2023年9月25日，Elsevier 旗下top期刊《Journal of Colloid and Interface Science》在线发表了云南师范大学化学与化工学院引进人才肖凤屏博士、能环学院胡鹏、陕西师范大学Na Li等团队合作的最新研究成果《Encapsulation of Sulfur in MoS2-Modified Metal-Organic Framework-Derived N, O-Codoped Carbon Host for Sodium–Sulfur Batteries》。第一作者单位为云南师范大学化学化工学院第一作者单位，肖凤屏、胡鹏和Na Li为共同通讯作者。

Abstract

Room-temperature sodium–sulfur batteries (RT Na-S) are promising energy storage systems with high energy densities and low costs. Nevertheless, drawbacks, including the limited cycle life and sluggish redox kinetics of sodium polysulfides, hinder their implementation. Herein, a heterostructure of MoS2 nanosheets coated on a metal-organic framework (MOF)-derived N, O-codoped flower-like carbon matrix (NOC) was designed as a sulfur host for advanced RT Na-S batteries. The NOC@MoS2 hierarchical host provided a sufficient space to guarantee a high sulfur loading and confinement for the volume expansion of sulfur during the charge/discharge process. According to first-principle calculations, the NOC@MoS2 composite exhibited metallic conductivity because electronic states crossed the Fermi level, which indicates that the introduction of NOC significantly improved the electronic conductivity of MoS2. Furthermore, electron transfer from MoS2 to the O-doped carbon sites was observed owing to the strong electronegativity of O, which can effectively increase the Lewis acidity of MoS2 and weaken the sodium–sulfur bonds in sodium polysulfides after adsorption on the cathode, leading to reductions in the Na2S dissociation energy barrier and Gibbs free energy for the rate-limiting step of the sulfur reduction process. Therefore, with the synthetic effects of MoS2 and N, O-codoped carbon, the obtained cathode exhibited a superior electrochemical performance.

https://doi.org/10.1016/j.jcis.2023.09.134