Fluorene‐containing cardo and fully aromatic single ion conducting polymer electrolyte for room temperature, high performance lithium ion batteries

Abstract

AbstractThe self‐assembly process between rigid fully aromatic single ion conducting polymer electrolytes (SIPEs) and flexible aliphatic binder for fabrication of macro‐scale porosity of membrane for enhancement of ionic conductivity has been demonstrated in our previous works. In this article, the bulky and rigid fluorene cardo groups are successfully introduced into the fully aromatic polymeric backbone to synthesize the fluorene‐containing cardo fully aromatic single ion conducting polymer electrolyte (fca‐SIPE). The synthesized fca‐SIPE is then blended with a flexible aliphatic PVDF‐HFP binder to prepare fca‐SIPE membrane via a solution cast method. By comparing with results of the previous works, in this case, not only the macro‐scale porous morphology derived from the self‐assembly process between PVDF‐HFP and fca‐SIPE, but also the interior nano‐scale lithium ion transport pathway throughout the free volume formed by the fluorene groups is obtained. The effect of the fluorene group on the key properties of membrane, such as ionic conductivity and battery performance, is systematically investigated. The excellent performance at high C‐rates at room temperature is demonstrated.