Construction of multi walled carbon nanotube decorated CoMn₂O₄ hexagonal nanoplates for high performance aqueous asymmetric supercapacitor

The fabrication of transition metal oxide with carbonaceous material results in hybrid electrode with good charge storage capacity, higher energy density and power density than transition metal oxide electrodes. In this work, hybrid electrode material of CoMn₂O₄ hexagonal nanoplates and multi-walled carbon nanotubes (MWCNTs) is synthesized by co-precipitation process. The transmission electron microscope (TEM) analysis of prepared material shows that CoMn₂O₄ nanoplates are uniformly anchored on MWCNTs which helps to keep good electronic channel throughout the electrode material. Further, the MWCNT/CoMn₂O₄ is widely examined as high-performance electrode material in supercapacitor and, its capacitive faradaic charge storage mechanism is studied. The synergistic interaction between MWCNTs and CoMn₂O₄ hexagonal nanoplates resulted in the specific capacity of 156.75 mAh g⁻¹ at 1 A g⁻¹ which is higher from the specific capacity of sole CoMn₂O₄ nanoplates (113.37 mAh g⁻¹ at 1 A g⁻¹). Further, asymmetric supercapacitor is designed and high energy density of 58.41 W h kg⁻¹ is observed at power density of 502.5 W kg⁻¹. Furthermore, four parallel connected yellow color LEDs and a toy motor fan are functionalized by MWCNT/CoMn₂O₄//AC device.