Anion exchange membranes based on carbazole-containing polyolefin for direct methanol fuel cells

• Published in: Journal of membrane science 2016-01, Vol.497, p.99-107
• Main Authors: Lai, Ao Nan, Zhou, Ke, Zhuo, Yi Zhi, Zhang, Qiu Gen, Zhu, Ai Mei, Ye, Mei Ling, Liu, Qing Lin
• Format: Article
• Language: English
• Subjects: Anion exchange membranes; Carbazole-containing polyolefin; Direct methanol fuel cells; Imidazolium cation
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2015.08.069

A series of anion exchange membranes was prepared from the copolymer of 1-vinyl imidazole and N-vinyl carbazole for direct methanol fuel cells (DMFCs). The structure of the membranes was studied using 1H NMR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and small angle X-ray scattering (SAXS). The thermal stability of the membranes was characterized by thermo-gravimetric analysis (TGA). The ion conductivity, methanol permeability, ionic exchange capacity (IEC), water uptake, swelling ratio, and alkaline stability of the membranes were investigated. It is found that the ion conductivity of the membranes varied from 9.34×10−2 to 20.28×10−2Scm−1 in deionized (DI) water and the methanol permeability varied from 4.5×10−8 to 12.3×10−8cm2s−1 at 30°C. All the as-prepared membranes are stable in a 1.0M KOH solution at 60°C for 1400h due to the polyolefin backbone. A methanol/O2 single cell evaluation exhibited an open circuit voltage of 0.93V and peak power density of 125.8mWcm−2. Therefore, the as-prepared membranes have great potential for application in alkaline fuel cells. [Display omitted] •Anion exchange membranes are prepared using 1-vinyl imidazole and N-vinyl carbazole.•Crosslinked membranes were synthesized using 1, 4-dibromobutane.•The ion conductivity is in the range of 9.34–20.28×10−2Scm−1 at 30°C.•The membranes are stable in a 1.0M KOH solution at 60°C for 1400h.