Boosting capacitive energy density of conjugated molecule modified porous graphene film as high-performance electrode materials

Abstract

The increasing demand for the electronic market has put forward large requirements for electrochemical capacitors with high energy and power density. Herein, the 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) modified flame reduced graphene oxide (FRGO) film (N/FRGO) is fabricated by π−π noncovalent interactions, which has abundant wavy wrinkles and fluffy pores to improve the interfacial contact performance, thus achieving large efficient ions storage areas. And the combined NTCDA molecules provide large numbers of additional redox-active sites. The N/FRGO based symmetric supercapacitor (SSC) exhibits a high capacitance value of 246.4 F g−1 at 0.2 A g−1, excellent rate capability of 65.5% capacitance retention at the increased current density of 50 A g−1, and the outstanding cyclability of 90% capacitance retention after 40,000 cycles. Moreover, by combining Zn deposition/stripping battery behavior, the N/FRGO film can achieve a high specific capacity of 217.0 mAh g−1. The N/FRGO based zinc ion capacitor (ZIC) has the maximum energy and power density of 166.5 Wh kg−1 and 29.0 kW kg−1, and can realize the prominent capacity retention under different bending angles and 800 bending cycles. Therefore, the N/FRGO shows a promising application in high energy density capacitors.