Constructing vertically aligned ZIF-67 microrod arrays on carbon cloth with commercial-level mass-loading for high-performance supercapacitors†

Abstract

A facile solution immersion was developed to construct three-dimensional (3D) vertically aligned zeolite imidazole framework ZIF-67 microrod arrays on 3D carbon cloth (CC) with commercial-level mass loading (12 mg cm⁻²). It was realized via in situ crystallization with the assistance of electrodeposited reactive cobalt layer and seed-oriented growth associated with a high concentration of Co²⁺. The as-obtained ZIF-67/CC hybrid featured a 3D/3D hetero-structure with easily accessible channels, abundant electroactive sites and highly conductive networks. As integrated electrodes for supercapacitors, they could achieve a high specific capacitance (3396 mF cm⁻² at 1 mA cm⁻²) with superior rate capability (91% at 10 mA cm⁻²) and long-term cyclic stability (over 99% after 10 000 cycles). Furthermore, the assembled asymmetrical supercapacitor delivered a maximum energy density of 380 mW h cm⁻² at a power density of 1600 mW cm⁻². Such characteristics suggest that the well-aligned ZIF-67 arrays on CC substrate have enormous potential for use in high-performance supercapacitors and can serve as an important platform for other applications, such as energy storage, catalysis and gas adsorption/separation.