The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X...The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X-ray diffraction results of the prepared NNMO without adding Na-excess content indicate sodium loss,while the mixed phase of P2/O′3-type layered NNMO presented after adding Na-excess content.Compared with the sol-gel method,the secondary phase of NiO is more suppressed by using the electrospinning method,which is further confirmed by field emission scanning electron microscope images.N_(2) adsorption-desorption isotherms show no remarkably difference in specific surface areas between different preparation methods and Na-excess contents.The analysis of X-ray absorption near edge structure indicates that the oxidation states of Ni and Mn are+2 and+4,respectively.For the electrochemical properties,superior electrochemical performance is observed in the NNMO electrode with a low Na-excess content of 5wt%.The highest specific capacitance is 36.07 F·g^(-1)at0.1 A·g^(-1)in the NNMO electrode prepared by using the sol-gel method.By contrast,the NNMO electrode prepared using the electrospinning method with decreased Na-excess content shows excellent cycling stability of 100%after charge-discharge measurements for 300 cycles.Therefore,controlling the Na excess in the precursor together with the preparation method is important for improving the electrochemical performance of Na-based electrode materials in supercapacitors.展开更多
We develop a new electrospinning method to prepare ultra-long ordered La1-xSrxMnO3 （LSMO） nanowires. The length is up to several centimeters and is only limited by the size of the collector. The well-ordered straigh...We develop a new electrospinning method to prepare ultra-long ordered La1-xSrxMnO3 （LSMO） nanowires. The length is up to several centimeters and is only limited by the size of the collector. The well-ordered straight-line structure ensures the transport measurement, which is impossible to be carried out for the random nanowires fabricated by the traditional electrospinning method. Magnetic and transport measurements indicate that the physical properties of the LSMO nanowires depend sensitively on the doping concentration. At the optimum doping, the LSMO wires are ferromagnetic at room temperature with a metal-insulator transition temperature close to room temperature. Magnetic force microscopy studies are also performed to provide a microscopic view of these ultra-long nanowires.展开更多
Amorphous hydroxide on a foamed nickel substrate was fabricated by a simple and efficient electrospinning method for the first time.In untreated alkaline medium,amorphous cobalt(Co)-iron(Fe)hydroxide showed oxygen-evo...Amorphous hydroxide on a foamed nickel substrate was fabricated by a simple and efficient electrospinning method for the first time.In untreated alkaline medium,amorphous cobalt(Co)-iron(Fe)hydroxide showed oxygen-evolution advantages over the typical reference catalyst(RuO_(2)).When tested with a three-electrode system in 1 M KOH,the obtained amorphous PVP/CoFe_(1.3)nanofibers possessed remarkable catalytic activity and stability for the oxygen evolution reaction(OER)with a low overpotential of 0.267 V at 100 mA cm^(-2)and a low Tafel slope of 47.43 mV dec^(-1).The amorphous CoFe microfibers were synthesized by electrospinning,and stable CoFe hydroxides can be further formed in the alkaline environment.The synergistic effect between two different amorphous CoFe-based hydroxides contributed to excellent electrocatalytic activity.Therefore,the design of amorphous CoFe hydroxide enabled the development of a high-efficiency OER catalyst and opens possibilities for the large-scale and environmentally friendly production of water splitting.展开更多
To effectively treat pollution and overcome the lack of selectivity of TiO_(2)-based photocatalysts,a 1D structure and molecular imprinting technology have been combined to produce TiO_(2)/SiO_(2) hybrid fibers by a s...To effectively treat pollution and overcome the lack of selectivity of TiO_(2)-based photocatalysts,a 1D structure and molecular imprinting technology have been combined to produce TiO_(2)/SiO_(2) hybrid fibers by a simple electrospinning method by directly adding templates into the precursor solution.In our design,TBOT acts as a titanium source and a functional monomer to combine with RhB and generate specific recognition sites,and SiO_(2) plays a role in inhibiting phase transition.The calcination process can not only remove the template and form an imprinting cavity but also enhance the crystallinity of photoca-talysts.The inorganic framework also overcomes the shortcomings of the instability of traditional organic molecularly imprinted layers.In contrast to a nonimprinted sample,imprinted fibers exhibit higher adsorp-tion capacity and selectivity,attributed to the specific combination through hydrogen bonds and space matching effect.The photocatalytic efficiency of the imprinted sample reached 100%within only 15 min,showing excellent photocatalytic performance and high selectivity.This work not only provides a novel,simple method to fabricate TiO_(2) fiber photocatalysts with high selectivity for the first time but also offers new strategies for the effective and selective treatment of pollutants in wastewater.展开更多
