Boosting the electrochemical performance of NiFe2O4/Carbon composite materials by nitrogen doping for supercapacitors application

Abstract

The development of high-performance anode materials is of great importance for improving the electrochemical performance of asymmetric supercapacitors. Here, nickel ferrite/porous carbon composite is synthesized via hydrothermal approach and the electrochemical properties are improved by nitrogen doping process. As the surface nitrogen content of the porous carbon precursor increased from 2.40 at.% to 9.53 at.%, the nickel ferrite/porous carbon composite exhibited substantial improvement in specific capacitance (increased from 136.4 to 201.4 F g−1 at 1 A g−1) in an alkaline aqueous electrolyte. The energy density of the assembled asymmetric supercapacitor was increased from 17.7 W h kg−1 to 11.2 W h kg−1, and the cycle retention rate after 10,000 cycles at 2 A g−1 was increased from 16.5 % to 85.7 %. Nitrogen atoms on the carbon surface provide active sites for the growth of nickel ferrite nanoparticles and enhance the interfacial effect between nickel ferrite nanoparticles and porous carbon materials, enhancing the charge transfer and preventing particle aggregation during charge and discharge processes. The fabricated nickel ferrite/nitrogen-doped porous carbon composite exhibits excellent capacitance and cycling stability, providing a new option for asymmetric supercapacitor anode materials.