(1. 日立(中国)研究开发有限公司上海分公司，上海 200020；
2. 上海交通大学-日立材料创新联合实验室，上海 200240;
3. 上海交通大学 化学化工学院，上海电化学能源器件工程技术研究中心，上海 200240)
摘 要: 将原位溶剂热法、冷冻干燥和高温煅烧相结合，制备了石墨烯基锡铜复合物(SnCu@GS)。对SnCu@GS的嵌钠特性和电化学性能进行了研究。结果表明：在溶剂热反应中，石墨烯构建了一个三维多孔导电网络且片层上均匀分布着直径约70 nm的锡铜纳米颗粒。通过相同方法制备的无石墨烯支撑的锡铜小球的粒径差异较大，分布范围为200~4 μm。这表明作为石墨烯导电网络来源的氧化石墨烯的引入可以有效防止纳米颗粒在反应过程中的二次团聚。SnCu@GS具有较好的循环稳定性和倍率性能，在200 mA/g电流密度下循环200次依然具有150 mA？h/g的可逆容量。
关键字: 石墨烯；溶剂热法；锡铜；纳米颗粒；钠离子电池
（1. Hitachi (China) Research & Development Corporation, Shanghai 200020, China;
2. Shanghai Jiao Tong University-Hitachi Materials Technology Innovation Joint Laboratory, Shanghai 200240, China;
3. Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:The SnCu@GS (SnCu nanoparticles anchored on graphene sheets) composite was successfully synthesized by a strategy integrating an in-situ solvothermal method and a freeze-drying process with a subsequent annealing procedure. The electrochemical performance of nano-sized SnCu granules anchored on graphene matrix as an anode for sodium-ion batteries was also investigated. The results reveal that graphene constructs a three-dimensional porous conductive framework in solvothermal reaction and leads to a well dispersion of SnCu nanoparticles with an average diameter of about 70 nm on graphene sheets. In contrast, SnCu spheres without graphene network obtained through the same route exhibit various diameters from 200 nm to 4 μm. The introduction of graphene oxide (GO) which is the original source of conductive GS network, can effectively inhibit the secondary aggregation of nanoparticles. The SnCu@GS composite shows superior cycling stability and rate capability. The specific reversible capacity of the SnCu@GS electrode can still maintain about 150 mA？h/g at a current density of 200 mA/g after 200 cycles.
Key words: graphene; solvothermal synthesis; tin-copper; nanoparticle; sodium-ion battery
