fumapem® PFSA membrane types

PEM Fuel CellsPEM Water Electrolysis

Fuel cells in generalFuel cells technology is well-established but still modern technol-ogy, where electrochemical conversion of Hydrogen and Oxygen produces current and heat while water is emitted as the only com-pound leaving the system. Typical application is stationary one of power range less than 5 kW and automotive one of power range few kW for a fork-lifts to 100 kW for passenger’s cars. Both applications have different requirement on membrane in terms of conductivity and thickness. Since both systems are running typi-cally at temperature close to boiling point of water – stationary one under 90 °C, automotive one under 120 °C – they are often called LTPEM (Low-Temperature Proton-Exchanged-Membrane).

Membrane’s selection for LTPEMThe membrane for both fuel cells’ applications is based on a PFSA polymer that is available as long-side chain one (LSC) or short-side chain one (SSC). As for stationary one, so called long-side-chain PFSA is historically used since 1990’s. This kind of membrane produced by FUMATECH is named fumapem® F-940-RFS. It is comprehensively characterised by various electrochemical methods suggesting very good durability chemical- and mechanical-wise.

For those aiming on broad range of power density and relative humidity, short side chain PFSA material is proper off. The mem-brane fumapem® FS-930-RFS shows low resistance and particu-larly good ability to equalise short term fluctuation of humidity during the operation without performance being affected.

Both membranes F-940-RFS & FS-930-RFS have been tested under diverse stress conditions with excellent result with respect to estimated lifetime.Regarding automotive application, short-side-chain fumapem® FS-715-RFS is typically used. The 15-µm thin reinforced mem-brane is characterised by particularly low resistance and ability of self-humidification under dry conditions when high current density applies so the cathode-produced water contributes to increase of membrane’s conductivity. Considering the thickness the membrane displays very good mechanical properties and low hydrogen cross-over in broad range of conditions.

fumapem® PFSA membrane types

Perfluorosulfonic acid / PTFE copolymer is a standard type of proton-exchange material for fuel cell and water electrolysis application. The membranes feature high chemical and mechanical durability that can be further improved by applying of reinforcement in order to secure longevity and handling.

Dependency of membranes’ resistance under various humidity conditions

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- EIS measurement R(RC) model -> first cut on X-axis reflects the membrane's resistance - c.d. 0,4 A/cm2 - H2 (stoich 1,5) and air (stoich 2,0)

- ambient pressure

FS-715-RFS FS-930-RFS F-940-RFS

Overview of fuel cell fumapem® membranes

Membrane Thickness [µm] IEC [meq/g] Reinforcement Conductivity in- plane [mS/cm]

Young Modulus [MPa]

Preferred application

FS-715-RFS 15 1.40 Yes > 150 > 250 AutomotiveFS-930-RFS 30 1.15 Yes > 120 > 250 Autom./stat.F-940-RFS 40 1.04 Yes > 95 > 300 StationaryF-950 50 1.04 No > 95 > 350 StationaryF-10100 100 1.04 No > 95 > 400 MilitaryF-10120 120 1.04 No > 95 > 400 MilitaryFS-990-PK 95 1.15 Yes > 120 > 1,000 Military

Operation profile of stack built with F-940-RFS (project partner’s data, by courtesy of IRD Fuel cells, Denmark), T (stack) = 69 °C

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ABLF [10-cell PEM stack]MEA type: KeePEMAlive Membrane fumapem®F-940rfs

Fuel OxidantType: H2 AirStoichiometry: Dead-end 2.5Purge interval: 120 s NADew point: 58±3ºC c.55ºC

Polarisation curves of stack built with F-940-RFS (project partner’s data, by courtesy of IRD Fuel cells, Denmark), T (stack) = 69 °C

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BoL271 h @ 0.4 A/cm2525 h @ 0.4 A/cm2827 h @ 0.4 A/cm2915 h @ 0.4 A/cm21175 h @ 0.4 A/cm2

