Single-ion conductors based on covalent organic frameworks(COFs)have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical vers...Single-ion conductors based on covalent organic frameworks(COFs)have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility.However,the sluggish Li+conduction has hindered their practical applications.Here,we present a class of solvent-free COF single-ion conductors(Li-COF@P)based on weak ion-dipole interaction as opposed to traditional strong ion-ion interaction.The ion(Li+from the COF)-dipole(oxygen from poly(ethylene glycol)diacrylate embedded in the COF pores)interaction in the Li-COF@P promotes ion dissociation and Li+migration via directional ionic channels.Driven by this single-ion transport behavior,the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance(88.3%after 2000 cycles)in organic batteries(Li metal anode||5,5’-dimethyl-2,2’-bis-p-benzoquinone(Me2BBQ)cathode)under ambient operating conditions,highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries.展开更多
A new one-dimensional aluminum fluorophosphate, AlP2O5(OH)3F·0.5[H2dien] (dien=diethylenetriamine), was solvothermally synthesized by using organic amine as the structure directing agent, and its structure wa...A new one-dimensional aluminum fluorophosphate, AlP2O5(OH)3F·0.5[H2dien] (dien=diethylenetriamine), was solvothermally synthesized by using organic amine as the structure directing agent, and its structure was determined by single-crystal X-ray diffraction. The complex inorganic architecture consists of trans-corner-sharing AlO4F2 octahedra chain decorated by phosphate tetrahedra along both sides of the -F-Al-F-Al-F- backbone displaying a series of Al2P three-membered rings, which will represent a new fundamental structural type in metal phosphates. The results of CHN elemental analysis, EDS, and TGA are also presented. Crystal data: C4H18Al2F2N3O16P4, monoclinic, space group P21/c with a=6.9107(14), b=15.749(3), c=8.9741(18) , β=109.829(2)o, V=918.8(3) 3, Z=2, Mr=580.05, Dc=2.097 g/cm3, μ=0.618 mm-1, S=1.022, F(000)=590, the final R=0.0510 and wR=0.1284 for 1607 observed reflections (I 〉 2σ(I)).展开更多
A solid-state electrolyte(SSE),which is a solid ionic conductor and electroninsulating material,is known to play a crucial role in adapting a lithium metal anode to a high-capacity cathode in a solid-state battery.Amo...A solid-state electrolyte(SSE),which is a solid ionic conductor and electroninsulating material,is known to play a crucial role in adapting a lithium metal anode to a high-capacity cathode in a solid-state battery.Among the various SSEs,the single Li-ion conductor has advantages in terms of enhancing the ion conductivity,eliminating interfacial side reactions,and broadening the electrochemical window.Covalent organic frameworks(COFs)are optimal platforms for achieving single Li-ion conduction behavior because of wellordered one-dimensional channels and precise chemical modification features.Herein,we study in depth three types of Li-carboxylate COFs(denoted LiOOC-COFn,n=1,2,and 3)as single Li-ion conducting SSEs.Benefiting from well-ordered directional ion channels,the single Li-ion conductor LiOOC-COF3 shows an exceptional ion conductivity of 1.36×10^(-5) S cm^(-1) at room temperature and a high transference number of 0.91.Moreover,it shows excellent electrochemical performance with long-term cycling,high-capacity output,and no dendrites in the quasi-solid-state organic battery,with the organic small molecule cyclohexanehexone(C_(6)O_(6))as the cathode and the Li metal as the anode,and enables effectively avoiding dissolution of the organic electrode by the liquid electrolyte.展开更多
Organic conductor is a kind of organic compound which has special electronic and magnetic properties. The research of the organic compounds has received considerable attention because of their potential applications i...Organic conductor is a kind of organic compound which has special electronic and magnetic properties. The research of the organic compounds has received considerable attention because of their potential applications in many areas. The molecular conductive units are theoretically investigated as well as their energy gap and charge distribution. The relationship of conductivity and micro mechanism is discussed.展开更多
