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论文类型： 期刊论文

发表时间： 2017-12-13

发表刊物： ACS APPLIED MATERIALS & INTERFACES

收录刊物： SCIE、EI、PubMed

卷号： 9

期号： 49

页面范围： 42836-42844

ISSN号： 1944-8244

关键字： atomic sulfur; silicene; phosphorene; borophene; intrinsic shuttle inhibition

摘要： Dissolution of intermediate lithium polysulfides, (LiPS) is an inevitable obstacle for the solid sulfur-based cathode in Li-S batteries. For the first time, herein, atomic sulfur is incorporated into silicene, phosphorene, and borophene to intrinsically eliminate the dissolution of LiPS. The small molecular sulfur species are anchored on the silicene surface with stronger Si-S interaction than the P-S and B-S ones. Meanwhile, a high atomic sulfur coverage (63.1 wt %) is achieved in silicene and concomitantly stabilizes the silicene layer. For the S-3-covered silicene, a high theoretical capacity of 857 mA h g(-1) is achieved with slight dissolution of LiPS originated from the loss of interior S atoms that are not directly bound with silicene surface. By realizing the elemental S-2 coverage on silicene with large surface area, the Li+ ions can react fast with the S-2 species, leading to a high theoretical capacity of 891 mA h g(-1) without dissolution and migration of the intermediate LiPS. Most interestingly, the discharge products of atomic layer of lithium sulfides on silicene surface exhibit completely different behaviors from the traditional discharge products of solid Li2S,which can function as effective adsorption and activation sites for the conversion of LiPS from long chain to short chain by accelerated redox reaction. The present study gains some key insights into how the atomic sulfur contributes to the intrinsic shuttle inhibition and offers a feasible way to design the atomic sulfur-based cathode materials of Li-S batteries with better electrochemical performance.