ABLF [10-cell PEM stack]MEA type: KeePEMAlive Membrane fumapem®F-940-RFS

Fuel OxidantType: H2 AirStoiciometry: Dead-end 2.5Purge interval: 120 s NADew point: 58±3ºC c.55ºC

Load cycling of F-940-RFS

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Load cycling protocol: 400 cycles OCV (30 min) - 0,4 A/cm2 (30 min) OCV (0) = 954 mV, OCV (400) = 915 mV Degradation @ 0,4 A/cm2: 200µV/cycle for 0-100 cycles; 28µV/cycle for 100-400 cycles

Dry OCV-hold test of fumapem® F-940-RFS at 85 °C. Hydrogen cross-over estimated by LSV measurement at 0,3 V as average from scan-up and scan-down curves.

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Membrane fumapem®F-940-RFSOCV-hold test:T(cell) = 65 °C, humidi�er at RT (about 23 °C, i.e. rh 5%)Stoich H2 1,5; stoich air 2,5Hydrogen cross-over at 190 hrs: 0,5 mA/cm 2

Period / hrs OCV loss in mV/hr45-65 2,5

65-135 0,3135-190 0,05

Dry OCV-hold

Some naval and aerospace application are utilising the PFSA fumapem® membranes in thickness 80 - 120 µm since high reliability is required. The system runs on pure Hydrogen and Oxygen and the fuel cell unit is operated at increased pressure on cathode side. Both LSC and SSC materials, either as plain or reinforced films meet the target values with respect power, dura-bility, pressure operation and very low hydrogen cross-over.

All fumapem® fuel cell’s membranes comply well with most com-mon membrane-electrode-assembly techniques, such as hot press-ing of membrane with GDE or transferring the electrode by decal method onto membrane’s surface or direct coating of membrane by catalytic ink.Selected properties of PEMFC membranes are summarised in the table below.

Water electrolysis in generalWater electrolysis carried out with CCM based on proton-exchanged membrane (PEM) represents recently the most advanced technology of Hydrogen production with respect to purity. By applying current, high purity water water is split to Oxygen and protons on anode. Protons migrate through proton-conductive membrane to cathode where they recombine with electron to Hydrogen. Because of possibility to work on cathode side at high backpressure and also at differential pressure, the PEMWE (Proton-Exchange-Membrane Water Electrolysis) matches the needs for compact decentralised Hydrogen produc-tion as key part of Hydrogen infrastructure. The cost of subse-quent compression can be thus partly saved since pressure on cathode up to 50 bar can be realised. Another advantage of the compact PEMWE station is offered by high throughput that takes only fraction of area, which is required by classic type of Hydrogen production such as alkaline electrolysis.

Membrane’s selection for PEMWEThe most commonly used membrane’s material is highly durable long-side chain PFSA polymer. In order to achieve expected longev-ity, using of a reinforced membrane is preferred. FUMATECH is the only company worldwide offering also reinforced short-side chain membrane. By selection of proper reinforcement mesh, membrane’s thickness 80-150 µm is realised. The choice of thickness depends mostly on what pressure difference between cathode and anode required is. The portfolio of PEMWE membranes include two thin-ner LSC-PFSA membranes fumasep® F-1075-PK and fumasep® F-10100-PK and one SSC-PFSA fumasep® FS-990-PK. The standard grade of reinforced 120µm-membrane is labelled fumasep® F-10120-PK and the membrane for high pressure operation 150 µm is available as fumasep® F-10150-PF.

Selected properties of PEMWE membranes are summarised in the table below.

Overview of water electrolysis fumasep® membranes

Membrane Thickness [µm] Reinforcement U @ 2A/cm2

@ 80 °C [V]HFR [Ohm.cm2]

@ 80 °CBreak-in period

[hrs]Max differential pressure [bar]

F-1075-PK 80 PEEK 1,71 120 < 1 5FS-990-PK 95 PEEK 1,71 123 < 0,1 10F-10100-PK 100 PEEK 1,79 145 < 1 10F-10120-PK 120 PEEK 1,83 162 < 1 15F-10150-PF 150 PFA 1,90 200 < 3 20

FuMA-Tech – functional membranes for fuel cells, batteries and electrolysisFUMATECH – functional membranes for fuel cells, batteries and electrolysis

FUMATECH draws its particular strengths as a leading producer of ion-exchange membranes from its membership in the BWT Best Water Technology Group.

