Hierarchically Nanocoral Reefs-like ZnCo2S4 Deposited on Ni Foam as an Electrode Material for High-Performance Battery-type Symmetric Supercapacitor

Abstract

The target for the development of electrode materials with unique architecture and tailored composition is important for influencing their electrochemical properties. The innovative porous zinc cobalt sulfide (ZnCo2S4/NF) nanocoral reef-like structure supported by 3D Ni foam (NF) is fabricated by the hydrothermal method here as an advanced electrode for supercapacitors (SCs), which demonstrates the notable electrochemical performance of the electrode in terms of the specific capacity of 2055.2 C g-1 (specific capacitance of 1957.4 F g-1) at 1 A g-1 and excellent cyclic stability of 89.2% capacity retention and 98% coulombic efficiency after 5000 cycles. Furthermore, the battery-type symmetric supercapacitors based on ZCS/NF have an ultrahigh energy density of 39.1 Wh kg-1 at a power density of 1637 W kg-1 with excellent cyclic stability, 93.3% capacity retention, and 100% coulombic efficiency after 6000 cycles. The outstanding characteristics can be attributed to the synergistic contribution of the ZnCo2S4/NF coral reef hierarchical architecture and the bimetallic sulfide with plentiful valence states for rich redox reactions and promising electrode material for battery type supercapacitor.