ZnO nanofibers with an average diameter of about 90 nm were prepared by an electrospinning method combined with a calcination process. The as-electrospun nanofibers before and after calcination were characterized by m...ZnO nanofibers with an average diameter of about 90 nm were prepared by an electrospinning method combined with a calcination process. The as-electrospun nanofibers before and after calcination were characterized by means of differential thermal analysis（DTA）, thermal gravimetric analysis（TGA）, X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The fibers after calcination at 600 °C belong to the hexagonal wurtzite structure. The sensor based on ZnO nanofibers exhibited excellent ethanol sensing properties at 206 °C such as good linear dependence in the low concentration（1―100 μL/L）, high response, and good selectivity. Fast response（less than 2 s） and recovery（about 16 s） were also observed in our investigations.展开更多
Li metal with high-energy density is considered as the most promising anode for the next-generation rechargeable Li metal batteries;however,the growth of Li dendrites seriously hinders its practical application.Herein...Li metal with high-energy density is considered as the most promising anode for the next-generation rechargeable Li metal batteries;however,the growth of Li dendrites seriously hinders its practical application.Herein,3D free-standing carbon nanofibers modified by lithiophilic metal particles(CNF/Me,Me=Sn,Fe,Co)are obtained in situ by the electrospinning method.Benefiting from the lithophilicity,the CNF/Me composite may effectively prevent the formation of Li dendrites in the Li metal batteries.The optimized CNF/Sn–Li composite electrode exhibits a stable cycle life of over 2350 h during Li plating/stripping.When matched with typical commercial LiFePO_(4)(LFP)cathode,the LFP//CNF/Sn–Li full cell presents a high initial discharge specific capacity of 139 mAh g^(−1)at 1 C,which remains at 146 mAh g^(−1)after 400 cycles.When another state-of-the-art commercial LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM(811))cathode is used,the assembled NCM//CNF/Sn–Li full cell shows a large initial specific discharge capacity of 206 mAh g^(−1)at substantially enhanced 10 C,which keeps at the good capacity of 99 mAh g^(−1)after 300 cycles.These results are greatly superior to the counterparts with Li as the anodes,indicating the great potential for practical utilization of the advanced CNF/Sn–Li electrode.展开更多
Nb-Doped LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)(Nb-NCM)nanobelts have been successfully fabricated for the first time through a facile electrospinning method by the delicate control of PAN pyrolysis and Nb-NCM formation(incl...Nb-Doped LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)(Nb-NCM)nanobelts have been successfully fabricated for the first time through a facile electrospinning method by the delicate control of PAN pyrolysis and Nb-NCM formation(including nucleation and subsequent growth processes).According to the experimental evidence from temperature-dependent characterization and isolation of the intermediates,the formation of nanobelts undergoes a morphology evolution from nanofibres to nanotubes,and finally to the nanobelts composed of subunit nanoparticles.When used as a cathode for lithium-ion batteries,the as-electrospun Nb-NCM nanobelts exhibit superior electrochemical performances,which could be attributed to their unique features,such as their 1D nanostructure,well-crystallized nature and Nb-doping.These features can improve the ionic conductivity of Nb-NCM nanobelts and stabilize the electrode/electrolyte interface.Therefore,the 1D Nb-NCM nanobelts developed in this study not only provide an excellent model to investigate the fabrication of multi-element oxides using the electrospinning method,but also open up a facile route for designing 1D layered cathodes with a complex component for high performance lithium-ion batteries.展开更多
LiCuVO_(4) has attracted increasing attention as an anode material for lithium ion batteries due to its good structural stability.However,the rate capability is limited by the inferior electronic conductivity and low ...LiCuVO_(4) has attracted increasing attention as an anode material for lithium ion batteries due to its good structural stability.However,the rate capability is limited by the inferior electronic conductivity and low lithium ion diffusion efficiency.Herein,we report the synthesis of LiCuVO_(4)/LiVO_(3)/C porous nanotubes by an electrospinning method with subsequent calcination in air.The unique morphology,carbonaceous material in the composite and the existence of LiVO_(3) enable the as-prepared composite to have high capacity,superior cycling stability and rate capability.The LiCuVO_(4)/LiVO_(3)/C electrode possesses a capacity of 636 mA h g^(-1) which is higher than the theoretical capacity of LiCuVO_(4)(576 mA h g^(-1)).Moreover,it can retain 77%of the capacity at 0.5 A g^(-1) after 300 cycles.These results demonstrate that LiCuVO_(4)/LiVO_(3)/C nanotubes are promising anode materials for lithium ion batteries.展开更多
