Built-In Catalysis in Confined Nanoreactors for High-Loading Li–S Batteries
Qingping Wu, Zhenguo Yao, Xuejun Zhou, Jun Xu, Fahai Cao, Chilin Li
Abstract
A cathode host with strong sulfur/polysulfide confinement and fast redox kinetics is a challenging demand for high-loading lithium–sulfur batteries. Recently, porous carbon hosts derived from metal–organic frameworks (MOFs) have attracted wide attention due to their unique spatial structure and customizable reaction sites. However, the loading and rate performance of Li–S cells are still restricted by the disordered pore distribution and surface catalysis in these hosts. Here, we propose a concept of built-in catalysis to accelerate lithium polysulfide (LiPSs) conversion in confined nanoreactors, i.e., laterally stacked ordered crevice pores encompassed by MoS2-decorated carbon thin layers. The functions of S-fixability and LiPS catalysis in these mesoporous cavity reactors benefit from the 2D interface contact between ultrathin catalytic MoS2 and conductive C pyrolyzed from Al-MOF. The integrated function of adsorption–catalysis–conversion endows the sulfur-infused C@MoS2 electrode with a high initial capacity of 1240 mAh g–1 at 0.2 C, long life cycle stability of at least 1000 cycles at 2 C, and high rate endurance up to 20 C. This electrode also exhibits commercial potential in view of considerable capacity release and reversibility under high sulfur loading (6 mg cm–2 and ∼80 wt %) and lean electrolyte (E/S ratio of 5 μL mg–1). This study provides a promising design solution of a catalysis–conduction 2D interface in a 3D skeleton for high-loading Li–S batteries.