Sulfurized polyacrylonitrile(SPAN)as a promising cathode material for lithium sulfur(Li-S)batteries has drawn increasing attention for its improved electrochemical performance in carbonate-based electrolyte.However,th...Sulfurized polyacrylonitrile(SPAN)as a promising cathode material for lithium sulfur(Li-S)batteries has drawn increasing attention for its improved electrochemical performance in carbonate-based electrolyte.However,the relatively poor electronic and ionic conductivities of SPAN limit its high-rate and lowtemperature performances.In this work,a novel one-dimensional nanofiber SPAN(SFPAN)composite is developed as the cathode material for Li-S batteries.Benefitting from its one-dimensional nanostructure,the SFPAN composite cathode provides fast channels for the migration of ions and electronics,thus effectively improving its electrochemical performance at high rates and low temperature.As a result,the SFPAN maintains a high reversible specific capacity^1200 mAh g−1 after 400 cycles at 0.3 A g−1 and can deliver a high capacity of^850 mAh g−1 even at a high current density of 12.5 A g−1.What is more,the SFPAN can achieve a capacity of^800 mAh g−1 at 0℃and^1550 mAh g−1 at 60℃,thus providing a wider temperature range of applications.This work provides new perspectives on the cathode design for high-rate lithium-sulfur batteries.展开更多
Sulfurized polyacrylonitrile(SPAN)represents a unique class of cathode material for lithium sulfur(Li-S)batteries as it eradicates the polysulfides shuttling issue in carbonate-based electrolyte.However,due to the ess...Sulfurized polyacrylonitrile(SPAN)represents a unique class of cathode material for lithium sulfur(Li-S)batteries as it eradicates the polysulfides shuttling issue in carbonate-based electrolyte.However,due to the essential chemical S-linking and organic nature of SPAN,the active mass percentage and rate capability are two bottleneck issues preventing its ultimate deployment outside of laboratories.In the current work,aiming to endow both the charge conductivity and catalytic activity to SPAN for maximizing the redox kinetics of S conversion,a freestanding nanofibrous SPAN cathode embedding conductive CNTs and atomically dispersed Co centers is fabricated via multivariate electrospinning.While the CNTs enable dramatically enhancing the fiber conductivity and generating mesoscopic porosity for facilitating charge and mass transportation,the cross-linking of SPAN by Co-N_(4) S motifs creates extra charge conduction pathways and further serves as the catalytic active sites for expediting redox S conversion.As a result,an extraordinary Li-SPAN performance is achieved with a high specific capacity up to 1856 mAh g^(-1)@0.2 C,a superb rate capability up to 10 C,and an ultra-long battery life up to 1500 cycles@1 C.Consequently,our study here provides insights into the adoption of coordination chemistry to maximize the sulfur utilization by ensuring a more complete redox conversion from SPAN to Li2 S,and vice versa.展开更多
Potassium-ion batteries(PIBs)have garnered significant attention as a promising alternative to commercial lithium-ion batteries(LIBs)due to abundant and cost-efficient potassium reserves.However,the large size of pota...Potassium-ion batteries(PIBs)have garnered significant attention as a promising alternative to commercial lithium-ion batteries(LIBs)due to abundant and cost-efficient potassium reserves.However,the large size of potassium ions and the resulting sluggish reaction kinetics present major obstacles to the widespread use of PIBs.Herein,we present a simple method to ingeniously encapsulate SnS_(2)nanoparticles within sulfurized polyacrylonitrile(SPAN)fibers(SnS_(2)@SPAN)for serving as a high-performance PIB anode.The large interlayer spacing of SnS_(2)provides a fast transport channel for potassium ions during charge–discharge cycles,while the one-dimensional SPAN skeleton offers massive binding sites and shortens the diffusion path for potassium ions,facilitating faster reaction kinetics.Additionally,the excellent ductility of SPAN can effectively accommodate the large volume changes that occur in SnS_(2)upon potassium-ion insertion,thereby enhancing the cyclic stability of SnS_(2).Benefiting from the above advantages,the SnS_(2)@SPAN composites exhibit impressive cyclability over 500 cycles at 4 A g−1,with a capacity retention rate close to 100%.This study provides an effective approach for stabilizing high-capacity PIB anode materials with large volume variations.展开更多
