MIL-88A Metal-Organic Framework as a Stable Sulfur-Host Cathode for Long-Cycle Li-S Batteries

Abstract

Lithium-sulfur (Li-S) batteries have received enormous interest as a promising energy storage system to compete against limited, non-renewable, energy sources due to their high energy density, sustainability, and low cost. Among the main challenges of this technology, researchers are concentrating on reducing the well-known "shuttle effect" that generates the loss and corrosion of the active material during cycling. To tackle this issue, metal-organic frameworks (MOF) are considered excellent sulfur host materials to be part of the cathode in Li-S batteries, showing efficient confinement of undesirable polysulfides. In this study, MIL-88A, based on iron fumarate, was synthesised by a simple and fast ultrasonic-assisted probe method. Techniques such as X-ray diffraction (XRD), Raman spectroscopy, Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), and N 2 adsorption/desorption isotherms were used to characterise structural, morphological, and textural properties. The synthesis process led to MIL-88A particles with a central prismatic portion and pyramidal terminal portions, which exhibited a dual micro-mesoporous MOF system. The composite MIL-88A@S was prepared, by a typical melt-diffusion method at 155 • C, as a cathodic material for Li-S cells. MIL-88A@S electrodes were tested under several rates, exhibiting stable specific capacity values above 400 mAh g −1 at 0.1 C (1C = 1675 mA g −1 ). This polyhedral and porous MIL-88A was found to be an effective cathode material for long cycling in Li-S cells, retaining a reversible capacity above 300 mAh g −1 at 0.5 C for more than 1000 cycles, and exhibiting excellent coulombic efficiency.

Ferroelectric Metal–Organic Framework as a Host Material for Sulfur to Alleviate the Shuttle Effect of Lithium–Sulfur Battery

“…In addition, the initial discharge specific capacities of the S@NUS-6, S@UiO-66(Hf) and S@CB electrodes were 972.2 mAh g À1 ,8 96.2 mAh g À1 and 830.2 mAh g À1 at 1C,r espectively,w hich is highert han other materials S@MOFse lectrode materials. [37][38][39] After 300 cycles, the capacity decay per cycle of S@NUS-6, S@UiO-66(Hf) and S@CB composite electrodes were 0.122 %, 0.157 %a nd 0.177 %, respectively ( Figure S5).…”

Water-based routes for synthesis of metal-organic frameworks: A review

“…In addition, MOF synthesis is largely conducted in solvothermal or hydrothermal conditions, which usually requires a high temperature and pressure with long reaction time, as indicated by the examples above [195,196]. These severe reaction conditions are also known to consume a lot of energy and reduce the production rate (in general STYs are below 300 kg m −3 per day) [55,197,198]. In addition, in terms of green applications, a crucial pre-requisite in the real world is the ability to achieve the low-cost synthesis of high-quality MOF materials in large quantities with high efficiency [45,199,200].…”

“…To date, many effective methods have been proposed for the green and cheap synthesis of UiO MOFs. However, there are few reports on their large-scale production from kilogram (kg) scale to commercialization at the ton (t) scale [6,55]. Recently, Karadeniz et al [154] reported a green mechanochemical synthesis approach for the continuous production of a series of Zr-MOFs (UiO-66, UiO-66-NH 2 , MOF-801 and MOF-804) using a non-conventional zirconium dodecanuclear acetate cluster and a small amount of water as the liquid-assisted grinding (LAG) additive.…”

“…To date, tremendous efforts have been made to develop alternative methods to mitigate and/or eliminate the use and generation of hazardous organic solvents in the synthesis of MOFs [48][49][50][51], including solvent-free method [52], aerosol route [53], microwave irradiation and ultrasound-assisted techniques [54,55]. These ap-proaches not only avoid the use of hazardous solvents in the synthesis of MOFs, but also have advantages, such as excellent stability, tunable porosity, high production rate, and continuous production in the resulting MOFs [56,57].…”

Thermal Decomposition and Kinetic Analysis of a Mil-88a Metal-organic Framework

“…The adsorption behavior for Bromophenol Blue was estimated. Benítez et al [16] synthesized MIL-88A@S composites by fast ultrasonic-assisted probe technique. The structural and electrochemical properties of the MIL-88A@S composite were investigated.…”