Constructing Co3S4 Nanosheets Coating N‐Doped Carbon Nanofibers as Freestanding Sulfur Host for High‐Performance Lithium–Sulfur Batteries. Issue 22 (11th October 2020)

• Record Type: Journal Article
• Authors: Zhang, Xuzi; Shang, Chaoqun; Akinoglu, Eser Metin; Wang, Xin; Zhou, Guofu
• Is Part Of: Advanced science. Volume 7:Issue 22(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-11
• Subjects: catalytic -- Co3S4 nanosheets -- fast conversion -- freestanding carbon nanofibers -- high sulfur loading; Science -- Periodicals; 505
• DOI: 10.1002/advs.202002037
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Lithium–sulfur batteries (LSBs) have shown great potential as a rival for next generation batteries, for its relatively high theoretical capacity and eco‐friendly properties. Nevertheless, blocked by the shuttle effect of lithium polysulfides (LPSs, Li2 S4 ‐Li2 S8 ) and insulation of sulfur, LSBs show rapid capacity loss and cannot achieve the practical application. Herein, a composite of carbon nanofibers coated by Co3 S4 nanosheets (denoted as CNF@Co3 S4 ) is successfully synthesized as freestanding sulfur host to optimize the interaction with sulfur species. The combination of the two materials can lead extraordinary cycling and rate performance by alleviating the shuttle of LPSs effectively. N‐doped carbon nanofibers serve as long‐range conductive networks and Co3 S4 nanosheets can accelerate the conversion of LPSs through its electrocatalytic and chemical adsorption ability. Benefiting from the unique structure, the transporting rate of Li + can be enhanced. Distribution of Li + is uniform for enough exposed negative active sites. As a result, the cell with CNF@Co3 S4 as sulfur host is able to stabilize at 710 mA h g −1 at 1 C after 200 cycles with average coulombic efficiency of 97.8% in a sulfur loading of 1.7 mg cm −2 and deliver 4.1 mA h cm −2 at 0.1 C even in 6.8 mg cm −2 for 100 cycles. Abstract : CNF@Co3 S4 as a freestanding sulfur host optimizes the interaction between sulfur species and the host material by the polarity and catalytical effect of Co3 S4 nanosheets. The electronegative property of Co3 S4 can further alleviate the growth of Li‐dendrites through realizing the uniform Li + flux and deposition. These advantages guarantee extraordinary cycling and rate performance of corresponding Li–S batteries.