Sea urchin-like NiCo2O4/Fe3O4 nanocomposite as a high-performance dual-functional material for advanced lithium-ion batteries and supercapacitors

Abstract

The development of advanced electrode materials with multifunctional electrochemical properties is critical for next-generation energy storage systems. In this study, mesoporous sea urchin-like nickel cobaltite/magnetite (NiCo₂O₄/Fe₃O₄) composite was synthesized and systematically investigated for lithium-ion batteries and supercapacitors. The resulting composite offers high specific surface area, improved conductivity, abundant active sites and favorable structural characteristics. Density Functional Theory (DFT) calculations reveal that the composite exhibits enhanced redox kinetics and improved charge transfer compared to pristine NiCo₂O₄, leading to superior electrochemical performance. As an anode for lithium-ion batteries, the NiCo₂O₄/Fe₃O₄ electrode delivers a high reversible capacity of ∼730 mAh g⁻¹ at 0.3 A g⁻¹ with excellent cycling stability, retaining 87.1 % of its capacity after 1000 cycles. For supercapacitor applications, the electrode exhibits an enhanced specific capacitance of 1330 F g⁻¹ at 1 A g⁻¹, outperforming both NiCo₂O₄ and Fe₃O₄. The assembled (NiCo₂O₄/Fe₃O₄//activated carbon) device achieved a specific capacitance of 221 F g⁻¹ and an energy density of 69.6 Wh kg⁻¹, along with excellent cycling stability, retaining ∼94 % capacitance after 8000 cycles. These results highlight the potential of NiCo₂O₄/Fe₃O₄ nanostructures for high-performance energy storage systems.