Polysulfide diffusion controlled, non-shrinkable, porous, PAN/PES electrospun membrane for high energy Li-S battery application. (June 2019)

• Record Type: Journal Article
• Authors: Aswathy, R.; Suresh, S.; Ulaganathan, M.; Ragupathy, P.
• Is Part Of: Materials today energy. Volume 12(2019)
• Page Start: 37
• Page End: 45
• Publication Date: 2019-06
• Subjects: Lithium-sulfur battery -- Polysulfide diffusion -- Electrospun membrane -- Polyethersulfone -- Charge-discharge; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2018.12.007
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: 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. Graphical abstract: The present work focusses on the utilization of electrospun polyacrylonitrile-polyethersulfone (PAN-PES) polymer blend membrane as separator for Li-S battery. The likeable attributes of the membrane includes its higher thermal stability, electrolyte uptake, porosity and dimensional stability over commercial separator facilitating the enhanced performance in terms of better capacity values and reasonable cyclability. Through detailed investigation, electrospun membrane is suggested as a promising material for application as separator in lithium-sulfur system.Image 1 Highlights: Polyacrylonitrile-polyethersulfone (PAN/PES) based blend electrospun membrane is prepared and employed as separator for the very first time in Li-S system. PAN/PES blend showed highly improved shrinkage, electrolyte uptake, porosity properties The prepared membranes showed better thermal stability (303 °C) and wettability. The cell tested by employing the newly developed PES15 membrane exhibited a specific capacity of 1175 mAh g −1 . Capacity retention of 72% and coulombic efficiency of 93% was also obtained over 100 cycles for PES15.