Microporous Layer Containing CeO₂-Doped 3D Graphene Foam for Proton Exchange Membrane Fuel Cells at Varying Operating Conditions

Abstract

To improve the interfacial mass-transfer efficiency, microporous layers (MPLs) containing CeO2 nanorods and the CeO2 nano-network were prepared for proton exchange membrane fuel cells (PEMFCs). In order to minimize the contact resistance, the three-dimensional (3D) graphene foam (3D-GF) was used as the carrier for the deposition of CeO2 nanorods and the nano-network. The CeO2-doped 3D-GF anchored at the interface between the catalyst layer and microporous layer manufactured several novel functional protrusions. To evaluate the electrochemical property, the normal MPL, the MPL containing raw 3D-GF, and MPLs containing different kinds of CeO2-doped 3D-GF were used to assemble the membrane electrode assemblies (MEAs). Measurements show that the CeO2-doped 3D-GF improved the reaction kinetics of the cathode effectively. In addition, the hydrophilic CeO2-doped 3D-GF worked as the water receiver to prevent the dehydration of MEAs at dry operating condition. Besides, at a high current density or humid operating condition, the CeO2-doped 3D-GF provided the pathway for water removal. Compared with the CeO2 nanorods, the CeO2 nano-network on 3D-GF revealed a higher adaptability at varying operating conditions. Hence, such composition and structure design of MPL is a promising strategy for the optimization of high-performance PEMFCs.

Three-Dimensional Sulfonated Graphene Oxide Proton Exchange Membranes for Fuel Cells

“…The respective conductivity data were evaluated from the Nyquist plot with the help of half circular curves through curve fitting. The equivalent circuit for the analysis of EIS and the representative Nyquist plot are illustrated in Figure S9. , As observed from Figure a, the proton transport ability of the respective film showed an upward fashion with RH. For the in-plane direction, at 40% RH and 25 °C, 3DGO yielded a σ-value of 9.80 × 10 –4 S cm –1 with respect to 1.7 × 10 –1 S cm –1 at 90% relative humidity.…”

“…GO forms a sheet-like graphene network by utilizing its various polar functional groups such as epoxy, carboxylic, and hydroxyl groups. − These materials have gained extensive attention due to their extraordinary physical and chemical characteristics such as high conductivity and amazing mechanical strength, which are useful for application in various fields including proton conductors. − The ion conduction primarily occurs by utilizing the epoxy groups throughout the edge and pinholes of the GO nanosheets. These sites can hold water molecules that construct the pathway for the conduction of proton using the Grotthuss mechanism. − Moreover, the surface property of GO can be altered through chemical modification, which enhances the water retention ability of the functionalized GO materials.…”

Study of substrate‐free microporous layer of proton exchange membrane fuel cells

“…Proton exchange membrane fuel cells (PEMFCs), used as the energy-conversion device for converting the chemical energy of the fuel into electrical energy, have been applied in transportation, household power and distributed power stations, benefiting from their environmentfriendly, low-noise, high energy-conversion efficiency and quick start-up characteristics. [1][2][3] However, the high cost, insufficient durability and specific power still impede the commercialisation of PEMFCs. [4][5][6] The gas diffusion layer (GDL), employed between the flow field (FF) and the catalyst layer (CL), is a critical component of PEMFCs, which distributes the gas, drains the generated water in the cathode, supports CL and conducts electrons between the bipolar plate and the CL.…”

“…17,18 Thus, a dry technique is proposed to prepare MPL for PEMFCs with convenient operation, solvent-free and excellent reproducibility. 19,20 Researchers have endeavored to enhance fuel cells' performance in terms of fabricating new materials, 3,[21][22][23][24] constructing favorable structures 17,[25][26][27][28] and optimizing components of GDL. [29][30][31] From the material aspect, some studies have demonstrated the use of carbon fiber (CF), carbon nanotube and graphene in MPL to improve the electrical performance and gas permeability of PEMFCs.…”

“…Proton exchange membrane fuel cells (PEMFCs), used as the energy‐conversion device for converting the chemical energy of the fuel into electrical energy, have been applied in transportation, household power and distributed power stations, benefiting from their environment‐friendly, low‐noise, high energy‐conversion efficiency and quick start‐up characteristics 1‐3 . However, the high cost, insufficient durability and specific power still impede the commercialisation of PEMFCs 4‐6 …”