氮掺杂石墨烯一维硅纳米复合结构制备方法及储锂机理研究

Development of high specific capacity, high energy density and stable electrode is the main task for lithium ion batteries, which not only has been the key point, but also been the most difficult obstacle in lithium battery (LIB) study. Silicon, which delivers the highest theoretical specific capacity in anode materials, has attracted tremendous interest. However, the large volume changes during the charging and discharging process will result in the serious crack of the electrode material, which leads to the instability of the electrode and further impedes the industrialization of the silicon based anodes. In our previous works, it has been observed that the composites of three-dimensional (3D) graphene and silicon nano thin film, graphene quantum dots (GQTs) decorated Si nanotubes were all shown enhanced LIB performance. In this project, the nitrogen-doped graphene and 1D Si nanoarchitectures will be proposed to build a new generation high performance LIB. The following aims will be achieved: 1) understand the role of nitrogen in the electrochemical process and find out the reason why it delivers so good performance; 2) reveal the nucleation process of 3D graphene and GQTs on silicon nanowire and silicon nanotube, and understand their further growth mechanisms; 3) explicit the nitrogen reaction kinetics in the chemical vapor deposition process and specify the bonding types of nitrogen in the graphene lattice. We propose that our project will benefit the design of high performance silicon based anodes and accelerate its industrialization process. Meanwhile, our project also provides evidence in how to grow high quality graphene on silicon surface and how to reach high efficient as well as effective nitrogen doping.

发展高能量密度，高功率密度和稳定的电极材料是锂离子电池开发的关键，也是当前锂电研究的重点和难点。硅材料由于具有超高的理论比容量从而引起人们广泛的关注，然而其在充放电过程中体积的剧烈变化导致电极结构不稳定，严重阻碍了硅基材料的产业化应用进程。申请人在前期工作中发现三维（3D）石墨烯，石墨烯量子点与硅纳米薄膜，硅纳米管的复合结构能显著提高电极稳定性。本项目将进一步结合氮掺杂的石墨烯，一维硅纳米结构构建高性能的锂离子电池，揭示氮原子对石墨烯/一维硅纳米材料电极的作用机理及高储锂能力的原因；明确高质量3D石墨烯，石墨烯量子点在硅纳米管，硅纳米线表面的形核生长机理；探究氮掺杂石墨烯等离子体化学气相沉积过程中氮原子反应动力学过程及其在石墨烯中的键和方式。本项目的预期结果将为构建硅基纳米电极及其产业化提供理论依据和实验指导。同时，本项目也为石墨烯在硅材料表面生长，石墨烯的氮掺杂提供了理论基础和科学依据。

发展高能量密度，高功率密度和稳定的电极材料是锂离子电池开发的关键，也是当前锂电研究的重点和难点。硅材料由于具有超高的理论比容量从而引起人们广泛的关注，然而其在充放电过程中体积的剧烈变化导致电极结构不稳定，严重阻碍了硅基材料的产业化应用进程。申请人在前期工作中发现三维（3D）石墨烯，石墨烯量子点与硅纳米薄膜，硅纳米管的复合结构能显著提高电极稳定性。本项目将进一步结合氮掺杂的石墨烯，一维硅纳米结构构建高性能的锂离子电池，揭示氮原子对石墨烯/一维硅纳米材料电极的作用机理及高储锂能力的原因；明确高质量3D石墨烯，石墨烯量子点在硅纳米管，硅纳米线表面的形核生长机理；探究氮掺杂石墨烯等离子体化学气相沉积过程中氮原子反应动力学过程及其在石墨烯中的键和方式。本项目的预期结果将为构建硅基纳米电极及其产业化提供理论依据和实验指导。同时，本项目也为石墨烯在硅材料表面生长，石墨烯的氮掺杂提供了理论基础和科学依据。