Novel FeNi2S4/TMD-based ternary composites for supercapacitor applications

Abstract

Ternary electrode materials based on graphene, FeNi₂S₄, and transition metal dichalcogenides (TMDs) were obtained via a one-pot synthesis method. Compared to binary materials, FeNi₂S₄–graphene (g)–2D-TMD nanocomposites exhibited better performance, which is a direct consequence of their unique ternary structures and the induced synergistic effect among their three components—ultrathin TMD nanosheets, highly conductive graphene networks, and FeNi₂S₄ nanoparticles. With the fabricated materials, we constructed electrodes to assess the electrochemical performance. The results are promising: the materials exhibited rapid electron and ion transport rates and large electroactive surface areas, testifying to their excellent electrochemical properties. In particular, the FeNi₂S₄–g–MoSe₂ electrode demonstrated a maximum specific capacitance of 1700 F g⁻¹ at a current density of 2 A g⁻¹ (8.5 F cm⁻² at a current density of 10 mA cm⁻²) and a capacitance retention of approximately 106% after 4000 cycles at a charge–discharge current density of 2 A g⁻¹. These electrochemical results indicate that the ternary composite, FeNi₂S₄–g–MoSe₂, is a promising candidate electrode material for high-performance supercapacitors.