CeO2 and Ce0.8M0.2O2-d films (M = Mn, Y, Gd, Sm, Nd and La) with (00l) preferred orientation have been prepared on biaxially textured Ni-W substrates by metal organic decomposition (MOD) method. The factors infl...CeO2 and Ce0.8M0.2O2-d films (M = Mn, Y, Gd, Sm, Nd and La) with (00l) preferred orientation have been prepared on biaxially textured Ni-W substrates by metal organic decomposition (MOD) method. The factors influencing the formation of cracks on the surface of these CeO2 and doped CeO2 films on Ni-W substrates were explored by X-ray diffraction (XRD), scanning electron microscopy (SEM) analysis, atomic force microscopy (AFM) and differential scanning calorimetry (DSC). The results indicate that many factors, such as the change of the ionic radii of doping cations, the transformation of crystal structure and the formation of oxygen vacancies in lattices at high annealing temperature, may be related to the formation of cracks on the surface of these films. However, the crack formation shows no dependence on the crystal lattice mismatch degree of the films with Ni-W substrates. Moreover, the suppression of surface cracks is related to the change of intrinsic elasticity of CeO2 film with doping of cations with a larger radius. SEM and AFM investigations of Ce0.8M0.2O2-d (M = Y, Gd, Sm, Nd and La) films reveal the dense, smooth and crack-free microstructure, and their lattice parameters match well with that of YBCO, illuminating that they are potentially suitable to be as buffer layer, especially as cap layer in multi-layer architecture of buffer layer for coated conductors.展开更多
YBa2Cu3O7-x(YBCO) films were fabricated on an LAO substrate using the trifluoroacetic acid-metal organic deposition(TFA-MOD) method and the effects of the humidity and heat treatment temperatures on the microstructure...YBa2Cu3O7-x(YBCO) films were fabricated on an LAO substrate using the trifluoroacetic acid-metal organic deposition(TFA-MOD) method and the effects of the humidity and heat treatment temperatures on the microstructure,degree of texture and critical properties of the films were evaluated.In order to understand the combined effects of the humidity and the calcining and firing temperatures on critical properties,heat-treatment was performed at various temperatures with the other processing variables fixed.The films were calcined at 400-430 ℃ and fired at 750-800 ℃ in a 0-12.1% humidified Ar-O2 atmosphere.The texture was determined by pole-figure analysis.The amount of the BaF2 phase was effectively reduced and a sharp and strong biaxial texture was formed under a humidified atmosphere,which led to increased critical properties.In addition,the microstructure varied significantly with firing temperature but changed little with calcining temperature.The highest IC of 40 A/cm-width,which corresponds to JC value of 1.8 MA/cm2,was obtained for the films fired at 775 ℃(in 12.1% humidity) after calcining at 400-430 ℃.It is likely that the highest IC value is due to the formation of a more pure YBCO phase,c-axis grains,and a denser microstructure.展开更多
Organic semiconductors have gradually become the super stars on the stage of optoelectronic materials, due to their low cost, flexibility and solution processability. Numerous organic semiconductors, including small m...Organic semiconductors have gradually become the super stars on the stage of optoelectronic materials, due to their low cost, flexibility and solution processability. Numerous organic semiconductors, including small molecules and conjugated polymers, have been designed and synthesized to explore the potential of organic materials in optoelectronic industry. One-dimensional micro/nanostructures of organic semiconductors generally have more ordered packing structure with fewer defects compared with thin films, and are thus thought to show intrinsic carrier mobility of organic materials. Moreover, the packing structure in micro/nanostructures is clear and relatively easy to analyze, which makes these micro/nanostructures a good platform to study structure-property relationship. Therefore, design of suitable organic molecules to form micro-/nanostructures and methods to obtain ideal micro/nanostructures for functional devices will be fully discussed in this mini review. Finally, the perspective and opportunity of 1D micro/nanostructured organic materials based OFETs in the near future are also addressed.展开更多
