XION Composite AQUIVION Membranes are ultra-thin, highly conductive, and highly stable reinforced proton exchange membranes (PEM). The membranes are based on a perfluorosulfonic acid (PFSA) ionomer developed by Solvay. The AQUIVION ionomer produced by Solvay has much shorter side chains than traditional NAFION, providing different ionomer morphology and therefore physical and chemical properties. A reinforcement layer is integrated into the structure of the membrane to provide enhanced mechanical properties. The enhanced mechanical properties allow Ultra-thin, Ultra-Strong, and Ultra-High-Performance free-standing membranes, i.e. providing higher ionic conductivity without sacrificing strength. Applications for XION Composite AQUIVION Membranes include fuel cells, electrolyzers, and sensors. XION Composite AQUIVION Membranes come in two variations based on the equivalent weight (EW) of the ionomer: 720EW has higher ionic conductivity, but 830EW has greater stability.