Boosting redox kinetics in CoS/Ti_(3)C_(2)heterostructure via interfacial charge redistribution for high-energy-density supercapacitorsOA

Supercapacitors are indispensable for next-generation energy storage,achieving high energy density and long-term durability remains a formidable challenge.Conventional CoS suffers from poor conductivity,while Ti_(3)C_(2)faces severe restacking.Herein,we report a novel synthesis strategy that integrates metal-organic framework(MOF)growth with electrostatic self-assembly to construct heterojunction of CoS nanotubes coated with ultrathin Ti_(3)C_(2)nanofilms.Material characterization via SEM,TEM,XRD,and XPS systematically confirms the heterostructure formation,and chemical composition.This rational design synergistically leverages CoS high pseudocapacitance and Ti_(3)C_(2)metallic conductivity while the heterostructure mitigates restacking,enhances charge transfer,and stabilizes interfacial interactions.Density functional theory(DFT)calculations reveal strengthened OH-adsorption at the Co-Ti interface(E_(ad)=1.106 eV).Consequently,the CoS/Ti_(3)C_(2)@CC delivers a remarkable specific capacitance of 1034.21 F g^(-1) at 1 A g^(-1).Assembled into a supercapacitor,CoS/Ti_(3)C_(2)@CC//AC achieves a high energy density of 74.22 Wh kg^(-1) at 800 W kg^(-1),maintaining 89.13%initial capacitance after 10,000 cycles.Significantly,it exhibits a remarkably low leakage current(0.23μA)and ultra-prolonged voltage retention(47.14%after 120 h),underscoring exceptional durability.This work pioneers a rational heterostructure engineering strategy by integrating MOF-derived architectures with conductive MXene nanofilms,offering critical insights for the development of ultra-durable supercapacitors.