“You have these at least two millennia old materials (carbon black and cement) that, when you combine them in a specific manner, you come up with a conductive nanocomposite, and that’s when things get really interesting.”, he says.”
Well, the best place to start is to remember that we’re literally talking about something foundational. The foundation of a home, the foundation of a wind turbine, the foundation of a highway. If all of these things which were formerly structural are now sources of energy storage, well, that changes things.
My concern is the application.
When capacitors fail they go with a bang. Old style televisions were notorious for this kind of failure, the loud bang which preceded the magic smoke was usually caused by capacitors suffering catastrophic dielectric failure, and releasing all their stored energy in a fraction of a second.
What concerns me is, if a TV capacitor explodes, abruptly releasing a few joules of energy, you spill your beer and curse a bit. But if a 10KWh household super capacitor goes, that’s 36 million joules of energy – equivalent to 8.6Kg of TNT, enough to turn your house into a sizeable crater.
10KW (10,000 watt hours) x 3600 seconds in an hour = 36,000,000 joules of energy
36,000,000 joules / 4,184 joules / gram = 8,604g = 8.6Kg of TNT
Even more interesting, brittle materials like concrete are vulnerable to mechanical shock. So that 8.6Kg of TNT equivalent, enough to utterly destroy a normal house, could trigger a chain reaction of adjacent dielectric failures, resulting in thousands or even millions of houses abruptly releasing their stored energy. And that’s not even considering the energy storage requirements of even greater concentrations of energy, like high-rise apartments and office buildings.