Membranes and anion conductive polymers

US11658322B2 · kind B2 · utility

Assignee

• Massachusetts Institute of Technology · US

Inventors

• Timothy M. Swager · Newton, US
• Jeffrey C. Grossman · Berkeley, US
• Sibo Lin · Cambridge, US
• Yoonseob Kim · Ann Arbor, US
• Yanming Wang · Beachwood, US
• Arthur France-Lanord · Watertown, US
• You Wu · Changzhou City, CN
• Yifan Li · Quincy, US
• Yichong Wang · Beijing, CN

Key dates

• Filing date: Nov 3, 2020
• Grant date: May 23, 2023
• Expiry date: May 26, 2041

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A major challenge in the development of anion exchange membranes for fuel cells is the design and synthesis of highly stable (chemically and mechanically) and conducting membranes. Membranes that can endure highly alkaline environments while rapidly transporting hydroxides are desired. A design for using cross-linked polymer membranes is disclosed to produce ionic highways along charge delocalized pyrazolium and homoconjugated triptycenes. The ionic highway membranes show improved performance in key parameters. Specifically, a conductivity of 111.6 mS cm−1 at 80° C. was obtained with a low 7.9% water uptake and 0.91 mmol g−1 ion exchange capacity. In contrast to existing materials, these systems have higher conductivities at reduced hydration and ionic exchange capacities, emphasizing the role of the highway. The membranes retain more than 75% of initial conductivity after 30 days of alkaline stability test. This effective water management through ionic highways is confirmed by density functional theory and Monte Carlo studies. A single cell with platinum group metal catalysts at 80° C. showed a high peak density of 0.73 W cm−2 (0.45 W cm−2 from silver-based cathode) and stable per…