Ultrathin ZnS nanosheet/carbon nanotube hybrid electrode for high-performance flexible all-solid-state supercapacitor

Flexible and easily reconfigurable supercapacitors show great promise for application in wearable electronics. In this study, multiwall C nanotubes (CNTs) decorated with hierarchical ultrathin zinc sulfide (ZnS) nanosheets (ZnS@CNT) are synthesized via a facile method. The resulting ZnS@CNT electrode, which delivers a high specific capacitance of 347.3 F·g–1 and an excellent cycling stability, can function as a high-performance electrode for a flexible all-solid-state supercapacitor using a polymer gel electrolyte. Our device exhibits a remarkable specific capacitance of 159.6 F·g–1, a high energy density of 22.3 W·h·kg–1, and a power density of 5 kW·kg–1. It also has high electrochemical performance even under bending or twisting. The all-solid-state supercapacitors can be easily integrated in series to power different commercial light-emitting diodes without an external bias voltage.