Fabrication and electrochemical evaluation of flexible spinel CdMn2O4 carbon nanofibers for advanced supercapacitor applications

Abstract

Manganese-based oxides, known for their favourable electrochemical properties, can potentially be electrode materials for energy storage applications. However, poor electrical conductivity and stability hinder their practical use. To overcome these limitations, we report the successful synthesis of one-dimensional (1D) porous CdMn₂O₄ carbon nanofiber composites via electrospinning and subsequent carbonization. The unique structure promotes charge transfer and protects CdMn₂O₄ from degradation, while the 1D porous architecture enhances ion diffusion and prevents structural collapse during charge–discharge cycles. As a result, the synthesized CdMn₂O₄ carbon nanofiber composites exhibit excellent capacitive performance and robust cycling stability. To evaluate their performance, electrochemical tests conducted in a three-electrode system using 1 M H₂SO₄ and 6 M KOH solutions revealed superior performance and stability in the acidic medium. A flexible symmetrical supercapacitor device constructed from the carbon nanofibers exhibited a specific capacitance of 570.57 F g⁻¹ at a current density of 1 A g⁻¹ in 1 M H₂SO₄ and retained 88.57% of its capacitance after 12 000 cycles, underscoring its excellent durability. These results emphasize the effectiveness of spinel CdMn₂O₄ carbon nanofibers in energy storage systems, particularly in acidic environments, and pave the way for their potential use in next-generation supercapacitors.