One-step preparation of reduced graphene oxide/carbon nanotube hybrid thin film by electrostatic spray deposition for supercapacitor applications

In this paper, we describe a binder-free reduced graphene oxide/carbon nanotube hybrid thin film electrode prepared using a one-step electrostatic spray deposition method. Though we introduce a novel method, we suspect that the greater potential impact is more related to the fact that this technique is able to accomplish producing an electrode with a single process and allows a degree of control over the film properties not yet found in other fabrication methods that require multiple steps (that include post processing). In order to investigate the effect of carbon nanotube as a nano-spacer on the electrochemical properties of the reduced graphene oxide/carbon nanotube hybrid thin film electrodes, the various content of carbon nanotube was incorporated between the 2 dimensional layered reduced graphene oxide sheets to prevent restacking among reduced graphene oxide sheets and their electrochemical properties were systemically investigated using cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy. The hybrid thin film electrode delivered a higher reversible specific capacitance of 187 F·g⁻¹ at 0.5 A·g⁻¹ and showed a better rate capability by maintaining 73% of the specific capacitance at 16 A·g⁻¹ (vs. 0.5 A·g⁻¹), which exhibit remarkable electrochemical performances than a RGO thin film electrodes for supercapacitor applications.