High-Performance Twisted Carbon Nanofibre Bundles And Gel Polymer Electrolytes Developed From Nanofiber Membranes

The research is based on electrospinning nanofiber membranes and divided into two big aspects, one is the exploration in the mechanical properties enhancement of nanofibers, turns out the preparation of twisted cabon nanofiber bundles. The other aspects is the application of nanofbers on Lithium-ion Batteries, turns out the preparation of gel polymer electrolytes with ’core-shell’ nanofiber structure. This two aspects is not isolated.Carbon fibres exhibit the highest specific strength and specific modulus among all commercial reinforcing fibres, widely used in their respective fields. While the reported values of mechanical strength of the research in recent years are far below the prediction because of the existence of structural defects as well as technological differences. In this study, the nanofibre bundles were developed from aligned electrospun nanofibre films using a laboratory-produced twisting device. Optimized stabilization and multi-step carbonization treatment were carried out, thus carbon nanofibre bundules with excellent mechanical properties was prepared, indicate a practicable approach to developing of new-type carbon reinforcement with high mechanical performance.Although PAN possesses good mechanical strength, heat resistance, chemical stability and good flame retardancy, PAN show bad compatibility with lithium electrodes.PMMA based GPEs satisfy the needs of basic electrochemical performance, especially they have good compatibility with lithium electrode, and low interface impedance, however, the poor mechanical strength also limits their application. In order to combine the performance advantages of different polymeric materials and polyporous structure, the polymer membranes consisting of nanofibres with core (PAN)-shell (PMMA) structure were prepared by using coaxial electrospinning in this paper. GPEs can be produced after the activation process of stacked polymer membranes in liquid electrolytes. Besides, GPEs based on the nest-like patterned nanofiber membranes with improved mechanical properties are prepared, leading to its applicable value in lithium-ion batteries.