We put forward a method of fabricating Aluminum(Al)/carbon fibers(CFs) composite sheets by the accumulative roll bonding(ARB) method. The finished Al/CFs composite sheet has CFs and pure Al sheets as sandwich and surf...We put forward a method of fabricating Aluminum(Al)/carbon fibers(CFs) composite sheets by the accumulative roll bonding(ARB) method. The finished Al/CFs composite sheet has CFs and pure Al sheets as sandwich and surface layers. After cross-section observation of the Al/CFs composite sheet, we found that the CFs discretely distributed within the sandwich layer. Besides, the tensile test showed that the contribution of the sandwich CFs layer to tensile strength was less than 11% compared with annealed pure Al sheet. With ex-situ observation of the CFs breakage evolution with-16%,-32%, and-45% rolling reduction during the ARB process, the plastic instability of the Al layer was found to bring shear damages to the CFs. At last, the bridging strengthening mechanism introduced by CFs was sacrificed. We provide new insight into and instruction on Al/CFs composite sheet preparation method and processing parameters.展开更多
The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performan...The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performance is mainly caused by lack of pyridine nitrogen,which often tends to escape because of high temperature in preparation process of hard carbon.In this paper,a high-rate kapok fiber-derived hard carbon is fabricated by cross-linking carboxyl group in 2,6-pyridinedicarboxylic acid with the exposed hydroxyl group on alkalized kapok with assistance of zinc chloride.Specially,a high nitrogen doping content of 4.24%is achieved,most of which are pyridine nitrogen;this is crucial for improving the defect sites and electronic conductivity of hard carbon.The optimized carbon with feature of high nitrogen content,abundant functional groups,degree of disorder,and large layer spacing exhibits high capacity of 401.7 mAh g^(−1)at a current density of 0.05 A g^(−1),and more importantly,good rate performance,for example,even at the current density of 2 A g^(−1),a specific capacity of 159.5 mAh g^(−1)can be obtained.These findings make plant-based hard carbon a promising candidate for commercial application of sodium-ion batteries,achieving high-rate performance with the enhanced pre-cross-linking interaction between plant precursors and dopants to optimize aromatization process by auxiliary pyrolysis.展开更多
A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characteriz...A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characterized by scanning electron microscope,Fourier transform infrared spectra and contact angle.Cyclic voltammetry and Tafel curves have been used to study its electro-chemical performances.Two identical electrodes in sea water as the electric field sensor will swiftly respond to applied electric field which causes positive and negative ions to move in opposite direction,resulting in a electric potential difference(ΔE).Test result indicates that the offset potential is typically below 1 m V with a drift of 60-170μVd^-1.Typical self noise level is 1.07 nV√Hz^(1/2)@1 Hz.The electric field response indicates that the modified electrode pair shows better response to AC sine signal of amplitude and frequency(5 mV and 1 mHz)respectively than its blank.The electric field response model of the modified electrodes is creatively presented according to its electric double layer capacitance and Faraday pseudo-capacitance.Many advantages of the carbon fiber electric field electrode will make it have potential application prospect.展开更多
Flexible carbon fiber cloth(CFC)is an important scaffold and/or current collector for active materials in the development of flexible self-supportive electrode materials(SSEMs),especially in lithium-ion batteries.Howe...Flexible carbon fiber cloth(CFC)is an important scaffold and/or current collector for active materials in the development of flexible self-supportive electrode materials(SSEMs),especially in lithium-ion batteries.However,during the intercalation of Li ions into the matrix of CFC(below 0.5 V vs.Li/Li+),the incompatibility in the capacity of the CFC,when used directly as an anode material or as a current collector for active materials,leads to difficulty in the estimation of its actual contribution.To address this issue,we prepared Ni_(5)P_(4)nanosheets on CFC(denoted CFC@Ni_(5)P_(4))and investigated the contribution of CFC in the CFC@Ni_(5)P_(4)by comparing to the powder Ni_(5)P_(4)nanosheets traditionally coated on a copper foil(CuF)(denoted P-Ni_(5)P_(4)).At a current density of 0.4 mA cm^(−2),the as-prepared CFC@Ni_(5)P_(4)showed an areal capacity of 7.38 mAh cm^(−2),which is significantly higher than that of the PNi_(5)P_(4)electrode.More importantly,theoretical studies revealed that the CFC has a high Li adsorption energy that contributes to the low Li-ion diffusion energy barrier of the Ni_(5)P_(4)due to the strong interaction between the CFC and Ni_(5)P_(4),leading to the superior Li-ion storage performance of the CFC@Ni_(5)P_(4)over the pristine Ni_(5)P_(4)sample.This present work unveils the underlying mechanism leading to the achievement of high performance in SSEMs.展开更多
