the electrolyte. The Li/LiMn2O4 cell with the best conducting ionanofluid electrolyte delivers a discharge capacity of about 131 mAh g(-1 ) at 25 degrees C at a current density of 24 mAg(-1), much higher than that obtained in conventional 0.2 M Li salt dissociated Pyr(14)TFSI electrolyte (87 mAh g(-1)). Excellent rate performance with outstanding capacity retention of the cell as compared to the conventional one indicate superior electrode-electrolyte interfacial compatibility, which further establishes great application potentiality of this optimized newly developed electrolyte for safer lithium metal batteries.