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Electrochemical performance of lithium-ion capacitor using reduced graphene oxide–carbon nanotube pre-lithiated by direct contact method

Tuesday, 15 May 2018
Ballroom 6ABC (Washington State Convention Center)
E. Adelowo, A. Rabiei Baboukani, R. Agrawal, and C. Wang (Florida International University)
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.