Exploring the Janus structure to improve kinetics in sulfur conversion of Li-S batteries. (May 2022)

• Record Type: Journal Article
• Authors: Gueon, Donghee; Kim, Taeyoung; Lee, Jungyeon; Moon, Jun Hyuk
• Is Part Of: Nano energy. Volume 95(2022)
• Publication Date: 2022-05
• Subjects: Li-S batteries -- Janus particles -- Sulfiphlic metal compounds -- Lithium polysulfides -- Li2S growth; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2022.106980
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Lithium-sulfur (Li-S) batteries with high theoretical capacity have been attracting attention as next-generation energy storage systems. The random deposition of electrically insulating solid lithium sulfide (Li2 S) from lithium polysulfides (LiPSs) limits the complete conversion of sulfur. The introduction of sulfiphlic metal compounds to facilitate the conversion is not accompanied by morphological control over Li2 S deposition. To tackle this issue, we demonstrate a Janus-structured particle of oxide/carbon that regulates the Li2 S growth. The Janus particles are prepared by directional thermal deposition of MoO3 onto CNT-agglomerated spherical particles. Under potentiostatic discharge, we observe that Li2 S is deposited predominantly on MoO3 -coated regions on CNT particles, accompanied by high discharge capacity. As the deposition of Li2 S is microscopically controlled, the diffusion path of ions/charges in the electrode is preserved. Moreover, it is confirmed that the adsorption and catalytic properties of MoO3 are greatly promoted by its lithiation during the charge/discharge process. Janus particle cathode cells achieve excellent performance, especially under kinetically limited conditions, such as ultra-high C-rates or high cathode sulfur densities. Graphical Abstract: ga1 Janus particles partially coated with sulfiphlic MoO3 on spherical CNT-agglomerated particles are applied as sulfur hosts for lithium-sulfur batteries. The Janus particle-based cathode achieves excellent performance at high C-rate or high cathode sulfur density by microscopically controlling the growth of lithium sulfides during discharge. Highlights: We demonstrate a Janus-structured particle of oxide/carbon that regulates the Li2 S growth. The Janus particles are prepared by thermal deposition of MoO3 onto CNT-agglomerated spherical particles. The Janus particle electrode shows a high discharge capacity by the formation of Li2 S predominantly on the MoO3 surface. The Janus particle cell delivers a specific capacity of 510 m Ah g −1 at a ultrafast rate of 10 C.