Engineering monodispersed 2 nm Sb₂S₃ particles embedded in a porphyrin-based MOF-derived mesoporous carbon network...

Sodium ion batteries (SIBs) are expected to replace lithium ion batteries (LIBs) as the next generation of large-scale energy storage applications because of their superior cost performance. However, the larger ionic radius of Na⁺ causes a remarkable volume expansion than that of Li⁺ during charge and discharge, which reduces the performance of the battery. In this work, we engineered a composite material in that monodispersed 2 nm Sb₂S₃ particles are uniformly loaded into a carbon matrix (Sb₂S₃/CZM), which is obtained by carbonization of a zirconium-based MOF with adsorption of Sb. The obtained composite material has a high specific surface area in favor of mass transfer, and the porous structure can resist many volume changes in the circulation process. Moreover, the ultrafine Sb₂S₃ particles are well-distributed in the composite material, which increases the utilization of the active substance and is promising for the storage of Na⁺. Based on its unique structure, the Sb₂S₃/CZM composite shows a specific capacity of 550 mA h g^-1 at 100 mA g^-1 and an excellent cycling stability of 88.9% retention after 1000 cycles at 3 A g^-1. The excellent electrochemical performance provides enlightenment for the rational design of hierarchical heterostructures for energy storage applications.