scholarly journals Effect of Dispersion Solvents in Catalyst Inks on the Performance and Durability of Catalyst Layers in Proton Exchange Membrane Fuel Cells

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 549 ◽  
Author(s):  
Chan-Ho Song ◽  
Jin-Soo Park
Keyword(s):  
Particle Size ◽  
Fuel Cells ◽  
High Performance ◽  
Proton Exchange Membrane ◽  
Porous Electrode ◽  
Carbon Particle ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Catalyst Layers ◽  
Exchange Membrane

Five different ionomer dispersions using water–isopropanol (IPA) and N-methylpyrrolidone (NMP) were investigated as ionomer binders for catalyst layers in proton exchange membrane fuel cells. The distribution of ionomer plays an important role in the design of high-performance porous electrode catalyst layers since the transport of species, such as oxygen and protons, is controlled by the thickness of the ionomer on the catalyst surface and the continuity of the ionomer and gas networks in the catalyst layer, with the transport of electrons being related to the continuity of the carbon particle network. In this study, the effect of solvents in ionomer dispersions on the performance and durability of catalyst layers (CLs) is investigated. Five different types of catalyst inks were used: (i) ionomer dispersed in NMP; (ii) ionomer dispersed in water–IPA; (iii) ionomer dispersed in NMP, followed by adding water–IPA; (iv) ionomer dispersed in water–IPA, followed by adding NMP; and (v) a mixture of ionomer dispersed in NMP and ionomer dispersed in water–IPA. Dynamic light scattering of the five dispersions showed different average particles sizes: ~0.40 μm for NMP, 0.91–1.75 μm for the mixture, and ~2.02 μm for water–IPA. The membrane-electrode assembly prepared from an ionomer dispersion with a larger particle size (i.e., water–IPA) showed better performance, while that prepared from a dispersion with a smaller particle size (i.e., NMP) showed better durability.

scholarly journals Effect of Stratification of Cathode Catalyst Layers on Durability of Proton Exchange Membrane Fuel Cells

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2975
Author(s):  
Zikhona Nondudule ◽  
Jessica Chamier ◽  
Mahabubur Chowdhury
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Electrochemical Impedance ◽  
Catalyst Layer ◽  
Cost Effective ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Potential Cycling ◽  
Catalyst Layers ◽  
Exchange Membrane

To decrease the cost of fuel cell manufacturing, the amount of platinum (Pt) in the catalyst layer needs to be reduced. In this study, ionomer gradient membrane electrode assemblies (MEAs) were designed to reduce Pt loading without sacrificing performance and lifetime. A two-layer stratification of the cathode was achieved with varying ratios of 28 wt. % ionomer in the inner layer, on the membrane, and 24 wt. % on the outer layer, coated onto the inner layer. To study the MEA performance, the electrochemical surface area (ECSA), polarization curves, and electrochemical impedance spectroscopy (EIS) responses were evaluated under 20, 60, and 100% relative humidity (RH). The stratified MEA Pt loading was reduced by 12% while maintaining commercial equivalent performance. The optimal two-layer design was achieved when the Pt loading ratio between the layers was 1:6 (inner:outer layer). This MEA showed the highest ECSA and performance at 0.65 V with reduced mass transport losses. The integrity of stratified MEAs with lower Pt loading was evaluated with potential cycling and proved more durable than the monolayer MEA equivalent. The higher ionomer loading adjacent to the membrane and the bi-layer interface of the stratified catalyst layer (CL) increased moisture in the cathode CL, decreasing the degradation rate. Using ionomer stratification to decrease the Pt loading in an MEA yielded a better performance compared to the monolayer MEA design. This study, therefore, contributes to the development of more durable, cost-effective MEAs for low-temperature proton exchange membrane fuel cells.

scholarly journals Structures of Membrane Electrode Assembly Catalyst Layers for Proton Exchange Membrane Fuel Cells

2012 ◽  
Vol 5 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Tzyy-Lung Leon Yu ◽  
Hsiu-Li Lin ◽  
Po-Hao Su ◽  
Guan-Wen Wang
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Catalyst Layers ◽  
Black Layer ◽  
Exchange Membrane ◽  
Pt Black

In this paper, we modify the conventional 5-layer membrane electrode assembly (MEA, in which a proton exchange membrane (PEM) is located at its center, two Pt-C-40 (Pt on carbon powder support, Pt content 40 wt.%) catalyst layers (CLs) are located on the surfaces of the both sides of the PEM and two gas diffusion layers (GDLs) are attached next on the outer surfaces of two Pt-C-40 layers) and propose 7-layer and 9-layer MEAs by coating thin Pt-black CLs at the interfaces between the Pt-C-40 layer and the GDL and between the PEM and the Pt-C-40 layer and reducing the Pt-C-40 loading. The reduced Pt loading quantity of the Pt-C-40 layer is equal to the increased Pt loading quantity of the Pt-black layer, thus the total amount of Pt loadings in the unmodified conventional MEA and the modified MEAs are at a fixed Pt loading quantity. These modified MEAs may complicate the manufacture process. The main advantage of these 7- and 9-layer MEAs is the thinner CL thickness and thus lower CL proton transport resistance. Because of the thin Pt-black layer thickness in MEA, we avoid agglomeration of the Pt-black particles and maintain high Pt catalytic activity. We show these new CL structure MEAs have better fuel cells performance than the conventional 5-layer MEA.

scholarly journals ZIF-derived Co–N–C ORR catalyst with high performance in proton exchange membrane fuel cells

2020 ◽  
Vol 30 (6) ◽  
pp. 855-860
Author(s):  
Ruixiang Wang ◽  
Pengyang Zhang ◽  
Yucheng Wang ◽  
Yuesheng Wang ◽  
Karim Zaghib ◽  
...  
Keyword(s):  
Fuel Cells ◽  
High Performance ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Exchange Membrane

A high performance polybenzimidazole–CNT hybrid electrode for high-temperature proton exchange membrane fuel cells

2014 ◽  
Vol 2 (19) ◽  
pp. 7015-7019 ◽  
Author(s):  
He-Yun Du ◽  
Chen-Hao Wang ◽  
Chen-Shuan Yang ◽  
Hsin-Cheng Hsu ◽  
Sun-Tang Chang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
High Performance ◽  
Proton Exchange Membrane ◽  
Electrochemical Activity ◽  
Proton Exchange ◽  
Exchange Membrane

A well-controlled Pt/PBI–CNT electrode provides not only good interfacial continuity but also numerous edge planes, which has strong electrochemical activity in HT-PEMFCs.

Sign in / Sign up

Export Citation Format

Share Document