Metal–Organic Framework-Assisted Synthesis of Three-Dimensional ZnCoS Effloresced Nanopillars@CNT Paper for High-Performance Flexible All-Solid-State Battery-Type Supercapacitors with Ultrahigh Specific Capacitance

In this study, we design and synthesize a conductive network of three-dimensional (3D) ZnCoS effloresced stone pillars grown on free-standing carbon nanotube (CNT) paper with strong adhesion via using two-dimensional ZnCo metal–organic framework arrays as the reactive template. The 3D mesoporous nanopillar structures of the ZnCoS@CNT electrode possess a high surface-to-volume ratio, which can not only provide the penetration of electrolyte ions and increase the employment of electrode materials but also easily permit the growth of other active materials, leading to a larger cyclic voltammogram area and longer charge–discharge times. The tailor-made ZnCoS@CNT paper electrode manifests an outstanding specific capacitance of 2957.6 F g^–1 (328.6 mAh g^–1) at a current density of 1 A g^–1. Additionally, the assembled ZnCoS@CNT//CNT foldable asymmetric solid-state supercapacitor (ASC) exhibits a prominent energy density of 68.8 Wh kg^–1 at a power density of 700 W kg^–1 and maintains long-term cycling with a specific capacitance preservation of 96% after 10,000 cycles. Moreover, the ASC device expresses distinguished performance uniformity and high flexibility without remarkable drops in capacitance in various flexing conditions. The 3D nanostructure of ZnCoS grown on CNT paper is expected to endow a great prospect for the development of cutting-edge foldable energy storage devices.