The colored poly(m-phenylene isophthalamide)(PMIA)spinning solution was prepared by wet spinning and the die-swell of the colored PMIA spinning solution was done when it was extruded from a die in this experiment.The ...The colored poly(m-phenylene isophthalamide)(PMIA)spinning solution was prepared by wet spinning and the die-swell of the colored PMIA spinning solution was done when it was extruded from a die in this experiment.The properties and structures of colored PMIA fibers were characterized by scanning electron microscopy(SEM).The colored PMIA spinning dopes were first commixed in a pressurizer and then spun into a coagulation bath.The effect of die swell on the colored PMIA solution was resulted from the viscoelastic properties of the colored PMIA solution in the spinning process.The results showed that the die-swell ratio of the colored PMIA solution increased linearly with increasing the pressure and die length/diameter ratio(L/D).At the same pressure and L/D,the die-swell ratio decreased with the increase of filter layers and temperature.Also,optimized spinning parameters of the dopedyed PMIA fiber were obtained.展开更多
Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion condu...Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion conductance and poor mechanical and thermal properties.Herein,poly(m-phenylene isophthalamide)(PMIA)is employed as a multifunctional additive to improve the overall properties of the PEO-based electrolytes.The hydrogen-bond interactions between PMIA and PEO/TFSI-can effectively prevent the PEO crystallization and meanwhile facilitate the LiTFSI dissociation,and thus greatly improve the ionic conductivity(two times that of the pristine electrolyte at room temperature).With the incorporation of the high-strength PMIA with tough amide-benzene backbones,the PMIA/PEO-LiTFSI composite polymer electrolyte(CPE)membranes also show much higher mechanical strength(2.96 MPa),thermostability(4190℃)and interfacial stability against Li dendrites(468 h at 0.10 mA cm-2)than the pristine electrolyte(0.32 MPa,364℃and short circuit after 246 h).Furthermore,the CPE-based LiFePO4/Li cells exhibit superior cycling stability(137 mAh g^-1 with 93%retention after 100 cycles at 0.5 C)and rate performance(123 mAh g^-1 at 1.0 C).This work provides a novel and effective CPE structure design strategy to achieve comprehensively-upgraded electrolytes for promising solid-state battery applications.展开更多
In this paper,the efect of poly(ethylene oxide)(PEO)as an additive on the structure and properties of poly(m-phenylene dimethylene terephthalamide)(PMIA)fbers obtained by wet spinning was investigated.The tensile stre...In this paper,the efect of poly(ethylene oxide)(PEO)as an additive on the structure and properties of poly(m-phenylene dimethylene terephthalamide)(PMIA)fbers obtained by wet spinning was investigated.The tensile strength of the composite fbers was substantially enhanced compared to the pure PMIA fber.This was due to the fact that the addition of PEO weakens the hydrogen bonding between PMIA molecular chains resulting in an improved orientation of the composite fbers.It was found that the optimum PEO addition was 2%and the tensile strength of the composite fber was 4.74 cN/dtex,which was 76%higher compared to the pure PMIA fber.However,the heat resistance and fame retardancy of the composite fbers were basically unchanged compared to the pure PMIA fber.The modifcation method is simple,with low raw material cost and good stability,and has not only good academic value but also excellent industrial value.展开更多
文摘The colored poly(m-phenylene isophthalamide)(PMIA)spinning solution was prepared by wet spinning and the die-swell of the colored PMIA spinning solution was done when it was extruded from a die in this experiment.The properties and structures of colored PMIA fibers were characterized by scanning electron microscopy(SEM).The colored PMIA spinning dopes were first commixed in a pressurizer and then spun into a coagulation bath.The effect of die swell on the colored PMIA solution was resulted from the viscoelastic properties of the colored PMIA solution in the spinning process.The results showed that the die-swell ratio of the colored PMIA solution increased linearly with increasing the pressure and die length/diameter ratio(L/D).At the same pressure and L/D,the die-swell ratio decreased with the increase of filter layers and temperature.Also,optimized spinning parameters of the dopedyed PMIA fiber were obtained.
基金supported partially by Natural Science Foundation of Beijing Municipality(L172036)Joint Funds of the Equipment Pre-Research and Ministry of Education(6141A020225)+3 种基金Par-Eu Scholars Program,Science and Technology Beijing 100 Leading Talent Training ProjectChina Postdoctoral Science Foundation(2018M631419)Fundamental Research Funds for Central Universities(2017ZZD02,2019QN001)NCEPU“Double First-Class”Graduate Talent Cultivation Program。
文摘Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion conductance and poor mechanical and thermal properties.Herein,poly(m-phenylene isophthalamide)(PMIA)is employed as a multifunctional additive to improve the overall properties of the PEO-based electrolytes.The hydrogen-bond interactions between PMIA and PEO/TFSI-can effectively prevent the PEO crystallization and meanwhile facilitate the LiTFSI dissociation,and thus greatly improve the ionic conductivity(two times that of the pristine electrolyte at room temperature).With the incorporation of the high-strength PMIA with tough amide-benzene backbones,the PMIA/PEO-LiTFSI composite polymer electrolyte(CPE)membranes also show much higher mechanical strength(2.96 MPa),thermostability(4190℃)and interfacial stability against Li dendrites(468 h at 0.10 mA cm-2)than the pristine electrolyte(0.32 MPa,364℃and short circuit after 246 h).Furthermore,the CPE-based LiFePO4/Li cells exhibit superior cycling stability(137 mAh g^-1 with 93%retention after 100 cycles at 0.5 C)and rate performance(123 mAh g^-1 at 1.0 C).This work provides a novel and effective CPE structure design strategy to achieve comprehensively-upgraded electrolytes for promising solid-state battery applications.
基金This work was supported by the National Natural Science Foundation of China(No.51473031).
文摘In this paper,the efect of poly(ethylene oxide)(PEO)as an additive on the structure and properties of poly(m-phenylene dimethylene terephthalamide)(PMIA)fbers obtained by wet spinning was investigated.The tensile strength of the composite fbers was substantially enhanced compared to the pure PMIA fber.This was due to the fact that the addition of PEO weakens the hydrogen bonding between PMIA molecular chains resulting in an improved orientation of the composite fbers.It was found that the optimum PEO addition was 2%and the tensile strength of the composite fber was 4.74 cN/dtex,which was 76%higher compared to the pure PMIA fber.However,the heat resistance and fame retardancy of the composite fbers were basically unchanged compared to the pure PMIA fber.The modifcation method is simple,with low raw material cost and good stability,and has not only good academic value but also excellent industrial value.
