Improving the performance of sulfonated polymer membrane by using sulfonic acid functionalized hetero‐metallic metal‐organic framework for DMFC applications

Abstract

Summary Proton transport played a crucial part in the fuel cells, sensors, and batteries. The electrolyte used in fuel cells should possess high proton conductivity and good chemical stability. Herein, taking advantage of the high proton conductivity of metal‐organic framework (MOF) and the good chemical stability of branched polymers, a new heterometallic mediated MOF (Zr‐Cr‐SO3H) is synthesized and utilized as a filler in the highly branched sulfonated polymer (BSP). In addition, Zr‐SO3H MOF is also prepared for comparison. Transmission electron microscope study shows that the prepared MOF particles are spherical in size and interconnected through nanosheets. The optimized quantity of MOFs inside the polymer matrix improves the water sorption, mechanical property, and proton conductivity. The composite membranes display an improved open‐circuit voltage than the pristine BSP membrane. By comparing the Zr‐SO3H MOF incorporated composite membrane, Zr‐Cr‐SO3H MOF incorporated composite membranes display higher proton conductivity and peak power density in a single‐cell test. In particular, the single‐cell fabricated with Zr‐Cr‐SO3H MOF incorporated composite membrane is able to reach the peak power density of 64.6 mWcm−2 at 60°C, which is 26% greater than the Nafion 212 membrane. Furthermore, this work offers a new strategy for the utilization of hetero‐metal MOF as a filler for proton exchange membrane applications.

Synthesis and characterization of poly 2‐ N ‐acrylamido‐2‐methyl−1‐propane sulfonic acid functionalized graphene oxide embedded electrolyte membrane using DOE for PEMFC

“…Cell performance is done at 120 C in anhydrous conditions. The open-circuit voltages of all membranes are 1.0 V. It shows that synthesized membranes have great ability to resist the gas (H 2 or O 2 ) flow, 3 because of the presence of modified graphene oxide (mGO). 69 The CPVC, PAMPS, and PAMPS-mGO-based composite membranes show current density in the range of 10.01 to 1536.69 mA/cm 2 and power density in the range of 3.1 to 566.47 mW/cm 2 .…”

“…Nafion-based membranes work well at hydrated conditions; however, at elevated temperatures such as 120 C dehydration of membrane occurs that declines its conductivity from 0.1 to 0.001 S/cm lead to the 95% loss in overall performance of fuel cell. [3][4][5][6] Low temperature operating systems have short cell life due to very frequent CO poisoning of Pt catalyst. Furthermore, low reaction kinetics at both electrodes and complicated heat and water management are also the drawbacks of low temperature operating fuel cells.…”

“…14 At higher temperatures (above 150 C), PA-doped PEMs undergo chemical degradation as well as loss rate of PA considerably increases which leads to acid depletion and ultimately decay in proton conductivity. 3,15 This mechanism increases with increasing current loads because of repressed formation of pyrophosphate. Thus, the lifetime of PEMFCs reduces to few 100 hours of operation at 190 C to 200 C. 16,17 Integrated inorganic fillers that is, zeolites, titania, silicon oxides, and carbon tubes have been effectively used to enhance the proton conductivity with the reduction of methanol permeability.…”

“…The operating temperatures of currently available commercial PEMFCs are below 80°C as they are based on perfluorosulfonic acid (PFSA) membranes (eg, Nafion). Nafion‐based membranes work well at hydrated conditions; however, at elevated temperatures such as 120°C dehydration of membrane occurs that declines its conductivity from 0.1 to 0.001 S/cm lead to the 95% loss in overall performance of fuel cell 3‐6 . Low temperature operating systems have short cell life due to very frequent CO poisoning of Pt catalyst.…”

Effects of assembling method and force on the performance of proton‐exchange membrane fuel cells with metal foam flow field

“…So, a drastic increase in the application of PEMFC is observed in the past decade. However, most of the researchers focus on materials' characterization 2,14‐22 and the effects of operation parameters on cell performance 11,12,23‐28 . Components of a PEMFC include bipolar plates (BP), gas diffusion layers (GDL), microporous layers (MPL), catalyst layers (CL), and a proton‐exchange membrane.…”