Antimony Nanocrystals Encapsulated in Carbon Microspheres Synthesized by a Facile Self-Catalyzing Solvothermal Method for High-Performance Sodium-Ion Battery Anodes.

Antimony/carbon (Sb@C) microspheres are initially synthesized via a facile self-catalyzing solvothermal method, and their applicability as anode materials for sodium-ion batteries is investigated. The structural and morphological characterizations reveal that Sb@C microspheres are composed of Sb nanoparticles (∼20 nm) homogeneously encapsulated in the C matrix. The self-catalyzing solvothermal mechanism is verified through comparative experiments by using different raw materials. The as-prepared Sb@C microspheres exhibit superior sodium storage properties, demonstrating a reversible capacity of 640 mAh g(-1), excellent rate performance, and an extended cycling stability of 92.3% capacity retention over 300 cycles, making them promising anode materials for sodium-ion batteries.