Porous worm-like NiMoO4 coaxially decorated electrospun carbon nanofiber as binder-free electrodes for high performance supercapacitors and lithium-ion batteries

The peculiar architectures consisting of electrospun carbon nanofibers coaxially decorated by porous worm-like NiMoO4 were successfully fabricated for the first time to address the poor cycling stability and inferior rate capability of the state-of-the-art NiMoO4-based electrodes caused by the insufficient structural stability, dense structure and low conductivity. The porous worm-like structure endows the electrode high capacitance/capacity due to large effective specific surface area and short electron/ion diffusion channels. Moreover, the robust integrated electrode with sufficient internal spaces can self-accommodate volume variation during charge/discharge processes, which is beneficial to the structural stability and integrity. By the virtue of rational design of the architecture, the hybrid electrode delivered high specific capacitance (1088.5 F g−1 at 1 A g−1), good rate capability (860.3 F g−1 at 20 A g−1) and long lifespan with a capacitance retention of 73.9% after 5000 cycles when used as supercapacitor electrode. For lithium-ion battery application, the electrode exhibited a high reversible capacity of 1132.1 mAh g−1 at 0.5 A g−1. Notably, 689.7 mAh g−1 can be achieved even after 150 continuous cycles at a current density of 1 A g−1. In the view of their outstanding electrochemical performance and the cost-effective fabrication process, the integrated nanostructure shows great promising applications in energy storage.