https://doi.org/10.5061/dryad.4qrfj6qn2

Description of the data and file structure

This dataset contains the experimental data underlying the article “Nanofiber Membranes for Enhanced Performance and Optimization of Proton Exchange Membrane Fuel Cells.” The study investigates the physicochemical properties and fuel-cell performance of polybenzimidazole (PBI)-based membranes for high-temperature proton exchange membrane fuel cells (HT-PEMFCs).

Three main membrane configurations were investigated:

1. Commercial PBI: A commercially available dense PBI membrane used as the reference material.

2. NFM: An electrospun PBI nanofiber membrane.

3. SSNFM: A sandwich-structured nanofiber membrane consisting of a dense solution-cast PBI membrane positioned between two electrospun PBI nanofiber membrane layers.

The membrane characterisation data include scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface-area and porosity analysis, water contact-angle measurements, nanofiber diameter distributions, mechanical properties, phosphoric acid doping level measurements, and micro–X-ray computed tomography (micro-X-ray CT).

The electrochemical data include fuel-cell polarisation and power-density curves, electrochemical impedance spectroscopy (EIS), accelerated stress tests (ASTs), and linear sweep voltammetry (LSV). The Commercial PBI membrane, NFM and SSNFM were tested as membrane electrode assemblies (MEAs), where applicable.

The dataset is organised by characterisation method and membrane type. The top-level folders are described below.

1. Acid Doping Level Measurement

This folder contains the experimental data used to determine the phosphoric acid doping levels of the investigated PBI membranes. The measurements are used to compare the phosphoric acid uptake and retention of the different membrane configurations, including measurements conducted before and after fuel-cell durability testing where applicable.

2. BET

This folder contains the BET surface-area and pore-characterisation data for the membrane samples. These measurements provide information about the specific surface area and porous structure of the membranes.

3. Commercial PBI MEA

This folder contains the electrochemical testing data for the membrane electrode assembly prepared using the commercial PBI membrane. The data provide the reference performance against which the NFM- and SSNFM-based MEAs were compared.

4. CT original image

This folder contains the original micro-X-ray CT image data used to examine the internal three-dimensional structures of the membranes. The images were used for three-dimensional reconstruction, visualisation and structural analysis of the membrane samples.

5. FTIR

This folder contains the FTIR spectra of the investigated membrane samples. These data were used to analyse the chemical structures and functional groups of the membranes and to compare potential chemical changes arising from membrane preparation or treatment.

6. NFM Contact angle

This folder contains the water contact-angle measurements for the PBI nanofiber membranes. The data were used to evaluate and compare the surface wettability of the membrane samples.

7. NFM diameter distribution

This folder contains measurements and statistical distributions of the nanofiber diameters determined from SEM images. These data describe the morphology and diameter uniformity of the electrospun PBI nanofibers.

8. NFM Mechanical properties

This folder contains the mechanical testing data for the nanofiber membranes, including the data used to evaluate their tensile behaviour and mechanical strength.

9. NFM Pol LSV EIS AST Electrochemical data

This folder contains the electrochemical data for MEAs prepared using the PBI nanofiber membranes. The folder includes:

• Pol: Fuel-cell polarisation and power-density data;

• LSV: Linear sweep voltammetry data used to evaluate hydrogen crossover and membrane integrity;

• EIS: Electrochemical impedance spectroscopy data used to investigate the ohmic and electrode-related resistances;

• AST: Accelerated stress-test data used to evaluate fuel-cell performance and durability over repeated operating cycles.

10. NFM TGA

This folder contains the thermogravimetric analysis data for the PBI nanofiber membranes. These measurements were used to evaluate mass loss and the thermal stability of the membranes.

11. SEM

This folder contains SEM images of the investigated membrane samples. The images show the membrane surface and cross-sectional morphologies and were used to evaluate nanofiber formation, fiber uniformity, membrane structure and layer interfaces.

12. SSNFM Pol EIS AST Electrochemical data

This folder contains the electrochemical data for MEAs prepared using the sandwich-structured nanofiber membranes. It includes fuel-cell polarisation and power-density data, electrochemical impedance spectroscopy data and accelerated stress-test data. These measurements were used to evaluate the initial performance, internal resistance and durability of the SSNFM-based MEAs.

Abbreviations

• AST: Accelerated stress test

• BET: Brunauer–Emmett–Teller analysis

• CT: Computed tomography

• EIS: Electrochemical impedance spectroscopy

• FTIR: Fourier-transform infrared spectroscopy

• HT-PEMFC: High-temperature proton exchange membrane fuel cell

• LSV: Linear sweep voltammetry

• MEA: Membrane electrode assembly

• NFM: Nanofiber membrane

• PBI: Polybenzimidazole

• Pol: Polarisation measurement

• SEM: Scanning electron microscopy

• SSNFM: Sandwich-structured nanofiber membrane

• TGA: Thermogravimetric analysis

The individual files retain the sample names and characterisation-method identifiers used during the experiments. Where multiple measurements are provided, the corresponding sample name and testing condition are indicated in the relevant filename or worksheet.