A Practical High-Performance Lithium-Ion Capacitor Fabricated with Dual Graphene-Based Electrode Materials

Lithium-ion capacitors (LICs) hold great promise by merging the benefits of lithium-ion batteries and supercapacitors. However, their performance is frequently constrained by a disparity in the kinetic properties of the cathode and anode. This study introduces a dual graphene-based approach aimed at improving the efficiency and functionality of LICs and demonstrates the successful large-scale production of graphene (SHSG) using a self-propagating high-temperature synthesis method. In the cathode, SHSG forms a continuous graphene network, reducing interfacial resistance, enhancing conductivity and achieving a capacity of 85.9 mAh g-1. In the anode, SHSG improves ion diffusion and reaction interfaces, increasing capacity from 247.9 to 286.6 mAh g-1. A full LIC cell assembled with 10% SHSG in both electrodes demonstrates a peak energy density of 106.3 Wh kg-1 and retains 33 Wh kg-1 at 4.4 kW kg-1, which is calculated based on the total mass of the electrodes. Additionally, a 1100 F LIC pouch cell is developed, showcasing its potential for practical energy storage. This work underscores the transformative role of graphene in optimizing LICs and advancing energy storage technologies.