Metal-electronegativity-induced sulfur-vacancies and heterostructures of MnS1-x/ZnS-NC@C with dual-carbon decoration for high-performance sodium-ion storage

Abstract Engineering unique architectural anode electrode materials with high storage capacity and stable structures to balance kinetics and capacity between anode and cathode possesses a huge challenge for sodium-ion hybrid capacitors (SIHCs). Herein, beginning with well-organized MnS nanoparticles, an elaborate design of introducing metal-organic frameworks and decorating with dual-carbon is presented to fabricate a desirable composite of bimetallic sulfide and carbon with carbon matrix/coating layers via electronegativity induction. The simultaneously formed rich sulfur-vacancies and heterostructures can significantly boost fast electron/ion diffusion kinetics and induce high reversible sodium-ion storage capacities. Moreover, dual-carbon decoration tactics allow the electrodes for superior electronic conductivity, guarantee a splendid structural stability and offer an avenue for electron transport, which enable MnS1-x/ZnS-NC@C (MSZNC) composites a steady capacity of 354 mAh g−1 for 1600 cycles at a high rate of 10 A g−1 in sodium-ion batteries (SIBs). Integrated with theoretical calculations, the systemic electrochemical kinetic analytical results reveal that the synergistic effect of heterostructures and sulfur-vacancies can furnish more reversible active sites and boost charge transfer, thereby accelerating reaction kinetics for an enhanced sodium-ion storage capability. As expected, the assembled SIHCs full cell based on MSZNC anode and AC cathode exhibits a high energy density of 116 W h kg−1 and a high power output of 95 W kg−1, a capacity retention of 87% at 2 A g−1 for 2000 cycles, certifying its practical applications potential on a wide scale for sodium-based energy storage devices.