A covalent organic frameworks(COFs)material with regular pores and stable structure can be used as the host of lithium-sulfur batteries to improve battery kinetics and polysulfides conversion.Herein,we designed and sy...A covalent organic frameworks(COFs)material with regular pores and stable structure can be used as the host of lithium-sulfur batteries to improve battery kinetics and polysulfides conversion.Herein,we designed and synthesized two kinds of rod-liked bulk COFs by adjusting different pore sizes(COF-BTD and COF-TFB),unfortunately,the active sites masking and sluggish kinetics have not met our expectations.Generally,the available layered COFs prepared from mechanochemical can expose abundant active sites and favorable kinetics than bulk COFs.Thus,simple mechanical ball milling is applied to activate the above COFs(M-COFs group).It is worth noting that layered R-COF-BTD is directly synthesized from rod-liked precursors by simple morphological reconstruction.A series of characterization methods are used to systematically explore the advantages of the group of M-COFs@S electrodes in the cycling process,including the effects of specific morphology on the kinetics and transformation of polysulfides.Our research provides a feasible plan for the development and selection of the host material of lithium-sulfur batteries.展开更多
Metal-organic frameworks have emerged as promising electrode materials for metal-ion batteries due to their superior structural customizability.However,they face challenges such as poor reversibility and easy degradat...Metal-organic frameworks have emerged as promising electrode materials for metal-ion batteries due to their superior structural customizability.However,they face challenges such as poor reversibility and easy degradation during electrochemical redox processes.Here,we report the synthesis ofπ-d conjugated coordination polymers through NH_(3)-vapor-assisted self-polymerization of NiCl_(2)·6H_(2)O with 1,2,4,5-benzenetetramine tetrahydrochloride(namely,Ni-BTA).The synthesized Ni-BTA exhibits an open lattice structure that enhances the capacity for metal-ion diffusion,ensuring prolonged electrochemical cycling stability.Moreover,electrochemical characterizations reveal that Ni-BTA functions as a bifunctional material,serving as both cathode and anode materials for lithium-ion batteries(LIBs).After 1,000 cycles at 1.0 A g^(−1),the cathode and anode show high discharge capacities of 199.7 and 338.4 mAh g^(−1),respectively.Additionally,symmetrical all-organic batteries constructed with Ni-BTA exhibit a high specific capacity of 30.6 mAh g-1 and an ultrastable coulombic efficiency of approximately≈100%after 6,000 cycles at 1.0 A g^(−1).Furthermore,Ni-BTA exhibits versatility as a robust cathode for aluminum ion batteries(AIBs),delivering a discharge capacity of 18.7 mAh g^(−1) after 10,000 cycles at 1.0 A g^(−1).These findings highlight the potential of Ni-BTA as a versatile and durable electrode materials for both LIBs and AIBs.展开更多
基金supported by the National Natural Science Foundation of China,China(No.81927809).
文摘A covalent organic frameworks(COFs)material with regular pores and stable structure can be used as the host of lithium-sulfur batteries to improve battery kinetics and polysulfides conversion.Herein,we designed and synthesized two kinds of rod-liked bulk COFs by adjusting different pore sizes(COF-BTD and COF-TFB),unfortunately,the active sites masking and sluggish kinetics have not met our expectations.Generally,the available layered COFs prepared from mechanochemical can expose abundant active sites and favorable kinetics than bulk COFs.Thus,simple mechanical ball milling is applied to activate the above COFs(M-COFs group).It is worth noting that layered R-COF-BTD is directly synthesized from rod-liked precursors by simple morphological reconstruction.A series of characterization methods are used to systematically explore the advantages of the group of M-COFs@S electrodes in the cycling process,including the effects of specific morphology on the kinetics and transformation of polysulfides.Our research provides a feasible plan for the development and selection of the host material of lithium-sulfur batteries.
基金support from the National Natural Science Foundation of China(Nos.U2267224 and 52076074)BRICS STI Framework Programme(No.52261145703)+4 种基金Higher Education Discipline Innovation Project(National 111 Project,No.B16016)the supports by Italy-Singapore Science and Technology Cooperation(Grant No.R23101R040)Singapore A*STAR SERC CRF Awardthe computing resources at the A*STAR Computational Resource CentreNational Supercomputer Centre,Singapore.
文摘Metal-organic frameworks have emerged as promising electrode materials for metal-ion batteries due to their superior structural customizability.However,they face challenges such as poor reversibility and easy degradation during electrochemical redox processes.Here,we report the synthesis ofπ-d conjugated coordination polymers through NH_(3)-vapor-assisted self-polymerization of NiCl_(2)·6H_(2)O with 1,2,4,5-benzenetetramine tetrahydrochloride(namely,Ni-BTA).The synthesized Ni-BTA exhibits an open lattice structure that enhances the capacity for metal-ion diffusion,ensuring prolonged electrochemical cycling stability.Moreover,electrochemical characterizations reveal that Ni-BTA functions as a bifunctional material,serving as both cathode and anode materials for lithium-ion batteries(LIBs).After 1,000 cycles at 1.0 A g^(−1),the cathode and anode show high discharge capacities of 199.7 and 338.4 mAh g^(−1),respectively.Additionally,symmetrical all-organic batteries constructed with Ni-BTA exhibit a high specific capacity of 30.6 mAh g-1 and an ultrastable coulombic efficiency of approximately≈100%after 6,000 cycles at 1.0 A g^(−1).Furthermore,Ni-BTA exhibits versatility as a robust cathode for aluminum ion batteries(AIBs),delivering a discharge capacity of 18.7 mAh g^(−1) after 10,000 cycles at 1.0 A g^(−1).These findings highlight the potential of Ni-BTA as a versatile and durable electrode materials for both LIBs and AIBs.
