Three-dimensional hollow ZnS/MXene heterostructures 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 methodologies. 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. Additionally, 3D hollow ZnSMX not only enhances the conductivity of ZnS, enabling rapid charge transfer, but also effectively show restacking of MXene nanosheets to maintain structural stability during the charge/discharge process. More importantly, the 3D porous structure provides ultrafast interfacial ion transport pathways and extra surficial and interfacial storage sites, thus boosting excellent storage performances in lithium-ion battery applications. The 3D ZnSMX exhibited a high capacity of 782.1 mA h 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 heterostructures can potentially be highly promising anode materials for high-multiplication lithium-ion batteries.