Nanofiber-Based Gas Diffusion Layer for Improve Performance in Air-Cathode Microbial Fuel Cells

Abstract

This work investigates a new nanostructured gas-diffusion-layer (nano-GDL) to improve performance of air-cathode Single-Chamber-Microbial-Fuel-Cells (a-SCMFCs). The new nano-GDLs improves the direct oxygen-reduction-reaction by exploiting the best of nanofibers from electrospinning in terms of high surface ratio to volume and high porosity, and laser-based processing to promote adhesion. Nano-GDLs by electrospinning were fabricated directly collecting two nanofibers mats on the same carbon-based electrode, acting as the substrate. Each layer was designed with a specific function: water resistant, oxygen permeable polyvinylidene-difluoride (PVDF) nanofibers served as a barrier to prevent water-based electrolyte leakage, while an inner layer of cellulose nanofibers was added to promote oxygen diffusion towards the catalytic sites. The maximum current density obtained for a-SCMFCs with the new nano-GDLs is (132.2 ± 10.8) mA m⁻², and it doubles the current density obtained with standard PTFE-based GDL (58.5 ± 2.4 mA m⁻²), used as reference material. The energy recovery (EF) factor, i.e. the ratio of the power output to the inner volume of the device, was then used to evaluate the overall performance of a-SCMFCs. a-SCMFCs with nano-GDL provided an EF value of 60.83 mJ m⁻³: one order of magnitude higher than the value of 3.92 mJ m⁻³ obtained with standard GDL

Key findings

• ▸The maximum current density obtained for a-SCMFCs with the new nano-GDLs is (132.2 ± 10.8) mA m⁻², doubling the current density obtained with standard PTFE-based GDL.
• ▸The energy recovery (EF) factor is not specified in the abstract, but is mentioned as a relevant metric.
• ▸The new nano-GDLs improve the direct oxygen-reduction-reaction by promoting adhesion and exploiting the high surface ratio to volume and high porosity of nanofibers.

Keywords

Identifiers

DOI

10.20944/preprints202309.1274.v2

Journal

Preprints.org

Year

2023