碳气凝胶修饰SnSb复合负极材料的制备及性能研究

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/SnSb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SnSb合金采用碳气凝胶修饰后,纳米SnSb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SnSb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/SnSb复合负极材料首次放电容量高达1120.2 mAh·g-1,循环50次后放电容量仍达到557.3 mAh· g-1,远高于未经碳气凝胶修饰的SnSb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SnSb合金在充放电过程中体积变化。

Systhesis and Performance of SnSb Anode Materials Modified by Carbon Aerogels

Carbon aerogels were synthesized by supercritical drying method, then a carbon aerogels/SnSb composite was successfully prepared from carbon aerogels modification of SnSb by a simple chemical reduction method. Both the structure and the morphology of the SnSb and CA/SnSb powders were characterized by X-ray diffraction and SEM. The samples were used as active anode materials for lithium-ion 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/SnSb is obtained when the SnSb was modified by carbon aerogels. The feature of CA/SnSb was carbon aerogels and SnSb particles mutually staggered distribution, and carbon aerogels particles were contained in the network backbone, then reunion of CA/SnSb was greatly improved. The first discharge capacity of CA/SnSb is measured as 1120. 2 mAh·g-1 and a large reversible capacity of 557. 3 mAh· g-1 is observed after 50 cycles, which is far higher than that of SnSb without modification by carbon aerogels. The capacity retention of CA/SnSb was improved due to the improving of reunion and alleviating volume expansion during the charge-discharge process by addition of carbon aerogels.