Elastic and hierarchical porous carbon nanofibrous membranes incorporated with NiFe2O4 nanocrystals for highly efficient capacitive energy storage

Abstract

Flexible membranes created from porous carbon nanofibers (CNFs) hold great promise in the next generation wearable energy storage devices, but challenges still remain due to the poor mechanical properties of porous carbon nanofibers. Here, we report a facile strategy to fabricate elastic and hierarchical porous CNF membranes with NiFe₂O₄ nanocrystals embedded via multicomponent electrospinning and nano-doping methods. Benefiting from the scattering effect of NiFe₂O₄ nanocrystals and graphitized carbon layers for the condensed stress, the resultant CNF membranes exhibit an enhanced elasticity with a bending radius <12 μm, rapid recovery from the deformations, and a superior softness. Quantitative pore size distribution and fractal analysis reveal that the CNFs possessed tunable porous structures with a high surface area of 493 m² g⁻¹ and a pore volume of 0.31 cm³ g⁻¹. Benefiting from the robust mechanical stability, hierarchical porous structures and good electrochemical properties, the NiFe₂O₄ doped CNF membranes demonstrate a high electrical capacitance of 343 F g⁻¹, and good reversibility with a cycling efficiency of 97.4% even after 10 000 cycles. The successful synthesis of elastic porous CNF membranes also provided a versatile platform for the design and development of functional CNF based materials for various applications.