Sulfurized polyacrylonitrile(S@pPAN)composite provides a conductive pathway for sulfur active material at the molecular level and has already become one of the most promising cathode materials in lithium-sulfur batter...Sulfurized polyacrylonitrile(S@pPAN)composite provides a conductive pathway for sulfur active material at the molecular level and has already become one of the most promising cathode materials in lithium-sulfur batteries because of its outstanding electrochemical performances via novel solid-solid conversion mechanism.Although there are a great number of researches on the S@pPAN composite material,the accurate structure of S@pPAN and its redox reaction mechanism during the charge-discharge process still have not been determined.The previous research and inferences about the structure of S@pPAN and its electrochemical reaction mechanism were summarized in this review,providing a reference for the future study of lithiumsulfur batteries.展开更多
Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithiu...Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithium dendrite formation.Herein,a highperformance SLSB is demonstrated by using a fiber network reinforced Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)based composite solid electrolyte(CSE)in combination with sulfurized polyacrylonitrile(SPAN)cathode.The CSE consisting of an electrospun polyimide(PI)film,LLZTO ionically conducting filler and polyacrylonitrile(PAN)matrix,which is named as PI-PAN/LLZTO CSE,possesses high room-temperature ionic conductivity(2.75×10^(-4)S/cm),high Li^(+)migration number(tLi+)of 0.67 and good interfacial wettability.SPAN is utilized due to its unique electrochemical properties:reasonable electronic conductivity and no polysulfides shuttle effect.The CSE enables a highly stable Li plating/stripping cycle for over 600 h and good rate performance.Moreover,the assembled SLSB exhibits good cycle performance of accomplishing 120 cycles at 0.2 C with the capacity retention of 474 mAh/g,good rate properties and excellent long-term cycling stability with a high capacity retention of 86.49%from 15^(th)to 1,000^(th)cycles at 1.0 C.This work rationalizes our design concept and may guide the future development of SLSBs.展开更多
Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur batteries.However,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kineti...Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur batteries.However,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical performance.In this study,an electrolyte with dual-additives comprising 2-fluoropyridine(2-FP)and lithium difluorobis(oxalato)phosphate(LiDFBOP)was used to improve the performance of Li||SPAN cells.2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte,leading to its prior reduction.A LiF-rich film can be formed on the electrode,effectively improving the stability of the electrolyte-electrode interfaces and prolonging the life.Simultaneously,LiDFBOP could form an electrolyte-electrode interface film containing a large amount of Li_(x)PO_(y)F_(z) species,compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode interface.Hence,an electrode-interface film with good chemical stability and high Li^(+) transport was established by LiF and Li_(x)PO_(y)F_(z)-rich species.The Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5%after 200 cycles at 1.0 C,25℃,comparing to 56.2%capacity retention without additives.Moreover,the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C,comparing to only 813.5 mAh/g using electrolyte without additives.Our results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.展开更多
Using 30% fuming sulfuric acid to sulfonate emeraldine base (EB), sulfonatedpolyaniline (SPAN) is synthesized .The results show that it has higher solubility and good conductivity, and SPAN with different sulfonation ...Using 30% fuming sulfuric acid to sulfonate emeraldine base (EB), sulfonatedpolyaniline (SPAN) is synthesized .The results show that it has higher solubility and good conductivity, and SPAN with different sulfonation degree (SD) possesses different conductivity. With the increase in SD of the SPAN, its conductivity(σ)decreases but its solubility is improved. UV-Vis spectra indicate that SPAN has a red shift compared with PANI. The colloid aggregates and loose structure have been found by using TEM.展开更多