Electrolytic water splitting by renewable energy is a technology with great potential for producing hydrogen(H_(2))without carbon emission,but this technical route is hindered by its huge energy(electricity)cost,which...Electrolytic water splitting by renewable energy is a technology with great potential for producing hydrogen(H_(2))without carbon emission,but this technical route is hindered by its huge energy(electricity)cost,which is mainly wasted by the anode oxygen evolution reaction(OER)while the value of the anode product(oxygen)is very limited.Replacing the high-energy-cost OER with a selective organic compound electrooxidation carried out at a relatively lower potential can reduce the electricity cost while producing value-added chemicals.Currently,H_(2) generation coupled with synthesis of value-added organic compounds faces the challenge of low selectivity and slow generation rate of the anodic products.One-dimensional(1D)nanocatalysts with a unique morphology,well-defined active sites,and good electron conductivity have shown excellent performance in many electrocatalytic reactions.The rational design and regulation of 1D nanocatalysts through surface engineering can optimize the adsorption energy of intermediate molecules and improve the selectivity of organic electrooxidation reactions.Herein,we summarized the recent research progress of 1D nanocatalysts applied in different organic electrooxidation reactions and introduced several different fabrication strategies for surface engineering of 1D nanocatalysts.Then,we focused on the relationship between surface engineering and the selectivity of organic electrooxidation reaction products.Finally,future challenges and development prospects of 1D nanocatalysts in the coupled system consisting of organic electrooxidation and hydrogen evolution reactions are briefly outlined.展开更多
Covalent organic frameworks(COFs) are attractive porous crystalline materials with extremely high stability, easy functionalization, and open channels, which are expected to be unique ion conductors/transporters in li...Covalent organic frameworks(COFs) are attractive porous crystalline materials with extremely high stability, easy functionalization, and open channels, which are expected to be unique ion conductors/transporters in lithium ion batteries(LIBs). Despite recent advances, low ion conductivity and low transference number, resulting in low charging/discharging rate, low energy density, and short battery life, are the main issues that limit their direct application as solid electrolytes in LIBs. Here, we designed and synthesized a novel polyimide COF, namely, TAPA-PDI-COF, with abundant C=O groups, which has been successfully employed as high-performance solid electrolytes by doping TAPA-PDI-COF and succinonitrile(SN). Both the well-defined nanochannels of COFs and SN confined in the well-aligned channels restricted the free migration of anions, while C=O on COFs and CN groups of SN enhanced Li^(+) transport, thus achieving a high ion conductivity of 0.102 m S cm^(-1)at 80 °C and a high lithium-ion transference number of 0.855 at room temperature. According to density functional theory(DFT)calculations, Li-ion migration mainly adopted in-plane transport rather than the axial pathway, which may be due to the shorter hopping distances in the planar pathway. The results suggest an effective strategy for the design and development of all-solidstate ionic conductors for achieving high-performance LIBs.展开更多
As a novel class of porous crystalline solids,covalent organic frameworks(COFs)based electrolyte can combine the advantages of both inorganic and polymer electrolytes,leading to such as higher structural stability to ...As a novel class of porous crystalline solids,covalent organic frameworks(COFs)based electrolyte can combine the advantages of both inorganic and polymer electrolytes,leading to such as higher structural stability to inhibit lithium dendrites and better processing facility for improving interfacial contact.However,the ionic components of Li salt tend to be closely associated in the form of ion pairs or even ionic aggregates in the channel of COFs due to strong coulombic interactions,thus resulting in slow ionic diffusion dynamics and low ionic conductivity.Herein,we successfully designed and synthesized a novel single-ion conducting nitrogen hybrid conjugated skeleton(NCS)as all solid electrolyte,whose backbone is consisted with triazine and piperazine rings.A loose bonding between the triazine rings and cations would lower the energy barrier during ions transfer,and electrostatic forces with piperazine rings could“anchor”anions to increase the selectivity during ions transfer.Thus,the NCSelectrolyte exhibits excellent room temperature lithium-ion conductivity up to 1.49 mS·cm−1 and high transference number of 0.84 without employing any solvent,which to the best of our knowledge is one of the highest COF-based electrolytes so far.Moreover,the fabricated all-solid-state lithium metal batteries demonstrate highly attractive properties with quite stable cycling performance over 100 cycles with 82%capacity reservation at 0.5 C.展开更多
