Hollow Carbon Spheres Embedded With Vn Quantum Dots As An Efficient Cathode Host For Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries are a prospective battery technology with high energy density, whereas the successful implementation of Li-S batteries is still impeded by many challenges, especially the shuttling effect of lithium polysulfides (LiPSs) and sluggish redox kinetics. Therefore, it is urgent to find a novel host material that could tackle these problems with a cost-effective manner. Herein, the mesoporous and hollow carbon sphere embedded with homogeneous VN quantum dots (noted as VN-H-C) is constructed and applied as an efficient host for a sulfur cathode, which features both physical and chemical trapping ability for soluble LiPSs. More importantly, VN quantum dots can significantly accelerate the electrochemical conversion of LiPSs. As a consequence, the S@VN-H-C cathode exhibits a high specific capacity of 856.5 mAh g(-1) at 1 C and maintains 602.5 mAh g(-1) after 500 cycles with a low capacity decay rate of only 0.059% per cycle. This study provides a feasible strategy for designing nanostructured materials as effective sulfur hosts in Li-S batteries.