Designing a 3D MXene microsphere encapsulating MOF-derived ZnSe nanoparticles as an anode for highly stable potassium-ion batteries

Abstract

The integration of metal–organic frameworks (MOF) into three-dimensional (3D) architectures has emerged as a promising strategy for enhancing the performance of energy storage devices. However, current approaches to achieve this integration are limited, especially for combining two-dimensional (2D) materials with MOFs to form complex 3D structures. In this study, 3D MXene-based microspheres encapsulating MOF-derived ZnSe@NC nanoparticles (3D MX/ZnSe@NC) were successfully fabricated by spray drying. The 3D structure effectively prevented restacking of MXene nanosheets and provided a large surface area with abundant ion storage sites. The uniform distribution of the ZnSe@NC nanoparticles within the MXene matrix not only prevented the aggregation of ZnSe crystals during cycling but also enhanced the electrical conductivity. Therefore, 3D MX/ZnSe@NC exhibited remarkable cycling stability (238 mA h g⁻¹ at 0.5 A g⁻¹ after 1000 cycles) and excellent rate performance (110 mA h g⁻¹ at 2.0 A g⁻¹), promoting its use as an anode material for potassium-ion batteries (PIBs). Furthermore, the K-ion storage mechanism was investigated to elucidate the reasons for the high performance of 3D MX/ZnSe@NC. The facile synthesis method and exceptional performance highlight the potential of 3D MX/ZnSe@NC as a high-performance anode material for PIBs. These findings contribute to the development of advanced electrode materials for next-generation energy storage devices.