▎ 摘　　要

In this work, large area graphene-carbon nanotube (G-CNT) composite as additive material for EDLC performance was grown on copper foil at low temperature (500 A degrees C) and at atmospheric pressure by using chemical vapor deposition (CVD). The growth state was characterized by field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. EDLC electrodes based on high surface area activated carbon (YP50F) and G-CNT were then fabricated by a facile step. Coin-type EDLC cells with two symmetrical carbon electrodes were assembled using the prepared carbon materials. The electrochemical performance of G-CNT based eletrodes were examined in an electrolyte solution of tetraethylammonium tetrafluoroborate ((C2H5)4NBF4, TEABF4) in propylene carbonate (C4H6O3, PC) and measured by galvanostatic charge/discharge and cyclic voltammetry methods.