Work

High-Flux Microporous Layers with Bimodal Pore Structures for Proton Exchange Membrane Fuel Cells

Year: 2025

Type: article

Abstract: Proton exchange membrane fuel cells (PEMFCs) are critical for heavy-duty transportation due to their high efficiency and environmental benefits. However, achieving optimal water management and gas transport in the microporous layer (MPL) remains a challenge to improving its performance. In this paper, a high-flux MPL is presented, which was prepared using pure carbon nanotubes (CNT) by adding a nonionic surfactant to improve the dispersion of hydrophobic CNT. This aimed to improve the performance of the membrane electrode assembly (MEA) for PEMFCs at high current densities and enhance its stability at high voltages. The morphology, pore size distribution, porosity, gas/water permeability, and hydrophilicity of the MPL were characterized by transmission electron microscopy, scanning electron microscopy, an automatic mercury porosimeter, a comprehensive membrane pore size analyzer, and a contact angle meter, respectively. Electrochemical performance analyses were conducted by polarization curves and electrochemical AC impedance spectroscopy. The results indicated that the MPL prepared with pure CNT exhibited a bimodal pore structure, which significantly improved the water/air permeability and water management capability of the MPL. Compared to commercial XC-72-MPL, CNT-90-MPL reduced the charge transfer resistance (Rct) and mass transport resistance (Rmt) of the MEA. The highest power density achieved by CNT-90-MPL was 1.813 W/cm2. Based on capillary pressure and bifunctional transport mechanism, the transport mechanism of water and air in the bimodal pore structure of the MLP was analyzed. Water primarily flows through the large pores in the MPL, while air diffuses oppositely via the small pores. This bifunctional transport mechanism is the primary factor contributing to the superior water management performance of CNT-90-MPL.

Source: ACS Omega

DOI: 10.1021/acsomega.5c01691

Authors: Chujie Lin, Kuangwei Cheng, Shang Li, Siyi Ouyang, Yadong Wang, Mu Pan

Institutions: Wuhan University of Technology, State Key Laboratory of Advanced Technology For Materials Synthesis and Processing

Language: English

Topic: Fuel Cells and Related Materials

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $1,935