The electrochemical behaviors (cyclic voltammetry, CV and different pulse voltammetry, DPV) of dopamine (DA) were studied in this paper. The result indicated that the oxidation of dopamine was controlled by diffusion...The electrochemical behaviors (cyclic voltammetry, CV and different pulse voltammetry, DPV) of dopamine (DA) were studied in this paper. The result indicated that the oxidation of dopamine was controlled by diffusion and adsorption simultaneously at nano-gold (NG) modified carbon fiber electrode (CFE). This modified electrode can separate the peak potentials of dopamine and ascorbic acid (AA). The peak current of DA in DPV curve was found to be linearly proportional to the concentration of DA at range of 2.0?0-6～1.5?0-5mol/L and 1.0?0-5～5.0?0-4mol/L, respectively.展开更多
Carbon fiber microelectrodes (CFEs) are useful when combined with electrochemical techniques for measuring changes in neurotransmitter concentrations. We addressed conflicting details regarding the use of CFEs. Experi...Carbon fiber microelectrodes (CFEs) are useful when combined with electrochemical techniques for measuring changes in neurotransmitter concentrations. We addressed conflicting details regarding the use of CFEs. Experimental groups consisted of CFEs at different ages (1 week, 1 month, or 2 months), cleaned in solvents (isopropanol or xylene), and exposed to in vitro use (flow cell calibrations) or in vivo use (in brain tissue). In order to determine if any of these factors affect CFE sensitivity, the present study utilized fixed potential amperometry and a flow injection system to calibrate CFEs for the measurement of dopamine. The sensitivity index (nA/μM per 100 μm of exposed carbon fiber) was not affected by the age of CFEs or pre-cleaning with xylene or isopropanol. CFE sensitivity of the in vitro exposure group also did not differ from untreated CFEs, indicating the calibration process did not alter sensitivity. However, in vivo use in brain tissue did reduce sensitivity. This effect was negated and sensitivity restored by cleaning CFEs in isopropanol or xylene following in vivo brain recordings. Given that variations in CFE sensitivity can skew results, our findings can help standardize CFE use and explain discrepancies between researchers.展开更多
During discharge, appropriately changing the development paths of electron avalanches and increasing the number of initial electrons can effectively inhibit the formation of filamentary discharge. Based on the aforeme...During discharge, appropriately changing the development paths of electron avalanches and increasing the number of initial electrons can effectively inhibit the formation of filamentary discharge. Based on the aforementioned phenomenon, we propose a method of using microdischarge electrodes to produce a macroscopic discharge phenomenon. In the form of an asymmetric structure composed of a carbon fiber electrode, an electrode structure of carbon fiber spiral-contact type is designed to achieve an atmospheric pressure glow discharge in air, which is characterized by low discharge voltage, low energy consumption, good diffusion and less ozone generation.展开更多
For addressing the critical problems in current collectors in the aluminium batteries,a variety of carbonbased current collectors,including carbon fiber textiles and three-dimensional(3D)biomass-derivative carbon(BDC)...For addressing the critical problems in current collectors in the aluminium batteries,a variety of carbonbased current collectors,including carbon fiber textiles and three-dimensional(3D)biomass-derivative carbon(BDC)networks,are employed for serving as lightweight non-metal current collectors.The results indicate that all the carbon-based current collectors have electrochemical stability in the acidic electrolyte environments.In the assembled aluminium batteries with all-carbon positive electrodes,thermal annealing process on the carbon-based current collectors has substantially promoted the entire electrochemical energy storage performance.Additionally,both the structure configuration and chemical components of the current collectors have also great impact on the rate capability and cycling stability,implying that the 3D BDC networks are more favorable to offer promoted energy storage capability.Implication of the results from suggests that the carbon-based current collectors and all-carbon positive electrodes are able to deliver more advantages in energy storage behaviors in comparison with the traditional positive electrodes with metal Mo current collectors.Such novel strategy promises a new route for fabricating highperformance positive electrodes for stable advanced aluminium batteries.展开更多
