A composite of hierarchical CoNiSe₂ (CNS) microspheres decorated with a CoFe₂Se₄ (CFS) nanorod-like architecture was successfully synthesized and the assembled symmetric supercapacitor achieves a superhigh energy density.

NiMoO ₄ @NiWO ₄ electrode with honeycomb-like structure exhibits very good specific capacitance and cyclic stability than the NiMoO ₄ electrode.

A bunch of PbMoO₄/CdMoO₄ nanocube-like structures exhibit superior specific capacitance and cycling stability to PbMoO₄ and CdMoO₄ electrodes.

Metal sulfides have attracted considerable interest owing to their notable electrochemical properties and multiple application areas, such as solar cells and supercapacitors (SCs). This paper describes the design and synthesis of nickel foams decorated with different metal sulfides, such as CoS/NF, CuS/NF, FeS/NF, and NiS/NF electrodes for SCs. The FeS/NF coral reef-like nanostructure exhibited outstanding electrochemical performance in SCs with a high specific capacitance (2007.61 F g⁻¹ at 2 A g⁻¹), good cycling stability (only 3% loss after 3000 cycles at 2 A g⁻¹), excellent rate capability (52.27% capacity retention at 20 A g⁻¹), and higher energy density (54.88 W h kg⁻¹ at a power density of 500 W kg⁻¹) compared to other electrodes. The elevated performance of the FeS/NF was attributed mainly to the coral reef-like nanostructure with a relatively high specific surface area, which offers a large interfacial area between the electrode and electrolyte and sufficient physical cavities for rapid ionic diffusion. These results suggest that the coral reef nanostructure can be used not only in large energy density applications, but also in large power density fields, such as energy storage devices, flexible electronics, and electric vehicles.

In the current work, cost-effective NiO nanosheets decorated with NiS nanoparticles were successfully fabricated on Ni foam by following a facile two-step hydrothermal route, and investigated as an efficient electrode material for supercapacitor applications for the first time. The obtained NiO/NiS hybrid electrode was found to deliver rapid diffusion of ions and fast electron transport, due to the high electrical conductivity, large surface area, and unique surface morphology of the NiO/NiS. As a result, this electrode exhibited a high specific capacitance of 386.7 F g⁻¹ at 1 A g⁻¹ and good cycling stability, specifically retaining 97.6% of the initial capacitance after 3000 charge–discharge cycles at 5 A g⁻¹. These results indicated NiO/NiS to be a promising electrode material for supercapacitor applications.

ZnMn ₂ O ₄ @ZnFe ₂ O ₄ microsphere-like structures exhibit superior specific capacitance and cyclic stability than the ZnMn ₂ O ₄ and ZnFe ₂ O ₄ electrodes.