It is highly desirable but challenging to design multi-functional materials for energy storage and electromagnetic(EM)wave absorption.Herein,core–shell CaSnO_(3)@N-doped carbon(CSO@NCNF)coaxial nanocables with one-di...It is highly desirable but challenging to design multi-functional materials for energy storage and electromagnetic(EM)wave absorption.Herein,core–shell CaSnO_(3)@N-doped carbon(CSO@NCNF)coaxial nanocables with one-dimensional(1D)architecture were synthesized by employing the electrospinning method combined with in situ polymerization and heat treatment.In the resulting structure,the CaSnO_(3) nanofiber(CSONF)core with an average diameter of 52.5 nm is confined in the high electronic conductivity of the N-doped carbon sheaths with a thickness ranging from 27.3 to 67.2 nm.The lithium storage performance of the CSO@NCNF nanocable electrode is much higher than that of the CSONF electrode;this is owing to the(i)large number of void spaces and active sites generated by the structure of the 1D core–shell nanocables,(ii)fast transport network constructed by carbon sheaths prominently enhancing the transport of both electrons and lithium ions,and(iii)structural stability achieved through the buffering mechanism created by CaSnO_(3)@NCNF coaxial construction.However,its ingenious structural design,multiple heterogeneous interfaces and multi-component strategy give rise to a synergistic mechanism of impedance matching,conductive loss,polarization loss and multiple reflection/scattering.The coaxial nanocables display good microwave absorption(MA)properties,featuring a reflection loss(RL)value of−47.0 dB at 8.2 GHz and 2.5 mm as well as an effective absorption bandwidth(EAB)of 4.7 GHz at 1.4 mm.This unique structural design is believed to provide a reference for the preparation of multi-functional materials.展开更多
Silicon oxides(SiO_(x))are regarded as one of the most potential anode materials for lithium-ion batteries with the advantages of a high theoretical capacity,low discharge platform(<0.5 V)and environmental friendli...Silicon oxides(SiO_(x))are regarded as one of the most potential anode materials for lithium-ion batteries with the advantages of a high theoretical capacity,low discharge platform(<0.5 V)and environmental friendliness.However,the low electronic conductivity and the degradation of the structure upon cycling have limited the electrochemical performance of SiO_(x).In this work,a conductive carbon fiber network wrapped SiO_(x)/C composite has been fabricated via combined electrospinning and carbonization methods.Importantly,the loading of SiO_(x) in the composite can be adjusted by changing the addition amounts of organosilica-polymer nanospheres during the electrospinning process.When utilized as an anode material for LIBs,the novel SiO_(x)/C composite exhibited good cycling stability and rate capabilities.The superior electrochemical performance can be ascribed to the special carbonaceous conductive network structure,which guarantees enhanced overall ion and electron transportation and structural integrity.The present work offers insights into the rational design of silicon-based materials for advanced lithium ion batteries.展开更多
The development of low-cost and eco-friendly gel polymer electrolytes (GPEs) with a wide window, ideal compatibility, and structural stability is an effective measure to achieve safe high-energy-density lithium-metal ...The development of low-cost and eco-friendly gel polymer electrolytes (GPEs) with a wide window, ideal compatibility, and structural stability is an effective measure to achieve safe high-energy-density lithium-metal batteries. Herein, a biodegradable composite polyacrylonitrile/poly-L-lactic acid nanofiber membrane (PAL) is synthesized and used as a robust skeleton for GPEs. The 3D nanofiber membrane (PAL-3-C12) prepared with an adjusted weight ratio of polyacrylonitrile (PAN)/poly-L-lactic acid (PLLA) and spinning solution concentration delivers decent thermal stability, biodegradability, and liquid electrolyte absorbability. The “passivation effect” of PAN upon lithium metal is effectively alleviated by hydrogen bonds formed in the PAL chains. These advantages enable PAL GPEs to work stably to 5.17 V while maintaining high ionic conductivity as well as excellent corrosion resistance and dielectric properties. The interfacial compatibility of optimized GPEs promotes the stable operation of a Li||PAL-3-C12 GPEs||Li symmetric battery for 1000 h at 0.15 mA cm^(−2)/0.15 mA h cm^(−2), and the LiFePO4 full cell retains capacity retention of 97.63% after 140 cycles at 1C.展开更多
基金financially supported by (i) Suranaree University of Technology,(ii) Thailand Science Research and Innovation,and (iii) National Science,Research and Innovation Fund(project codes 90464 and 160363)。
