Extending the potential window of aqueous supercapacitors (SCs) up to 2.0 V is still a great challenge.Based on their good dynamic structural reversibility and open framework structure,the coordination superamolecular...Extending the potential window of aqueous supercapacitors (SCs) up to 2.0 V is still a great challenge.Based on their good dynamic structural reversibility and open framework structure,the coordination superamolecular networks (CSNs) exhibit rapid charge/discharge ability and excellent cycle stability.As a typical coordination superamolecular network (CSN),Prussian blue (denoted as CSN-PB),which self-assembled by the CN-ligand and iron ions is firstly in-situ grown on carbon cloth,followed by electro-deposition of MnO2 to form CSN-PB/MnO2 composite electrode.Benefiting from synergistic effect of the constituent components,as well as the open framework structure of CSN-PB,this composite electrode reaches a high potential window of 1.4 V (vs.Ag/AgCl) and delivers a good specific capacitance of 315.3 F·g^-1 in aqueous electrolyte.An aqueous asymmetric device,constructed with CSN-PB/MnO2 composite as cathode and activated carbon as anode,can work in a stable potential window of 2.4 V,exhibits a high energy density of 46.13 Wh·kg^-1 and excellent cycling stability with 85.5% capacitance retention after 20,000 cycles.This work provides a new concept of high dynamic structural reversibility from CSNs to increase the cell voltage of asymmetric SCs for further boosting energy density.展开更多
A supramolecular complex of Cd（II） with 1D water tapes as pillars[Cd2（dpa）2（phen）2（H2O）2]·6H2O 1 （H2dpa = diphenic acid, phen = phenanthroline）, has been synthesized and characterized by elemental analy...A supramolecular complex of Cd（II） with 1D water tapes as pillars[Cd2（dpa）2（phen）2（H2O）2]·6H2O 1 （H2dpa = diphenic acid, phen = phenanthroline）, has been synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction analysis. The crystal is of triclinic, space group P1^- with a = 9.7029（4）, b = 11.9601（5）, c = 12.1788（4） A, α = 71.6990（10）, β = 71.8740（10）, γ = 74.4680（10）°, V = 1252.39（8） A^3, C52H48Cd2N4O16, Mr = 1209.76, Z= 1, Dc = 1.604 g/cm^3,μ = 0.925 mm^-1, F（000） = 612, R = 0.0679 and wR = 0.2514 for 3870 observed reflections （I 〉 2σ（I））. Two intramolecular Cd（II） centers of this complex are encircled by two dpa^2- ligands forming an 18-membered ring, which is further assembled into a pillared three-dimensional （3D） supramolecular architecture through the synergetic effect of intermolecular face-to-face π…π stacking and weak O-H…O hydrogen-bonding interactions. Moreover, this complex exhibits photoluminescence with the main emission bands located at about 456 nm upon excitation at 355 nm in the solid state at room temperature.展开更多
基金the National Natural Science Foundation of China (Nos.51472275,20973203 and 91022012)Guangdong Natural Science Foundation (No.2014A030313207)as well as Laboratory Open Fund Project of Sun Yat-sen University (No.201610310003).
文摘Extending the potential window of aqueous supercapacitors (SCs) up to 2.0 V is still a great challenge.Based on their good dynamic structural reversibility and open framework structure,the coordination superamolecular networks (CSNs) exhibit rapid charge/discharge ability and excellent cycle stability.As a typical coordination superamolecular network (CSN),Prussian blue (denoted as CSN-PB),which self-assembled by the CN-ligand and iron ions is firstly in-situ grown on carbon cloth,followed by electro-deposition of MnO2 to form CSN-PB/MnO2 composite electrode.Benefiting from synergistic effect of the constituent components,as well as the open framework structure of CSN-PB,this composite electrode reaches a high potential window of 1.4 V (vs.Ag/AgCl) and delivers a good specific capacitance of 315.3 F·g^-1 in aqueous electrolyte.An aqueous asymmetric device,constructed with CSN-PB/MnO2 composite as cathode and activated carbon as anode,can work in a stable potential window of 2.4 V,exhibits a high energy density of 46.13 Wh·kg^-1 and excellent cycling stability with 85.5% capacitance retention after 20,000 cycles.This work provides a new concept of high dynamic structural reversibility from CSNs to increase the cell voltage of asymmetric SCs for further boosting energy density.
基金the State Key Basic Research and Development Plan of China (001CB108906)the Knowledge Innovation Program of the Chinese Academy of Sciences, the NSF (2006J0015)the Major Special Foundation of Fujian Province (2005HZ1027, 2005HZ01-1)
文摘A supramolecular complex of Cd（II） with 1D water tapes as pillars[Cd2（dpa）2（phen）2（H2O）2]·6H2O 1 （H2dpa = diphenic acid, phen = phenanthroline）, has been synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction analysis. The crystal is of triclinic, space group P1^- with a = 9.7029（4）, b = 11.9601（5）, c = 12.1788（4） A, α = 71.6990（10）, β = 71.8740（10）, γ = 74.4680（10）°, V = 1252.39（8） A^3, C52H48Cd2N4O16, Mr = 1209.76, Z= 1, Dc = 1.604 g/cm^3,μ = 0.925 mm^-1, F（000） = 612, R = 0.0679 and wR = 0.2514 for 3870 observed reflections （I 〉 2σ（I））. Two intramolecular Cd（II） centers of this complex are encircled by two dpa^2- ligands forming an 18-membered ring, which is further assembled into a pillared three-dimensional （3D） supramolecular architecture through the synergetic effect of intermolecular face-to-face π…π stacking and weak O-H…O hydrogen-bonding interactions. Moreover, this complex exhibits photoluminescence with the main emission bands located at about 456 nm upon excitation at 355 nm in the solid state at room temperature.
