Modified Bricks Can House Energy, Too

What if building an emergency battery were as easy as painting conductive plastic onto bricks, stacking them, and charging them up? Researchers at Washington University in St. Louis have done just that — they’ve created supercapacitors by modifying regular old red bricks from various big-box hardware stores.

The bricks are coated in poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), a conductive polymer that soaks readily into the bricks’ porous surface. When the coated brick is connected to a power source such as a solar panel, the polymer soaks up ions like a sponge. PEDOT:PSS reacts with the iron oxide in the bricks, the rust that gives them their reddish-orange color. Check out the demonstration after the break — it’s a time lapse that shows three PEDOT-coated bricks powering a white LED for ten minutes.

We envision a future where a brick house could double as a battery backup when the power goes out. The researchers thought of that too, or at least had their eye on the outdoors. They waterproofed the PEDOT-coated bricks in epoxy and found they retain 90% of their capacitance and are still efficient after 10,000 charge-discharge cycles. Since this doesn’t take any special kind of brick, it seems to us that any sufficiently porous material would work as long as iron oxide is also present for the reaction. What do you think?

If you can get your hands on the stuff, PEDOT:PSS has all kinds of uses from paper-thin conductors to homebrew organic LEDs.

Thanks for the tip, [Qes]!

43 thoughts on “Modified Bricks Can House Energy, Too

  1. Let’s say this white LED is getting 3V, which needs a current of 20mA. It’s powered for 10 minutes, from 6 bricks. So. To get to mAh we need to do 20mA * (10min/60min) = 3.33mAh of stored power. Just ignoring a few things for simplicity, but that’s really nothing.

    Quick google says that a small house is 8000 bricks. Which stores then as much energy as a few AA batteries.

    1. The heat energy stored in bricks even the night after a sunny day would be much higher.

      I imagine if the bricks could be coated with a material that can turn “black” or “white” in the IR field (black during the day, white during the night) and then some way to harvest this energy (water lines? Peltier elements?) one can store way more energy this way.

      Firebricks are used for centuries as heat storage near blast furnaces in the form of Cowper stoves, see

        1. When the outside it’s cold and your house is warm you definitely don’t want a black roof if you are trying to conserve heat!
          You’d want the colour change to happen based on incoming radiation, not air temperature.

          1. The Painted surfaces temperature will be related to the radiated energy its absorbing – ambient temps and its surface area will skew but not make thermal triggers invalid. Unless you keep your house stupidly warm no matter how long you wait it won’t be a sufficient heat soak to push the roof to transition – especially on the cold day as those days what heat makes it to the roof is lost more easily to the atmosphere thanks to the greater differential.

    2. I didn’t see anywhere where the researchers are claiming this is ready for the market but you critique it as if it were. The researchers themselves have aknowlegend that there is plently of work to do before it’s a viable technology and have already outline areas where they can start making improvments. Was your comment just to show that you know ohms law?

      I swear, if Hackaday exisisted back when the first carbon filament was used to generate a light source you’d get comments like this decrying how useless it is because of it’s short life span.

      1. You did get exactly those comments back then, from the other gentile scientist types. Just because we now have a community that spans the globe, with much faster comminations and a larger range of backgrounds doesn’t change that people behave like people with many naysayers and constructive criticism armchair contributions- and they do have a very valid point this is a ridiculously poor battery – which is something its important to make clear. Unless you want to end up with the political type morons throwing money into this project because its got good press despite the fact its nowhere near ready and may never be (solar roads??).

        In the building trade I’d say the house insulation is the obvious way to add some free energy stores – you already have sheets of foil on the insulation – just add a few extra layers and you have massive sheet capacitors. (still not sure its a good idea but its out of the elements so should be safer from chemical and physical damage.)

      1. They’re hoping to increase that, maybe by adding more iron to bricks. I suspect that might affect their price and structural properties?

        Interesting as this is, it seems unlikely to ever be anywhere near as efficient For the investment as solar hot water, or even solar PV. Or even cavity wall insulation.

    1. The whole point of a peer review is to identify ways that the paper can be improved, not as a simple binary “good/not good” gate. The quantity of issues raised is not directly indicative of the quality or novelty of the research, just how it’s presented. It’s only how the issues are addressed that is important.

      1. Agreed. This also appears to be at least partly in the realm of basic research rather than applied research. Clearly it is not a practical way to generate electricity, and it may remain impractical. But it has extended our knowledge, which is the point of basic research.

        Zone refining as a method of purification worked but had few real uses when it was developed (after all, apart from a few chemists, who needs 99.999% pure *anything*?). But without that work we would not have the electronic devices that we are all using right now.

  2. Just adding in here that pedot:pss is very, very expensive, in the $100 range for a few cl. Also its effectiveness is fairly short lived, I’ve built OLEDs using it, they usually stop working in the range of one hour to one week, they can be made to last longer with more complex processes.

  3. Coating all my bricks in epoxy doesn’t seem like a great plan – either environmentally (that’s a lot of epoxy), for durability – whilst epoxy is tough, bricks do take damage and weather over time – or breathability of a building (I understand bricks are intended to breath a bit to allow moisture out of cavities?)

    1. Absolutely, the ability to breathe is important if you don’t want your house to be rotting from the inside out. Another concern is the thermal expansion and contraction cycle a brick house goes through during the day.

  4. PDOT is a early inefficient fuel cell PEM material. It did get into orbit and the Moon on Gemini and Apollo. If you want to try this and see if it works you can easily make it at home with a bit of acetone, some battery acid and a few styrofoam cups as you monomer “doner” lol. You get a bit better ionic transfer with fresh styrene but not by that much. Interesting concept tho.

  5. Im wondering how much R&D budget went into making an energy storage device with less power density than the lemon and salt experiment I did in fourth grade science class.

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