Porous Flow Field for Next-Generation Proton Exchange Membrane Fuel Cells: Materials, Characterization, Design, and Challenges

Abstract

Porous flow fields distribute fuel and oxygen for the electrochemical reactions of proton exchange membrane (PEM) fuel cells through their pore network instead of conventional flow channels. This type of flow fields has showed great promises in enhancing reactant supply, heat removal, and electrical conduction, reducing the concentration performance loss and improving operational stability for fuel cells. This review presents the research and development progress of porous flow fields with insights for next-generation PEM fuel cells of high power density (e.g., ∼9.0 kW L–1). Materials, fabrication methods, fundamentals, and fuel cell performance associated with porous flow fields are discussed in depth. Major challenges are described and explained, along with several future directions, including separated gas/liquid flow configurations, integrated porous structure, full morphology modeling, data-driven methods, and artificial intelligence-assisted design/optimization.

Construction of dense H-bond acceptors in the channels of covalent organic frameworks for proton conduction

“…Proton exchange membrane fuel cells (PEMFCs) that realize efficient conversion of chemical energy to electrical energy are key for clean and high-power energy. [1][2][3][4][5] As a signicant component for determining whether the fuel cell can operate efficiently, PEMs require excellent proton conductivity, outstanding thermal and chemistry stability. [6][7][8][9][10][11] However, the most advanced PEMs (e.g., Naon) experience a plunge in conductivity at high temperature due to the low relative humidity (RH).…”

Molecular Complexation of Polymers and Metal Oxide Clusters for Semicrystalline, Thermoplastic Anhydrous Proton Exchange Membranes in Fuel Cells

“…Because PEG–SiW 12 nanocomposites are prone to material softening and deformation under realistic test conditions above 80 °C and high gas back pressure thus leading to device failure, we explore the performance of a H 2 /O 2 fuel cell with PEG400–80%SiW 12 as the proton exchange membrane at 45, 55, and 70 °C without a humidifier. The obtained maximum open-circuit voltage and maximum power density are 0.96 V and 476 mW cm –2 at 70 °C, respectively, implying that the PEG–POM nanocomposites have potential for further development in the field of anhydrous PEMFCs (Figure d). − …”

Progress and Perspective for In Situ Studies of Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells

“…One of the most effective ways to utilize hydrogen is proton exchange membrane fuel cells (PEM-FCs) which can directly convert chemical energy stored in hydrogen into electrical energy with high conversion efficiency, zero-emission, and moderate operating temperatures. [1][2][3] However, there are still some critical issues that need to be addressed to expand the commercialization of PEMFCs. One of the most significant obstacles is the high cost of the only practical Pt-based catalysts, which make up to more than 40% of the total fuel cell stack cost.…”