High energy and power lithium-ion capacitors based on Mn₃O₄/3D-graphene as anode and activated polyaniline-derived carbon nanorods as cathode

Recently, high performance energy storage devices are increasingly required in many new fields such as smartphone, pilotless automobile. Lithium-ion capacitors (LICs) have become the promising energy storage devices because of the higher power density, electrostatic capacity and long cycle life. Nevertheless, the limitation of the battery-type anode electrode and the capacitance-type cathode electrode with slow kinetics and low specific surface area leads to the LICs remaining lower energy density in high current density. In this report, a high performance LIC assembled by Mn₃O₄-graphene coupled with activated polyaniline-derived carbon (APDC) is firstly presented. Mn₃O₄-G composite material exhibits an outstanding invertible capacity of 489.8 mAh g⁻¹ (at 1 A g⁻¹) in a wide working window (0.01–3 V vs. Li/Li⁺) with an excellent coulombic efficiency in half cell, which is the highest capacitance reported for Mn₃O₄ so far. By utilization of Mn₃O₄-G composite as anode and APDC with the large surface of 1641.9 m² g⁻¹ as cathode, the assembled LIC of Mn₃O₄-G//APDC possesses an energy density of 97.2 Wh kg⁻¹ at power density of 62.5 W kg⁻¹, even at a relatively higher power density of 6250 W kg⁻¹, its energy density can retain 5.0 Wh kg⁻¹.