A mulberry-like hollow carbon cluster decorated by Al-doped ZnO particles for advanced lithium-sulfur cathode

Highlights: • Interconnected primary particles provide stable and conductive network. • Less surface area exposed in electrolyte decreases polysulfides dissolution. • Polar Al-doped ZnO provides chemical adsorption and reduce capacity decay. • Conductive AZO particles enhances rate performance and delivers higher capacity. -- Abstract: To improve the electrochemical performances of lithium-sulfur (Li-S) batteries and extend their cycle life, a mulberry-like Al-doped ZnO (AZO) particles decorating carbon cluster composite (C@AZO cluster) is synthesized as the Li-S cathode material. The C@AZO/S composite, with the sulfur content of 70 wt% and the sulfur mass loading of 2.2 mg cm⁻², delivers a high initial specific capacity of 974.2 mAh g⁻¹ at the current density of 0.5C (1C = 1675 mAh g⁻¹) and a low capacity decay of 0.12% per cycle over 300 cycles. In this composite, the interconnected primary carbon spheres decorated by conductive AZO particles provide a fast charge transmission network which could greatly enhance the reaction kinetics and rate performance of Li-S batteries. Meanwhile, the integrated architecture of carbon cluster and the polarity brought by AZO could effectively reduce the dissolution of polysulfides to improve the cycle stability.