Abstract：The hybrid capacitors were assembled by using lithium titanate/multi-walled carbon nanotubes composite as anode and activated carbon/nickel cobalt manganese acid lithium composite as cathode. The electrode materials were analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractomer (XRD), Raman spectrometer (Raman) and thermal gravimetric analyzer (TGA). The electrochemical performance of hybrid capacitors was tested by galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results indicate that the addition of multi-walled carbon nanotubes and lithium nickel cobalt manganese oxide can greatly improve the electrochemical performance of hybrid capacitors. The hybrid capacitors achieve a specific capacitance of 161.5 mAh/g at the current density of 0.1 A/g with an additive of 5% (mass fraction) multi-walled carbon nanotubes. The maximum power density and energy density reach 993.2 W/kg and 52.2 Wh/kg in the current range of 0.1-1 A/g,respectively. The continuous galvanostatic charge-discharge cycling tests reveal that the hybrid capacitors maintain capacitance rate retention of 92.2% and Coulomb efficiency of 99.1% after 5000 cycles. The hybrid capacitors show an excellent cycle performance with high energy and power density.
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