Copolymerization of Sulfur Chains with Vinyl Functionalized Metal−Organic Framework for Accelerating Redox Kinetics in Lithium−Sulfur Batteries

Abstract

Lithium−sulfur batteries (LSBs) are regarded as one of the most promising candidates for energy storage devices. However, the severe shuttling effect of soluble polysulfides (PSs) limits its further application. Metal−organic frameworks (MOFs) have emerged as a new kind of sulfur host for their talents in confining and trapping PSs. However, the shuttle effect has not been fully stressed as a significant drawback for most MOFs that leads to sluggish redox kinetics, resulting in low specific capacity and short lifetime, especially at high sulfur loading. In this work, a MOF‐sulfur copolymer (CNT@UiO‐66‐V‐S) is elaborated by copolymerization of sulfur with vinyl functionalized MOFs. Systematic electrochemical experiments and in situ Raman spectroscopy analysis indicate that the cathode exhibits a radical reaction mechanism and can accelerates LiPSs conversion. The CNT@UiO‐66‐V‐S cathode delivers over 100% improved discharge capacity and lowers decay rate at both low and high (5.6 mg cm–2) sulfur loadings compared to the physically mixed MOF/S cathode. The strategy of MOF‐sulfur copolymerization provides a new solution for promoting reaction kinetics and tackling the shuttle effect, and is expected to inspire the design of advanced sulfur hosts applied for high‐performance LSBs.

A new covalently linked ferrocene-containing organosulfur cathode material for high stability lithium–sulfur batteries

“…Furthermore, the absorption bands at 1646 cm −1 , 3276 cm −1 and 2098 cm −1 which can be attributed to the CC, CH and CC groups, respectively, don't exist for S–Ferrocene acetylene–dbCNT. 30,31 This result implies that there are no remaining ethylene and acetylene groups in the S–ferrocene-acetylene–dbCNTs after the reaction. Raman spectroscopy is used to explore the form of sulfur in the prepared materials.…”

“…This result reveals the difference in thermal stability between covalent organic sulfur materials and conventional composites, which may be because formation of the C-S bonds in the organosulfur cathode improves the thermal stability of the material. 31,36 Furthermore, S-Ferrocene acetylene/CNT shows more mass loss than S-Ferrocene acetylene-dbCNT, revealing that covalently linked CNT are conducive to promoting the thermal stability. 37,38 To evaluate the sulfur content in the above materials, elemental analysis is carried out.…”

“…3a, the C 1s spectrum of S-Ferrocene acetylene-dbCNT shows four characteristic peaks, which can be attributed to C-O (293.01 eV), C-S (286.74 eV), C-C (284.80 eV) and carbide (283.06 eV). 31 Particularly, the existence of the C-S bond further veries that the elemental sulfur is in the form of a covalent linkage in Sferrocene acetylene-dbCNTs. For the S@Ferrocene/CNT, the C 1s picture shows only one peak (284.8 eV), which is attributed to the C-C bond of CNT (Fig.…”

Abundant Dislocation Layered Double Hydroxides Synthesis by Molten Salt with Bound Water Boosting Oxygen Evolution

“…The scarce earth reserves and high prices severely limit the application on a large scale. [4,5] dislocations as well as changing the octahedral configuration, resulting in the enhancement of OER performance.…”

A composite material based on nano‐metal‐organic framework MIL‐53(Fe) for adsorbing dyes from water

“…Due to their tunable pore size, large specific surface and modifiable functionality, MOFs exhibited satisfactory performance in gas adsorption/storage, luminescent sensing, catalyze, biomedicine and adsorption. [16][17][18][19][20][21][22][23][24][25][26][27][28][29] Particularly in the field for adsorption, high specific surface areas and post functional modification promoted interactions between adsorbent and adsorbate. For example, Zhang et al [30] developed two MOFs (MIL-101-Cr and MIL-53-Al) with large specific surface areas and accessible pore windows, which showed excellent adsorption performance for MO.…”