Fe系过渡金属-N/C复合材料的制备及其锂硫电池性能研究

硫正极存在导电性差、“穿梭效应”严重等问题，极大限制了锂硫电池的商业化应用。本项目提出对硫正极引入单原子催化理念，制备Fe系过渡金属-N/C复合材料；通过Fe系过渡金属（M）的单原子高效硫还原催化及掺杂N的协同作用，为锂硫电池多硫化物“穿梭效应”的解决提供新的途径。基于上述思路，本项目从碳材料可控氧化出发，研究氧化碳材料与掺N碳材料结构组成之间的转换关系，获得碳材料可控掺N工艺；对掺N碳材料实施Fe系过渡金属单原子掺杂，通过形成的M-Nx结构与掺杂工艺的关系研究，揭示掺N碳材料的Fe系过渡金属掺杂机制；对比研究碳材料、掺N碳材料、Fe系过渡金属-N/C复合材料作为硫正极载体的电化学性能，阐明Fe系过渡金属的单原子催化硫还原机制，揭示掺N和掺Fe系过渡金属对碳材料电化学性能改善的协同作用；最终优化制备出高效、稳定的Fe系过渡金属-N/C复合材料，为锂硫电池的商业化应用提供技术指导。

The poor intrinsic conductivity and serious “shuttle effect” greatly restrict the commercialization of lithium-sulfur battery. This proposal introduces the concept of single-atom catalysis into sulfur cathodes, and synthesizes Fe-series transition metal-N/C hybrid. The co-effect of the high sulfur reduction capability of Fe-series transition metal and doped N atoms open new avenue for overcoming the “shuttle effect”. Based on the above thought, this proposal firstly investigates the relationship of structure and composition between oxidized carbon and N-doped carbon from the perspective of controllableoxidation of pristine carbon, and obtains the corresponding controllable N doping crafts. Then we dope Fe-series transition metal into N-doped carbon, and study the Fe-series transition metal doping mechanism by analyzing the as-formed M-Nx structure and related doping crafts, Besides, we plans to uncover the sulfurreduction catalysis mechanism of single-atom Fe-series transition metal by comparing the electrochemical performance of pristine carbon, N-doped carbon and Fe-series transition metal-N/C hybrid. Finally, it is expected to prepare high-performance Fe-series transition metal-N/C hybrid, which is beneficial to the commercialization of lithium-sulfur battery.