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

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. (C) 2019 Elsevier Ltd. All rights reserved.