Polysulfide diffusion controlled, non-shrinkable, porous, PAN/PES electrospun membrane for high energy Li-S battery application

In recent years, Li-S battery has received much attention owing to its high theoretical specific capacity of 1675 mAh g(-1). However, diffusion of the polysulfide across the electrodes during charge-discharge process strictly affects the cell characteristics. To avoid such ion diffusion, usage of an appropriate separator is highly appreciable. A suitable separator, particularly in Li-S system, should act as selective ion diffusion medium and as better electrolyte absorber during the cell operando. Hence, in the present study, polyacrylonitrile-polyethersulfone (PAN/PES) based blend electrospun membrane is developed and employed as separator for the very first time in Li-S system. Physical characteristics such as shrinkage, electrolyte uptake, porosity were studied using various techniques. Concurrently, feasibility of the prepared electrospun membrane in Li-S battery is analysed using various electrochemical studies such cyclic voltammetry, galvanostatic charge-discharge studies and electrochemical impedance spectroscopy. The obtained characteristics of the synthesised membrane were also compared with the commercial Celgard 2320 separator. It is noteworthy to mention that the cell delivered an initial specific capacity of 1175 mAh g(-1) at 0.1C for synthesised membrane which surpasses that of commercial one. Upon prolonged cycling, the cell showed more than 90% coulombic efficiency; thus, it clearly reveal the better Li ion diffusivity and control of polysulfide diffusion as compared to commercial separator. (C) 2018 Elsevier Ltd. All rights reserved.