The stated project objectives will be achieved by the engineering and demonstration of a mechanically tough, chemically stable, high-performance membrane utilizing nafion™ perfluorosulfonic acid…

The stated project objectives will be achieved by the engineering and demonstration of a mechanically tough, chemically stable, high-performance membrane utilizing nafion™ perfluorosulfonic acid (PFSA) polymer manufactured on assets enabling gigawatt SCALE and proven consistency through repeatability trials for the composite membrane and all subcomponents. To facilitate the development cycle, load- cycling short stack testing data will be buttressed by specific MEA testing protocols aimed at accelerating and understanding chemical and mechanical failure. In addition, EX-situ mechanical protocols simulating failure modes will elucidate interactions such as those between ionomer and other membrane subcomponents (such as reinforcement) as well as composite membrane and other MEA features (i.e., porous transport layers (PTLS)). Membranes will be manufactured where direct innovation in essential subcomponents and membrane processing will be paired with partnerships with key suppliers (reinforcement, gas recombination catalyst (GRC), radical scavenger) to iterate upon the best composite membrane combination. In addition, single-cell MEA testing capability at all relevant partner facilities will be deployed to screen materials and will contribute chemical durability testing/evaluation protocols to the accelerated stress test (AST) development. Mechanical portions of the AST will be contributed through a custom-engineered pressure and temperature cycling apparatus, which will be combined with a chemical AST to deliver a "combined" protocol eere_T_540.131 template version 3/8/2022 working draft contains confidential, proprietary, or privileged information exempt from public disclosure. 2 analogous in principle to those used in PEM fuel cells. Asts will be developed in single cell test stands, intended to correlate with observed stack failures. Short stack MEA evaluation at all stages of the project will also be a component of the project, increasing in complexity (SCALE) as the membranes reach specified maturity thresholds. Stack testing will comprise representative load protocols for what is expected in application, along with asts applied once single cell protocols have been defined and proven to accelerate real failure mechanisms. A semi-empirical modeling capability to project membrane lifetime based on load-cycling and accelerated data will flow from the AST developed in the project. In addition to electrochemical tests, observed/hypothesized failure modes will be used to develop EX- situ protocols aimed at replicating how membranes fail operando, enabling rapid prototyping to expedite solutions. Work will also comprise the simulation of MEA integration issues known to cause membrane deformation/failure. These protocols will be revised as new mechanical failure data is available.