(Photos: D.Michon/Artechnique-CEA)

MEAs

Aiming at reducing the cost of fuel cells, PaxiTech develops, produces and commercialises the principal fuel cell component, a MEA. It consists of a polymer membrane sandwiched between an anode where the oxidation of hydrogen takes place, and a cathode, where the reduction of oxygen takes place. The production techniques developed and optimised were chosen for their simplicity and their relative facility for a future transfer to an industrial production process. These techniques are based on ink deposition by pulverisation (spray method) or by coating on either fibres or polymer materials and present many advantages including their low cost and superior electrochemical performances.

These components can be used for all fuel cells indifferent of their power range or their application. Their size varie from a few cm² to a few hundred of cm² and the number of cells that can be stacked from tens to hundred. For example, a fuel cell stack for an electric vehicle delivers between 50 and 70kW could consist of up to 250 cells of 400cm². The composition of the MEAs varies depending on the specifications of the fuel cell running conditions :

nature of fuel (pur hydrogen or reformate)
nature of oxidant ( pure oxygen or air)
maximum temperature (from ambient to 100°C)
reactants pressure
...

The different components of the MEAs must possess coherent mechanical properties. Thus one of the development projects at PaxiTech aims at studying different materials and their assembly in order to comfirme their mechanical and electrical properties, so as to obtain the optimum electrochemical performances.

This activity "components" consists of transforming and assembling the raw materials (polymers, catalysers, carbon materials) into an Electrode/Membrane Assembly, in accordance with the specifications defined by the integrator. These components are divided into a few categories :

Basic components (gaskets, diffusion layers)
MEAs adapted to integrator's specifications :

3 layers : electrolyte + catalytic layers
5 layers : 3 layers + diffusion layers
5 layers + subgasket
7 layers : 5 layers + gaskets

These products are of interest to PEMFC producers and fuel cells users in all applications fields (space, residential, transport, portable).

Examples of polarisation curves obtainde under different experimental conditions are shown on the page MEAs performance.