It is of great significance to develop high-temperature anhydrous proton conducting materials.Herein,we report a new strategy to significantly enhance the proton conductivity of covalent organic frameworks(COFs)throug...It is of great significance to develop high-temperature anhydrous proton conducting materials.Herein,we report a new strategy to significantly enhance the proton conductivity of covalent organic frameworks(COFs)through expanding the dimensionality of proton conduction.Three COF-based composites,COF-1@PA,COF-2@PA,and COF-3@PA(PA:phosphoric acid),are prepared by PA doping of three COFs with similar pore sizes but different amounts of hydrophilic groups.With the increase of hydrophilic groups,COFs can load more PA because of the enhanced hydrogen–bonding interactions between PA and the frameworks.powder X-ray diffraction(PXRD),scanning electron microscopy(SEM),and two-dimensional(2D)solid-state nuclear magnetic resonance(NMR)analyses show that PA can not only enter the channels of COF-3,but also insert into its 2D interlayers.This expands the proton conduction pathways from one-dimensional(1D)to three-dimensional(3D),which greatly improves the proton conductivity of COF-3.Meanwhile,the confinement effect of 1D channels and 2D layers of COF-3 also makes the hydrogen-bonded networks more orderly in COF-3@PA-30(30μL of PA loaded on COF-3).At 150℃,COF-3@PA-30 exhibits an ultrahigh anhydrous proton conductivity of 1.4 S·cm−1,which is a record of anhydrous proton conductivity reported to date.This work develops a new strategy for increasing the proton conductivity of 2D COF materials.展开更多
Fast ion conductor is a kind of solid material possessing excellent character of translation ion at room temperature. Its translation ion power is almost the same as that of melt salt. In recent years, a few natural m...Fast ion conductor is a kind of solid material possessing excellent character of translation ion at room temperature. Its translation ion power is almost the same as that of melt salt. In recent years, a few natural minerals with the open structure are found that they展开更多
基金supported by the Basic Science Research Program (No.RS-2024-00344021) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future Planningthe financial support from the National Natural Science Foundation of China (52103277)+2 种基金the Program for Science & Technology Innovation Talents in Universities of Henan Province (23HASTIT015)Natural Science Foundation of Henan Province (242300421073)supported by the Technology Innovation Program (20010960) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea)
文摘Single-ion conductors based on covalent organic frameworks(COFs)have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility.However,the sluggish Li+conduction has hindered their practical applications.Here,we present a class of solvent-free COF single-ion conductors(Li-COF@P)based on weak ion-dipole interaction as opposed to traditional strong ion-ion interaction.The ion(Li+from the COF)-dipole(oxygen from poly(ethylene glycol)diacrylate embedded in the COF pores)interaction in the Li-COF@P promotes ion dissociation and Li+migration via directional ionic channels.Driven by this single-ion transport behavior,the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance(88.3%after 2000 cycles)in organic batteries(Li metal anode||5,5’-dimethyl-2,2’-bis-p-benzoquinone(Me2BBQ)cathode)under ambient operating conditions,highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries.
基金supported by the National Natural Science Foundation of China (Nos. 20971064 and 21071074)the Foundation of Education Committee of Henan Province (No. 092102210315)
文摘A new one-dimensional aluminum fluorophosphate, AlP2O5(OH)3F·0.5[H2dien] (dien=diethylenetriamine), was solvothermally synthesized by using organic amine as the structure directing agent, and its structure was determined by single-crystal X-ray diffraction. The complex inorganic architecture consists of trans-corner-sharing AlO4F2 octahedra chain decorated by phosphate tetrahedra along both sides of the -F-Al-F-Al-F- backbone displaying a series of Al2P three-membered rings, which will represent a new fundamental structural type in metal phosphates. The results of CHN elemental analysis, EDS, and TGA are also presented. Crystal data: C4H18Al2F2N3O16P4, monoclinic, space group P21/c with a=6.9107(14), b=15.749(3), c=8.9741(18) , β=109.829(2)o, V=918.8(3) 3, Z=2, Mr=580.05, Dc=2.097 g/cm3, μ=0.618 mm-1, S=1.022, F(000)=590, the final R=0.0510 and wR=0.1284 for 1607 observed reflections (I 〉 2σ(I)).
