Polyacrylonitrile Separator for High-Performance Aluminum Batteries with Improved Interface Stability

Herein we report, for the first time, an overall evaluation of commercially available battery separators to be used for aluminum batteries, revealing that most of them are not stable in the highly reactive 1-ethyl-3-methylimidazolium chloride:aluminum trichloride (EMIMCl:AlCl3) electrolyte conventionally employed in rechargeable aluminum batteries. Subsequently, a novel highly stable polyacrylonitrile (PAN) separator obtained by the electrospinning technique for application in high-performance aluminum batteries has been prepared. The developed PAN separator has been fully characterized in terms of morphology, thermal stability, and air permeability, revealing its suitability as a separator for battery applications. Furthermore, extremely good compatibility and improved aluminum interface stability in the highly reactive EMIMCl:AlCl3 electrolyte were discovered. The use of the PAN separator strongly affects the aluminum dissolution/deposition process, leading to a quite homogeneous deposition compared to that of a glass fiber separator. Finally, the applicability of the PAN separator has been demonstrated in aluminum/graphite cells. The electrochemical tests evidence the full compatibility of the PAN separator in aluminum cells. Furthermore, the aluminum/graphite cells employing the PAN separator are characterized by a slightly higher delivered capacity compared to those employing glass fiber separators, confirming the superior characteristics of the PAN separator as a more reliable separator for the emerging aluminum battery technology

Fluorohexane network and sulfonated PEEK based semi-IPNs for fuel cell membranes

International audienceThe purpose of this study has been to develop new proton-exchange membranes based on semiinterpenetrating polymer network (semi-IPN) architectures for application in polymer electrolyte fuel cells. A series of semi-IPNs combining a fluorinated hexane network and a linear sulfonated poly(aryl ether ether ketone) (SPEEK) has been obtained by varying the SPEEK content from 50 to 80 wt.%. A telechelic functionalized acrylate oligomer was obtained by acrylation of , -fluorinated hexanediol, while SPEEK was synthesized by polycondensation of sulfonated difluorobenzophenone with the bisphenol 6F. These semi-IPN membranes have been characterized by infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and small-angle X-ray scattering. A semi-IPN containing 60 wt.% SPEEK has been tested as a fuel cell membrane