New Breakthrough in Energy Storage – MIT Engineers Create Supercapacitor out of Ancient Materials::Constructed from cement, carbon black, and water, the device holds the potential to offer affordable and scalable energy storage for renewable energy sources. Two of humanity’s most ubiquitous historical materials, cement and carbon black (which resembles very fine charcoal), may form the basis for
A capacitor can’t ‘dump’ it’s energy any faster than tbe circuit attached to it can use it, as illustrated by Ohm’s law (ignoring the capacitor’s self discharge rate, which for a purpose like this can be kept very low).
With a low self discharge rate there’s also nothing brief about the length of time a capacitor can store energy. Think of it like a bucket with a small leak (self discharge rate). We’re adding water/energy to it each day (from solar panels or similar), and taking some out as needed. As long as the leak is small in comparison to the amount of water/energy being put in it’ll still be well topped up when you need it.
With regard to a crack, it sounds like that will just lead to a reduction in storage capacity to worst, if a chunk actually falls off. The carbon forms a branching network throughout the entire block, so just breaking some strands wont stop it being conductive. You’d definitely want to deplete it before working on it though, even a small cap can give you a nasty whack.