Polyacrylonitrile （PAN）, PAN/cellulose acetate （CA）, and PAN/CA-Ag based activated carbon nanofiber （ACNF） were prepared using electrostatic spinning and further heat treatment. Thermogravimetrylifferential scan...Polyacrylonitrile （PAN）, PAN/cellulose acetate （CA）, and PAN/CA-Ag based activated carbon nanofiber （ACNF） were prepared using electrostatic spinning and further heat treatment. Thermogravimetrylifferential scanning calorimetry （TG-DSC） analysis indicated that the addition of CA or Ag did not have a significant impact on the thermal decomposition of PAN materials but the yields of fibers could be improved. Scanning electron microscopy （SEM） analysis showed that the micromorphologies of produced fibers were greatly influenced by the viscosity and conductivity of precursor solutions. Fourier transform infrared spectroscopy （FT-IR） analysis proved that a cyclized or trapezoidal structure could form and the carbon scaffold composed of C=C bonds appeared in the PAN-based ACNFs. The characteristic dif- fraction peaks in X-ray diffraction （XRD） spectra were the evidence of a turbostratic structure and silver existed in the PAN/CA-Ag based ACNF. Brurmer-Emmett-Teller （BET） analysis showed that the doping of CA and Ag increased surface area and micropore volume of fi- bers; particularly, PAN/CA-Ag based ACNF exhibited the best porosity feature. Furthermore, SO2 adsorption experiments indicated that all the three fibers had good adsorption effects on lower concentrations of SO2 at room temperature; especially, the PAN/CA-Ag based ACNF showed the best adsorption performance, and it may be one of the most promising adsorbents used in the fields of chemical industry and en- vironment protection.展开更多
基金supported by the National Natural Science Foundation of China(Grant nos.21773077,51632001,and 51532005)the Ministry of Science and Technology“973”program(Grant No.2015CB258400)the National Key R&D Program of China(2018YFB0905400)。
文摘Sulfurized polyacrylonitrile(SPAN)as a promising cathode material for lithium sulfur(Li-S)batteries has drawn increasing attention for its improved electrochemical performance in carbonate-based electrolyte.However,the relatively poor electronic and ionic conductivities of SPAN limit its high-rate and lowtemperature performances.In this work,a novel one-dimensional nanofiber SPAN(SFPAN)composite is developed as the cathode material for Li-S batteries.Benefitting from its one-dimensional nanostructure,the SFPAN composite cathode provides fast channels for the migration of ions and electronics,thus effectively improving its electrochemical performance at high rates and low temperature.As a result,the SFPAN maintains a high reversible specific capacity^1200 mAh g−1 after 400 cycles at 0.3 A g−1 and can deliver a high capacity of^850 mAh g−1 even at a high current density of 12.5 A g−1.What is more,the SFPAN can achieve a capacity of^800 mAh g−1 at 0℃and^1550 mAh g−1 at 60℃,thus providing a wider temperature range of applications.This work provides new perspectives on the cathode design for high-rate lithium-sulfur batteries.
基金supported by the National Natural Science Foundation of China(No.21805201)the NSFC-NRF China-Korea International Joint Research Project(No.51911540473)+1 种基金the Postdoctoral Research Foundation of China(No.2018T110544 and No.2017 M611899)the support by Suzhou Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies。
文摘Sulfurized polyacrylonitrile(SPAN)represents a unique class of cathode material for lithium sulfur(Li-S)batteries as it eradicates the polysulfides shuttling issue in carbonate-based electrolyte.However,due to the essential chemical S-linking and organic nature of SPAN,the active mass percentage and rate capability are two bottleneck issues preventing its ultimate deployment outside of laboratories.In the current work,aiming to endow both the charge conductivity and catalytic activity to SPAN for maximizing the redox kinetics of S conversion,a freestanding nanofibrous SPAN cathode embedding conductive CNTs and atomically dispersed Co centers is fabricated via multivariate electrospinning.While the CNTs enable dramatically enhancing the fiber conductivity and generating mesoscopic porosity for facilitating charge and mass transportation,the cross-linking of SPAN by Co-N_(4) S motifs creates extra charge conduction pathways and further serves as the catalytic active sites for expediting redox S conversion.As a result,an extraordinary Li-SPAN performance is achieved with a high specific capacity up to 1856 mAh g^(-1)@0.2 C,a superb rate capability up to 10 C,and an ultra-long battery life up to 1500 cycles@1 C.Consequently,our study here provides insights into the adoption of coordination chemistry to maximize the sulfur utilization by ensuring a more complete redox conversion from SPAN to Li2 S,and vice versa.
