Tungsten in fast charging EV batteries, page-41

Here's another new use for our critical mineral - if this keeps up, the market will be fighting tooth and nail to secure supply

http://www.hydrogenfuelnews.com/hydrogen-fuel-cell-wo3-research/8561759/

Tungsten oxide gives hydrogen fuel cell electrodes a performance upgrade

November 24, 2023 0 By ERIN KILGORE

A group of researchers from POSTECH have made an innovative discovery.

Theresearchers are making headlines in the academic world for introducing atungsten oxide (WO3) coating to hydrogen fuel cell electrodes, which functionsas a shield for these electrodes, effectively enhancing their durability,performance and efficiency.

Overcoming the catalyst degradation challenge.

Thediscovery made by the group of researchers from POSTECH (Pohang University ofScience and Technology) could be welcome news for the hydrogen fuel cellvehicle market. The reason is that when hydrogen vehicles are started orsuddenly stopped, the vehicle takes in air from the outside. An unintendedelectrochemical reaction within the fuel cell is activated by the oxygen in this external air. This reaction accelerates the deterioration of the catalyst. Since the frequent starting and stopping of a vehicle is unavoidable, significant catalyst degradation occurs.

To overcomethis challenge, the research team harnessed the concept of metal-insulatortransition (MIT). Metal-insulator transition is a phenomenon in which aninsulator develops the capability of conducting electricity when exposed toexternal factors such as changes in the concentration or temperature of ambientgas.

Tungstenoxide can exploit the MIT phenomenon because it possesses the unique propertyof selectively conducting electricity as protons areintercalated/deintercalated. The researchers applied a coating of the tungstenoxide to a catalyst layer at the anode of the membrane-electrode assembly (MEA), a vital component of hydrogen fuel cells.

The coatingselectively obstructs current flow only during starting up and shutting downconditions, which stops electrochemical reactions that result in the corrosionof the catalyst.

A corrosion-free hydrogen fuel cell catalyst.

Theresearchers found that when the tungsten oxide-coated MEA was integrated intoan actual hydrogen fuel cell, the catalyst stayed free of corrosion duringstart-up and shut-down (SU/SD) events. This led to an incredible 94%performance retention rate.

Theresearch showed that the team’s tech enhanced the fuel cell’s durability whileat the same time delivering the advantage of integration into the existing mass production process for membrane-electrode assemblies.

Practical and readily applied.

“Thisinnovation will directly and significantly contribute to enhancing thedurability of commercial hydrogen fuel cell vehicles,” said one of the leadresearchers, Professor Yong-Tae Kim from the Department of Materials Scienceand Engineering and the Graduate Institute of Ferrous & Eco MaterialsTechnology.

“What’smore, it can be readily applied to mass production processes of MEAs,simplifying its practical implementation,” Kim said.