Breton Electrochemical Division

What is TiF?

TiF is titanium dioxide having anatse structure doped with fluorine atoms. It shows a polydisperse submicrometric grains structure

Fuel: H2 flow rate: 800 mL min-1  - Oxidant:  O2  flow rate: 500 mL min-1  - Temperature of reagents and cell: 85 °C.

Fuel cell tests evidence a higher maximum power density in both 100% RH and at lower RH values of reagents streams.
Nafion™ + 10% wt TiF at RH 25% shows up to 0.206 W cm-2  vs. 0.121 W cm-2  of pristine Nafion™

TiF, is a novel fluorine-doped metal oxide patented by Breton.

We used TiF as compounding material in a series of hybrid inorganic-organic proton-polymer electrolytes, to be used for novel fuel cell applications. Procedure involves the dispersion of a sub-micrometric powder of TiF in a Nafion host polymer. The resulting Nafion/TiF membranes include up to 10% or 15% wt. of inorganic filler.

TiF forms dynamic crosslinks with the polymer matrix, witnessed to marked improvements in mechanical properties of the hybrid membranes, in comparison with the pristine Nafion. Remarkably, good mechanical properties are shown even at temperatures up to 200 °C, paving the use of this hybrid material for high-temperatures applications.

In agreement with this model, experiments carried out on test cells assembled with these novel hybrid membranes showed a remarkable power density equal to 0.625 W cm-2, vs. 0.429 W cm-2 of the bare Nafion membrane reference.

At lower relative humidity of about 25%, it is measured a maximum power density equal to 0.206 W cm-2, vs. 0.121 W cm-2 of the reference. Given these results, Nafion/TiF materials are indeed promising candidates for the development of proton-conducting membranes, for application in fuel cells operating with reduced hydration and at a higher temperature, in comparison with the state-of-the-art materials.