Optimization of porosity and tensile strength of electrospun polyacrylonitrile nanofibrous membranes

Abstract

Abstract We prepared polyacrylonitrile (PAN) nanofibrous membranes via electrospinning and investigated the effects of the oven-drying and thermal-pressing conditions on their porosity and tensile strength. A total of 27 different samples were prepared via the Taguchi design method (based on an L27 orthogonal array) using Minitab to optimize the process parameters for the porosity and tensile strength of the samples. PAN 1 (porosity of 56.75% and tensile strength of 36.21\u202fMPa), PAN 2 (porosity of 60.80% and tensile strength of 32.66\u202fMPa), and PAN 3 (porosity of 67.26% and tensile strength of 20.62\u202fMPa) exhibited high porosity and tensile strength. The optimized PAN nanofibrous membranes were used as lithium-ion coin-cell separators. The coin cell with the PAN 2 membrane as the separator exhibited the highest specific capacity of 117.92 mAhg−1 at a C-rate of 1\u202fC. Additionally, this coin cell showed a Coulombic efficiency of up to 99.6% and retained 89.36% of its initial capacity at the 1\u202fC rate. The results indicate that the PAN membranes prepared in this study can be used as separators in lithium-ion batteries.