Microwave Water Splitting for Breakthroughs for Making Hydrogen, Oxygen and Fast Battery Charging

Researchers from the Polytechnic University of Valencia and the Spanish National Research Council (CSIC) report contactless H2 production via water electrolysis mediated by the microwave-triggered redox activation of solid-state ionic materials at low temperatures (less than 250 °C).

This will simplify and significantly cheapen the process for hydrogen production.

Water was reduced via reaction with non-equilibrium gadolinium-doped CeO2 that was previously in situ electrochemically deoxygenated by the sole application of microwaves. The microwave-driven reduction was identified by an instantaneous electrical conductivity rise and O2 release. This process was cyclable, whereas H2 yield and energy efficiency were material- and power-dependent. Deoxygenation of low-energy molecules (H2O or CO2) led to the formation of energy carriers and enabled CH4 production when integrated with a Sabatier reactor. This method could be extended to other reactions such as intensified hydrocarbons synthesis or oxidation.

Ultra-fast Charging of Batteries and Space Exploration Applications

The technology could also be applied for ultra-fast charging of batteries. It could enable a practically instantaneous decrease in the size of the electrode (metallic anode) that stores energy. We would go from a layer-based progressive charging process, which can take hours, to a simultaneous process in the entire electrolyte, which would make it possible to charge a battery in a few seconds,” says José Manuel Catalá.

Another use would be the direct generation of oxygen with microwaves, which opens a broad spectrum of new uses. This could enable direct production of oxygen with extra-terrestrial rocks which would be huge for enabling the colonization of the Moon, Mars or other rock bodies of the solar system.

A Short History of the Discovery

Ionic materials that were treated with microwaves showed unusual changes in their properties, especially their electronic conductivity. This did not happen when they were heated conventionally.

Microwaves interact with these materials by accelerating the electrons and giving way to the release of molecules of oxygen from their structure (which is also called reduction). This change manifested itself specifically with sudden alterations to the conductivity at relatively low temperatures (approximately 300ºC).

Nature Energy – Hydrogen production via microwave-induced water splitting at low temperature

SOURCES- Nature Energy, R&I World
Written By Brian Wang, Nextbigfuture.com

12 thoughts on “Microwave Water Splitting for Breakthroughs for Making Hydrogen, Oxygen and Fast Battery Charging”

  1. Hello Jim, I believe that charging the battery system at a higher voltage would accomplish the goal and reconfigure the battery for lower voltage and higher current when being used might resolve the issues. The Charging of the system is always susceptible to i^2R power losses , so higher voltage lowers the heating of the power connection. We should always assume based on my experience that 600 amps is the magic common number for maximum current of the charging system and we can vary the voltage value to achieve maximum charge rate at minimum cost of the infrastructure. we just need to solid state switch the battery configuration to allow higher voltage charging and lower voltage higher current operations.

  2. If you can charge fast, and can do so frequently (like a shuttle bus), then you can use smaller batteries, which saves a lot of money.

  3. Ultrafast charging implies:
    – you'll pay for the speed because your time is valuable.
    – the thing being charged is valuable and having a higher utilisation rate by being charged faster makes the cost of faster charging economic.
    There's always applications that will want it. Yes not everything justifies it, but the trend is towards faster.

    And it is also a question of scale. A phone that mostly charges in 1 minute instead of 30 is attractive to plenty people
    An electric ferry boat that has a short turnaround time can do extra journeys in a day and transfer more people and cargo, for just the electricity cost and slight wear. A shore-based battery bank to provide the energy when needed would avoid oversized grid connections.

  4. You are missing my point about the generators & wires being used only *part* of the time, thus making them uneconomic.

  5. Thanks! Figure 5d looks like it’s in the range from 50-80 kWh/kg, which is a little worse than current electrolysis systems, but not by much.

  6. High capacity generators feeding high capacity lines works if all they do is feed charging stations. This is actually the replacement for gas stations.

  7. This still leaves the other problem with ultrafast battery charging. You need high capacity wires to bring the electricity to the battery & high capacity generators to make the electricity. Those high capacity generators & wires then get used only a small fraction of the time which makes the whole thing uneconomic.

    Set things up so batteries are charged at a modest rate & swapped out for discharged batteries when a BEV comes in with discharged batteries

  8. Making H, fuel cells to make electricity from it, and solar cells are all improving, all can be further improved. The future of Space Solar is bright! Wonder if the power beam micros will do this trick directly as they come down from the sky? edit, this produces, with microwaves, an O absorbing sponge that has many uses, not just releasing H from water. It is done without large contact areas, so very practical sort of efficiency.

  9. They say it's "efficient", but don't say how much energy it needs. Wikipedia says the best systems for electrolysis of water to produce hydrogen use 50 kWh/kg, with a theoretical limit of 39.4 kWh/kg. So is this microwave system better than 50? Or is it worse? How much worse?

    I'm also curious whether it produces the O2 and H2 separated, or does it produce them mixed. The nice thing about electrolysis with electrodes is that the two gasses are separated. I wonder if this system without electrodes can do the same.

    It looks like this is the paper, but it's behind a paywall, and the abstract just says "efficient" without giving the minor detail of the actual number. The article here says it "significantly cheapens" hydrogen production. But without the minor detail of any numbers for that, either.

    https://www.nature.com/articles/s41560-020-00720-6

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