Regulating Li<sub>2</sub>S Deposition and Accelerating Conversion Kinetics through Intracavity ZnS toward Low-Temperature Lithium–Sulfur Batteries
Hao Ding, Zhonghui Chen, Huiyu Li, Hong Li Suo, Chaozhong Liu, Huanan Yu, Jingkun Yuan, Zixu Sun, Yanyan Zhu, Bo Song
Abstract
The uncontrolled deposition behavior and sluggish conversion kinetics of the discharging product (solid Li 2 S) severely deteriorate the electrochemical performance of lithium–sulfur (Li–S) batteries, especially under high S loading and low-temperature conditions. Herein, a multifunctional S cathode host consisting of ZnS nanoparticles (NPs) confined in hollow porous carbon spheres (ZnS@HPCS) is synthesized via a unique capillary force-driven melting-diffusion strategy. The porous carbon shell of ZnS@HPCS provides a space-confined reservoir for soluble polysulfides and solid Li 2 S, while the intracavity ZnS NPs trap polysulfides, induce Li 2 S inside deposition, and accelerate conversion kinetics. Thus, Li–S batteries with ZnS@HPCS-S cathodes exhibit excellent electrochemical performance at both room and low temperatures (−40 °C) and high reversible capacities under high S loading (5.2 mg cm –2 ). Furthermore, Li 2 S nucleation/deposition, in situ Raman, and theoretical analyses reveal the underlying mechanism. This work offers fundamental insights into regulating Li 2 S deposition and designing S hosts for high-performance Li–S batteries.