High Performance Anion Exchange Membrane Fuel Cells Enabled by Fluoropoly(olefin) Membranes

Abstract

Although the peak power density of anion exchange membrane fuel cells (AEMFCs) has been raised from ≈0.1 to ≈1.4 W cm −2 over the last decade, a majority of AEMFCs reported in the literature have not been demonstrated to achieve consistently high performance and steady-state operation. Poly(olefin)-based AEMs with fluorine substitution on the aromatic comonomer show considerably higher dimensional stability compared to samples that do not contain fluorine. More importantly, fluorinated poly(olefin)-based AEMs exhibit high hydroxide conductivity without excessive hydration due to a new proposed mechanism where the fluorinated dipolar monomer facilitates increased hydroxide dissociation and transport. Using this new generation of AEMs, a stable, high-performance AEMFC is operated for 120 h. When the fuel cell configuration is subjected to a constant current density of 600 mA cm −2 under H 2 /O 2 flow, the cell voltage declines only 11% (from 0.75 to 0.67 V) for the first 20 h during break-in and the cell voltage loss is low (0.2 mV h −1 ) over the subsequent 100 h of cell testing. The ease of synthesis, potential for low-cost commercialization, and remarkable ex situ properties and in situ performance of fluoropoly(olefin)-based AEM renders this material a benchmark membrane for practical AEMFC applications.

Using operando techniques to understand and design high performance and stable alkaline membrane fuel cells

“…5b). In AEM and AEI design, quaternary benzyl trimethylammonium is often used as the functional head group for hydroxide ion transport 3,5,11,22 . Density functional theory (DFT) simulations indicate that the energy barrier for nucleophilic attack by OH − on the quaternary benzyl trimethylammonium is much lower under drier conditions than highly humidified conditions 15,24,25 , indicating the degradation rate of AEMs is much faster at low RH than that at high RH in operating AMFCs.…”

“…To help improve AMFC device stability, much of the literature to date has focused at the material level, which has led to the creation of AEMs with high alkaline stability (1000’s of hours in concentrated KOH with negligible degradation) and good mechanical properties 3 , 9 , 11 – 13 . The PtRu/C and Pt/C electrocatalysts that are deployed at the anode and cathode, respectively, are also known to be stable for over 1000’s of hours fuel cell operation 14 .…”

Ionizing Radiation for Preparation and Functionalization of Membranes and Their Biomedical and Environmental Applications

“…They are all based on similar working frameworks, with the consumption of fuel (hydrogen or methanol) and oxidant, producing water or CO2. Although many achievements have been accomplished in the development of PEMs and AEMs for application in fuel cells, there is still a need for more improvement, which has prompted researchers to develop new IEMs, giving rise to an increasing number of publications and several reviews [41,43,[78][79][80][81][82][83].…”

Anion Exchange Membrane Based on Interpenetrating Polymer Network with Ultrahigh Ion Conductivity and Excellent Stability for Alkaline Fuel Cell

“…In all kinds of fuel cells, alkaline anion exchange membrane fuel cells (AEMFCs) have attracted more and more attentions, since nonprecious catalyst can be adopted to reduce the cost, and the kinetic of oxygen reduction is faster, as well as less corrosion problems in alkaline condition. [1][2][3][4][5][6] As a crucial component in AEMFCs, anion exchange membranes (AEMs) segregate the fuel (anode) from oxidant (cathode) and provide an ion transport pathway simultaneously. [7] Therefore, high ion conductivity and excellent mechanical and chemical stability are essential for ideal AEMs.…”