Enhancing the Charge Storage Capacity of Lithium-Ion Capacitors Using Nitrogen-Doped Reduced Graphene Oxide Aerogel as a Negative Electrode: A Hydrodynamic Rotating Disk Electrode Investigation

An energy storage device having both high energy and power density is crucial for many applications such as electric vehicles and mobile phones. Herein, pre-lithiated three-dimensional (3D) nitrogen-doped reduced graphene oxide aerogel (N-rGO aerogel) was introduced as a negative electrode to overcome the kinetic sluggish of lithium ions and activated carbon (AC) was used as a positive electrode of lithium-ion capacitor (LIC). The electrochemical property of electrode materials was studied in a three-electrode system using a hydrodynamic rotating disk electrode at different rotation rates confirming the lithium ion chemisorption on the N-rGO aerogel. The as-fabricated LIC tested in a cell voltage window of 2.0-4.0 V can provide a maximum specific energy of 170.28 Wh kg(-1) (144.79 Wh L-1), a maximum specific power of 25.75 kW kg(-1) (21.89 kW L-1) with similar to 100% capacity retention and 100% coulombic efficiency over 2000 cycles. The excellent performance stems from the nitrogen-containing group and 3D interconnected structure of the N-rGO aerogel. The LIC in this work may be used in many high energy and power applications. (C) 2018 The Electrochemical Society.