A novel long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) membrane for vanadium redox flow battery

摘要: Abstract A novel long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (S-L-PPO) membrane was successfully prepared for VRFB applications. The long side chains were introduced onto the PPO backbones by a simple and controllable acylation with 4-fluorobenzoyl chloride subsequent condensation sodium 4-hydroxybenzenesulfonate. introduction of drives formation good hydrophilic/hydrophobic micro-phase separation structure, which is evidenced AFM. S-L-PPO degree sulfonation (DS) 51% showed an ultralow vanadium permeability (4.3 × 10−9 cm2 s−1) decent proton conductivity (44 mS cm−1). As result, energy efficiency S-L-PPO-51% up to 81.8% that higher than Nafion 212 (78.0%) at current density 120 mA cm−2. In addition, self-discharge duration cell 222 h nine times longer (23 h). All these indicate here promising application in VRFB.