▎ 摘　　要

SnO based material is one of the most promising anode materials for lithium-ion batteries owing to its high theoretical capacity. However, the difficult synthesis process, large volume expansion and rapid capacity decay, etc., limited its further application. Herein, graphene encapsulated SnO nanospheres, self-assembled from numerous nano-sized secondary nanoparticles, have been successfully synthesized through an efficient one-pot solvothermal method within three hours. The graphene encapsulation and secondary particle assembly structure effectively improves the conductivity of SnO, shortens the ion transmission path and reduces its volume expansion during cycling, thus achieving cycle stability. SnO/G-3 H composite delivers a discharge capacity of 1307 mA h g-1 after 700 cycles at 800 mA g-1, and maintained an enhanced rate capability of 423 mA h g-1 at 3000 mA g-1. This simple, economic, and environmental-friendly synthesis route can be extended to the preparation of other transition metal oxide materials.