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Influence of the electrolyte on the electrochemical performance of a polyimide ...

The charge storage on organic polymers has led to increasing application of these new materials such as active electrodes in rechargeable batteries [1, 2]. Taking advantage of the redox properties of aromatic polyimide imide group [3], which allows it to be electrochemically oxidized and reduced reversibly, we will present the advances made on the electrochemical studies carried out with a polyimide derivative ...

Characterisation and performance studies of a LiFePO4 cathode material synthesi...

Lithium iron phosphate with incorporated carbon, LiFePO4-C, was synthesized by the microwave-assisted method. X-ray diffraction analyses showed higher crystallization degrees for samples submitted to higher irradiation times. A particle-agglomerated morphology was associated as revealed by scanning electron microscopy. The electrochemical character-istics of a composite cathode containing the synthesized produc...

The effect of chloride as catalyst layer contaminant on the degradation of PEMFCs

In this work, the effect of chloride as a catalyst contaminant was studied on the performance and durability of a low power open-cathode fuel cell, intended for passive management of water. In an ex-situ study, cyclic voltammetry was used to assess the redox behaviour of platinum in chloride contaminated solutions at room temperature.The cell was operated integrating a range of relative humidity (RH) from ~30 t...

Development of new organic electrod materials for organic electro-active recha...

Platinum instability in PEM fuel cells MEA’s subjected to chloride contamination

In this work a low power fuel cell, intended for passive management of water, was operated integrating a range of relative humidity (RH) from ~30 to 80% and temperatures from 5 to 55 ºC. The stack was fed with pure hydrogen. An open air cathode was designed for easy water removal and stack cooling. The stack uses own design flow field drawn on graphite plates from Schunk and a commercial MEA with carbon support...

Materials degradation mechanisms in an open cathode low power PEM Fuel Cell

In this work, a low power PEM fuel cell intended for passive management of water was operated integrating a range of relative humidity (RH) from 30 to 80% and temperatures from 5 to 55ºC. An open air cathode, provided with an excess air stoichiometry condition, was designed for easy water removal and stack cooling. The 4 cell stack was fed with pure hydrogen and uses own design flow field drawn on graphite plat...

PEM Fuel Cell performance at sub-zero temperatures

In this work a study of the performance of a low power fuel cell at sub-freezing temperatures has been undertaken. Knowledge in this area is still scarce. After global characterization of the stack on a wide range of temperatures and relative humidity’s the behaviour at negative temperatures (-5ºC -10ºC, -15ºC) has been established. Furthermore, performance was evaluated after the cell was submitted to cycles f...

PEM Fuel Cells: materials ageing and degradation

As fuel cell technology matures and time scale to commercialization decreases, the need for a more comprehensive knowledge of materials ageing mechanisms is essential to attain specified lifetime requirements for applications. In this work, the membrane-electrode assembly (MEA) degradation of an eight cell PEM low power stack was evaluated, during and after fuel cell ageing in extreme testing conditions. The st...

SPP: portable power technologies for the dismounted soldier

The project aims at the development of a portable power system as standard equipment for defence use, and is being developed by a Portuguese consortium leaded by SRE, a fuel cell developer, LNEG (Portuguese National Laboratory for Energy and Geology) and EID (Electronics and Telecommunications for Army) through a SRE/ Ministry of Defence contract. The system uses a SRE H2 PEM Fuel Cell and a Li battery buffer (...

Assessing performance and degradation in PEM Fuel Cells by electrochemical impe...