FUMATECH is committed to develop new products that willaccelerate progress in polymer electrolyte fuel cells.

The company is both competent und competitive as a leading supplier of polymers and membranes for manufacturing of membrane electrode assemblies.

The high performance membranes are the heart of a protonexchange membrane (PEM) fuel cell stack.

FUMATECH produces and develops   polyelectrolytes (fumion® ionomers),   proton conductive membranes (fumapem® membranes) and   separation membranes (fumasep® membranes)

based on proprietary technology and designed for high precision mass manufacturing.

  fumion® ionomer resin as granular polymer, in solution form or in dispersion   fumion® FF granular perfluorosulfonyl fluoride resin for extrusion   fumapem® F perfluorosulfonic acid membranes for PEMFC   fumapem® AM polybenzimidazole membranes for high temperature PEMFC   fumapem® ST hydrocarbon membranes for DMFC and PEMFC   fumapem® P,E hydrocarbon membranes for DMFC   fumapem® FAA anion-exchange membrane for alkaline FC   fumasep® FAP anion-exchange membrane for redox flow batteries   fumasep® FBM bipolar membrane   fumasep® HF hollow fibre cartridge for gas humidification   fumasep® ion-exchange membranes for humidifier, electrodialysis and electrolysis   fumea® catalyst coated membranes for water electrolysis

The company

Focussing on water as the basis of all forms of life, and energy as the basis for a higher quality of life, FUMATECH “Functional Membranes and Plant Technology“ combines the important tasks of providing energy and water. The company is engaged in the field of fuel cell technology and membrane separation technology, particularly for the treatment of aqueous solutions.

For further information:For further information:

Dru

ck: 1

6041

2DK

www.fumatech.com

The Best Water Technology Group is Europe’s leading water technology company with 3,300 employees and a vast network of partner companies, service staff, installers, planners, archi-tects and hygiene experts. Our R&D teams apply state-of-the-art methods and use the latest processes and materials to create products that are both economical and green. One of the key objectives is to reduce the resource and energy consumption levels of our products, resulting in a reduction in CO2 emissions.

Practically everywhere where water is involved, BWT’s pioneering products have proved their worth millions of times over; where domestic water enters a building (‘point of entry’) and at its tapping point (‘point of use’), for the treatment of seawater, drinking water, mineral water, ultrapure water for pharmaceuticals, water for swimming pools, heating and process water, boiler water, cool-ing water and water for air-condi-tioning systems. Our numerous innovations enable our customers to

enjoy the highest levels of safety, hygiene and health in their daily use of water – the precious elixir of life. Among these are: SEPTRON®, the world’s first Electrodeionisation module (EDI) with spiral winding, the MDA (manganese oxide activation) method for effective removal of manganese, AQA total bipolar technology for chemical-free limescale protection, SANISAL – the world’s first regeneration salt for softening systems that also disinfects at the

same time, and the revolutionary new Mg2+ technology for better tasting filtered water, coffee and tea.

BWT, with its unique, high-performance membranes for fuel cells and batteries,

is setting the 21st century standard for the supply of clean energy.

BWT – For You and Planet Blue signifies our mission to take ecologi-cal, economic and social responsi-bility, and to provide our customers with the best products, systems, technologies and services in all areas of water treatment, while making a valuable contribution to

the preservation of our blue planet’s global resources.

BWT – The Company

BWT AktiengesellschaftWalter-Simmer-Straße 4A-5310 MondseeTel.: +43/6232/5011-0Fax: +43/6232/4058E-Mail: office@bwt-group.comwww.bwt-group.com

FUMATECH BWT GmbHCarl-Benz-Straße 4D-74321 Bietigheim-BissingenTel.: +49/7142/3737-900Fax: +49/7142/3737-999E-Mail: office@fumatech.com