In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expa...In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expansion and exfoliation always occur for electrode materials. Herein, an integrated electrode Co3O4/carbon fiber paper (CFP) is prepared as the anode of DIB. As the Co3O4 nanosheets grow on CFP substrate vertically, it promotes the immersion of electrolyte and shortens the pathway for ionic transport. Besides, the strong interaction between Co3O4 and CFP substrate reduces the possibility of sheet exfoliation. An integrated-electrode-based DIB is therefore packaged using Co3O4/CFP as anode and graphite as cathode. As a result, a high energy density of 72 Wh/kg is achieved at a power density of 150 W/kg. The design of integrated electrode provides a new route for the development of high-performance DIBs.展开更多
In order to improve the wettability and bonding performance of the interface between carbon fiber and aluminum matrix,nickel-and copper-coated carbon fiber-reinforced aluminum matrix composites were fabricated by the ...In order to improve the wettability and bonding performance of the interface between carbon fiber and aluminum matrix,nickel-and copper-coated carbon fiber-reinforced aluminum matrix composites were fabricated by the squeeze melt infiltration technique.The interface wettability,microstructure and mechanical properties of the composites were compared and investigated.Compared with the uncoated fiber-reinforced aluminum matrix composite,the microstructure analysis indicated that the coatings significantly improved the wettability and effectively inhibited the interface reaction between carbon fiber and aluminum matrix during the process.Under the same processing condition,aluminum melt was easy to infiltrate into the copper-coated fiber bundles.Furthermore,the inhibited interface reaction was more conducive to maintain the original strength of fiber and improve the fiber−matrix interface bonding performance.The mechanical properties were evaluated by uniaxial tensile test.The yield strength,ultimate tensile strength and elastic modulus of the copper-coated carbon fiber-reinforced aluminum matrix composite were about 124 MPa,140 MPa and 82 GPa,respectively.In the case of nickel-coated carbon fiber-reinforced aluminum matrix composite,the yield strength,ultimate tensile strength and elastic modulus were about 60 MPa,70 MPa and 79 GPa,respectively.The excellent mechanical properties for copper-coated fiber-reinforced composites are attributed to better compactness of the matrix and better fiber−matrix interface bonding,which favor the load transfer ability from aluminam matrix to carbon fiber under the loading state,giving full play to the bearing role of carbon fiber.展开更多
Native calf thymus double stranded DNA (ct-dsDNA) is successfully immobilized from solution onto carbon substrates by covalent linkages under an optimized deposition potential of 1 .8±0.3 V vs. 50 mmol/L NaCl-Ag/...Native calf thymus double stranded DNA (ct-dsDNA) is successfully immobilized from solution onto carbon substrates by covalent linkages under an optimized deposition potential of 1 .8±0.3 V vs. 50 mmol/L NaCl-Ag/AgCl. The long chain DNA fabricates a layer of well conductive nano-netting intertexture, which is stable in pH 14 alkaline solution and in boiling water. The ct-dsDNA modified carbon fiber disk electrode shows two to three orders of magnitude enlarged electrode effective surface area and similarly enlarged voltammetric responses to Co(phen)33+ and dopamine. Thermal dissociated single stranded ct-DNA can also lead to similar result. This modified electrode will find wide applications in the fields of DNA-based electrochemical biosensors.展开更多
Monolithic carbon electrodes with robust mechanical integrity and porous architecture are highly desired for capacitive deionization but remain challenging.Owing to the excellent mechanical strength and electroconduct...Monolithic carbon electrodes with robust mechanical integrity and porous architecture are highly desired for capacitive deionization but remain challenging.Owing to the excellent mechanical strength and electroconductivity,commercial carbon fibers cloth demonstrates great potential as high-performance electrodes for ions storage.Despite this,its direct application on capacitive deionization is rarely reported in terms of limited pore structure and natural hydrophobicity.Herein,a powerful metal-organic framework-engaged structural regulation strategy is developed to boost the desalination properties of carbon fibers.The obtained porous carbon fibers features hierarchical porous structure and hydrophilic surface providing abundant ions-accessible sites,and