Mesoporous MnCo2O4.5 nanoneedle arrays electrode for high-performance asymmetric supercapacitor application

Abstract The aligned mesoporous nanoneedle arrays of MnCo 2 O 4.5 (MNA-MnCo 2 O 4.5 ) are synthesized on Ni foam by using a calcination-process assisted hydrothermal method. Each MnCo 2 O 4.5 nanoneedle features abundant mesopores on the surface. The as-fabricated unique MNA-MnCo 2 O 4.5 exhibits the prominent electrochemical performances as evidenced by the high specific capacity of 517.9 C g −1 at 3.6 A g −1 , and 98.3% capacity retention after 1000 cycles at a current density of 7.2 A g −1 . An asymmetric MNA-MnCo 2 O 4.5 //active carbon supercapacitor is further fabricated to explore the merits of MNA-MnCo 2 O 4.5 electrode, which manifests i) an energy storage density of 40.5 Wh kg −1 at 376 W kg −1 , ii) a power density of 3.06 kW kg −1 at 19.3 Wh kg −1 and iii) an outstanding long-term cycle stability with 7.3% capacity loss after 5000 cycles. These results indicate that the synthesized MNA-MnCo 2 O 4.5 is promising towards the practical application as high-performance supercapacitor electrode in future.