Novel Hydrocarbon Ionomers for Durable Proton Exchange Membranes

The Department of Fuel Cell Technology Office has identified a need for durable, low cost membranes that offer enhanced energy efficiency to power zero emission vehicles. Specifically, a cost effective alternative to expensive commercial perfluorosulfonic acid ionomers are sought. Current affordable hydrocarbon membranes do not yet offer the performance or durability needed for fuel cell vehicle membranes. The objective of this program is to develop and demonstrate high temperature hydrocarbon based membranes that meet the chemical, thermal, and mechanical properties necessary to qualify for the demanding environments within a fuel cell vehicle. The approach involves the synthesis of novel high molecular weight aromatic hydrocarbon membranes that possess polar moieties along the polymer backbone and pendant quaternary ammonium groups. In Phase I, quaternary ammonium containing hydrocarbon polymers with polar pendant groups shall be synthesized and utilized to fabricate stable phosphoric acid (H3PO4) doped membrane composites. Proton conductivity shall be evaluated as a function of percent functionalization in a wide range of fuel cell vehicle operating conditions, including low humidity. The prototypes will be evaluated in-house for film formation quality, permeability, thermal, chemical, and mechanical durability to reach a Technology Readiness Level 5, and demonstrated in a cost effective, scalable manufacturing process. Technology Readiness Level 7 shall be reached via membrane incorporation within a 5 cm2 single cell, impedence testing, and short term fuel cell durability testing at an Independent National Laboratory. The Department of Energy’s Fuel Cell Office has identified a need for robust, affordable fuel cell membranes. Innovative, hydrocarbon membranes shall be manufactured at a small business in the United States to advance our nation’s energy savings. Commercial Applications and Other Benefits: Durable, high temperature, proton conducting hydrocarbon-based membranes shall be commercialized primarily as fuel cell membranes with several major automakers. These membranes shall then be transitioned for use in stationary power applications, including primary power, backup power, and combined heat and power.