continuous graphitized carbon core ensuring rapid electrons transport.The catalytic-etching mechanism involving oxidation of Co and subsequent carbonthermal reduction is proposed and highly relies on annealing temperature and holding time.When directly evaluated as a current collector-free capacitive deionization electrode,the porous carbon fibers demonstrates much superior desalination capability than pristine carbon fibers,and remarkable cyclic stability up to 20 h with negligible degeneration.Particularly,the PCF-1000 showcases the highest areal salt adsorption capacity of 0.037 mg cm^(−2) among carbon microfibers.Moreover,monolithic porous carbon fibers-carbon nanotubes with increased active sites and good structural integrity by in-situ growth of carbon nanotubes are further fabricated to enhance the desalination performance(0.051 mg cm^(−2)).This work demonstrates the great potential of carbon fibers in constructing high-efficient and robust monolithic electrode for capacitive deionization.展开更多
The electroless nickel plating on the surface of carbon fibers was prepared by pretreating the carbon fibers in order to increase their conductivity,and consequently enhance the EMI shielding effectiveness of the comp...The electroless nickel plating on the surface of carbon fibers was prepared by pretreating the carbon fibers in order to increase their conductivity,and consequently enhance the EMI shielding effectiveness of the composites.The relationship between the performance of depositing coat and pH value,temperature,reaction time and the way of agitation was studied.Results show that the depositing quality is stable under pH between 4.5 and 5.0,temperature between 75 ℃ and 85 ℃,reaction time for 10 min and air agitation.The uniform and compact nickel layer deposited on carbon fibers was proved by XRD and SEM,and the electrical resistivity of carbon fibers with nickel coating was tested.Results indicate that the electrical resistivity of carbon fibers with electroless nickel plating is decreased by an order of magnitude compared with that of carbon fibers.It means that nickel coating can greatly improve the electromagnetic interference shielding properties of carbon fibers.展开更多
基金Supported by Innovation and Technology Fund (No.ITP/045/19AP)Commercial Research&Development (CRD) Funding Supported by Hong Kong Productivity Council (No.10008787)。
文摘We put forward a method of fabricating Aluminum(Al)/carbon fibers(CFs) composite sheets by the accumulative roll bonding(ARB) method. The finished Al/CFs composite sheet has CFs and pure Al sheets as sandwich and surface layers. After cross-section observation of the Al/CFs composite sheet, we found that the CFs discretely distributed within the sandwich layer. Besides, the tensile test showed that the contribution of the sandwich CFs layer to tensile strength was less than 11% compared with annealed pure Al sheet. With ex-situ observation of the CFs breakage evolution with-16%,-32%, and-45% rolling reduction during the ARB process, the plastic instability of the Al layer was found to bring shear damages to the CFs. At last, the bridging strengthening mechanism introduced by CFs was sacrificed. We provide new insight into and instruction on Al/CFs composite sheet preparation method and processing parameters.
基金supported by National Natural Science Foundation of China(51903113 and 52073133)China Postdoctoral Science Foundation(2022T150282)+1 种基金Lanzhou Young Science and Technology Talent Innovation Project(2023-QN-101the Program for Hongliu Excellent and Distinguished Young Scholars at Lanzhou University of Technology.
文摘The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performance is mainly caused by lack of pyridine nitrogen,which often tends to escape because of high temperature in preparation process of hard carbon.In this paper,a high-rate kapok fiber-derived hard carbon is fabricated by cross-linking carboxyl group in 2,6-pyridinedicarboxylic acid with the exposed hydroxyl group on alkalized kapok with assistance of zinc chloride.Specially,a high nitrogen doping content of 4.24%is achieved,most of which are pyridine nitrogen;this is crucial for improving the defect sites and electronic conductivity of hard carbon.The optimized carbon with feature of high nitrogen content,abundant functional groups,degree of disorder,and large layer spacing exhibits high capacity of 401.7 mAh g^(−1)at a current density of 0.05 A g^(−1),and more importantly,good rate performance,for example,even at the current density of 2 A g^(−1),a specific capacity of 159.5 mAh g^(−1)can be obtained.These findings make plant-based hard carbon a promising candidate for commercial application of sodium-ion batteries,achieving high-rate performance with the enhanced pre-cross-linking interaction between plant precursors and dopants to optimize aromatization process by auxiliary pyrolysis.
