▎ 摘　　要

The graphene anode was investigated in an ionic liquid electrolyte (0.7 M lithium bis(trifluoromethanesulfonyl)imide (LiNTf2)) in room temperature ionic liquid (N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide (MPPyrNTf(2))). SEM and TEM images suggested that the electrochemical intercalation/deintercalation process in the ionic liquid electrolyte without vinylene carbonate (VC) leads to small changes on the surface of graphene particles. However, a similar process in the presence of VC results in the formation of a coating (SEI-solid electrolyte interface) on the graphene surface. During charging/discharging tests, the graphene electrode working together with the 0.7 M LiNTf2 in MPPyrNTf(2) electrolyte lost its capacity, during cycling and stabilizes at ca. 200 mAh g(-1) after 20 cycles. The addition of VC to the electrolyte (0.7 M LiNTf2 in MPPyrNTf(2) + 10 wt.% VC) considerably increases the anode capacity. Electrodes were tested at different current regimes: ranging between 50 and 1,000 mA g(-1). The capacity of the anode, working at a low current regime of 50 mA g(-1), was ca. 1,250 mAh g(-1), while the current of 500 mA g(-1) resulted in capacity of 350 mAh g(-1). Coulombic efficiency was stable and close to 95 % during ca. 250 cycles. The exchange current density, obtained from impedance spectroscopy, was 1.3 x 10(-7) A cm(-2) (at 298 K). The effect of the anode capacity decrease with increasing current rate was interpreted as the result of kinetic limits of the electrode operation.