Mn-doped MoS₂-based nano-cored-yarn electrode with high voltage energy storage

Yarn-like energy storage devices are recognized for their high integrability, wearable compatibility, and mechanical flexibility. However, integrating multi-dimensional nanomaterials with varying energy storage synergies in situ on a single yarn while ensuring high binding stability and energy density remains a significant challenge. Herein, the 1T/2H phase Mn-doped MoS₂ was synthesized via a one-step hydrothermal method, optimizing the doping ratio and lattice distortion induced by cationic point defects, which effectively extends the layer spacing and mitigates the hazardous and challenging conditions typically required for the synthesis of the 1T phase. Subsequently, nano-cored-yarn electrodes were fabricated with activated carbon fibers as the core layer and CF/MnₓMoS₂-CNF nanofibers as the shell layer through conjugated electrospinning, followed by twisting, winding, and carbonization. Due to the unique structural design and effective defect regulation, coordination inhibits water decomposition in aqueous electrolytes at high operating voltages, resulting in the stable electrochemical performance at an output voltage of 1.6 V for the assembled nano-cored-yarn solid-state supercapacitors (NYCs). The symmetrically NYCs achieved a maximum energy density of 308.7 μWh/cm³ (power density of 5.5 mW/cm³) and a maximum power density of 16.9 mW/cm³ (energy density of 258.1 μWh/cm³), which still maintained 86.4% of the original capacity after 5000 charge/discharge cycles. This research provides innovative ideas and solutions for the design and integration of nano-cored-yarn capacitors characterized by a high voltage window and high energy density.