In‐Plane heterostructured FeCoS@NiCo-LDH nanosheets with improved interfacial charge transfer for hybrid supercapacitors

Engineering a heterogeneous structure with distinctive morphology and nanostructure is deemed to be an efficacious tactic for realising high energy density supercapacitors (SCs). Herein, the FeCo 2 S 4 @NiCo-LDH(FeCoS@NiCo-LDH)/NF nanocomposite heterostructure is successfully constructed through a facile two-step electrodeposition method. This heterostructure merges the merits of FeCoS with high electrical conductivity and NiCo-LDH with ultra-high specific surface area, which not only can deliver sufficient electroactive central sites, but also provide shorter routes for expedited ion diffusion, even more significantly, the heterogeneous interfaces that emerge in composites can moderate their electronic structure and augment electrical conductivity. Density functional theory (DFT) calculations indicate that the heterostructured FeCoS@NiCo-LDH/NF displays preferable electrochemical activeness and enhanced adsorption ability. Thanks to the abundance of heterogeneous interfaces and synergistic effects of the various active ingredients, FeCoS/NiCo-LDH electrodes exhibit an extraordinary specific capacity of 930 C g −1 at 1 A g −1 together with remarkable cycle longevity (10.9 % capacity decay after 10,000 cycles). In addition, a hybrid FeCoS@NiCo-LDH/NF//AC exhibits a high energy density of 52.81 Wh kg −1 at the 750 W kg −1 .