Bimetallic Metal-Organic Framework with High-Adsorption Capacity toward Lithium Polysulfides for Lithium–sulfur Batteries

The practical application of Li-S batteries is largely impeded by the“shuttle effect”generated at the cathode which results in a short life cycle of the battery.To address this issue,this work discloses a bimetallic metal-organic framework(MOF)as a sulfur host material based on Al-MOF,commonly called(Al)MIL-53.To obtain a high-adsorption capacity to lithium polysulfides(Li_(2)S_(x),4≤x≤8),we present an effective strategy to incorporate sulfiphilic metal ion(Cu^(2+))with high-binding energy to Li_(2)S_(x) into the framework.Through a one-step hydrothermal method,Cu^(2+) is homogeneously dispersed in Al-MOF,producing a bimetallic Al/Cu-MOF as advanced cathode material.The macroscopic Li2S4 solution permeation test indicates that the Al/Cu-MOF has better adsorption capacity to lithium polysulfides than monometallic Al-MOF.The sulfur-transfusing process is executed via a melt-diffusion method to obtain the sulfur-containing Al/CuMOF(Al/Cu-MOF-S).The assembled Li-S batteries with Al/Cu-MOF-S yield improved cyclic performance,much better than that of monometallic AlMOF as sulfur host.It is shown that chemical immobilization is an effective method for polysulfide adsorption than physical confinement and the bimetallic Al/Cu-MOF,formed by incorporation of sulfiphilic Cu^(2+) into porous MOF,will provide a novel and powerful approach for efficient sulfur host materials.

Recent Progress of Metal Organic Frameworks-Based Electrocatalysts for Hydrogen Evolution,Oxygen Evolution,and Oxygen Reduction Reaction

Exploring efficient and cost-saving electrocatalysts is essential to the renewable energy storage and utilization,which is still in its embryonic period.MOFs have drawn tremendous attention due to their adjustability,abundant active sites,and plentiful pores.Notably,satisfactory electrocatalytic performance has been achieved by MOFs-based electrocatalysts comparable to traditional electrocatalysts.State-of-the-art works about the MOFs-based electrocatalysts for hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and ORR were summarized in this review.This review comprises a series of modifying strategies of MOFs and their derivatives,from aspects of structure,composition,and morphology.Furthermore,the active sites and functional mechanisms’recognition are involved in this review expecting to provide reference for rationally designing efficient electrocatalysts.At last,the current status,challenges,and perspectives of MOFs-based electrocatalysts are also discussed.

Metal organic frameworks-based cathode materials for advanced Li-S batteries: A comprehensive review

Li-S batteries(LSBs)have been considering as new and promising energy storage systems because of the high theoretical energy density and low price.Nevertheless,their practical application is inhibited by several factors,including poor electrical conductivity of electrode materials,greatly volumetric variation,as well as the polysulfide formation upon the cycling.To address these problems,it is imperative to develop and design effective and suitable sulfur host anode materials.Metal organic frameworks(MOFs)-based cathode materials,possessing their good conductivity and easy morphology design,have been extensively studied and exhibited enormously potential in LSBs.In this review,a comprehensive overview of MOFs-based sulfur host materials is provided,including their electrochemical reaction mechanisms,related evaluation parameters,and their performances used in LSBs in the past few years.In particular,the recent advances using in-situ characterization technologies for investigating the electrochemical reaction mechanism in LSBs are presented and highlighted.Additionally,the challenges and prospects associated with future research on MOF-related sulfur host materials are discussed.It is anticipated to offer the guidance for the identification of suitable MOFs-based sulfur cathode materials for high-performance LSBs,thereby contributing for the achievement of a sustainable and renewable society.

One-Step Synthesis of Ultrathin Carbon Nanoribbons from Metal–Organic Framework Nanorods for Oxygen Reduction and Zinc–Air Batteries

Two-dimensional(2D)carbon nanostructures play a critical role in energy-related applications,but developing facile and efficient strategies to synthesize these kinds of nanostructures is extremely rare.Herein,ultrathin carbon nanoribbons(CNRibs),with a thickness of 2–6 nm and length over 100 nm,have been strategically fabricated via a one-step pyrolysis of one-dimensional(1D)metal–organic framework nanorods(MOF NRods).Manipulating the diameters of MOF NRods will result in the formation of porous carbon nanostructures in 1D or 2D morphologies.Functional CNRibs with N doping or metal active site immobilization have also been studied.The CNRibs decorated with iron nanoclusters and single atoms have been used as excellent catalysts for the oxygen reduction reaction under both alkaline and acidic conditions,as well as zinc–air batteries.This work gives deep insights into the structural evolution from 1D to 2D morphology,providing an efficient approach to fabricate low-dimensional nanomaterials with controllable morphologies and functionalities for electrochemical applications.