Fully Hydrocarbon Membrane Electrode Assemblies for Proton Exchange Membrane Fuel Cells and Electrolyzers: An Engineering Perspective

Abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/aenm.202103559.

Fuel cell performance improvement via the steric effect of a hydrocarbon-based binder for cathode in proton exchange membrane fuel cells

“…Hydrocarbon-based electrolyte polymers typically require significantly higher amounts of sulfonic acid functional groups (-SO 3 H) per repeating unit to achieve ion conductivity similar to that of Nafion, resulting a higher IEC. The obscure separation between the hydrophobic and hydrophilic phases in BP-SPES due to the densely located functional groups and flexible backbone produces narrow and unconnected domains that hinder proton conductivity and yield a higher swelling degree 15 , 24 . In contrast, the attractive force between the cardo-type fluorenyl groups in the two different FL-SPES–bones is advantage as a cathodic binder as one compartment maintains distinct phase separation regardless of the IEC.…”

“…Among the many promising hydrocarbon polymers 5 – 11 , sulfonated poly(ether sulfone) (SPES) is low-cost due to its simple synthesis method, has a low gas permeability due to its dense and rigid structure, and has excellent thermal stability compared to Nafion 6 – 8 . Although significant progress has been made in the study of using hydrocarbon polymer electrolytes as membranes 9 , 10 , little research has been conducted on the role of binders in catalyst layers 11 – 14 because hydrocarbon polymers exhibit lower oxygen permeability coefficients than PFSA 13 – 15 . Because the oxygen reduction reaction (ORR) occurring at the cathode is slower than the hydrogen oxidation reaction (HOR) at the anode, the ORR at the cathode is a major cause of polarization loss and is the key factor controlling the electrochemical reaction rate in PEMFC operation 14 – 16 .…”

Improving the efficiency of fully hydrocarbon-based proton-exchange membrane fuel cells by ionomer content gradients in cathode catalyst layers

“…Solvay, 3M, Dow, Asahi Kasei Corporation, and Chemours Company) owing to the costly and complex fluorine chemistry. The desired technical goals to higher operating conditions (4100 1C) 1,2 and the mid-term environmental goals to avoid fluorinated materials 3,4 have raised interest in developing alternative and scalable cation exchange materials to PFSA in fuel cell research.…”

Evaluation of properties and performance of poly(ether sulfone ketone) membranes in proton exchange membrane fuel cells

“…PFSAs are preferred membranes because of their excellent performance and superior thermal, chemical, and mechanical properties in the fuel cell environment. Nevertheless, PSFAs are expensive, and their outstanding performance is highly related to the humidity levels of the membrane and also limited to temperatures below 100°C 7,8 . These limitations cause extensive efforts to develop economical and suitable alternative materials 9 .…”

“…Nevertheless, PSFAs are expensive, and their outstanding performance is highly related to the humidity levels of the membrane and also limited to temperatures below 100 C. 7,8 These limitations cause extensive efforts to develop economical and suitable alternative materials. 9 Sulfonated aromatic hydrocarbons and poly (arylene ether)s emerged as promising candidates.…”