Synthesis and characterization of modified centrifuged-electrospun carbon nanofibers for high-performance supercapacitor electrodes

Background: Incorporating novel multifunctional effective materials into supercapacitors electrode is an ongoing requirement for hybrid supercapacitors with enhanced electrochemical performance. Methods: Herein, modified plasma-grafted multiwalled carbon nanotubes (CMS) with improved dispersion are embedded within centrifugal-spun carbon nanofibers as a hierarchical template (CNFs-CMS) to facilitate the growth of subsequent active materials. CNFs-CMS is then electroless plated with acicular nickel (Ni) balls, followed by one-step hydrothermal co-deposition to grow Ni(OH)₂₋MnO₂ hybrid nanosheets. Significant findings: A binder-free, 3D interconnected nanostructures of CNFs-CMS@Ni@Ni(OH)₂₋MnO₂ electrode material is employed for an all-in-one hybrid supercapacitor that exhibits excellent electric double layer (EDLC), battery-like and pseudocapacitance (PC) properties, along with a high surface area (665 m² g⁻¹) and conductivity (2.96 S cm⁻¹). The as-fabricated electrode demonstrates specific capacitance (C_s) of 1063.33 F g⁻¹ at a high current density of 20 A g⁻¹ in 3 M KOH electrolyte, maintaining capacitance retention of 92.5 % after 10,000 galvanostatic charge-discharge cycles. An asymmetric supercapacitor pairing CNFs-CMS@Ni@Ni(OH)₂₋MnO₂ with CNFs-CMS is established, attributes comparably high energy density (52.54 Wh kg⁻¹) and power density (59 kW kg⁻¹) across a potential window of 1.2 V.