In-situ embedding MOFs-derived copper sulfide polyhedrons in carbon nanotube networks for hybrid supercapacitor with superior energy density

The binder-free flexible electrode materials have greatly potential for portable flexible new energy equipment. Herein, we rationally fabricate a flexible composite electrode by connecting the HKUST-1 derived copper sulfide (CuS) polyhedrons with carbon nanotubes (CNT). Because of the synergistic interaction of the HKUST-1 derived CuS polyhedrons and the CNTs network, many excellent electrochemical properties of the composite thin film are obtained working as supercapacitors electrodes. The specific capacitance of the as-prepared electrode can achieve 606.7 F g(-1) at a current density of 1 A g(-1). Moreover, the as-fabricated asymmetric supercapacitors by using HKUST-1 derived CuS polyhedrons and nitrogen-doped carbon polyhedrons interspersed into carbon nanotubes films act as positive (CCS) and negative (CNC) electrodes deliver up to a higher energy density of 38.4 W h kg(-1) at a power density of 750 W kg(-1), which also show a favourable cycle life (87.0% capacity retention after 6000 cycles). It indicates that the electrodes we fabricated are potential electrode materials and our research offers a valuable inspiration for high performance energy storage devices. (C) 2019 Elsevier Ltd. All rights reserved.