中文摘要：

以维生素C（VC）为还原剂，通过溶剂热还原法制备了纳米二氧化锡／三维大孔石墨烯复合负极材料（SnO2／3D（打）。SEM和TEM测试表明，SnO2／3DGr具有均匀分布的微米级孔隙，其中SnO2晶粒尺寸为6-8nm，且均匀分布在石墨烯片层表面。电化学测试表明所制备的SnO2／3DGr复合电极材料具有优异的电化学性能，该材料在电流密度为100ma／g时，循环100周之后仍然具有1678mAh／g的可逆比容量，在极高电流密度5A／g下，仍然保持405mAh／g的可逆比容量，表现出非常优异的循环稳定性和倍率性能。该材料独特的三维大孔结构以及SnO2与石墨烯的协同作用，很好地抑制了SnO2在循环过程中的体积效应，大大改善了SnO2负极材料的电化学性能。

英文摘要：

Three dimensional macroporous nano-SnO2/graphene composite （SnO2/3D Gr） was prepared using vitamin C as reducing agent via a facile two-step solvothermal method. SEM and TEM characterizations show that SnO2 nanocrystals with particle size of 6-8 nm are homogenously dispersed on the graphene nanosheets of the SnO2/3D Gr composite The as- prepared SnO2/3D Gr composite electrode exhibits excellent cycling stability and rate capability, which retains a reversible specific capacity of 1678 mAh/g after 100 cycles at a current density of 100 mA/g, and even at a very high current density of 5 A/g, still displays a reversible capacity of 405 mAh/g. The outstanding electrochemical performance of the SnO2/3D Gr composite could be credit to its unique three dimensional maocroporous structure and the synergistic effect between SnO2 nano- particles and graphene, which greatly hinders the volume expansion of SnO2 upon cycling.