Boosting Charge Transport and Catalytic Performance in MoS₂ by Zn²⁺ Intercalation Engineering for Lithium–Sulfur Batteries

Abstract

Transition metal dichalcogenides (TMDs) have been widely studied as catalysts for lithium−sulfur batteries due to their good catalytic properties. However, their poor electronic conductivity leads to slow sulfur reduction reactions. Herein, a simple Zn 2+ intercalation strategy was proposed to promote the phase transition from semiconducting 2H-phase to metallic 1T-phase of MoS 2 . Furthermore, the Zn 2+ between layers can expand the interlayer spacing of MoS 2 and serve as a charge transfer bridge to promote longitudinal transport along the c-axis of electrons. DFT calculations further prove that Zn-MoS 2 possesses better charge transfer ability and stronger adsorption capacity. At the same time, Zn-MoS 2 exhibits excellent redox electrocatalytic performance for the conversion and decomposition of polysulfides. As expected, the lithium−sulfur battery using Zn 0.12 MoS 2 -carbon nanofibers (CNFs) as the cathode has high specific capacity (1325 mAh g −1 at 0.1 C), excellent rate performance (698 mAh g −1 at 3 C), and outstanding cycle performance (it remains 604 mAh g −1 after 700 cycles with a decay rate of 0.045% per cycle). This study provides valuable insights for improving electrocatalytic performance of lithium−sulfur batteries.

Boron-Doped Dinickel Phosphide to Enhance Polysulfide Conversion and Suppress Shuttling in Lithium–Sulfur Batteries

“…However, their intrinsic poor conductivities decrease electron conduction and hinder the further improvement of slow Li–S redox kinetics. Compared to most oxides and sulfides, transition metal phosphides (TMPs) usually have high electronic conductivities. , Pan and co-workers built a unique structure of Zn 2+ intercalated MoS 2 , which not only possesses better charge transfer ability and stronger adsorption capacity but also exhibits excellent electrocatalytic activity for the sulfur reduction reactions. In addition, TMPs also demonstrated great potential to catalyze hydrodesulfurization (HDS) processes. − Among various reported TMPs, Ni 2 P has been identified as the most promising HDS catalyst because of its rich coordination environments and special interaction with substrate molecules.…”