High-Performance Supercapacitor with Plasma-Assisted AlN and Graphitic Carbon Nitride Composite Electrode

Developing low-cost, highly conductive, and porous electrode materials for superior electrochemical energy storage applications is indeed a challenging task, particularly in large-scale production without any impurities. The present investigation centers on the synthesis of a mesoporous nanocomposite material comprising highly conductive graphitic carbon nitride (g-CN) enveloping aluminum nitride (AlN) nanoparticles, denoted as AlN/g-CN, designed for enhanced supercapacitor performance. The AlN/g-CN nanocomposite was synthesized through a thermal plasma arc discharge process utilizing nitrogen (N2) and ammonia (NH3) gas environments, starting with AlN nanoparticles. Concurrently, the g-CN component was synthesized using a straightforward pyrolysis approach starting from melamine. Subsequently, the formation of the highly mesoporous AlN/g-CN nanocomposite was accomplished via a facile ultrasonication process. The phase, crystal structure, morphology, elemental composition, and chemical state analysis of the prepared sample were investigated. The electrochemical performance of the prepared samples, including AlN, g-CN, and AlN/g-CN electrodes, was assessed for their suitability in electrochemical capacitor applications. Notably, the AlN/g-CN nanocomposites exhibited remarkable electrochemical pseudocapacitive behavior, showcasing a substantially higher specific capacitance of 434.1 F/g at a current density of 1 A/g. Additionally, the AlN/g-CN electrode displayed outstanding cycling stability, retaining 93.2% of its initial capacitance after 5000 charge–discharge cycles at a current density of 10 A/g. The maximum energy density of 6.52 Wh/kg is achieved at a power density of 269.7 W/kg. These findings underscore the potential of mesoporous AlN/g-CN nanocomposites as promising electrode materials in the context of supercapacitor applications.