Self-supported hierarchical MnCo2O4@Ni3S2 core–shell heterostructures on Ni foam as a binder-free electrode for high-performance supercapacitors

Abstract

Abstract Despite considerable efforts have been devoted to the design and synthesis of advanced electrode materials for supercapacitors (SCs), it is still a huge challenge to achieve high-performance electrode materials with the large practical capacity and high rate capability. Herein, novel self-supported MnCo 2 O 4 @Ni 3 S 2 core–shell heterostructures (CSHs) as a binder-free electrode are rationally designed and constructed by homogeneously growing Ni 3 S 2 nanosheets onto the hexagonal prism-like MnCo 2 O 4 microstructures on Ni foam (NF). Impressively, compared with the pristine MnCo 2 O 4 and Ni 3 S 2 electrodes, the prepared MnCo 2 O 4 @Ni 3 S 2 CSHs electrode demonstrates a remarkably enhanced specific capacitance (2807 F g −1 at 3 A g −1 ) along with a significantly improved rate capability (69% capacitance retention at 30 A g −1 ). These findings not only suggest the promising application of self-supported MnCo 2 O 4 @Ni 3 S 2 CSHs as advanced SCs electrode materials but also provide an alternative way for constructing next-generation high-performance SCs with remarkably improved electrochemical performance.