Ball-milled MoO3@NiCo2Se4 composite for supercapacitor electrode

Abstract

Ternary selenides are an attractive choice for supercapacitor electrode materials owing to their multiple oxidation states, higher electronic conductivity, and better electro activity. However, to attain improved charge storage performance, the electrode materials must be strategically tailored as nanostructured hybrid composites. Herein, we experimentally explore the electrochemical charge storage characteristics of MoO₃@NiCo₂Se₄ nanostructure. MoO₃@NiCo₂Se₄ is synthesized via hydrothermal route coupled with ball milling, varying the milling duration from 0 to 4 h. The MoO₃@NiCo₂Se₄ composite obtained by 4 h ball milling process produced well mixed polymeric molybdates and NiCo₂Se₄ nanostructures with highest surface area of 5.9 m² g⁻¹. The specific capacities obtained from 3-electrode electrochemical measurements are 147 C g⁻¹, 267 C g⁻¹, 286 C g⁻¹, and 366 C g⁻¹, respectively, for MoO₃, NiCo₂Se₄, MoO₃@NiCo₂Se₄-0 h, and MoO₃@NiCo₂Se₄-4 h nanostructures at 2 A g⁻¹. An asymmetric Swagelok device is fabricated for MoO₃@NiCo₂Se₄-4 h//AC electrode material delivering a maximum energy density of 30.4 Wh kg⁻¹ and power density of 1499 W kg⁻¹. This study highlights the significance of MoO₃ in tuning the functional characteristics of NiCo₂Se₄ nanostructures for charge storage applications. The newly developed material shows significant promise as electrode material for further exploration and real-world implementation within the energy storage sector.