Nitrogen-doped activated carbon for a high energy hybrid supercapacitor

Abstract

The present work provides a novel one-step synthesis for nitrogen-doped activated carbon. The excellent performance of the N-doped AC allows its further application in a hybrid-type supercapacitor, which utilizes a combination of the capacitor electrode and a Li-ion battery anode.

Abstract

Nitrogen-doped activated carbons (NACs) were prepared through a one-step process. The obtained NACs show high surface areas of up to 2900 m ² g ⁻¹ with a moderate N content of up to 4 wt%. Electrochemical evaluation of the NACs shows a high specific capacity of 129 mA h g ⁻¹ (185 F g ⁻¹) in an organic electrolyte at a current density of 0.4 A g ⁻¹, as well as excellent rate capability and cycling stability. The hybrid-type supercapacitor assembled using the NACs and a Si/C electrode exhibits a high material level energy density of 230 W h kg ⁻¹ at 1747 W kg ⁻¹. The hybrid device achieved 76.3% capacity retention after 8000 cycles tested at 1.6 A g ⁻¹.