Facile synthesis of multilayer graphene nanoplatelets/ZnCo2O4 microspheres with enhanced performance for asymmetric supercapacitors

Multilayer graphene nanoplatelets/ZnCo2O4 (MGNs/ZnCo2O4) microspheres were prepared by two-step method using multilayer graphene exfoliated by polymer mixing method as scaffold. Benefiting from the structural stability of spherical structure and the added active sites of mesoporous construction for redox reactions, the MGNs/ZnCo2O4 microspheres electrode delivers an enhanced specific capacitance of 960 F g(-1) at 1 A g(-1) and a cycling stability of 78.9% at 5 A g(-1) after 2000 cycles. Furthermore, the MGNs/ZnCo2O4//active carbon asymmetric supercapacitor (ASC) exhibits an energy density of 17.78 Wh kg(-1) at a power density of 0.75 kW kg(-1). The innovative addition of multilayer graphene nanoplatelets to improve conductivity and structure stability is very enlightening to other composite material in supercapacitor. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The multilayer graphene nanoplatelets/ZnCo2O4 microspheres electrode shows enhanced specific capacitance and cycling stability, achieving an energy density of 17.78 Wh kg(-1). The innovative addition of multilayer graphene nanoplatelets improves conductivity and structure stability, providing enlightenment for other composite materials in supercapacitors.