Electrospun flexible aluminum silicate nanofibers as a flame-resistant separator for the high performance supercapacitor

The flexible aluminum silicate nanofibers separators are prepared by electrospinning method. The results suggest the presence of amorphous phase in aluminum silicate fibers, and the diameters of fibers are mostly in the range of 100~200 nm. The porosity and BET specific surface area of aluminum silicate nanofibers separator with 150 μm thickness are 56.1% and 113.5 m2/g, greater than that of commercial PP separator. When tested in supercapacitors, their ionic conductivity and ion diffusion resistance are 0.041 S/cm and 1.09 Ω, better than that of the commercial PP separator (0.029 S/cm and 2.74 Ω). The specific capacitance of supercapacitors prepared with aluminum silicate nanofibers of 150-μm thickness as separator is up to 150 F/g, which is higher than that of the commercial PP separator (65 F/g). The cyclic and rate performances of supercapacitors prepared with aluminum silicate nanofibers separator are also improved significantly. Compared with commercial PP separator, the aluminum silicate nanofibers separator shows outstanding thermal stability and flame resistance. Hence, the obtained aluminum silicate nanofibers separator has good practical application prospect in supercapacitor.