Design of high-performance supercapacitor electrodes based on in-situ anchored NiCoFe-LDH arrays on electrospun carbon nanofibers

To address the challenge of balancing high energy density with long-term cycling stability in supercapacitor electrodes, this study proposes a collaborative design strategy that combines active-ion doping with conductive scaffold construction. Using a one-step hydrothermal method, redox-active Fe 3 + was introduced into the nickel-cobalt layered double hydroxide (NC-LDH) matrix and simultaneously anchored in situ on a highly conductive electrospun carbon nanofibers (CNFs) scaffold, yielding the NCF-LDH/CNF composite electrode. Within this architecture, the CNF skeleton not only effectively suppresses the aggregation of NCF-LDH nanosheets but also establishes continuous pathways for rapid electron transport. Meanwhile, Fe 3+ doping offeres additional electroactive sites and has a certain regulating effect on the electronic structure of the LDH layers. The combined benefits of these components significantly improve the electrochemical performance of the composite. Electrochemical tests demonstrate that at a Ni:Co:Fe mass ratio of 4:1:0.75, the resulting N 4 C 1 F 0.75 -LDH/CNF composite exhibits optimal performance, delivering a specific capacitance of 2457.4 F g −1 at a current density of 1 A g −1 . When configured as the positive electrode against an activated carbon (AC) negative electrode, an asymmetric supercapacitor based on this composite achieves an energy density of 56 Wh kg −1 at a power density of 800.6 W kg −1 , along with a capacitance retention of 85.1% after 8000 cycles at 3 A g −1 . The results highlight the N 4 C 1 F 0.75 -LDH/CNF composite is a promising candidate for high-energy-density and long- cycle -life energy storage devices. Download: Download high-res image (248KB) Download: Download full-size image