Hollow carbon nanospheres confining Te-doped MoS2 with anionic vacancies: A synergistic design for efficient sodium storage

Abstract

The pursuit of high-performance anode materials with exceptional cycling stability and high rate capability is critical for the advancement of sodium-ion batteries and hybrid capacitors. Herein, a core-shell composite of Te-doped MoS 2 nanosheets enclosed in hollow porous carbon spheres (HPCs) was synthesized via a hydrothermal-tellurization strategy. The incorporation of Te heteroatoms effectively expands the interlayer spacing of MoS 2 and introduces anionic defects, which greatly improves the reaction kinetics for sodium storage. The HPCs shell buffers volume expansion of MoS 2 , while the mesoporous structure facilitates rapid ion transport. DFT calculations further reveal that the carbon shell actively participates in charge transfer and enhances Na + adsorption in synergy with Te doping. The Te-MoS 2 @HPCs electrode delivers a high discharge capacity and excellent cycling stability in sodium-ion half-cells. In addition, sodium-ion hybrid capacitors fabricated with the Te-MoS 2 @HPCs anode exhibited a notable energy/power density of 101 Wh kg −1 /17394 W kg −1 and maintained 92.5% capacity after 8000 cycles. Furthermore, sodium-ion full-cells assembled from the Te-MoS 2 @HPCs anode and a commercial NVP cathode exhibited excellent energy/power density and stable cycling performance. This study presents a synergistic design paradigm for hollow-structured composites in advanced energy storage applications.