Hydrogen fuel cells have found their groove

Thursday, June 22nd, 2023

Hydrogen fuel cells have found their groove, IEEE Spectrum reports:

Now scientists have found that adding grooves to PEM fuel cells can improve the performance of these devices by up to 50 percent compared with state-of-the-art conventional electrodes under standard operating conditions.

[…]

Conventional PEM fuel cell electrodes are composed of a carbon-supported platinum catalyst and ion-conducting polymers known as ionomers, which are mixed in an ink slurry and deposited on a membrane or other structure as a porous electrode. This creates a random electrode structure with a complex, mazelike network of narrow pores that limits the flow within the fuel cell. This structure has largely stayed the same for more than 30 years, the researchers note.

In contrast, the new electrodes feature catalyst ridges loaded with ionomers separated by empty grooves. The ridges improve proton transport, while the grooves simultaneously help oxygen flow.

In conventional PEM fuel cell electrodes, a high ionomer content may enhance proton transport, but it typically also limits oxygen flow. By separating proton and oxygen flow along grooves and ridges, the new electrodes help improve the transport of both. This also helps keep reaction rates uniform in the fuel cell, boosting catalyst performance.

The scientists fabricated the new electrodes by depositing a mixture of carbon-supported platinum catalyst and ionomer in a patterned silicon template, followed by a transfer to a membrane made of the common polymer electrolyte known as Nafion. They experimented with electrodes with grooves 1 to 2 micrometers wide, and had grooves repeat across the electrodes every 3 to 6 µm. The narrower the grooves and the shorter the distances between them, the better the performance.

[…]

The best-performing grooved electrodes were also significantly more durable than regular electrodes, displaying 170 percent higher current density after 500 cycles of activity. The researchers note that pores in conventional electrodes collapse over time due to corrosion, hampering their performance. By contrast, the grooved electrode structures remained relatively intact.

Comments

  1. Bruce says:

    Terraform Industries @TerraformIndies

    ‘We will produce $1/kg green hydrogen from which to synthesize natural gas. There are a couple of necessary preconditions.

    1) Electricity <$10/MWh. There is no other way, the math dictates cheap energy needs cheap energy.

    2) Electrolyzer <$100/kW for speedy ROI.'

    Terraform Industries looks liked a better bet to me.

  2. Bob Sykes says:

    Besides the problem of cheap electricity, there is the problem of storing and transporting hydrogen. Embrittlement of steel is the issue there. Embrittlement is compounded by the need to store hydrogen at extremely high pressures, because otherwise the energy density (J/m^3) is way too low.

    A modern economy requires fossil fuels. We will have such an economy only as long as fossil fuels last, probably a thousand years or so at current rates of consumption.

    The climate lunatics will not only shut down industry, they will also shut down modern agriculture. That will lead to massive population decline and the return of some form of slavery. Every pre-industrial society, including hunter-gatherers, was a slave society — no exceptions.

  3. Gavin Longmuir says:

    “A modern economy requires fossil fuels. We will have such an economy only as long as fossil fuels last …”

    Technically, our economy (especially construction and transport) requires liquid hydrocarbon fuels. At the moment, the most economic way of providing those fuels is directly from fossil fuels. However, once nuclear fission is properly restarted (see, for example, China’s massive build out of nuclear power), it will be possible to manufacture liquid hydrocarbon fuels as required.

    The “greenie” suicide of the West from rejecting both fossil fuels and nuclear fission is optional. Other societies will make better choices — and will survive & prosper.

Leave a Reply