Study on Protocols for Evaluating Durability of PEFC Electrolyte Membranes
Under the NEDO Project called Cell Evaluation Project, Daido University(DU) decided the evaluation protocol of membrane chemical and mechanical durability based on the protocol recommended by FCCJ and DOE. Table1 and Table 2 shows the OCV and Dry-wet cycle test protocols were decided by DU. Using these protocols, chemical durability and mechanical durability of fluorine based and hydrocarbon membranes from all over the world have been evaluated with single cells.
Regarding to OCV test protocol, the criterion of this test is set which quantity of cross leak current reached at 10 times of the initial current. As the OCV test is going, chemical degradation of membranes are caused by hydrogen peroxide is produced, and then membranes are gradually broken and finally hydrogen leak current larger increase.
Recently, the protocol that combined a OCV test and a Dry-wet cycle test has been suggested by ENE-FORM companies to evaluate and accelerate membranes chemical and mechanical durability of membranes.
In this study, to clarify the degree of the chemical degradation of hydrocarbon-based membranes in the OCV test, DU examine a newly protocol of evaluating for membrane’s chemical durability by OCV test with the new diagnosis method to use dry-wet cycle test.
Table3 shows DU newly protocol for membrane chemical durability based on the protocol recommended by ENE-FORM companies. As seen this table, OCV tests with diagnosis method of membrane’s chemical durability were conducted on single cells with Nafion HP membrane and hydrocarbon-based membranes. Dry-wet cycle test was conducted for diagnosis method to evaluate degree of membrane chemical durability.