Three-Dimensional Hollow ZnS/MXene Heterostructure with Stable Ti-O-Zn Bonding for Enhanced Lithium-Ion Storage

Abstract

An effective way to improve the cycling performance of metal sulfide materials is to blend them with conductive materials. In this paper, three-dimensional (3D) hollow MXene/ZnS heterostructures (ZnSMX) were prepared via a two-step process involving hydrothermal and template methodology. The formation of Ti-O-Zn bonds enables the firm bonding between ZnS nanoparticles and the MXene substrate at heterogeneous interfaces, which can act as "electron bridges" to facilitate electron and charge transfer. Most importantly, 3D hollow ZnSMX not only enhances the conductivity of ZnS, enabling rapid charge transfer, but also effectively restacking of MXene nanosheets to maintain structural stability during the charge/discharge process. More importantly, the 3D macroporous structure provides ultrafast interfacial ion transport pathways and extra surficial and interfacial storage sites, and thus, boosts the excellent storage performances in lithium-ion batteries applications. The 3D ZnSMX exhibited a high capacity of 782.1 mAh g-1 at 1 A g-1 current, excellent cycling stability (providing a high capacity of 1027.8 mA h g-1 after 350 cycles at 2 A g-1), and excellent rate performance. This indicates that 3D ZnS/MXene heterostructure has the potential to be a highly promising anode material for high-multiplication lithium-ion batteries.