Efficient synergism of electrocatalysis and physical confinement leading to durable high-power lithium-sulfur batteries. (March 2019)

• Record Type: Journal Article
• Authors: Du, Lingyu; Wu, Qiang; Yang, Lijun; Wang, Xiao; Che, Renchao; Lyu, Zhiyang; Chen, Wei; Wang, Xizhang; Hu, Zheng
• Is Part Of: Nano energy. Volume 57(2019)
• Page Start: 34
• Page End: 40
• Publication Date: 2019-03
• Subjects: Efficient synergism -- Metal-free electrocatalytic function -- Nitrogen-doped sp2-carbon -- Physical confinement -- High-power lithium-sulfur batteries; 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.2018.12.019
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Lithium-sulfur batteries are facing the big challenge of high-rate charge/discharge with long durability owing to the severe shuttle and polarization effects. Herein, we report a durable high-power cathode for lithium-sulfur batteries by employing multifunctional hierarchical nitrogen-doped carbon nanocages (hNCNC) to encapsulate sulfur and serve as interlayer. The highly-efficient electrocatalytic function of nitrogen-doped sp 2 -carbon to lithium-polysulfides conversion reactions is revealed by electrocatalytic experiments and density functional theory simulations. The excellent catalytic and charge-transfer functions of hNCNC, together with its physical confinement and chemical adsorption to the polysulfides, effectively suppress the polarization and shuttle effects, leading to the high-power performance with a capacity of 539 mAh g −1 at ultrahigh current density of 20 A g −1 for the sulfur cathode with the areal loading of 0.8 mg cm −2 . The superb durability is demonstrated by 1000 cycles at 10 A g −1 with a retained capacity of 438 mAh g −1 . When the areal sulfur loading is increased to 3 mg cm −2, a high capacity of 605 mAh g −1 is still obtained at the high current density of 3 A g −1 . This study provides an effective approach to durable high-power lithium-sulfur batteries by designing suitable electrocatalytic-active carbon-based hosts. Graphical abstract: Electrocatalytic function of N-doped sp 2 carbon for the conversion of lithium polysulfides was revealed by electrocatalytic experiments and density functional theory simulations. By uniting the mutual-promoted physical confinement, chemical adsorption and electrocatalysis with unique hierarchical nitrogen-doped carbon nanocages, durable high-power lithium-sulfur batteries were achieved owing to the efficient suppression of polarization and shuttle effects. fx1 Highlights: The electrocatalysis of N-doped sp 2 carbon for LiPS conversion is revealed by combined experimental and theoretical study. The hNCNC unites the mutual-promoted functions of physical confinement, chemical adsorption and electrocatalysis together. A record-high power performance and an excellent durability of Li-S batteries are achieved by using hNCNC. The performance-structure correlation is well-established.