文摘The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X-ray diffraction results of the prepared NNMO without adding Na-excess content indicate sodium loss,while the mixed phase of P2/O′3-type layered NNMO presented after adding Na-excess content.Compared with the sol-gel method,the secondary phase of NiO is more suppressed by using the electrospinning method,which is further confirmed by field emission scanning electron microscope images.N_(2) adsorption-desorption isotherms show no remarkably difference in specific surface areas between different preparation methods and Na-excess contents.The analysis of X-ray absorption near edge structure indicates that the oxidation states of Ni and Mn are+2 and+4,respectively.For the electrochemical properties,superior electrochemical performance is observed in the NNMO electrode with a low Na-excess content of 5wt%.The highest specific capacitance is 36.07 F·g^(-1)at0.1 A·g^(-1)in the NNMO electrode prepared by using the sol-gel method.By contrast,the NNMO electrode prepared using the electrospinning method with decreased Na-excess content shows excellent cycling stability of 100%after charge-discharge measurements for 300 cycles.Therefore,controlling the Na excess in the precursor together with the preparation method is important for improving the electrochemical performance of Na-based electrode materials in supercapacitors.
基金Supported by the National Basic Research Program of China under Grant Nos 2016YFA0300700,2013CB932901 and2014CB921104the National Natural Science Foundation of China under Grant Nos 11274071 and 11504053the Shanghai Municipal Natural Science Foundation under Grant No 11ZR140260
文摘We develop a new electrospinning method to prepare ultra-long ordered La1-xSrxMnO3 （LSMO） nanowires. The length is up to several centimeters and is only limited by the size of the collector. The well-ordered straight-line structure ensures the transport measurement, which is impossible to be carried out for the random nanowires fabricated by the traditional electrospinning method. Magnetic and transport measurements indicate that the physical properties of the LSMO nanowires depend sensitively on the doping concentration. At the optimum doping, the LSMO wires are ferromagnetic at room temperature with a metal-insulator transition temperature close to room temperature. Magnetic force microscopy studies are also performed to provide a microscopic view of these ultra-long nanowires.
基金National Natural Science Foundation of China(21473013,51203008,21771021,and 21822501)Beijing Nova Program(xx2018115)+1 种基金Fundamental Research Funds for the Central UniversitiesAnalytical and Measurements Fund of Beijing Normal University。
文摘Amorphous hydroxide on a foamed nickel substrate was fabricated by a simple and efficient electrospinning method for the first time.In untreated alkaline medium,amorphous cobalt(Co)-iron(Fe)hydroxide showed oxygen-evolution advantages over the typical reference catalyst(RuO_(2)).When tested with a three-electrode system in 1 M KOH,the obtained amorphous PVP/CoFe_(1.3)nanofibers possessed remarkable catalytic activity and stability for the oxygen evolution reaction(OER)with a low overpotential of 0.267 V at 100 mA cm^(-2)and a low Tafel slope of 47.43 mV dec^(-1).The amorphous CoFe microfibers were synthesized by electrospinning,and stable CoFe hydroxides can be further formed in the alkaline environment.The synergistic effect between two different amorphous CoFe-based hydroxides contributed to excellent electrocatalytic activity.Therefore,the design of amorphous CoFe hydroxide enabled the development of a high-efficiency OER catalyst and opens possibilities for the large-scale and environmentally friendly production of water splitting.
基金supported by the National Natural Science Foundation of China(52073120).
文摘To effectively treat pollution and overcome the lack of selectivity of TiO_(2)-based photocatalysts,a 1D structure and molecular imprinting technology have been combined to produce TiO_(2)/SiO_(2) hybrid fibers by a simple electrospinning method by directly adding templates into the precursor solution.In our design,TBOT acts as a titanium source and a functional monomer to combine with RhB and generate specific recognition sites,and SiO_(2) plays a role in inhibiting phase transition.The calcination process can not only remove the template and form an imprinting cavity but also enhance the crystallinity of photoca-talysts.The inorganic framework also overcomes the shortcomings of the instability of traditional organic molecularly imprinted layers.In contrast to a nonimprinted sample,imprinted fibers exhibit higher adsorp-tion capacity and selectivity,attributed to the specific combination through hydrogen bonds and space matching effect.The photocatalytic efficiency of the imprinted sample reached 100%within only 15 min,showing excellent photocatalytic performance and high selectivity.This work not only provides a novel,simple method to fabricate TiO_(2) fiber photocatalysts with high selectivity for the first time but also offers new strategies for the effective and selective treatment of pollutants in wastewater.
