百纳米三维石墨烯网络的CVD合成及其在超快能源存储的应用

The high development of portable electronics, electric tools and electric vehicles raises with the demand of better batteries with high energy density and high power density, which is mostly limited by the transport of electrons. Few effort has been made to improve it. Here, it is proposed to build 3D graphene nano-network to solve this problem. Without the increase of weight of inactive material in the electrode and the decrease of the volumetric energy density, by emmbedding active mateirals uniformly in the light-weight and highly conductive 3D graphene nano-network, the power density of Li-ion battery and the energy density of pseudo-supercapacitor can be significantly enhanced. By systematically investigating the factors related to the transport of Li ions and electrons one by one, the relationship between the structure and electrochemical performance can be mapped, which provides a novel route and full solution for reaching high energy and high power energy storage. In the meantime, the innovative 3D graphene can be fabricated in a simple and verstaile method, which can be broadly used in the fields of energy storage, sensor, catalysis and hydrogen production.

便携式电子设备，电动工具和电动汽车等的高速发展对于电池设备提出了高能量高功率的要求，其中电池电极的电子输运能力是制约其高功率输出的主要因素，但缺乏有效解决途径。本项目提出用百纳米级别的三维石墨烯网络结构来有效解决这一问题，在不显著增加体系无用质量和不显著降低体系体积能量密度的前提下，使电池活性材料均匀分布在一个质地又轻导电又优的石墨烯多孔网络当中，从而实现锂离子和电子的快速输运来显著提高锂离子电池和赝电容的电化学性能。通过分立调控锂离子和电子输运的各个因素，建立清晰的结构与电化学性质的物理相图，为解决高能量高功率能量存储提供了新的物理思路和系统解决方案。同时，本项目提供了一种新颖的三维石墨烯结构，可以被广泛应用于电池、传感器、催化和制氢等领域。

本项目针对百纳米三维石墨烯导电网络的构建及其在能源存储中的应用等关键问题开展了系统研究，通过多种方法构建了不同结构的石墨烯三维网络，尺寸从百微米级到百纳米级连续可调，针对不同的能源存储条件，有针对性的采取复合方案，实现了在锂离子电池尤其是硅基负极材料和铝离子电池中的应用，由于三维石墨烯导电网络的帮助，极大提升了所制备电极材料的电化学性能，主要提升了电极的结构稳定性及电化学循环特性，更为重要的是三维石墨烯的导电网络提供了良好的电子通道以及离子通道，因此在硅基负极材料、锂硫电池以及铝离子电池中获得了极为优异的倍率性能。本研究对于未来三维石墨烯网络的构建及其在能源存储中的应用奠定了理论基础并提供了一些指导方向。目前已发表SCI论文6篇，已申请发明专利2项，一共培养研究生5名，其他技术人员2名。