Controllable growth of hierarchical MoSe2 hollow microspheres for enhanced sodium storage

Abstract Molybdenum selenide has attracted considerable attention for sodium-ion batteries (SIBs) due to its excellent reactivity and large capacity compared to other transition metal dichalcogenides (TMDs). Herein, a facile template-free hydrothermal process is conducted to synthesize hierarchical MoSe2 hollow microspheres with the diameters of ∼1.5 μm. The as-prepared MoSe2 hollow microspheres consist of cross-linked nanosheets. As an anode of SIBs, the hierarchical MoSe2 hollow microspheres exhibit a high initial discharge capacity of 710.2 mAh g-1. When the current density is as high as 1000 mA g-1, the specific capacity can still maintain at 290 mAh g-1. The excellent cycling performance and rate capability are due to the hollow microspherical architecture, which shortens the diffusion length of Na+, promotes the penetration of electrolyte into active materials and accommodates the volume stress. It is a successful case to obtain hollow architectures to shed some lights on the high-performance SIBs.