2P-436: Chemical Degradation of Polymer Electrolyte Membranes based on Imidazolium-brominated Polyphenylene Oxide for Vnanadium Redox Flow Battery (VRFB)

Imidazolium-brominated polyphenylene oxide (Im-bPPO) is fabricated on the functionalization of bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) using 1-Methylimdazole. For the purpose of long cycle life of vanadium redox battery (VRB), the chemical stability of Im-bPPO, sPPO, Nafion and Fumatech membranes were evaluated firstly in the 0.1 M vanadium (V) solution dissolved in 3 M sulfuric acid (H2SO4) for 72 h and UV analyses of the degradation products proved that ether bond in PPO backbone was vulnerable to be attacked by vanadium (V) ion. It was found that the membranes had slightly weight loss after soaking in STS pressure vessel with 2 ml distilled water at 200 °C for 24 h. Further evaluation on the degradation mechanism of the membranes was carried out in fenton`s reagent solution at 50 °C for 72 h. The Fumatech membranes exhibit better performance than AEM and CEM, but Nafion 212 still suffers the chemical degradation.