掺杂型钴酸镍/石墨烯气凝胶复合材料的协同固硫机制与储能特性

锂硫电池是极具发展潜力的下一代储能系统，但存在电导率低、“穿梭效应”、锂枝晶生长等问题，严重阻碍了其发展。近年来正极的研究通常采用强极性材料以实现多硫化物的强吸附，进而抑制“穿梭效应”。但近期的理论研究表明，过强的吸附可能会导致多硫化物的直接分解并影响电池充电过程。因此，硫电极中多硫化物吸附强度对锂硫电池的影响，以及合适吸附强度范围的界定是重要的研究课题。本申请设计新型的Zn、Fe、N、S等元素掺杂的钴酸镍（NiCo2O4）固硫载体，通过便利的掺杂手段，系统调控NiCo2O4的电子结构及多硫化物的“化学吸附”强度，探索合适的吸附强度范围，并进一步结合石墨烯气凝胶的“物理吸附”作用，协同抑制“穿梭效应”。拟探索掺杂型NiCo2O4的形成机制和石墨烯气凝胶复合材料的结构演变规律，揭示多硫化锂的吸附规律与机制，探明储能特性和转化反应历程。研究结果为进一步设计高性能锂硫电池提供一定的理论基础。

Lithium-sulfur battery is one of the most promising next-generation energy storage systems, however, its development is severely hindered by the technical obstacles, such as the poor electronic conductivity, the shuttle effect, and the formation of lithium dendrites, etc. To restrain the shuttle effect and strongly adsorb the polysulphides, materials with strong polarity are often applied in the cathode research in recent years. However, recent theoretical research shows that too strong adsorption may cause the direct decomposition of the polysulphides and affect the battery charge process. Therefore, the effects of the polysulphides adsorption strength in the sulfur electrode on the lithium-sulfur battery performance and definition of appropriate adsorption strength are important research subjects. In this proposal, the novel sulfur host of the Zn、Fe、N、S doped NiCo2O4 will be designed, the electronic structure and chemical adsorption strength of NiCo2O4 will be systematically tuned, to explore the appropriate range of the adsorption strength. The physical adsorption of graphene aerogel will be further combined, to synergistically restrain the shuttle effect. The formation mechanisms of the doped NiCo2O4 and the structure evolution mechanisms of the graphene aerogel composite will be systematically explored, the law and mechanisms of the polysulphides adsorption and the strength range will be revealed, and the energy storage characteristics and relevant conversion reaction processes will be clarified. These results will provide reliable theoretical bases for the further design of high-performance lithum-sulfur battery.