石墨作为锂离子电池的负极材料已经使用了很长时间。但由于其嵌锂容量低,已不能满足动力电池快速发展的需求。而锡可以与锂形成合金,有可能取代石墨成为下一代锂离子电池负极材料。但是单纯的金属锡在电池循环过程中发生巨大的体积变化,容易导致电极材料的粉化。而碳材料具有较高的导电性,良好的机械性能和储锂性能。为了充分发挥金属锡和碳材料的优势,锡-碳(Sn-C)复合材料得到了广泛研究。本文详细介绍了无定型碳、石墨(G)、石墨烯(GP)、碳纳米管(CNT)、碳纳米纤维(CNF)等碳材料作为惰性的导电基体与锡形成的二元复合物,阐述了锡与其它金属(M)形成的碳基三元、多元复合物的结构和性能。通过总结近些年对锡碳复合物结构与性能的研究,相信多元复合和多种结构的应用是提高锡-碳复合负极材料的关键。其中,以Sn-Co-C为基础的多元复合负极材料最有可能走向市场应用。
Graphite has been used as the negative electrode in lithium ion batteries for more than a decade. But it can't meet the needs of power battery application due to the lowspecific capacity. To attain higher energy density batteries,tin,which can alloy reversibly with lithium,has been considered as a replacement for graphite.However,tin anodes always suffer from high volume changes during charge / discharge cycling,leading to premature degradation of the anode. Since carbonaceous materials exhibit high electrical conductivity,good mechanical compliance,and stable lithium storage capacities with a small volume expansion,people have paid more attention to them. In order to make full use of the advantages of both tin and carbon,different matrix phases are evaluated for tin-carbon( Sn-C) nanocomposites in this paper. Several carbonaceous materials including amorphous carbon,graphite( G),graphene( GP),carbon nanotubes( CNT),and carbon nanofibers( CNF) have been exploited as an inert and conductive matrix in Sn-based anode materials,thus providing various tin-carbon composite anode materials. After reviewing that,the focus turns to alloys of tin with metal( M) and carbon,forming ternary and multiple composite anode materials. Based on the progress that has already been made on the relationship between the properties and microstructures of Sn-carbon-based anodes,it is believed that manipulating the multi-phase and multi-scale structures could offer important means for furtherimproving the capacity and cyclability of Sn anodes. Overall,the Sn-Co-C-based composite anode materials may open the door to application.