Facile fabrication of flexible electrodes with poly(vinylidene fluoride)/Si3N4 composite separator prepared by electrospinning for sodium-ion batteries

By direct electrospinning poly(vinylidene fluoride) (PVDF)/Si(3)N(4 )blend solution on the Na2Ni[Fe(CN)(6)] electrode, a flexible separator@electrode combination is obtained. This combination is closely cross-linked by the -CH2-CF2- chain of beta-PVDF in the separator and electrode, which delivers unique advantages in flexibility, thermal stability, tensile strength and interfacial resistance. Meanwhile, the PVDF/Si3N4 separator has a higher porosity (84.2%) and ionic conductivity (4.1 x 10(-3) S cm(-1)), making the combination display an excellent electrochemical performance with a high initial coulombic efficiency of 96.8%, capacity retention rate of 92.2% after 503 cycles and rate capability of 78 mAh g(-1) at 5 C. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.