Growth of polyaniline thorns on hybrid electrospun CNFs with nickel nanoparticles and graphene nanosheets as binder-free electrodes for high-performance supercapacitors

Improving the conductivity and active surface area of electrospun carbon nanofibers is beneficial to develop binder-free supercapacitor electrodes for practical application prospects in energy storage field. Herein, we propose a facile and low-cost synthesis of hybrid electrospun carbon nanofibers composites (Ni-G-CNFs) coated with polyaniline throns (Ni-G-CNFs@PANI) via a combination of electrospinning and followed by carbonization and in situ polymerization processes. The prepared Ni-G-CNFs@PANI as a novel binder-free electrode exhibits a high specific capacitance of 318.0Fg(-1) at a current density of 0.5Ag(-1) and an acceptable capacitance retention of 62.1% when the current density increased from 0.5 Ag-1 to 10 Ag-1 in three-electrode system. Furthermore, a symmetric all solid-state supercapacitor was assembled by two binder-free electrodes, and the maximum energy density of 14.4 Whkg(-1) and maximum power density of 3750.2 Wkg(-1) were achieved in a potential window of 1.5 V. Capacitance retention remained 85.8% after 1000 cycles of charge-discharge process even at a high current density of 10 Ag-1. This strategy for growing PANI on electrospun hybrid CNFs paves a new avenue for construction of high-performance binder-free energy storage devices.