Electrochemical Performance of Lithium-Ion Capacitors Using Pre-Lithiated Multiwalled Carbon Nanotubes as Anode

Pre-lithiated multiwalled carbon nanotube anode was prepared by internal short circuit approach (ISC) for 5min, 30min, 60min and 120min respectively. Lithium ion capacitors (LICs) were assembled by using pre-lithiated multiwalled carbon nanotubes as anodes and activated carbon (AC) as cathodes. The structure of multiwalled carbon nanotubes and electrodes were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical performance of pre-lithiated multiwalled carbon nanotube electrodes and pristine carbon nanotube electrodes were tested by galvanostatic charge/discharge and electrochemical impedance. The results indicated that pre-lithiation carbon nanotubes greatly improved the charge/discharge performance of LICs. The energy density was four times than conventional electric double-layer capacitors (EDLCs) at the current density of 100 mA/g. The LICs achieved a specific capacitance of 59.3 F/g at the current density of 100 mA/g with 60min pre-lithiatiation process. The maximum energy density and power density was 96 Wh/kg and 4035 W/kg, respectively. The energy density still remained about 89.0% after 1000 cycles. The LIC showed excellent supercapacitor performance.