Flexible Fe O and V O Nanofibers as Binder-Free Electrodes for High-Performance All-Solid-State Asymmetric Supercapacitors.

Flexible, highly porous Fe O and V O nanofibers (NFs) have been synthesized by a facile electrospinning method followed by calcination. They have been directly used as binder-free electrodes for high-performance supercapacitors. These Fe O and V O NFs interconnect with one another and construct three-dimensional hierarchical porous films with high specific surface areas. Benefitting from their unique structural features, binder-free Fe O and V O porous nanofiber electrodes offer high specific capacitances of 255 F g and 256 F g , respectively, at 2 mV s in 1 m aqueous Na SO as electrolyte. An all-solid-state asymmetric supercapacitor (ASC) has been fabricated using Fe O and V O nanofibers as negative and positive electrodes, respectively. It could be operated at up to 1.8 V, taking advantage of the wide and opposite potential windows of the respective electrodes. The assembled all-solid-state ASC achieved a high energy density up to 32.2 W h kg at an average power density of 128.7 W kg , and exhibited excellent cycling stability and power capability. The effective and facile synthesis method and superior electrochemical performance described herein make electrospun Fe O and V O NFs promising electrode materials for high-performance ASCs.