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The thermosetting polyimide PI nano -fibers based nonwoven membrane is prepared by electrospinning technique and followed by thermal imidization. The physical and mechanical properties of PI nano-fibers based nonwoven separators are tested and the electrochemical performance of the PI membrane for lithium ion battery at different charge cut-off voltage herein common voltage 4.2 V and higher 4.4 V is investigated. The results show that the average diameter of PI nano-fibers is as fine as 276 nm the porosity of PI nano-fibers based nonwoven separators is up to 92% and they exhibit better wettability for the polar electrolyte compared to the commercial Celgard 2400 membrane After 50 cycles at 0.2C/0.2C charge and discharge rate the capacity retention ratio of the cell assembled with PI nano-fibers based nonwoven separators at both voltage range is higher than 80% especially that of 4.4 V charge is up to 91.6% which are obviously superior to commercial Celgard 2400 membrane moreover the special capacity of PI separators fades slower than Celgard 2400 membrane with the increase of discharge rate at both situation. [ABSTRACT FROM AUTHOR]

In this paper, flexible mesoporous Si-doped Al 2 O 3 ultrafine fibers were successfully prepared by electro-blow spinning (EBS) technology followed by a calcination process. The effects of spinning parameters, including air pressure, voltage, and solution injection rate on the morphology and diameter of fibers were investigated. The results showed that the spinning parameters played a key role on determining the morphology and diameter of fibers, and the specific surface area of fibers significantly increased with the increasing content of pore forming agents (polytetrafluoroethylene, PTFE), at the same time the pore size distribution was mainly concentrated at ~5 nm. Most importantly, Si(OC 2 H 5 ) 4 was introduced to act as the flexible regulator which could inhibit the growth of alumina crystal, decrease the crystal size, and thus the flexibility of obtained mesoporous Si-doped Al 2 O 3 ultrafine fibers can be improved. Moreover, the fibers productivity by EBS method was higher than that of traditional electro-spinning. In the future, the mesoporous Si-doped Al 2 O 3 ultrafine fibers may perform desired function and spread their applications in different areas. [ABSTRACT FROM AUTHOR]

Porous CeO 2 /CuO/Al 2 O 3 fibers were successfully prepared, for the first time by electro-blown spinning method. The size of fibers diameter and the number of pores on fibers surface could be controlled by adjusting spinning parameters. The composite fibers showed continuous line feature and porous morphologies after heat treatment. To obtain the optimum spinning parameters, the effects of polyvinyl pyrrolidone (PVP) concentrations, air pressures, high voltages, injection rates, polytetrafluoroethylene (PTFE) contents and calcination temperatures were investigated. The morphologies and structures of the CeO 2 /CuO/Al 2 O 3 fibers were investigated by Scanning electron microscopy (SEM), Energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). This novel electro-blown spinning method may realize the industrialized production of high performance ceramics fibers. [ABSTRACT FROM AUTHOR]