High performance for electric double-layer capacitors based on CNT–CG composite synthesized as additive material by CVD method

Abstract

Abstract Carbon nanotubes (CNTs) were successfully grown on chemically synthesized graphene at a low temperature (700 °C) under atmospheric pressure by using chemical vapor deposition (CVD) and used as novel, suitable electrode materials for electric double-layer capacitors (EDLCs) was demonstrated. The growth state of the CNT–CG sample was characterized by SEM, TEM, and Raman spectroscopy. Then, EDLC electrodes with high surface area activated carbon (YP50F) and CNT–CG were fabricated in a simple step. Slurry type EDLCs cells were assembled using the prepared carbon materials. The electrochemical performance of the carbon electrodes was measured by galvanostatic charge/discharge and cyclic voltammetry methods With more than 80% of their capacitance was retained after 30 cycles, the YCG8 samples exhibited excellent stability and reliability at high current charge/discharge cycles. The high stability of the supercapacitors at different densities suggests that these energy storage devices are suitable for fast charging applications. Herein, CNT–graphene synthesized by the CVD method is presented as a promising substitute to conventional electrode materials for EDLCs.