Mesoporous NiCo2Se4 tube as an efficient electrode material with enhanced performance for asymmetric supercapacitor applications

Abstract

Electrode materials play a vital role for supercapacitors. The development of an efficient and reproducible strategy for the fabrication of hollow mesoporous materials with specific morphologies and microstructures has attracted considerable research interest in recent years. Herein, NiCo₂Se₄ with a mesoporous surface and one-dimensional tubular hollow structure is synthesized using carbon nanofibers as the template for use as the positive electrode material in asymmetric supercapacitors. Because of the bimetallic selenide component and the unique structure, mesoporous NiCo₂Se₄ tubes demonstrate exceptional energy-storage performance. When evaluated as an electrode material for supercapacitors, these mesoporous NiCo₂Se₄ tubes show a specific capacitance of 209.1 mA h g⁻¹ (1762.1 F g⁻¹) at a current density of 1 A g⁻¹, with a retention of 82% after 10 000 cycles at 5 A g⁻¹. Even when the current density increased to 20 A g⁻¹, 61% is still retained. Asymmetric supercapacitors are assembled by mesoporous NiCo₂Se₄ tubes and active carbon shows a high energy density of 24.03 W h kg⁻¹ at a power density of 1.055 kW kg⁻¹ as well as long-term cycle stability (94% retention of the initial specific capacitance after 10 000 cycles at 5 A g⁻¹). All experimental results highlight that mesoporous NiCo₂Se₄ tubes will be a promising electrode material for practical supercapacitor applications.