Study of a graphene-like anode material in N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid for Li-ion batteries

摘要

Graphene nanosheets or reduced graphite oxide materials recently have attracted great attention because of their excellent electrochemical properties such as excellent electrical conductivity and high specific capacity originating from their structure, i.e., two-dimensional layers with one-atomic thickness. This work is focused on reduced graphite oxide (RGO) applied as negative electrode in Li-ion cell with ionic liquid (N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, Pyl3TFSI) as electrolyte. Three different electrochemical techniques, e.g., galvanostatic charging/discharging, cyclic voltam-metry and electrochemical impedance spectroscopy were applied for full electrochemical characterisation of these materials. The results proved that RGO gives good reversible capacity of ca. 550 mAh g~(-1) (at current density of 50 mA g~(-1)) working together with the ionic liquid. This value is comparable to that characteristic for cells operating with conventional electrolyte (cyclic carbonates).