(1. 日立(中國(guó))研究開發(fā)有限公司上海分公司，上海 200020；
2. 上海交通大學(xué)-日立材料創(chuàng)新聯(lián)合實(shí)驗(yàn)室，上海 200240;
3. 上海交通大學(xué) 化學(xué)化工學(xué)院，上海電化學(xué)能源器件工程技術(shù)研究中心，上海 200240)
摘 要: 將原位溶劑熱法、冷凍干燥和高溫煅燒相結(jié)合，制備了石墨烯基錫銅復(fù)合物(SnCu@GS)。對(duì)SnCu@GS的嵌鈉特性和電化學(xué)性能進(jìn)行了研究。結(jié)果表明：在溶劑熱反應(yīng)中，石墨烯構(gòu)建了一個(gè)三維多孔導(dǎo)電網(wǎng)絡(luò)且片層上均勻分布著直徑約70 nm的錫銅納米顆粒。通過(guò)相同方法制備的無(wú)石墨烯支撐的錫銅小球的粒徑差異較大，分布范圍為200~4 μm。這表明作為石墨烯導(dǎo)電網(wǎng)絡(luò)來(lái)源的氧化石墨烯的引入可以有效防止納米顆粒在反應(yīng)過(guò)程中的二次團(tuán)聚。SnCu@GS具有較好的循環(huán)穩(wěn)定性和倍率性能，在200 mA/g電流密度下循環(huán)200次依然具有150 mA？h/g的可逆容量。
關(guān)鍵字: 石墨烯；溶劑熱法；錫銅；納米顆粒；鈉離子電池
（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