基金National Natural Science Foundation of China,Grant/Award Number:52064049Key National Natural Science Foundation of Yunnan Province,Grant/Award Numbers:2018FA028,2019FY003023+1 种基金International Joint Research Center for Advanced Energy Materials of Yunnan Province,Grant/Award Number:202003AE140001Key Laboratory of Solid State Ions for Green Energy of Yunnan University,Grant/Award Number:2019。
文摘A solid-state electrolyte(SSE),which is a solid ionic conductor and electroninsulating material,is known to play a crucial role in adapting a lithium metal anode to a high-capacity cathode in a solid-state battery.Among the various SSEs,the single Li-ion conductor has advantages in terms of enhancing the ion conductivity,eliminating interfacial side reactions,and broadening the electrochemical window.Covalent organic frameworks(COFs)are optimal platforms for achieving single Li-ion conduction behavior because of wellordered one-dimensional channels and precise chemical modification features.Herein,we study in depth three types of Li-carboxylate COFs(denoted LiOOC-COFn,n=1,2,and 3)as single Li-ion conducting SSEs.Benefiting from well-ordered directional ion channels,the single Li-ion conductor LiOOC-COF3 shows an exceptional ion conductivity of 1.36×10^(-5) S cm^(-1) at room temperature and a high transference number of 0.91.Moreover,it shows excellent electrochemical performance with long-term cycling,high-capacity output,and no dendrites in the quasi-solid-state organic battery,with the organic small molecule cyclohexanehexone(C_(6)O_(6))as the cathode and the Li metal as the anode,and enables effectively avoiding dissolution of the organic electrode by the liquid electrolyte.
文摘Organic conductor is a kind of organic compound which has special electronic and magnetic properties. The research of the organic compounds has received considerable attention because of their potential applications in many areas. The molecular conductive units are theoretically investigated as well as their energy gap and charge distribution. The relationship of conductivity and micro mechanism is discussed.
基金Funded by the National Natural Science Foundation of ChinaNational 863 Program of China(Nos.50872115and2009AA03Z203)
文摘CeO2 and Ce0.8M0.2O2-d films (M = Mn, Y, Gd, Sm, Nd and La) with (00l) preferred orientation have been prepared on biaxially textured Ni-W substrates by metal organic decomposition (MOD) method. The factors influencing the formation of cracks on the surface of these CeO2 and doped CeO2 films on Ni-W substrates were explored by X-ray diffraction (XRD), scanning electron microscopy (SEM) analysis, atomic force microscopy (AFM) and differential scanning calorimetry (DSC). The results indicate that many factors, such as the change of the ionic radii of doping cations, the transformation of crystal structure and the formation of oxygen vacancies in lattices at high annealing temperature, may be related to the formation of cracks on the surface of these films. However, the crack formation shows no dependence on the crystal lattice mismatch degree of the films with Ni-W substrates. Moreover, the suppression of surface cracks is related to the change of intrinsic elasticity of CeO2 film with doping of cations with a larger radius. SEM and AFM investigations of Ce0.8M0.2O2-d (M = Y, Gd, Sm, Nd and La) films reveal the dense, smooth and crack-free microstructure, and their lattice parameters match well with that of YBCO, illuminating that they are potentially suitable to be as buffer layer, especially as cap layer in multi-layer architecture of buffer layer for coated conductors.
基金supported by Samsung Research Fund,Sungkyunkwan University,2006
文摘YBa2Cu3O7-x(YBCO) films were fabricated on an LAO substrate using the trifluoroacetic acid-metal organic deposition(TFA-MOD) method and the effects of the humidity and heat treatment temperatures on the microstructure,degree of texture and critical properties of the films were evaluated.In order to understand the combined effects of the humidity and the calcining and firing temperatures on critical properties,heat-treatment was performed at various temperatures with the other processing variables fixed.The films were calcined at 400-430 ℃ and fired at 750-800 ℃ in a 0-12.1% humidified Ar-O2 atmosphere.The texture was determined by pole-figure analysis.The amount of the BaF2 phase was effectively reduced and a sharp and strong biaxial texture was formed under a humidified atmosphere,which led to increased critical properties.In addition,the microstructure varied significantly with firing temperature but changed little with calcining temperature.The highest IC of 40 A/cm-width,which corresponds to JC value of 1.8 MA/cm2,was obtained for the films fired at 775 ℃(in 12.1% humidity) after calcining at 400-430 ℃.It is likely that the highest IC value is due to the formation of a more pure YBCO phase,c-axis grains,and a denser microstructure.
