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

•Mesoporous nanoneedle arrays of MnCo2O4.5 are synthesized on Ni foam.•The MnCo2O4.5 nanoneedle arrays electrode exhibits the prominent electrochemical performances.•The asymmetric device with high energy storage density and outstand cycling stability is successfully fabricated.

The aligned mesoporous nanoneedle arrays of MnCo2O4.5 (MNA-MnCo2O4.5) are synthesized on Ni foam by using a calcination-process assisted hydrothermal method. Each MnCo2O4.5 nanoneedle features abundant mesopores on the surface. The as-fabricated unique MNA-MnCo2O4.5 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-MnCo2O4.5//active carbon supercapacitor is further fabricated to explore the merits of MNA-MnCo2O4.5 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-MnCo2O4.5 is promising towards the practical application as high-performance supercapacitor electrode in future.