基金supported by the National Defense Science and Technology Innovation Zone Project(No.18-H863-05-ZT-001-018-09)
文摘A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characterized by scanning electron microscope,Fourier transform infrared spectra and contact angle.Cyclic voltammetry and Tafel curves have been used to study its electro-chemical performances.Two identical electrodes in sea water as the electric field sensor will swiftly respond to applied electric field which causes positive and negative ions to move in opposite direction,resulting in a electric potential difference(ΔE).Test result indicates that the offset potential is typically below 1 m V with a drift of 60-170μVd^-1.Typical self noise level is 1.07 nV√Hz^(1/2)@1 Hz.The electric field response indicates that the modified electrode pair shows better response to AC sine signal of amplitude and frequency(5 mV and 1 mHz)respectively than its blank.The electric field response model of the modified electrodes is creatively presented according to its electric double layer capacitance and Faraday pseudo-capacitance.Many advantages of the carbon fiber electric field electrode will make it have potential application prospect.
基金National Natural Science Foundation of China,Grant/Award Numbers:21875292,21902188National Key Research and Development Program of China,Grant/Award Number:2019YFA0705702+2 种基金Hunan Provincial Natural Science Foundation,Grant/Award Number:2021JJ30087Natural Science Foundation of Guangdong Province,Grant/Award Number:2020A1515010798Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy,Grant/Award Number:2020CB1007。
文摘Flexible carbon fiber cloth(CFC)is an important scaffold and/or current collector for active materials in the development of flexible self-supportive electrode materials(SSEMs),especially in lithium-ion batteries.However,during the intercalation of Li ions into the matrix of CFC(below 0.5 V vs.Li/Li+),the incompatibility in the capacity of the CFC,when used directly as an anode material or as a current collector for active materials,leads to difficulty in the estimation of its actual contribution.To address this issue,we prepared Ni_(5)P_(4)nanosheets on CFC(denoted CFC@Ni_(5)P_(4))and investigated the contribution of CFC in the CFC@Ni_(5)P_(4)by comparing to the powder Ni_(5)P_(4)nanosheets traditionally coated on a copper foil(CuF)(denoted P-Ni_(5)P_(4)).At a current density of 0.4 mA cm^(−2),the as-prepared CFC@Ni_(5)P_(4)showed an areal capacity of 7.38 mAh cm^(−2),which is significantly higher than that of the PNi_(5)P_(4)electrode.More importantly,theoretical studies revealed that the CFC has a high Li adsorption energy that contributes to the low Li-ion diffusion energy barrier of the Ni_(5)P_(4)due to the strong interaction between the CFC and Ni_(5)P_(4),leading to the superior Li-ion storage performance of the CFC@Ni_(5)P_(4)over the pristine Ni_(5)P_(4)sample.This present work unveils the underlying mechanism leading to the achievement of high performance in SSEMs.
基金The authors gratefully acknowledge financial support from the Natural Science Foundation of Anhui Provincethe Natural Science Foundation of Anhui Education Committee(2001kj185).
文摘The electrochemical behaviors (cyclic voltammetry, CV and different pulse voltammetry, DPV) of dopamine (DA) were studied in this paper. The result indicated that the oxidation of dopamine was controlled by diffusion and adsorption simultaneously at nano-gold (NG) modified carbon fiber electrode (CFE). This modified electrode can separate the peak potentials of dopamine and ascorbic acid (AA). The peak current of DA in DPV curve was found to be linearly proportional to the concentration of DA at range of 2.0?0-6～1.5?0-5mol/L and 1.0?0-5～5.0?0-4mol/L, respectively.
文摘Carbon fiber microelectrodes (CFEs) are useful when combined with electrochemical techniques for measuring changes in neurotransmitter concentrations. We addressed conflicting details regarding the use of CFEs. Experimental groups consisted of CFEs at different ages (1 week, 1 month, or 2 months), cleaned in solvents (isopropanol or xylene), and exposed to in vitro use (flow cell calibrations) or in vivo use (in brain tissue). In order to determine if any of these factors affect CFE sensitivity, the present study utilized fixed potential amperometry and a flow injection system to calibrate CFEs for the measurement of dopamine. The sensitivity index (nA/μM per 100 μm of exposed carbon fiber) was not affected by the age of CFEs or pre-cleaning with xylene or isopropanol. CFE sensitivity of the in vitro exposure group also did not differ from untreated CFEs, indicating the calibration process did not alter sensitivity. However, in vivo use in brain tissue did reduce sensitivity. This effect was negated and sensitivity restored by cleaning CFEs in isopropanol or xylene following in vivo brain recordings. Given that variations in CFE sensitivity can skew results, our findings can help standardize CFE use and explain discrepancies between researchers.