基金supported by the National Basic Research Program of China(2013CB933501)the National Natural Science Foundation of China
文摘Organic semiconductors have gradually become the super stars on the stage of optoelectronic materials, due to their low cost, flexibility and solution processability. Numerous organic semiconductors, including small molecules and conjugated polymers, have been designed and synthesized to explore the potential of organic materials in optoelectronic industry. One-dimensional micro/nanostructures of organic semiconductors generally have more ordered packing structure with fewer defects compared with thin films, and are thus thought to show intrinsic carrier mobility of organic materials. Moreover, the packing structure in micro/nanostructures is clear and relatively easy to analyze, which makes these micro/nanostructures a good platform to study structure-property relationship. Therefore, design of suitable organic molecules to form micro-/nanostructures and methods to obtain ideal micro/nanostructures for functional devices will be fully discussed in this mini review. Finally, the perspective and opportunity of 1D micro/nanostructured organic materials based OFETs in the near future are also addressed.
文摘Electrolytic water splitting by renewable energy is a technology with great potential for producing hydrogen(H_(2))without carbon emission,but this technical route is hindered by its huge energy(electricity)cost,which is mainly wasted by the anode oxygen evolution reaction(OER)while the value of the anode product(oxygen)is very limited.Replacing the high-energy-cost OER with a selective organic compound electrooxidation carried out at a relatively lower potential can reduce the electricity cost while producing value-added chemicals.Currently,H_(2) generation coupled with synthesis of value-added organic compounds faces the challenge of low selectivity and slow generation rate of the anodic products.One-dimensional(1D)nanocatalysts with a unique morphology,well-defined active sites,and good electron conductivity have shown excellent performance in many electrocatalytic reactions.The rational design and regulation of 1D nanocatalysts through surface engineering can optimize the adsorption energy of intermediate molecules and improve the selectivity of organic electrooxidation reactions.Herein,we summarized the recent research progress of 1D nanocatalysts applied in different organic electrooxidation reactions and introduced several different fabrication strategies for surface engineering of 1D nanocatalysts.Then,we focused on the relationship between surface engineering and the selectivity of organic electrooxidation reaction products.Finally,future challenges and development prospects of 1D nanocatalysts in the coupled system consisting of organic electrooxidation and hydrogen evolution reactions are briefly outlined.
基金supported by National Key R&D Program of China (2023YFB3608904)the National Natural Science Foundation of China (62004106, 62274097, 21835003, 62005126)+7 种基金the Natural Science Foundation of Jiangsu Province (BE2019120,BK20210601)the Foundation of Key Laboratory of Flexible Electronics of Zhejiang Province (2023FE002)Program for Jiangsu Specially-Appointed Professors (RK030STP15001)the Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions (TJ217038)the Six Talent Peaks Project of Jiangsu Province (TD-XCL-009)the 333 Project of Jiangsu Province (BRA2017402)the Project of State Key Laboratory of Organic Electronics and Information Displays,NJUPT (GZR2023-010016)Natural Science Foundation of NJUPT (NY223079)。
文摘Covalent organic frameworks(COFs) are attractive porous crystalline materials with extremely high stability, easy functionalization, and open channels, which are expected to be unique ion conductors/transporters in lithium ion batteries(LIBs). Despite recent advances, low ion conductivity and low transference number, resulting in low charging/discharging rate, low energy density, and short battery life, are the main issues that limit their direct application as solid electrolytes in LIBs. Here, we designed and synthesized a novel polyimide COF, namely, TAPA-PDI-COF, with abundant C=O groups, which has been successfully employed as high-performance solid electrolytes by doping TAPA-PDI-COF and succinonitrile(SN). Both the well-defined nanochannels of COFs and SN confined in the well-aligned channels restricted the free migration of anions, while C=O on COFs and CN groups of SN enhanced Li^(+) transport, thus achieving a high ion conductivity of 0.102 m S cm^(-1)at 80 °C and a high lithium-ion transference number of 0.855 at room temperature. According to density functional theory(DFT)calculations, Li-ion migration mainly adopted in-plane transport rather than the axial pathway, which may be due to the shorter hopping distances in the planar pathway. The results suggest an effective strategy for the design and development of all-solidstate ionic conductors for achieving high-performance LIBs.
