Pyrene-4,5,9,10-tetraone(PTO),with a high theoretical capacity of 408 mAh·g^(−1),is a promising candidate for rechargeable aqueous zinc-ion batteries(RAZIBs),but its zincated products during discharge process suf...Pyrene-4,5,9,10-tetraone(PTO),with a high theoretical capacity of 408 mAh·g^(−1),is a promising candidate for rechargeable aqueous zinc-ion batteries(RAZIBs),but its zincated products during discharge process suffer from high solubility in electrolytes.Herein,aβ-ketoenamine-linked two-dimensional(2D)covalent organic framework(COF)based on a 2,7-diaminopyrene-4,5,9,10-tetraone(4KT-BD)monomer and a 2,4,6-trihydroxy-benzene-1,3,5-tricarbaldehyde(Tp)node(4KT-Tp-COF)is synthesized to address the above issue.The well-designed 4KT-Tp-COF displays low solubility in 3 M Zn(CF3SO3)2 owing to the favorableπ-πstacking as well as extended structure.Besides,the ingenious structural design of the active molecule and the long-range ordered nano-channels alter the intramolecular electron distribution,which facilitates the ionic diffusion.Consequently,the 4KT-Tp-COF cathode exhibits a stable capacity of 181 mAh·g^(−1)at 0.2 A·g^(−1),superior rate capability of 139 mAh·g^(−1)at 20 A·g^(−1),and a long lifetime of 1000 cycles without capacity loss at 30 A·g^(−1).Even at a low temperature of−20°C,the electrode also performs an ultralong cycling life of 9000 cycles with a capacity of 106 mAh·g^(−1)at 5 A·g^(−1).The comprehensive characterizations of ex-situ analyses together with the theoretical calculations validate that the groups of C=O can contribute highly accessible redox-active sites for Zn^(2+)storage.The ultra-stable 4KT-Tp-COF cathode provides important insights for designing robust organic electrodes for sustainable and large-scale electrochemical energy storage.展开更多
基金the National Natural Science Foundation of China(Nos.22279063 and 52001170)the Fundamental Research Funds for the Central Universities,and Tianjin Natural Science Foundation(No.22JCYBJC00590)+3 种基金Shanxi Supercomputing Center of China,and the calculations were performed on TianHe-2.K.Z.would like to acknowledge for the National Key Research and Development Program of China(No.2022YFB2402200)the National Natural Science Foundation of China(Nos.22121005,22005155,and 52072186)the Fundamental Research Funds for the Central Universities(Nos.63233017,63231002,and 63231198)J.T.would like to acknowledge for the Development Project of Large-scale Instrument Experiment Technology of Nankai University(No.23NKSYJS02).
文摘Pyrene-4,5,9,10-tetraone(PTO),with a high theoretical capacity of 408 mAh·g^(−1),is a promising candidate for rechargeable aqueous zinc-ion batteries(RAZIBs),but its zincated products during discharge process suffer from high solubility in electrolytes.Herein,aβ-ketoenamine-linked two-dimensional(2D)covalent organic framework(COF)based on a 2,7-diaminopyrene-4,5,9,10-tetraone(4KT-BD)monomer and a 2,4,6-trihydroxy-benzene-1,3,5-tricarbaldehyde(Tp)node(4KT-Tp-COF)is synthesized to address the above issue.The well-designed 4KT-Tp-COF displays low solubility in 3 M Zn(CF3SO3)2 owing to the favorableπ-πstacking as well as extended structure.Besides,the ingenious structural design of the active molecule and the long-range ordered nano-channels alter the intramolecular electron distribution,which facilitates the ionic diffusion.Consequently,the 4KT-Tp-COF cathode exhibits a stable capacity of 181 mAh·g^(−1)at 0.2 A·g^(−1),superior rate capability of 139 mAh·g^(−1)at 20 A·g^(−1),and a long lifetime of 1000 cycles without capacity loss at 30 A·g^(−1).Even at a low temperature of−20°C,the electrode also performs an ultralong cycling life of 9000 cycles with a capacity of 106 mAh·g^(−1)at 5 A·g^(−1).The comprehensive characterizations of ex-situ analyses together with the theoretical calculations validate that the groups of C=O can contribute highly accessible redox-active sites for Zn^(2+)storage.The ultra-stable 4KT-Tp-COF cathode provides important insights for designing robust organic electrodes for sustainable and large-scale electrochemical energy storage.
