论文部分内容阅读
电极是实现高效电化学储能的基础,而常规的电极大多采用半导体甚至绝缘体为活性材料,不仅存在导电性差、电化学利用率低、倍率性能差等问题,而且部分电极材料在反应过程中还存在体积膨胀严重、中间产物流失等缺点,导致电极循环稳定性差.解决这些问题的有效途径之一是从电极材料的微纳结构入手,设计兼具高电化学活性及高结构稳定性的材料.石墨烯具有优异的导电性、超高的比表面积、柔性的二维结构及良好的机械性能,可用于构建高性能复合电极.石墨烯基电极材料结构主要包括核壳结构、三维网络结构、多级孔结构、三明治结构等,这些结构均对电化学储能器件的性能有不同程度的提升.本文以结构设计为主线总结了石墨烯在二次电池(如锂离子电池、锂硫电池和锂空气电池)电极材料结构设计中的应用,分析了不同结构类型在改善电化学性能方面的优势,为提高电化学储能体系的性能带来启示.
Electrodes are the basis of high-efficiency electrochemical energy storage. However, conventional electrodes mostly use semiconductors or even insulators as active materials, not only have poor conductivity, low electrochemical utilization, poor rate performance, etc., but also some of the electrode materials in the reaction process There are some shortcomings such as serious volume expansion and intermediate loss, which leads to poor cycle stability of the electrode.One of the effective ways to solve these problems is to design the material with high electrochemical activity and high structural stability from the micro / nano structure of the electrode material. Graphene has excellent conductivity, high specific surface area, flexible two-dimensional structure and good mechanical properties, which can be used to build high performance composite electrode. Graphene-based electrode materials mainly include core-shell structure, three-dimensional network structure, Level hole structure, sandwich structure, etc. These structures all improve the performance of electrochemical energy storage devices.In this paper, the structural design of the main line summarizes the graphene in the secondary battery (such as lithium-ion battery, lithium-sulfur battery and lithium Air battery) electrode material structure design, analysis of the different types of structures in improving the electrochemical properties Plane, bringing enlightenment to improve the performance of electrochemical energy storage systems.