【摘要】 采用超临界干燥法制备了碳气凝胶(Carbon Aerogels,CA),然后通过简单的化学还原法制备CA/Sn Sb复合负极材料。采用XRD和SEM等手段对材料的结构及形貌进行了表征,利用恒电流充放电测试了材料的循环性能。研究结果表明,碳气凝胶表现出纳米多孔三维网络结构,当对Sn Sb合金采用碳气凝胶修饰后,纳米Sn Sb颗粒包含在碳气凝胶的网络骨架中,呈现出碳气凝胶和纳米Sn Sb合金颗粒相互交错分布的结构,极大改善了复合材料的团聚性。CA/Sn Sb复合负极材料首次放电容量高达1120.2 m Ah·g-1,循环50次后放电容量仍达到557.3 m Ah·g-1,远高于未经碳气凝胶修饰的Sn Sb合金。循环性能的改善主要归因于碳气凝胶的引入,不仅极大的改善了复合材料的团聚现象,而且可以缓冲Sn Sb合金在充放电过程中体积变化。更多还原

【Abstract】 Carbon aerogels were synthesized by supercritical drying method,then a carbon aerogels / Sn Sb composite was successfully prepared from carbon aerogels modification of Sn Sb by a simple chemical reduction method. Both the structure and the morphology of the Sn Sb and CA / Sn Sb powders were characterized by X-ray diffraction and SEM. The samples were used as active anode materials for lithiumion batteries,and their cycle performance was examined by constant current charge-discharge cycling.The results show that carbon aerogels exhibited nano porous three-dimensional network structure,and CA / Sn Sb is obtained when the Sn Sb was modified by carbon aerogels. The feature of CA / Sn Sb was carbon aerogels and Sn Sb particles mutually staggered distribution,and carbon aerogels particles were contained in the network backbone,then reunion of CA / Sn Sb was greatly improved. The first discharge capacity of CA / Sn Sb is measured as 1120. 2 m Ah·g- 1and a large reversible capacity of 557. 3 m Ah·g- 1is observed after 50 cycles,which is far higher than that of Sn Sb without modification by carbonaerogels. The capacity retention of CA / Sn Sb was improved due to the improving of reunion and alleviating volume expansion during the charge-discharge process by addition of carbon aerogels.更多还原