Characteristics of a Graphene Nanoplatelet Anode in Advanced Lithium‐Ion Batteries Using Ionic Liquid Added by a Carbonate Electrolyte

A Cu‐supported, graphene nanoplatelet (GNP) electrodes are reported a as high performance anode in lithium ion battery. The electrode precursor is an easy‐to‐handle aqueous ink cast on cupper foil and following dried in air. The scanning electron microscopy evidences homogeneous, micrometric flakes‐like morphology. Electrochemical tests in conventional electrolyte reveal a capacity of about 450 mAh g −1 over 300 cycles, delivered at a current rate as high as 740 mA g −1 . The graphene‐based electrode is characterized using a N‐butyl‐N‐methyl‐pyrrolidiniumbis (trifluoromethanesulfonyl) imide, lithium‐bis(trifluoromethanesulfonyl)imide (Py 1,4 TFSI–LiTFSI) ionic liquid‐based solution added by ethylene carbonate (EC): dimethyl carbonate (DMC). The Li‐electrolyte interface is investigated by galvanostatic and potentiostatic techniques as well as by electrochemical impedance spectroscopy, in order to allow the use of the graphene‐nanoplatelets as anode in advanced lithium‐ion battery. Indeed, the electrode is coupled with a LiFePO 4 cathode in a battery having a relevant safety content, due to the ionic liquid‐based electrolyte that is characterized by an ionic conductivity of the order of 10 −2 S cm −1 , a transference number of 0.38 and a high electrochemical stability. The lithium ion battery delivers a capacity of the order of 150 mAh g −1 with an efficiency approaching 100%, thus suggesting the suitability of GNPs anode for application in advanced configuration energy storage systems.