基于异原子掺杂多孔碳/碳量子点催化材料的空气电极设计及其电化学性能提升机制研究

Alkaline zinc-air batteries could be one of ideal next-generation energy storage devices with high energy and power density. However, the weak catalytic activity and poor life severely limit its large-scale commercial application. In order to meet these challenges above, a novel electrocatalyst, is proposed in this project. The catalytic active sites on the surface of catalyst can be controlled by combining carbon quantum dot with porous carbon. Then the heteroatom-doping process is carried out to enhance its catalytic activity, which finally leads to a highly active and stable carbon catalyst. The modification of air cathode is based on the optimized catalyst which is distributed in the catalytic layer/ gas diffusion layer/Ni foam as much-little-none. Through these two effective methods (highly active electrocatalyst and new-type design of air electrode), the electrochemical performance of air cathode can be enhanced. This project mainly focuses on the controllable mechanism of carbon quantum dot on the surface active sites, which can further reveal the effect of the microstructure, surface defects and doping atom types of above-mentioned carbon material on catalytic activity. By balancing the composition of layers of air electrode, optimizing the structure of electrode，the mechanism of O2 reduction reaction enhancement can be obtained, which can offer theoretical guide for the research of long-life and high-power density zinc-air batteries.

碱性水系锌/空气电池作为下一代清洁高比能储能器件研究热点之一，其空气电极的催化活性差、寿命短，严重制约了其规模化应用。为了有效解决空气电极存在的问题，本项目设计了一种新型电催化材料，通过将碳量子点和多孔碳材料进行复合来调控催化剂的表面活性位点，再对其进行异原子掺杂获得高稳定性、高催化活性的碳催化剂；并基于此材料构建新型空气电极，使催化剂材料在电极中的催化层/防水透气层/导电镍网三层中呈多-少-无分布；从而使电极在高活性催化剂材料与新型结构设计的双重作用下，电化学性能得到提升。项目重点研究碳量子点的引入对碳催化材料表面活性位点的调控机理，揭示碳材料微观结构、表面缺陷及掺杂对其电催化活性的影响机制；通过平衡空气电极各层组分，优化电极结构，阐明新型空气电极对氧气还原反应的促进机制，为获得高比能、长寿命的锌/空气电池提供理论指导。

碱性水系锌/空气电池由于比能量高，安全无污染等优点受到人们广泛关注，其空气电极的催化活性差、寿命短，严重制约了其规模化应用。为了有效解决空气电极该问题，本项目通过将碳量子点和石墨烯材料进行复合来调控催化剂的表面活性位点，再对其进行异原子掺杂，以获得高稳定性、高催化活性的碳催化剂。项目重点研究了碳量子点的引入以及异原子掺杂对碳催化材料表面活性位点的调控机理，揭示碳材料微观结构、表面缺陷及掺杂对其电催化活性的影响机制。并在此类新型材料基础上，构建高性能一次锌/空气电池空气电极。 此外，本项目还通过开发了一系列金属复合异原子掺杂碳材料，通过对材料的组分和结构进行优化调控，实现了二次锌/空气电池空气电极的高效发挥。同时阐明材料结构对空气电极电化学性能的影响机制，为获得高比能、长寿命的锌/空气电池提供理论支撑。项目研究期间，所有工作均围绕上述研究目标进行，并如期完成，共发表学术论文12篇，授权专利4项，培养博士研究生2名，硕士研究生3名。