Carbon nanotubes interpenetrating MOFs-derived Co-Ni-S composite spheres with interconnected architecture for high performance hybrid supercapacitor

Abstract

Recently, carbon nanotubes (CNT)-based interconnected architectures exhibit promising prospects in supercapacitors due to their flexibility and high electrical conductivity. Herein, a three-dimensional (3D) interconnected network structure combined with conductive carbon nanotubes interpenetrating MOFs-derived Co-Ni-S composite spheres (Co-Ni-S/CNTs) was synthesized. Such 3D interconnected architecture significantly leads to a favorable electronic structure, fast charge-transfer capacity, and more pseudocapacitive. The Co-Ni-S/CNTs-based hybrid electrode exhibits an extraordinary specific capacitance of 540.6C g−1 at 1 A g−1 and competitive rate performance (capacity retention rate of 69.9% when the current density increases to 10 times). Subsequently, a hybrid supercapacitor is assembled using Co-Ni-S/CNTs as the positive electrode and commercial activated carbon as negative electrode. The device delivers a high energy density of 63.5 W h kg−1 at 800 W kg−1 and keeps 83.0% initial capacitance retention after 10,000 cycles. The encouraging performances demonstrate the significant contribution of the 3D interconnected architecture for the future energy storage.