Hierarchical MnCo2O4@MnWO4 core-shell nanoarrays on Ni foam as binder-free electrode for asymmetric supercapacitors

Supercapacitors (SCs) are generally perceived as competitive possibilities for portable electronic products due to their exceptionally high power density and extended operational lifespan. Nevertheless, the relatively low energy density remains a crucial obstacle to its widespread application. A hierarchical MnCo2O4@MnWO4 core-shell nanoarrays on nickel foam (NF) was designed and synthesized by utilizing the MnCo2O4 nanosheet array as the backbone and the MnWO4 nanosheet array as the shell via hydrothermal procedure and calcination. The MnCo2O4@MnWO4/NF electrode achieves 1428.5 F g(-1) at 1 A g(-1) with 97.8 % of its pristine capacity after 4000 cycles. The superior energy storage characteristic is a result of several factors, including the binder-free integrated electrode design, the synergistic effect between MnCo2O4 and MnWO4, and abundant active sites. The assembled asymmetric supercapacitor (ASC) has an energy density of 36.46 Wh kg(-1) at 750 W kg(-1), and 85.4 % capacity reserved after 5000 cycles.