The voltage seems key here. From the article: > they fabricated button-size capacitors capable of holding 1 volt ... As the next step, Ulm says the team is now

The voltage seems key here. From the article: > they fabricated button-size capacitors capable of holding 1 volt ... As the next step, Ulm says the team is now focused on developing a 12-V supercapacitor using these materials. If I remember my physics correctly, charge is proportional to voltage, so if they can achieve 12 volts max voltage, shouldn't it result in 12X energy density? If so, that would reduce the required volume (for 10 kilowatt-hours of storage) from 45 to 3.75 cubic meters. Apparently concrete slab foundations are typically 4-6 inches (10-15 cm) thick[1], so in a single-story 1000 square foot (92 m^2) house, the volume of the foundation would be 9.4 to 14.1 cubic meters. Which means you could store around 25 to 35 kilowatt-hours in that foundation. So it seems like it's in the right ballpark for what they're aiming for. EDIT: Another article[2] says this: > Having proved the principle, they now plan to build a series of larger versions, starting with ones about the size of a typical 12-volt car battery, then working up to a 45-cubic-meter version to demonstrate its ability to store a house-worth of power. Given the main article is not very technical, and both articles mention 12 volts but in different ways, I'm now less sure what the researchers are aiming to do. Maybe they are trying to improve the max voltage of this type of capacitor or maybe not. --- [1] https://wilsonexteriors.com/a-comprehensive-guide-to-concrete-slab-thickness-for-residential-projects/ https://wilsonexteriors.com/a-comprehensive-guide-to-concret... [2] https://news.mit.edu/2023/mit-engineers-create-supercapacitor-ancient-materials-0731 https://news.mit.edu/2023/mit-engineers-create-supercapacito...