Membrane electrode assembly

Membrane electrode assembly

A membrane electrode assembly (MEA) is an assembled stack of proton exchange membranes (PEMs) or alkali anion exchange membrane (AAEMs), catalyst and flat plate electrode used in a fuel cell[1].

Contents

PEM-MEA

The PEM is sandwiched between two electrodes which have the catalyst embedded in them. The electrodes are electrically insulated from each other by the PEM. These two electrodes make up the anode and cathode respectively.

The PEM is a proton permeable but electrical insulator barrier. This barrier allows the transport of the protons from the anode to the cathode through the membrane but forces the electrons to travel around a conductive path to the cathode. Companies such as DuPont, Dow and E-TEK produce PEMs. DuPont's PEM offering can be found under the trade name Nafion. The most commonly used Nafion PEMs are Nafion 112[2], 115, 117, and 105.

The electrodes are heat pressed onto the PEM. Commonly used materials for these electrodes are carbon cloth or Toray carbon fiber paper [3]. E-TEK produce a carbon cloth called ELAT which maximizes gas transport to the PEM as well as moves water vapor away from the PEM. Imbedding ELAT with Noble metal catalyst allows this carbon cloth to also act as the electrode.

Complete MEAs are made by several companies, including PEMEAS (now a division of BASF Fuel Cell). Many of these companies specialize in high volume products. There are companies which produce custom or low quantity MEAs, allowing different shapes, catalysts or membranes to be evaluated[citation needed]. There are hands-on workshops focused on preparation and evaluation of membrane electrode assemblies as well as fuel cell testing[4].

Platinum is one of the most commonly used catalysts, however other platinum group metals are also used. Ruthenium and platinum are often used together, if CO is a product of the electro chemical reaction as CO poisons the PEM and impacts the efficiency of the fuel cell. Due to the high cost of these and other similar materials, research is being undertaken to develop catalysts that use lower cost materials as the high costs are still a hindering factor in the wide spread economical acceptance of fuel cell technology.

Current service life is 7,300 hours under cycling conditions, while at the same time reducing platinum group metal loading to 0.2 mg/cm2.[5]

Research

  • 2009 - Research is ongoing at the Fuel Cell Research Center, Korea Institute of Energy Research to enhance the performance of the MEA.[6]
  • 2009 - EMSL/PNNL-Functionalized graphene sheets with a Pt layer [7]

See also

References

External links


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Membrane échangeuse de protons — Une membrane échangeuse de protons ou membrane à électrolyte polymère (PEM) est une membrane semi perméable fabriquée à partir d’ionomères permettant la conduction protonique tout en étant imperméable aux gaz tels que le dioxygène ou le… …   Wikipédia en Français

  • Electrode — For other uses, see Electrode (disambiguation). Electrodes used in arc welding An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte or a …   Wikipedia

  • Proton exchange membrane fuel cell — Diagram of a PEM fuel cell Proton exchange membrane fuel cells, also known as polymer electrolyte membrane (PEM) fuel cells (PEMFC), are a type of fuel cell being developed for transport applications as well as for stationary fuel cell… …   Wikipedia

  • Proton exchange membrane — A proton exchange membrane or polymer electrolyte membrane (PEM) is a semipermeable membrane generally made from ionomers and designed to conduct protons while being impermeable to gases such as oxygen or hydrogen.cite web… …   Wikipedia

  • Artificial membrane — An artificial membrane, also called a synthetic membrane, is a membrane prepared for separation tasks in laboratory and industry. Its active part, which permits selective transport of material, usually consists of polymers or ceramics, seldom… …   Wikipedia

  • MEA — Membrane Electrode Assembly (Medical » Human Genome) ** Maine Educational Assessment (Community » Educational) ** Multilateral Environmental Agreement (Governmental » US Government) * Mead Corporation (Business » NYSE Symbols) * Minimum Enroute… …   Abbreviations dictionary

  • Glossary of fuel cell terms — The Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to name but …   Wikipedia

  • Fuel cell — For other uses, see Fuel cell (disambiguation). Demonstration model of a direct methanol fuel cell. The actual fuel cell stack is the layered cube shape in the center of the image A fuel cell is a device that converts the chemical energy from a… …   Wikipedia

  • Electroosmotic pump — An electroosmotic pump (EOP), or EO pump, is used for removing liquid flooding water from channels and gas diffusion layers and direct hydration of the proton exchange membrane in the membrane electrode assembly (MEA) of the proton exchange… …   Wikipedia

  • Pila de combustible — Saltar a navegación, búsqueda Pila de hidrógeno. La celda en sí es la estructura cúbica del centro de la imagen. Una pila de combustible, también llamada célula o celda de combustible es un dispositivo electroquímico de conversión de energía… …   Wikipedia Español

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”