Design Multifunctional Catalytic Interface: Toward Regulation of Polysulfide and Li2S Redox Conversion in Li–S Batteries

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 15; no. 51
• Main Authors: Fan, Shuang, Huang, Shaozhuan, Pam, Mei Er, Chen, Song, Wu, Qingyun, Hu, Junping, Wang, Ye, Ang, Lay Kee, Yan, Congcong, Shi, Yumeng, Yang, Hui Ying
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 20.12.2019
• Subjects: Catalytic converters; Chemical reactions; Chemisorption; Cycles; Decomposition reactions; Electrolytes; Electron transfer; Graphene; Interlayers; Li2S nucleation–growth–decomposition; Lithium sulfur batteries; multifunctional catalytic interfaces; Nanotechnology; Niobium nitride; niobium nitride electrocatalysis; Nucleation; Organic chemistry; Polysulfides; Reaction kinetics; Sulfur
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201906132

The polysulfide shuttle effect and sluggish reaction kinetics hamper the practical applications of lithium–sulfur (Li–S) batteries. Incorporating a functional interlayer to trapping and binding polysulfides has been found effective to block polysulfide migration. Furthermore, surface chemistry at soluble polysulfides/electrolyte interface is a crucial step for Li–S battery in which stable cycling depends on adsorption and reutilization of blocked polysulfides in the electrolyte. A multifunctional catalytic interface composed of niobium nitride/N‐doped graphene (NbN/NG) along the soluble polysulfides/electrolyte is designed and constructed to regulate corresponding interface chemical reaction, which can afford long‐range electron transfer surfaces, numerous strong chemisorption, and catalytic sites in a working lithium–sulfur battery. Both experimental and theoretical calculation results suggest that a new catalytic interface enabled by metal‐like NbN with superb electrocatalysis anchored on NG is highly effective in regulating the blocked polysulfide redox reaction and tailoring the Li2S nucleation–growth–decomposition process. Therefore, the Li–S batteries with multifunctional NbN/NG barrier exhibit excellent rate performance (621.2 mAh g−1 at 3 C) and high stable cycling life (81.5% capacity retention after 400 cycles). This work provides new insights to promote Li–S batteries via multifunctional catalytic interface engineering. A multifunctional catalytic niobium nitrides/N‐doped graphene (NbN/NG) interface with strong binding for sulfur species, high conductive and numerous electrocatalytic mediators can play an important role for regulating the kinetic conversion of soluble polysulfides, controlling the nucleation, growth, and decomposition of Li2S during the charge–discharge process.