Self-templating construction of NiCo2S4/CoO multi-shelled hollow spheres as electrodes for hybrid supercapacitors

The strategy of combining well-designed hollow structure with compositional engineering has been aroused wide interest in the fields of energy storage. Herein, starting from Ni-Co coordination polymer spheres as self-templates, the NiCo2S4/CoO multi-shelled hollow spheres (NiCo2S4/CoO HMSs) are con-structed through calcination and sulfurization, in which the shells consist of a large number of nano-particles with heterostructures. By virtue of its structural and compositional advantages, the NiCo2S4/CoO HMSs present desirable energy storage properties including high specific capacity (860.1 C g(-1) at 1 A g(-1)), outstanding rate performance and good cycling durability. It is also found that the NiCo2S4/CoO HMSs possess accelerated reaction kinetics. Furthermore, a hybrid supercapacitor device, assembled by NiCo2S4/CoO as the positive electrode and hierarchically porous carbon as the negative electrode, yields a high energy density of 55.35 Wh kg(-1) at 790 W kg(-1). This work would contribute to designing advanced het-erostructures for high-performance electrode materials. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The researchers constructed NiCo2S4/CoO multi-shelled hollow spheres using Ni-Co coordination polymer spheres as self-templates and found that they exhibit excellent energy storage properties and accelerated reaction kinetics. Furthermore, when applied in a hybrid supercapacitor device, it achieved a high energy density.