Synchronous Regulation of S-Deficient ZnS-MoS₂ Heterostructure Nanoreactor for Fast and Durable Sodium Storage.

Abstract

The enhancement of charge transfer and the relief of volume stress of anode materials contribute to fully exploiting electrochemical performance for sodium ion storage. Herein, a hollow carbon polyhedra nanoreactor adhered with a ZnS-MoS₂ heterostructure with tunable sulfur vacancy content (denoted as <i>hp</i>-ZMS-600/700/800) is prepared by self-assembly and a temperature dependent sulfurization procedure. The intimate heterointerface and moderate sulfur vacancies provide fast ion/electron transfer channels, and the hollow nanoreactors afford large volume variation and maintain structural integrity during the sodiation/desodiation process. Theoretical calculations and in situ/ex situ characterization techniques reveal both excellent electron/ion diffusion dynamics and a sodium storage mechanism. As a result, the optimized <i>hp</i>-ZMS-700 anode in sodium-ion batteries delivers a high initial Coulombic efficiency of 96.3%, a high capacity of 398 mAh g^-1 at 0.1 A g^-1, good rate capability of 119.8 mAh g^-1 at 5 A g^-1, and an excellent capacity retention of 84.6% after 1000 cycles at 2 A g^-1.