基金National Natural Science Foundation of China,Grant/Award Numbers:22109023,22179022,22209027Industry‐University‐Research Joint Innovation Project of Fujian Province,Grant/Award Number:2021H6006+3 种基金Youth Innovation Fund of Fujian Province,Grant/Award Numbers:2022J05046,2021J05043FuXia Quan National Independent Innovation Demonstration Zone Collaborative Innovation Platform Project of Fuzhou Science and Technology Bureau,Grant/Award Number:2022‐P‐027Award Program for Fujian Minjiang Scholar ProfessorshipTalent Fund Program of Fujian Normal University。
文摘Potassium-ion batteries(PIBs)have garnered significant attention as a promising alternative to commercial lithium-ion batteries(LIBs)due to abundant and cost-efficient potassium reserves.However,the large size of potassium ions and the resulting sluggish reaction kinetics present major obstacles to the widespread use of PIBs.Herein,we present a simple method to ingeniously encapsulate SnS_(2)nanoparticles within sulfurized polyacrylonitrile(SPAN)fibers(SnS_(2)@SPAN)for serving as a high-performance PIB anode.The large interlayer spacing of SnS_(2)provides a fast transport channel for potassium ions during charge–discharge cycles,while the one-dimensional SPAN skeleton offers massive binding sites and shortens the diffusion path for potassium ions,facilitating faster reaction kinetics.Additionally,the excellent ductility of SPAN can effectively accommodate the large volume changes that occur in SnS_(2)upon potassium-ion insertion,thereby enhancing the cyclic stability of SnS_(2).Benefiting from the above advantages,the SnS_(2)@SPAN composites exhibit impressive cyclability over 500 cycles at 4 A g−1,with a capacity retention rate close to 100%.This study provides an effective approach for stabilizing high-capacity PIB anode materials with large volume variations.
基金supported by the National Key Research and Development(R&D)Program of China(No.2021YFB2400300)the National Natural Science Foundation of China(No.22179083)+1 种基金Program of Shanghai Academic Research Leader(No.20XD1401900)Key-Area Research and Development Program of Guangdong Province(No.2019B090908001).
文摘Sulfurized polyacrylonitrile(S@pPAN)composite provides a conductive pathway for sulfur active material at the molecular level and has already become one of the most promising cathode materials in lithium-sulfur batteries because of its outstanding electrochemical performances via novel solid-solid conversion mechanism.Although there are a great number of researches on the S@pPAN composite material,the accurate structure of S@pPAN and its redox reaction mechanism during the charge-discharge process still have not been determined.The previous research and inferences about the structure of S@pPAN and its electrochemical reaction mechanism were summarized in this review,providing a reference for the future study of lithiumsulfur batteries.
基金The authors are indebted to the National Key Research and Development Program of China(No.2019YFE0122500)the National Natural Science Foundation of China(Nos.21878185 and 51772188)the Natural Science Foundation of Shanghai(No.21ZR1434800).
