for an engineering class I had to create an electrical energy storage device and I began thinking about thunderstorms (I think it was a cloudy day) and how they create lighting. I know it's not feasible, but would it be possible to store a charge in water vapor (maybe like a capacitor). Could that water vapor then be stored in a container and be discharged whenever you connect the container (I am thinking like a metal lead coming out of a soda bottle) to a ground? The thought of a thunderstorm in a bottle seems like a very dangerous but cool idea (not that I would use it for my project, I was just wondering if this would be possible).
A "bottle capacitor" is called a Leyden Jar. The original one was full of wine, and held in a damp human hand. The wine is one capacitor-plate, the hand is the other.
Thunderstorms themselves are storing charge on their raindrops. Not on vapor.
That way, if all the raindrops get charged the same, they can't zoom rapidly outwards from repulsion (because they're large heavy objects, not tiny molecules.)
And, if they did start repelling outwards, well, the region of falling rain might be a half-mile wide. The drops won't be repelled apart significantly, compared to a half mile.
Inside a tiny bottle, any charged droplets (or vapors) will repel outwards within about a second or two. They end up stuck against the glass. You'll have a charged bottle surface, with neutral gas inside.
What solves this problem? CAPACITORS! If you put any region of negative charge right next to a region of positive charge, then insert a barrier so they cannot attract together and cancel ...then you can store some electrical energy (stored in the barrier, stored in the strong e-fields between the two.)
Thunderstorms do this by having positive charge on small droplets, and negative charge on larger drops, then letting the positive droplets lag behind as they're falling. Gravity and air friction acts as the "virtual barrier" between the two regions of falling, opposite-charged drops.
Thoughts on storing electricity in water vapor
If that read storing electrical energy in water vapor, it would have been a viable concept. Because vapor of a few hundred degrees Celsius can store tremendous amounts of energy. It's also cheap and reasonably safe, and easy to turn back into electricity. The technology already exists, too.