石墨烯基氧化锡复合电极材料的电子加速器辐照方略及其电化学性能

Graphene and tin dioxide are advanced functional materials with important application value, which have the broad application prospects in the fields of electrochemical industry and electrode materials. Since the tin dioxide in the charge/discharge process during lithium ions insertion/extraction generated insurmountable volume expansion led to instability of the electrode structure and a sharp decrease of the battery capacity, it greatly limits the effective applications of the tin dioxide anode materials. To solve this problem, the present study mainly focused on the graphene and tin dioxide composites, which improve the electrochemical performance of the tin dioxide to some extent, but failed to obtain an excellent electrode material. This project aims to explore the influence of electron-beam irradiation dose and irradiation time in the electron accelerator on the micro/nanostructures and electrochemical performance of graphene, tin dioxide and their composites. We believe that the electron-beam irradiation can induce changes in the graphene layer spacing; tin dioxide nucleation and growth; surface/interface functional groups, dangling bonds and defects (radiation damage); and radiation thermal effects, which will lead to a series of important implications in electrochemical performance. We will explore the relationship between the optimal irradiation conditions, such as irradiation dose and irradiation time, and its electrochemical performance, and provide some scientific bases for the potential applications of electron-beam irradiated tin dioxide/graphene composites used as electrode materials.

石墨烯和二氧化锡是具有重要应用价值的功能材料，它在电化学工业、电极材料等领域具有广泛的应用前景。由于二氧化锡在充/放电过程中锂离子嵌入/脱出产生难以克服的体积膨胀而导致电极结构的不稳定和电池容量的急剧降低，极大地限制了二氧化锡负极材料的有效应用。为了解决这个问题，目前研究主要致力于将石墨烯和二氧化锡复合，在一定程度上改善了二氧化锡的电化学性能，但仍未能获得优良的电极材料。本项目旨在深刻探索在电子加速器中电子束的辐射剂量和辐照时间对石墨烯、二氧化锡及其复合材料的微纳米结构和电化学性能的影响。我们认为电子束辐照可能诱导石墨烯层间距的变化；二氧化锡的成核与生长；表面/界面官能团、悬键及缺陷(辐照损伤)的变化；辐照热效应等对其电化学性能或许产生一系列重要的影响。我们将探寻最佳辐照条件(如：辐照剂量和辐照时间等)与其电化学性能的相互关联，为电子束辐照后二氧化锡/石墨烯复合电极的潜在用途提供科学依据。

石墨烯和二氧化锡是具有重要应用价值的功能材料，它在电化学工业、电极材料等领域具有广泛的应用前景。由于二氧化锡在充/放电过程中锂离子嵌入/脱出产生难以克服的体积膨胀而导致电极结构的不稳定和电池容量的急剧降低，极大地限制了二氧化锡负极材料的有效应用。本项目设计并合成了一系列石墨烯负载二氧化锡，及其与金属单质纳米颗粒、氧化锡/硫化锡异质结构复合材料，研究了电子束辐照等方法对石墨烯结构、二氧化锡的成核与生长、表面/界面官能团、悬键及缺陷的变化的影响；并围绕材料结构设计、形貌结构调控、结构演变过程、石墨烯与活性材料之间导电骨架及限域作用的构建，及电化学性能改善机理进行了系统研究，得到了克比容量发挥高、首次库伦效率提升、循环及倍率性能大幅改善的一系列纳米二氧化锡/石墨烯复合材料。