Manganese Dioxide/Nickel Cobalt Layered Double Hydroxide Composite Electrodes for Asymmetric Supercapacitors
Abstract
At present, the low energy density poses a challenge that hinders the advancement and use of supercapacitors. Selecting appropriate techniques to enhance the performance of electrode materials is a viable approach, and designing these materials is crucial. This study involves the chemical deposition of a manganese dioxide (MnO2) nanosheet layer onto activated carbon cloth (CF), followed by the electrochemical deposition of a cobalt-nickel layered double hydroxide (CoNi LDH) layer on the former, giving rise to the creation of the CF/MCN electrode. This bilayer heterostructure can effectively exploit the synergistic effect of different materials and provide more excellent electrochemical performance. The constructed asymmetric supercapacitor of CF/MCN//activated carbon (AC), demonstrated 1.6 V voltage range, 151 F g-1 specific capacitance at 1 A g-1, and 53.69 W h kg-1 energy density at 800.02 W kg-1 power density. Moreover, following 10,000 cycles, the device exhibits 90.35% capacitance retention as well as approaches nearly 100% coulombic efficiency. The device demonstrates significant potential for application in the realm of innovative energy technologies. This research contributes novel insights that may enhance the structural design of electrode materials for future generations of supercapacitors.