400 cycles doesn't cut it we need 10,000. For stationary applications it would be like building a brick wall out of marshmallows ie not durable enough. For portable applications it would need to be light under 1 kg per litre of volume. For grid storage it would ideally need to be cheap say $50 per Mwh levelised cost.

While batteries might eventually compete on price with gas turbines for grid backup at say $200-$250 per Mwh they go flat after a couple of hours while the turbines keep going. That's why they need to be long lived, energy dense and cheap. At the user premises or home coupled with solar panels they may be cost competitive as they eliminate the middle man. It looks like we'll have to learn to recycle lithium batteries.

Anyone have any thoughts on super conductors? I have believed in them for years. I don't know how the research/development is going but I want to believe that if more research went into them we might end up with a more viable product (than batteries) which would tick all the boxes. Any thoughts? Anyone?

Oh dear!

The vapourware experts and flim-flam sales folk will be onto this Great New Thing (GNT®) before the ink's dry on the page. And before reading the caveat about 5+ years.

Singleton engineer, I'm a technical person and a little retarded in the world of jokes and sarcasm, so I'm not sure what you mean, nor who you are targeting your response at. Would it be droll of me to ask you to elaborate in a more direct way?