【摘要】 开发新的亲硫催化材料是解决锂硫电池正极多硫化锂存在的严重的穿梭效应和缓慢的动力学转化等问题的有效方案。构建了一种潜在的锂硫电池正极锚定材料—Janus过渡金属二硫属化物CoSTe单层膜，采用第一性原理计算发现多硫化物Li₂S_n团簇在CoSTe单层膜表面吸附能适中（0.88～2.85 eV）,大于石墨烯表面和有机电解液中的吸附能，且高阶Li₂S_n团簇的表面吸附在一定范围内得到了优化；Li₂S_n团簇的分解不太容易自发地在CoSTe膜层上发生；Li₂S_n团簇在CoSTe单层膜表面的扩散有其微观上的“通道”;Li₂S的解离能优于石墨烯表面，CoSTe单层膜比石墨烯表面更利于硫还原反应的顺利进行；CoSTe单层膜的金属特性在吸附Li₂S_n团簇后得以保留。综上，理论上Janus CoSTe单层膜表面在锂硫电池电极中具备优异的电化学性能，具有开发应用的潜力和价值。更多还原

【Abstract】 Developing new thiophilic catalytic materials is an effective way to solve the problems of the serious shuttle effect and slow kinetic transformation of the lithium polysulfide positive electrode in lithium-sulfur batteries. A potential cathode anchoring material for lithium-sulfur batteries based on a Janus transition metal disulfide CoSTe monolayer has been investigated. First-principles calculations show that the adsorption energy of polysulfide Li₂S_n clusters on the surface of the CoSTe monolayer is between 0.88 and 2.85 eV. These values are higher than those for adsorption on the surface of graphene and for organic electrolytes. The surface adsorption of high-order Li₂S_n was optimized in a certain range. The analysis showed that: the decomposition of Li₂S_n groups does not occur spontaneously on the CoSTe monolayer; the diffusion of Li₂S_n clusters on the surface of a CoSTe monolayer has its own microscopic “channel”; the dissociation energy of Li₂S is better than that for graphene, and the dissociation energy of the CoSTe monolayer is better than that of graphene; the metallic properties of the CoSTe monolayer are retained after the adsorption of Li₂S_n clusters. The results show that the surface of the Janus CoSTe monolayer has an excellent theoretical electrochemical performance as a lithium-sulfur battery electrode and suggests it has potential for practical application in batteries.更多还原