基金Supported by the National Natural Science Foundation of China under Grant No 51577011
文摘During discharge, appropriately changing the development paths of electron avalanches and increasing the number of initial electrons can effectively inhibit the formation of filamentary discharge. Based on the aforementioned phenomenon, we propose a method of using microdischarge electrodes to produce a macroscopic discharge phenomenon. In the form of an asymmetric structure composed of a carbon fiber electrode, an electrode structure of carbon fiber spiral-contact type is designed to achieve an atmospheric pressure glow discharge in air, which is characterized by low discharge voltage, low energy consumption, good diffusion and less ozone generation.
基金Financial support from National Key R&D Program of China(Grant No.2018YFB0104400)the National Natural Science Foundation of China(Grant Nos.11672341,11572002 and 51874019)+2 种基金Innovative Research Groups of the National Natural Science Foundation of China(Grant No.11521202)National Materials Genome Project(Grant No.2016YFB0700600)Beijing Natural Science Foundation(Grant Nos.16L00001 and 2182065).
文摘For addressing the critical problems in current collectors in the aluminium batteries,a variety of carbonbased current collectors,including carbon fiber textiles and three-dimensional(3D)biomass-derivative carbon(BDC)networks,are employed for serving as lightweight non-metal current collectors.The results indicate that all the carbon-based current collectors have electrochemical stability in the acidic electrolyte environments.In the assembled aluminium batteries with all-carbon positive electrodes,thermal annealing process on the carbon-based current collectors has substantially promoted the entire electrochemical energy storage performance.Additionally,both the structure configuration and chemical components of the current collectors have also great impact on the rate capability and cycling stability,implying that the 3D BDC networks are more favorable to offer promoted energy storage capability.Implication of the results from suggests that the carbon-based current collectors and all-carbon positive electrodes are able to deliver more advantages in energy storage behaviors in comparison with the traditional positive electrodes with metal Mo current collectors.Such novel strategy promises a new route for fabricating highperformance positive electrodes for stable advanced aluminium batteries.
基金Supports from the National Natural Science Foundation of China (51872115 and 51802110)the National Key R&D Program of China (2016YFA0200400)+2 种基金the Jilin Province/Jilin University Co-construction Project-Funds for New Materials (SXGJSF20173, Branch-2/440050316A36)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, 2017TD-09)“Double-First Class” Discipline for Materials Science & Engineering, are greatly acknowledged
文摘In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expansion and exfoliation always occur for electrode materials. Herein, an integrated electrode Co3O4/carbon fiber paper (CFP) is prepared as the anode of DIB. As the Co3O4 nanosheets grow on CFP substrate vertically, it promotes the immersion of electrolyte and shortens the pathway for ionic transport. Besides, the strong interaction between Co3O4 and CFP substrate reduces the possibility of sheet exfoliation. An integrated-electrode-based DIB is therefore packaged using Co3O4/CFP as anode and graphite as cathode. As a result, a high energy density of 72 Wh/kg is achieved at a power density of 150 W/kg. The design of integrated electrode provides a new route for the development of high-performance DIBs.
基金The authors are grateful for the financial supports from Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics(U1630129).
