A novel long-side-chain sulfonated poly(2, 6-dimethyl-1, 4-phenylene oxide) membrane for vanadium redox flow battery. (4th January 2018)

• Record Type: Journal Article
• Authors: Yan, Xiaoming; Sun, Jiahui; Gao, Li; Zheng, Wenji; Dai, Yan; Ruan, Xuehua; He, Gaohong
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 1(2018)
• Page Start: 301
• Page End: 310
• Publication Date: 2018-01-04
• Subjects: Cation exchange membrane -- PPO -- Long side chain -- Vanadium redox flow battery -- Microphase separation; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.10.143
• Languages: English
• ISSNs: 0360-3199

Abstract

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