Hmm...

Intriguing idea!

Here are some of my thoughts:

Lithium Ion is kind of dangerous/expensive, at least for a proof-of-concept design. Perhaps NiMH or NiCad could be used instead? Not only are they somewhat safer (I think?), but also I believe they don't require fancy charging circuitry, which would greatly simplify it. Once the basic design is set up and you know it works, you can add on more "bells-and-whistles".

The CRT requires some high voltages. I kind of want to know exactly how many volts it requires, how is it derived from 12V, and how much current it draws?

Aside from that, I don't see why it wouldn't work.

Let's see what the "experts" think...

c