Abstract
Meta- and para-linked homopolymers bearing 3-methylphenyl (Me) pendent groups were postsulfonated to create sulfonated poly(ether ether ketone ketone) (SPEEKK) backbone isomers, which are referred to as Me-p-SPEEKK and Me-m-SPEEKK. Their thermal and oxidative stability, mechanical properties, dimensional stability, methanol permeability, and proton conductivity are characterized. Me-p-SPEEKK and Me-m-SPEEKK proton conductivities at 100 °C are 116 and 173 mS cm−1, respectively. Their methanol permeabilities are 3.3–3.9 × 10−7 cm2 s−1, and dimensional swelling at 100 °C is 16.4–17.5%. Me-p-SPEEKK and Me-m-SPEEKK were fabricated into membrane electrode assemblies (MEAs), and electrochemical properties were evaluated within a direct methanol fuel cell (DMFC) and proton-exchange membrane fuel cell (PEMFC). When O2 is used as the oxidant at 80 °C and 100% RH, the maximum power density of Me-m-SPEEKK reaches 657 mW cm−2, which is higher than those of Nafion 115 (552 mW cm−2). DMFC performance is 85 mW cm−2 at 80 °C with 2.0 M methanol using Me-p-SPEEKK due to its low MeOH crossover. In general, these electrochemical results are comparable to Nafion. These ionomer properties, combined with a potentially less expensive and scalable polymer manufacturing process, may broaden their potential for many practical applications.
Original language | English (US) |
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Pages (from-to) | 30-37 |
Number of pages | 8 |
Journal | Journal of Power Sources |
Volume | 368 |
DOIs | |
State | Published - 2017 |
Keywords
- Dimensional stability
- Fuel cells
- Membrane electrode assemblies
- Proton exchange membrane
- poly(ether ketone)s and ionomer
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering