Novel Side-Chain-Type Polybenzimidazole and Siloxane Cross-linked Membranes for Anion Exchange Membrane Fuel Cells

Abstract

In this study fluorine-containing polybenzimidazole (6F-PBI) was successfully synthesized A 6FPBI-BrIm1 2 polymer was synthesized by adding 3-(6-Bromohexyl)-1 2-dimethylimidazolium (Br-6-Im1 2) ionic liquid as a pendant side chain 6FPBI-10S-BrIm1 2 copolymer was synthesized by adding 10% (3-Chloropropyl)triethoxysilane and 90% Br-6-Im1 2 A cross-linked membrane was prepared using a 6FPBI-10S-BrIm1 2 copolymer with ionic liquid 1-methyl-3-[3-(trimethoxy-λ4-silyl)propyl]imidazolium chloride as the cross-linker which exhibited improved dimensional stability mechanical properties and oxidative stability The 6FPBI-BrIm1 2 and 6FPBI-10S-BrIm1 2 membranes showed hydroxide conductivities of 0 0318 and 0 0132 S/cm at 60 ℃ respectively Both reached the hydroxide conductivity criteria established in recent research (>10-2 S/cm) The highest hydroxide conductivity was 0 0502 S/cm by 6FPBI-BrIm1 2 membrane at 80 ℃ In the single cell test we used a 4 cm2 commercial gas diffusion electrode (FuMA-Tech) with a Pt loading of 1 mg/cm2 and then compared the cell performance with the 6FPBI-BrIm1 2 and commercial (FAA-30-5) membranes Both of them exhibited open circuit voltages of over 0 95V In the case of the 6FPBI-BrIm1 2 MEA the power density reached 22 mW/cm2 at 50 ℃ which was higher than that of the commercial MEA under the same testing conditions

Date of Award	2020
Original language	English
Supervisor	Lien-Chung Hsu (Supervisor)