Rational fabrication and optimized design of hierarchical Ni3S2-MOF electrodes for enhanced electrochemical energy storage

How to design and synthesize of advanced MOF-based electrode materials for high-performance supercapacitors is still a huge challenge, herein, CoNi-MOF@Ni 3 S 2 and ZIF-67/Ni 3 S 2 with unique heterostructures are rationally designed and constructed. The composite electrode materials not only make up for the poor conductivity of MOF, but also improve the structural stability of Ni 3 S 2 . As expected, the optimized ZIF-67/Ni 3 S 2 and CoNi-MOF@Ni 3 S 2 electrode demonstrates a remarkably enhanced specific capacitance of 1017.13 F g −1 and 1930.04 F g −1 at 1 A g −1 , respectively, which are higher than those of their respective monomeric components. Finally, ZIF-67/Ni 3 S 2 //AC and CoNi-MOF@Ni 3 S 2 //AC devices were assembled, which delivered an impressive energy density of 94.49 and 125.34 Wh kg −1 , along with the corresponding power density of 966.34 W kg −1 971.86 W kg −1 , respectively. Moreover, by comparison, the CoNi-MOF@Ni 3 S 2 electrode material exhibits better supercapacitor performance than ZIF-67/Ni 3 S 2 . This effective protective strategy provides an alternative way for constructing MOF or sulfide electrodes with remarkably improved energy storage performance.