基金Supported by the National High-Tech Research and Development Program of China(No.2009AA03Z402)the National Natural Science Foundation of China(Nos.60977031, 50977038)the Doctoral Fund of Ministry of Education of China(No.20090061110040)
文摘ZnO nanofibers with an average diameter of about 90 nm were prepared by an electrospinning method combined with a calcination process. The as-electrospun nanofibers before and after calcination were characterized by means of differential thermal analysis（DTA）, thermal gravimetric analysis（TGA）, X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The fibers after calcination at 600 °C belong to the hexagonal wurtzite structure. The sensor based on ZnO nanofibers exhibited excellent ethanol sensing properties at 206 °C such as good linear dependence in the low concentration（1―100 μL/L）, high response, and good selectivity. Fast response（less than 2 s） and recovery（about 16 s） were also observed in our investigations.
基金supported by the Chinese National Natural Science Foundation(No.22075008,21571010,U0734002)National Basic Research Programs of China(973 Program,No.2014CB931800,2011CB935700)+1 种基金Chinese Aeronautic Project(No.2013ZF51069)111 Project(No.B14009).
文摘Li metal with high-energy density is considered as the most promising anode for the next-generation rechargeable Li metal batteries;however,the growth of Li dendrites seriously hinders its practical application.Herein,3D free-standing carbon nanofibers modified by lithiophilic metal particles(CNF/Me,Me=Sn,Fe,Co)are obtained in situ by the electrospinning method.Benefiting from the lithophilicity,the CNF/Me composite may effectively prevent the formation of Li dendrites in the Li metal batteries.The optimized CNF/Sn–Li composite electrode exhibits a stable cycle life of over 2350 h during Li plating/stripping.When matched with typical commercial LiFePO_(4)(LFP)cathode,the LFP//CNF/Sn–Li full cell presents a high initial discharge specific capacity of 139 mAh g^(−1)at 1 C,which remains at 146 mAh g^(−1)after 400 cycles.When another state-of-the-art commercial LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM(811))cathode is used,the assembled NCM//CNF/Sn–Li full cell shows a large initial specific discharge capacity of 206 mAh g^(−1)at substantially enhanced 10 C,which keeps at the good capacity of 99 mAh g^(−1)after 300 cycles.These results are greatly superior to the counterparts with Li as the anodes,indicating the great potential for practical utilization of the advanced CNF/Sn–Li electrode.
基金supported by the National Natural Science Foundation of China(grant no.21601148)the Natural Science Foundation of Fujian Province(grant no.2017J05090).
文摘Nb-Doped LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2)(Nb-NCM)nanobelts have been successfully fabricated for the first time through a facile electrospinning method by the delicate control of PAN pyrolysis and Nb-NCM formation(including nucleation and subsequent growth processes).According to the experimental evidence from temperature-dependent characterization and isolation of the intermediates,the formation of nanobelts undergoes a morphology evolution from nanofibres to nanotubes,and finally to the nanobelts composed of subunit nanoparticles.When used as a cathode for lithium-ion batteries,the as-electrospun Nb-NCM nanobelts exhibit superior electrochemical performances,which could be attributed to their unique features,such as their 1D nanostructure,well-crystallized nature and Nb-doping.These features can improve the ionic conductivity of Nb-NCM nanobelts and stabilize the electrode/electrolyte interface.Therefore,the 1D Nb-NCM nanobelts developed in this study not only provide an excellent model to investigate the fabrication of multi-element oxides using the electrospinning method,but also open up a facile route for designing 1D layered cathodes with a complex component for high performance lithium-ion batteries.
基金work was supported by the National Natural Science Foundation of China(Grant No.51874362,51872334)the Natural Science Foundation of Hunan Province,China(Grant No.2018JJ1036)the Innovation Project of Central South University(2017CX001).
