Tuesday, 15 May 2018
Ballroom 6ABC (Washington State Convention Center)
Electrical double layer capacitors (EDLCs) are among important electrochemical energy storage devices for a wide variety of electronic systems, due to the fast charge and discharge capabilities, long cycle life and high power density they can provide. However, their low energy density remains a major drawback impeding their wide-spread applications. In order to overcome the low energy density limitation of EDLCs, lithium-ion based hybrid supercapacitors widely known as lithium-ion capacitor (LIC) have gained much attention. Lithium-ion capacitors basically combine the high energy density capability of lithium ion batteries and the high-power density of EDLCs. This is typically achieved by using a battery-type lithium intercalating anode material as the high energy density source, and a capacitor-type cathode as the high-power density source, in a lithium based organic electrolyte. Carbon in various forms is the most widely used and examined electrode material in electrochemical energy storage systems. Specifically, graphene, a two-dimensional (2D) carbon material is of great interest for electrochemical energy storage applications due to its attractive properties. In this work we employed lithiated reduced graphene oxide-carbon nanotubes (rGO-CNT) thin film as anode and pure rGO-CNT as cathode for lithium-ion capacitor. The thin films were prepared by electrostatic spray deposition (ESD). CNT was introduced to act as a spacer material to prevent the restacking of layered graphene and to enhance electrical conductivity of the graphene electrode material. Electrochemical performance of the LIC was evaluated by cyclic voltammetry, charge/discharge capacity, and electrochemical impedance spectroscopy (EIS). Material studies were also carried out on the electrode materials by scanning electron microscopy (SEM), X-Ray Diffractometry (XRD) and Fourier Transfer Infra-Red (FTIR). Detailed results obtained as well as the balancing strategy will be presented and discussed at the meeting.