Material Science and Engineering

Biography

Biography: Lixin Xue

Abstract

High performance ionic conducting polymers are widely used in the energy conversion and storage devices, desalination processes and other areas. Commercially available per fluorinated polymer based ionomers bearing perfluroalkylsulfonic acid groups such as Nafion® polymer have shown great electrochemical stability and good ionic conductivity. However, its relatively high cost and low solvent barrier property have limited its applications in many areas. None fluorinated ionomers such as sulfonated polysulfone, sulfonated polyimide and others have been developed as lower cost alternatives, but they lack the electrochemical stability and ionic conductivity to support long term energy related applications. In this talk, we will discuss our strategy in creating lower cost high performance ionic conducting polymers with aromatic backbones bearing fluorinated side chains connecting to fluorinated alkyl sulfonimide groups. Due to the strong electronic withdrawing effects from the fluoroalkylsulfonyl groups, the negative charged on the nitrogen of sulfonimide anion could be widely delocalized and stabilized, resulting in the high mobility of the counter cations in the system. The materials showed improved solvent barrier properties because of its tighter ionic conducting channels. After summarizing our work in the syntheses of the materials, we will discuss recent progress in developing potential applications in rechargeable lithium ion battery, all vanadium redox flow battery, low energy cost electro-dialysis device, and total heat exchange energy recovery ventilation system.