文摘LiCuVO_(4) has attracted increasing attention as an anode material for lithium ion batteries due to its good structural stability.However,the rate capability is limited by the inferior electronic conductivity and low lithium ion diffusion efficiency.Herein,we report the synthesis of LiCuVO_(4)/LiVO_(3)/C porous nanotubes by an electrospinning method with subsequent calcination in air.The unique morphology,carbonaceous material in the composite and the existence of LiVO_(3) enable the as-prepared composite to have high capacity,superior cycling stability and rate capability.The LiCuVO_(4)/LiVO_(3)/C electrode possesses a capacity of 636 mA h g^(-1) which is higher than the theoretical capacity of LiCuVO_(4)(576 mA h g^(-1)).Moreover,it can retain 77%of the capacity at 0.5 A g^(-1) after 300 cycles.These results demonstrate that LiCuVO_(4)/LiVO_(3)/C nanotubes are promising anode materials for lithium ion batteries.
基金supported by the Natural Science Foundation of Fujian Province of China(2020J01393)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24-4101).
文摘It is highly desirable but challenging to design multi-functional materials for energy storage and electromagnetic(EM)wave absorption.Herein,core–shell CaSnO_(3)@N-doped carbon(CSO@NCNF)coaxial nanocables with one-dimensional(1D)architecture were synthesized by employing the electrospinning method combined with in situ polymerization and heat treatment.In the resulting structure,the CaSnO_(3) nanofiber(CSONF)core with an average diameter of 52.5 nm is confined in the high electronic conductivity of the N-doped carbon sheaths with a thickness ranging from 27.3 to 67.2 nm.The lithium storage performance of the CSO@NCNF nanocable electrode is much higher than that of the CSONF electrode;this is owing to the(i)large number of void spaces and active sites generated by the structure of the 1D core–shell nanocables,(ii)fast transport network constructed by carbon sheaths prominently enhancing the transport of both electrons and lithium ions,and(iii)structural stability achieved through the buffering mechanism created by CaSnO_(3)@NCNF coaxial construction.However,its ingenious structural design,multiple heterogeneous interfaces and multi-component strategy give rise to a synergistic mechanism of impedance matching,conductive loss,polarization loss and multiple reflection/scattering.The coaxial nanocables display good microwave absorption(MA)properties,featuring a reflection loss(RL)value of−47.0 dB at 8.2 GHz and 2.5 mm as well as an effective absorption bandwidth(EAB)of 4.7 GHz at 1.4 mm.This unique structural design is believed to provide a reference for the preparation of multi-functional materials.
基金supported by the National Key Research and Development Program of China(2018YFB0104200).
文摘Silicon oxides(SiO_(x))are regarded as one of the most potential anode materials for lithium-ion batteries with the advantages of a high theoretical capacity,low discharge platform(<0.5 V)and environmental friendliness.However,the low electronic conductivity and the degradation of the structure upon cycling have limited the electrochemical performance of SiO_(x).In this work,a conductive carbon fiber network wrapped SiO_(x)/C composite has been fabricated via combined electrospinning and carbonization methods.Importantly,the loading of SiO_(x) in the composite can be adjusted by changing the addition amounts of organosilica-polymer nanospheres during the electrospinning process.When utilized as an anode material for LIBs,the novel SiO_(x)/C composite exhibited good cycling stability and rate capabilities.The superior electrochemical performance can be ascribed to the special carbonaceous conductive network structure,which guarantees enhanced overall ion and electron transportation and structural integrity.The present work offers insights into the rational design of silicon-based materials for advanced lithium ion batteries.
基金supported by the National Natural Science Foundation of China(Grant No.51874362,51932011).
文摘The development of low-cost and eco-friendly gel polymer electrolytes (GPEs) with a wide window, ideal compatibility, and structural stability is an effective measure to achieve safe high-energy-density lithium-metal batteries. Herein, a biodegradable composite polyacrylonitrile/poly-L-lactic acid nanofiber membrane (PAL) is synthesized and used as a robust skeleton for GPEs. The 3D nanofiber membrane (PAL-3-C12) prepared with an adjusted weight ratio of polyacrylonitrile (PAN)/poly-L-lactic acid (PLLA) and spinning solution concentration delivers decent thermal stability, biodegradability, and liquid electrolyte absorbability. The “passivation effect” of PAN upon lithium metal is effectively alleviated by hydrogen bonds formed in the PAL chains. These advantages enable PAL GPEs to work stably to 5.17 V while maintaining high ionic conductivity as well as excellent corrosion resistance and dielectric properties. The interfacial compatibility of optimized GPEs promotes the stable operation of a Li||PAL-3-C12 GPEs||Li symmetric battery for 1000 h at 0.15 mA cm^(−2)/0.15 mA h cm^(−2), and the LiFePO4 full cell retains capacity retention of 97.63% after 140 cycles at 1C.
