乳液分散法制备高分散纳米锡/介孔碳复合材料及其电化学性能

Emulsion Disperse Synthesis of High Scattered Nanotin-Based Mesoporous Carbon Composite and Its Electrochemical Performance

以间苯二酚和糠醛聚合而成的可溶性树脂为碳源,SnCl2为锡源,表面活性剂F127为模板剂,通过乳液分散法将锡源原位复合嵌入于介孔碳材料中,制备了纳米锡基材料高度分散于介孔碳中的复合材料。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、N2吸脱附(BET)、循环伏安(CV)等对材料的微观结构和电化学性能进行了表征。结果显示锡基材料在介孔碳中较为密集,分布均匀,粒径小于5 nm。介孔碳丰富的孔道结构有效限制和缓解了锡基材料的生长、团聚和体积膨胀,同时高比表面积增加了电解液与锡基活性材料的接触,提供了更多的反应活性点,从而获得了更高的电化学活性。充放电测试结果显示,700℃热处理后,锡/介孔碳纳米复合材料经过50次循环后实际放电比容量达203.4 mAh.g-1,表现出良好的电化学性能。

The tin-based particles with the average particle size of ～5 nm were embedded in the mesoporous carbon structure in emulsion disperse synthesis using soluble resorcinolfurfural oligomer as carbon precursor,F127 as template and SnCl2·2H2O as tin source.The effect on the electrochemical properties and performance of tin-based mesoporous carbon nanocomposites from different heat treatment in term of synthesis process has been evaluated and analyzed.The structures and electrochemical properties of the tin-based carbon nanocomposites were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,nitrogen adsorption/desorption,cyclic voltammetry（CV） and galvanostatic charge-discharge.The SnO2-SnO-Sn mixture phases were detected in XRD results.The tin-based mesoporous carbon nanocomposite prepared at 700 ℃ shows the improved electrochemical performance,and the practical discharge capacity still achieves 203.4 mAh·g^-1 after 50 cycles.