文摘In order to improve the wettability and bonding performance of the interface between carbon fiber and aluminum matrix,nickel-and copper-coated carbon fiber-reinforced aluminum matrix composites were fabricated by the squeeze melt infiltration technique.The interface wettability,microstructure and mechanical properties of the composites were compared and investigated.Compared with the uncoated fiber-reinforced aluminum matrix composite,the microstructure analysis indicated that the coatings significantly improved the wettability and effectively inhibited the interface reaction between carbon fiber and aluminum matrix during the process.Under the same processing condition,aluminum melt was easy to infiltrate into the copper-coated fiber bundles.Furthermore,the inhibited interface reaction was more conducive to maintain the original strength of fiber and improve the fiber−matrix interface bonding performance.The mechanical properties were evaluated by uniaxial tensile test.The yield strength,ultimate tensile strength and elastic modulus of the copper-coated carbon fiber-reinforced aluminum matrix composite were about 124 MPa,140 MPa and 82 GPa,respectively.In the case of nickel-coated carbon fiber-reinforced aluminum matrix composite,the yield strength,ultimate tensile strength and elastic modulus were about 60 MPa,70 MPa and 79 GPa,respectively.The excellent mechanical properties for copper-coated fiber-reinforced composites are attributed to better compactness of the matrix and better fiber−matrix interface bonding,which favor the load transfer ability from aluminam matrix to carbon fiber under the loading state,giving full play to the bearing role of carbon fiber.
文摘Native calf thymus double stranded DNA (ct-dsDNA) is successfully immobilized from solution onto carbon substrates by covalent linkages under an optimized deposition potential of 1 .8±0.3 V vs. 50 mmol/L NaCl-Ag/AgCl. The long chain DNA fabricates a layer of well conductive nano-netting intertexture, which is stable in pH 14 alkaline solution and in boiling water. The ct-dsDNA modified carbon fiber disk electrode shows two to three orders of magnitude enlarged electrode effective surface area and similarly enlarged voltammetric responses to Co(phen)33+ and dopamine. Thermal dissociated single stranded ct-DNA can also lead to similar result. This modified electrode will find wide applications in the fields of DNA-based electrochemical biosensors.
基金We gratefully acknowledge financial supports from the Natural Science Founda-tion of Shandong Province (No.ZR2020QE066)Taishan Scholar Project (No.ts201511080)+1 种基金the fellowship of China Postdoctoral Science Foundation (No.2020M672081)Opening Project of State Key Laboratory of Advanced Tech-nology for Float Glass (No.2020KF08).
文摘Monolithic carbon electrodes with robust mechanical integrity and porous architecture are highly desired for capacitive deionization but remain challenging.Owing to the excellent mechanical strength and electroconductivity,commercial carbon fibers cloth demonstrates great potential as high-performance electrodes for ions storage.Despite this,its direct application on capacitive deionization is rarely reported in terms of limited pore structure and natural hydrophobicity.Herein,a powerful metal-organic framework-engaged structural regulation strategy is developed to boost the desalination properties of carbon fibers.The obtained porous carbon fibers features hierarchical porous structure and hydrophilic surface providing abundant ions-accessible sites,and continuous graphitized carbon core ensuring rapid electrons transport.The catalytic-etching mechanism involving oxidation of Co and subsequent carbonthermal reduction is proposed and highly relies on annealing temperature and holding time.When directly evaluated as a current collector-free capacitive deionization electrode,the porous carbon fibers demonstrates much superior desalination capability than pristine carbon fibers,and remarkable cyclic stability up to 20 h with negligible degeneration.Particularly,the PCF-1000 showcases the highest areal salt adsorption capacity of 0.037 mg cm^(−2) among carbon microfibers.Moreover,monolithic porous carbon fibers-carbon nanotubes with increased active sites and good structural integrity by in-situ growth of carbon nanotubes are further fabricated to enhance the desalination performance(0.051 mg cm^(−2)).This work demonstrates the great potential of carbon fibers in constructing high-efficient and robust monolithic electrode for capacitive deionization.
文摘The electroless nickel plating on the surface of carbon fibers was prepared by pretreating the carbon fibers in order to increase their conductivity,and consequently enhance the EMI shielding effectiveness of the composites.The relationship between the performance of depositing coat and pH value,temperature,reaction time and the way of agitation was studied.Results show that the depositing quality is stable under pH between 4.5 and 5.0,temperature between 75 ℃ and 85 ℃,reaction time for 10 min and air agitation.The uniform and compact nickel layer deposited on carbon fibers was proved by XRD and SEM,and the electrical resistivity of carbon fibers with nickel coating was tested.Results indicate that the electrical resistivity of carbon fibers with electroless nickel plating is decreased by an order of magnitude compared with that of carbon fibers.It means that nickel coating can greatly improve the electromagnetic interference shielding properties of carbon fibers.
