Design of honeycomb-like WSe2@ZnS coated NH4NiPO4.H2O hybrids for flexible all-solid-state asymmetric supercapacitors

Abstract

Supercapacitors are a commercially available form of energy storage that exhibit both the ability to store energy and a high rate of charging and discharging. All-solid-state flexible asymmetric supercapacitors (ASCs) have great potential for wearable electronic devices, and the reasonable design of electrode materials is a crucial step in their development. In this study, we demonstrated that NH4NiPO4.H2O can be merely hybridized with WSe2@ZnS. When compared to pure NH4NiPO4.H2O, the resulting NH4NiPO4.H2O@WSe2/ZnS composites demonstrate increased specific capacity of 1542 F g−1 at a current density of 1 A g−1and enhanced stability. Employing the Activated carbon on carbon cloth (AC//CC) as a negative electrode and a NH4NiPO4.H2O/WSe2@ZnS//CC as a positive electrode, and solid electrolyte PVA-KOH gel as both of the electrolyte and the separator, the fabricated all-solid-state flexible ASC can exhibit a specific capacity of 146 F g−1 at the current density of 1 A g−1, and a maximum energy density of 160.8 Wh kg−1 at a power density of 8.85 kW kg−1. More than 92 % of its initial capacity is still present in the ASC device after 10,000 cycles.