Oxygen transport across the cathode gas diffusion layer (GDL) in polymer electrolyte membrane (PEM) fuel cells was examined by varying the O2/N2 ratio and by varying the area of the GDL extending laterally from the gas flow channel under the bipolar plate (under the land). As the cathode is depleted of oxygen, the current density becomes limited by oxygen transport across the GDL. Oxygen deplet...

The development of the robot EcoBot II, which exhibits some partial form of energetic autonomy, is reported. Microbial Fuel Cells were used as the onboard self-sustaining power supply, which incorporated bacterial cultures from sewage sludge and employed oxygen from free air for oxidation in the cathode. This robot was able to perform phototaxis, temperature sensing and wireless transmission of...

We report the results of experiments in which CR-39 plastic particle-detection chips were exposed in various environments within and surrounding operating electrolysis cells. Because CR-39 detectors record only particles with energies in excess of about 0.2 MeV the detected particles must have arisen in nuclear reactions. Evidence for such reactions was found in deuterium gas behind a palladium...

The electrochemical performance and electrode reaction using AuePd nanoparticle (NP) supported mesoporous b-MnO2 as a cathode catalyst for rechargeable Lithium-Air (Li-Air) battery is reported here for the first time. In this study, AuePd NP-supported mesoporous b-MnO2 was successfully synthesized by hydrothermal process using a silica KIT-6 template. It has an initial discharge capacity of ca....

Microbial fuel cells (MFC) with 30% wet-proofed air cathodes have previously been optimized to have 4 diffusion layers (DLs) in order to limit oxygen transfer into the anode chamber and optimize performance. Newer MFC designs that allow close electrode spacing have a separator that can also reduce oxygen transfer into the anode chamber, and there are many types of carbon wet-proofed materials a...

Much effort has been devoted to the synthesis of novel nanostructured MnO2 materials because of their unique properties and potential applications as cathode catalyst in Microbial fuel cell. Hybrid MnO2 nanostructures were fabricated by a simple hydrothermal method in this study. Their crystal structures, morphology, and electrochemical characters were carried out by FESEM, N2-adsorption-desorp...

To efficiently generate electricity using bacteria in microbial fuel cells (MFCs), highly conductive noncorrosive materials are needed that have a high specific surface area (surface area per volume) and an open structure to avoid biofouling. Graphite brush anodes, consisting of graphite fibers wound around a conductive, but noncorrosive metal core, were examined for power production in cube (C...

Maximum power densities by air-driven microbial fuel cells (MFCs) are considerably influenced by cathode performance. We show here that application of successive polytetrafluoroethylene (PTFE) layers (DLs), on a carbon/PTFE base layer, to the air-side of the cathode in a single chamber MFC significantly improved coulombic efficiencies (CEs), maximum power densities, and reduced water loss (thro...

in this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (gdl) of pem fuel cell is modeled. the governing equations including energy, mass and momentum conservation equations are solved by numerical methods. also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (gdl) thickness and inlet relative humidity are calculated...

Microbial fuel cells (MFCs) represent a promising technology for simultaneous bioelectricity generation and wastewater treatment. Catalysts are significant portions of the cost of microbial fuel cell cathodes. Many materials have been tested as aqueous cathodes, but air-cathodes are needed to avoid energy demands for water aeration. The sluggish oxygen reduction reaction (ORR) rate at air catho...