文摘Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithium dendrite formation.Herein,a highperformance SLSB is demonstrated by using a fiber network reinforced Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)based composite solid electrolyte(CSE)in combination with sulfurized polyacrylonitrile(SPAN)cathode.The CSE consisting of an electrospun polyimide(PI)film,LLZTO ionically conducting filler and polyacrylonitrile(PAN)matrix,which is named as PI-PAN/LLZTO CSE,possesses high room-temperature ionic conductivity(2.75×10^(-4)S/cm),high Li^(+)migration number(tLi+)of 0.67 and good interfacial wettability.SPAN is utilized due to its unique electrochemical properties:reasonable electronic conductivity and no polysulfides shuttle effect.The CSE enables a highly stable Li plating/stripping cycle for over 600 h and good rate performance.Moreover,the assembled SLSB exhibits good cycle performance of accomplishing 120 cycles at 0.2 C with the capacity retention of 474 mAh/g,good rate properties and excellent long-term cycling stability with a high capacity retention of 86.49%from 15^(th)to 1,000^(th)cycles at 1.0 C.This work rationalizes our design concept and may guide the future development of SLSBs.
基金financial support from the National Natural Science Foundation of China(Nos.52072378,22209189)the National Key R&D Program of China(No.2022YFB3803400)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA22010602 and 2022YFB3803400)Shenyang Science and Technology Program(No.22-322-3-19)。
文摘Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur batteries.However,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical performance.In this study,an electrolyte with dual-additives comprising 2-fluoropyridine(2-FP)and lithium difluorobis(oxalato)phosphate(LiDFBOP)was used to improve the performance of Li||SPAN cells.2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte,leading to its prior reduction.A LiF-rich film can be formed on the electrode,effectively improving the stability of the electrolyte-electrode interfaces and prolonging the life.Simultaneously,LiDFBOP could form an electrolyte-electrode interface film containing a large amount of Li_(x)PO_(y)F_(z) species,compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode interface.Hence,an electrode-interface film with good chemical stability and high Li^(+) transport was established by LiF and Li_(x)PO_(y)F_(z)-rich species.The Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5%after 200 cycles at 1.0 C,25℃,comparing to 56.2%capacity retention without additives.Moreover,the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C,comparing to only 813.5 mAh/g using electrolyte without additives.Our results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.
文摘Using 30% fuming sulfuric acid to sulfonate emeraldine base (EB), sulfonatedpolyaniline (SPAN) is synthesized .The results show that it has higher solubility and good conductivity, and SPAN with different sulfonation degree (SD) possesses different conductivity. With the increase in SD of the SPAN, its conductivity(σ)decreases but its solubility is improved. UV-Vis spectra indicate that SPAN has a red shift compared with PANI. The colloid aggregates and loose structure have been found by using TEM.
基金financially supported by the Natural Science Foundation of China (Nos. 21076028 and 50802010)
文摘Polyacrylonitrile （PAN）, PAN/cellulose acetate （CA）, and PAN/CA-Ag based activated carbon nanofiber （ACNF） were prepared using electrostatic spinning and further heat treatment. Thermogravimetrylifferential scanning calorimetry （TG-DSC） analysis indicated that the addition of CA or Ag did not have a significant impact on the thermal decomposition of PAN materials but the yields of fibers could be improved. Scanning electron microscopy （SEM） analysis showed that the micromorphologies of produced fibers were greatly influenced by the viscosity and conductivity of precursor solutions. Fourier transform infrared spectroscopy （FT-IR） analysis proved that a cyclized or trapezoidal structure could form and the carbon scaffold composed of C=C bonds appeared in the PAN-based ACNFs. The characteristic dif- fraction peaks in X-ray diffraction （XRD） spectra were the evidence of a turbostratic structure and silver existed in the PAN/CA-Ag based ACNF. Brurmer-Emmett-Teller （BET） analysis showed that the doping of CA and Ag increased surface area and micropore volume of fi- bers; particularly, PAN/CA-Ag based ACNF exhibited the best porosity feature. Furthermore, SO2 adsorption experiments indicated that all the three fibers had good adsorption effects on lower concentrations of SO2 at room temperature; especially, the PAN/CA-Ag based ACNF showed the best adsorption performance, and it may be one of the most promising adsorbents used in the fields of chemical industry and en- vironment protection.