基金We thank the financial support from the Natural Science Foundation of Shandong(Nos.ZR2020JQ21 and ZR2021ZD24)National Natural Science Foundation of China(Nos.51873231 and 22138013)+1 种基金Taishan Scholar Project(No.tsqn201909062)the Technology Foundation of Shandong Energy Group Co.,LTD.(YKZB2020-176,YKKJ2019AJ08JG-R63)。
文摘As a novel class of porous crystalline solids,covalent organic frameworks(COFs)based electrolyte can combine the advantages of both inorganic and polymer electrolytes,leading to such as higher structural stability to inhibit lithium dendrites and better processing facility for improving interfacial contact.However,the ionic components of Li salt tend to be closely associated in the form of ion pairs or even ionic aggregates in the channel of COFs due to strong coulombic interactions,thus resulting in slow ionic diffusion dynamics and low ionic conductivity.Herein,we successfully designed and synthesized a novel single-ion conducting nitrogen hybrid conjugated skeleton(NCS)as all solid electrolyte,whose backbone is consisted with triazine and piperazine rings.A loose bonding between the triazine rings and cations would lower the energy barrier during ions transfer,and electrostatic forces with piperazine rings could“anchor”anions to increase the selectivity during ions transfer.Thus,the NCSelectrolyte exhibits excellent room temperature lithium-ion conductivity up to 1.49 mS·cm−1 and high transference number of 0.84 without employing any solvent,which to the best of our knowledge is one of the highest COF-based electrolytes so far.Moreover,the fabricated all-solid-state lithium metal batteries demonstrate highly attractive properties with quite stable cycling performance over 100 cycles with 82%capacity reservation at 0.5 C.
基金We are grateful for financial support from the National Natural Science Foundation of China(Nos.21771193 and 22275210)Key Research and Development Projects of Shandong Province(No.2019JZZY010331).
文摘It is of great significance to develop high-temperature anhydrous proton conducting materials.Herein,we report a new strategy to significantly enhance the proton conductivity of covalent organic frameworks(COFs)through expanding the dimensionality of proton conduction.Three COF-based composites,COF-1@PA,COF-2@PA,and COF-3@PA(PA:phosphoric acid),are prepared by PA doping of three COFs with similar pore sizes but different amounts of hydrophilic groups.With the increase of hydrophilic groups,COFs can load more PA because of the enhanced hydrogen–bonding interactions between PA and the frameworks.powder X-ray diffraction(PXRD),scanning electron microscopy(SEM),and two-dimensional(2D)solid-state nuclear magnetic resonance(NMR)analyses show that PA can not only enter the channels of COF-3,but also insert into its 2D interlayers.This expands the proton conduction pathways from one-dimensional(1D)to three-dimensional(3D),which greatly improves the proton conductivity of COF-3.Meanwhile,the confinement effect of 1D channels and 2D layers of COF-3 also makes the hydrogen-bonded networks more orderly in COF-3@PA-30(30μL of PA loaded on COF-3).At 150℃,COF-3@PA-30 exhibits an ultrahigh anhydrous proton conductivity of 1.4 S·cm−1,which is a record of anhydrous proton conductivity reported to date.This work develops a new strategy for increasing the proton conductivity of 2D COF materials.
基金Project supported by the National Natural Science Foundation of China
文摘Fast ion conductor is a kind of solid material possessing excellent character of translation ion at room temperature. Its translation ion power is almost the same as that of melt salt. In recent years, a few natural minerals with the open structure are found that they