Vertically aligned 1T-2H MoS2 on 3D porous carbon for ultrahigh-performance flexible energy storage device

Abstract

The capacitance, conductivity, and ion migration ability of electrode materials are key factors affecting the energy density of supercapacitors (SCs). The synergistic application of porous carbon and two-dimensional (2D) materials can solve these problems. In this study, we successfully constructed porous B, N co-doped carbon (BNC) scaffolds on the surface of carbon cloth (CC), and vertically ordered 1T-2H MoS₂ (1T-2H MS) nanosheets with large interlayer spacing were then assembled on their surfaces, providing highly distributed active sites and large specific surface areas, and rapid charge transfer capability for high-capacity electrode materials. Refined structural characterization and density functional theory (DFT) calculations indicated that 1T-2H MS@BNC/CC heterostructures have reasonable structural/phase design advantages, with a conversion rate of up to 77%. Benefiting from the structure and metal phase advantages, the 1T-2H MS@BNC/CC electrode exhibited a good electrochemical storage mechanism under alkaline conditions, with an ultrahigh-performance of 994.3 F g⁻¹ at a current density of 0.5 A g⁻¹, and cycling stability was maintained at 80% even after 6000 cycles. Furthermore, the resulting 1T-2H MS@BNC/CC//AC/CC asymmetrically flexible, all-solid-state supercapacitors (FASCs) achieved a dramatically high energy density of 92.3 Wh kg⁻¹ at 349.7 W kg⁻¹ and remarkable cycling lifespan (∼91% retention over 1000 cycles). Surprisingly, a single FASC could successfully activate the electronic clock for 15 minutes, and two FASCs in a series could light up the LED for 10 minutes. The outstanding FASCs exhibited perfect structural and durable stability upon bending, indicating their superiority in flexible energy storage devices.