石墨相氮化碳/共轭导电聚合物网络复合材料可控合成及作为锂氧电池氧电极性能研究

The lithium-oxygen battery has attracted considerable interests due to its far higher theoretical specific energy density than that of the conventional lithium-ion battery. Among different factors, the activity of the oxygen electrode plays a pivotal role in determining the charging/discharging overpotential and cycling stability of the device. The current project focuses on the graphitic carbon nitride/three-dimensional conducting polymer network composites, aiming to reduce the overpotential in the oxygen reduction reaction/oxygen evolving reaction and relate the catalytic performance of the composites to their microstructure and surface properties. In details, we will develop the controllable synthesis of the composites, measure their catalytic activities in the oxygen reduction reaction/oxygen evolving reaction and study the working mechanism of the composites as the oxygen electrode in the lithium-oxygen battery. The current project is expected to render a new avenue to the tunable synthesis and structure optimization of the oxygen electrode for lithium-oxygen batteries and find the structure-activity relationship of the composites to clarify the working mechanism, thus providing theoretical and experimental data to develop highly-efficient next-generation metal-free oxygen electrodes used in the lithium-oxygen battery.

锂–氧气电池（简称锂氧电池）因其远超现有锂离子电池的高理论比能量密度受到广泛关注。在众多因素中，氧电极的活性对锂氧电池充放电过电位和循环性能有着重要的影响。本项目以石墨相氮化碳/共轭导电聚合物三维网络复合材料为研究对象，研究复合材料组成、微观结构及表面性质与其催化氧还原反应和析氧反应性能的内在联系，并构建锂氧电池高效无金属氧电极。项目的具体研究内容包括石墨相氮化碳/共轭导电聚合物三维网络复合材料的可控合成、复合材料催化氧还原反应和析氧反应的性能测试、锂氧电池氧电极的构建及其工作机理研究。本项目将发展锂氧电池氧电极可控制备与性能优化的新方法，建立复合材料结构与氧电极性能的内在关联，阐明其工作机理，为开发活性更高的无金属氧电极提供理论和实验基础。

项目围绕石墨相氮化碳/共轭导电聚合物复合材料的可控合成及其在锂氧电池氧电极和其他电化学储能器件中的应用来开展多项研究工作，制备出形貌可控、成分可调和高孔隙率的石墨相氮化碳/共轭导电聚合物复合材料，作为可逆氧电极。进一步以石墨相氮化碳和导电聚合物为活性组分，制备了一系列无金属/非贵金属复合材料，并构建了低过电势、长循环的锂氧电池。同时，创新性地提出了解耦正负极载流子策略，设计并构建高比容量柔性水系Zn-S混合电池。在项目的资助下，目前已在Advanced Materials、Advanced Energy Materials、Joule、Nano Energy、Chemical Engineering Journal、Journal of Materials Chemistry A和《科学通报》等国内外著名SCI学术期刊上发表论文23篇，其中影响因子10以上的文章有12篇，同时本项目发挥主要资助作用而作为第一顺序进行标注的文章共13篇。此外，本项目执行期间，共培养博士1名和硕士4名，其中1位硕士生获得北京市优秀毕业生和北京理工大学优秀硕士论文等荣誉。同时，通过本项目的资助，项目组参加国内外学术会议9人次，应邀做学术报告4人次，有力地促进了研究的开展及成果交流。