Co_1–x–yNi_xZn_y(CO₃)_0.5(OH)·0.11H₂O Nanoneedles–NiCo-Layered Double Hydroxide Nanosheet Composites on Vulcanized Ni Foams for Supercapacitors

Herein, we construct Co1–x–yNixZny(CO3)0.5(OH)·0.11H2O nanoneedles–NiCo-layered double hydroxide (NiCo-LDH) nanosheet hierarchical architecture on vulcanized Ni foam (Ni3S2-NF) based on a multistep reaction route. The internal Ni3S2-NF matrix not only greatly boosts charge transfer but also is employed to load the active materials. The Co1–x–yNixZny(CO3)0.5(OH)·0.11H2O nanoneedles–NiCo-LDH nanosheet hierarchical architecture presents an open and orderly structure, which could both enable rich contact sites and integrate the merits of every component, thus generating a synergistic electrochemical enhancement. As expected, the hierarchical architecture electrode serves as a supercapacitive positive material, which displays high rate capacities (763.2 C g–1 at 1 A g–1 and 598 C g–1 at 20 A g–1) and long-term cyclic duration (retaining 88.71% capacity after 7000 cycles at 10 A g–1). Additionally, a hybrid supercapacitor (HSC) based on such positive material is assembled, which also exhibits an energy density of 42.8 Wh kg–1 (at 800 W kg–1) and outstanding cyclic stability (retaining 80% capacity after 10 000 cycles at 5 A g–1). Remarkably, a blue light-emitting diode (LED) can be triggered by two series-connection HSCs for more than 24 min, making it have a broad application prospect in energy storage.