A new strategy for the preparation of multi-walled carbon nanotubes/NiMoO4 nanostructures for high-performance asymmetric supercapacitors

Abstract

Over the past decade, boosting the electrical conductivity of nickel molybdate materials has been established to improve their supercapacitive performance. Nevertheless, it is significant to investigate a different approach from economic efficiency and operation time perspectives. Herein, we first prepare NiMoO4 nanoparticles using a simple ball-milling technique and then serve them in two different multi-walled carbon nanotubes (MWCNTs)/NiMoO4 composites fabricated using simple blending and ball-milling. The ball-milled nanocomposite delivers outstanding supercapacitive properties because of its good surface area, outstanding conductivity, fast kinetics, and many active sites. Its specific capacitance reached 727.2 F g−1 at 1 A g−1 and 709.8 at 10 mV sec−1, and cycling stability was measured to be 86.8 % after 2000 cycles at a current density of 20 A g−1, surpassing the other two samples. An asymmetric device based on ball-milled composite nanostructure resulted in a high specific energy of 40.9 Wh kg−1, a remarkable specific power of 918.5 W kg−1, an appealing rate performance of 73.6 % at 50 A g−1 current density, and a superb cycling durability of 85.4 %. As a result, combining storage attributes of NiMoO4 and MWCNTs with the ball-milling route provides a new strategy to enhance the electrochemical properties of nickel molybdate.