Batteries contain electricity. Electricity contains well energy, and with a lot of energy comes the power to explode, sorry, you cannot (at this time) use a "fire proof" battery, you are sort of misunderstanding the purpose of batteries which is to store and discharge electrons or whatever electricity is made of, and I have a feeling that I am demonstrating only a slightly higher understanding of batteries than yourself, what I am trying to say is that it is really hard to be dealing with stored energy and wattage and all that stuff without the possibility of fire.
I mean, you could go vape one in the rain I guess, but that wouldn't make it fireproof.
You could also rig up a stationary bike to collect your kinesthetic energy and transfer it to your vape, potentially without the use of a battery for storage, but I don't know how much fun that would be.
And, despite being a battery idiot myself, I do know sort of the RIGHT stuff which is how to obtain, use, and store batteries as safely as possible, which is actually what you WANT to know and here are a few blogs that may get you there even if you are NOT a journeyman electrician, and they helped me, and I just demonstrated that I am a battery and electrical idiot, so cheer up if I can do it, you can too. Mostly mechs, protections in regulated mods can and do fail.
Also, I checked and my phone is like OVER five years old, so while the battery does not hold a charge enthusiastically, I must be doing something right there too. Probably by using it 5% of its capacity (mainly because it's all I know) so not heavy usage, but still.
https://www.e-cigarette-forum.com/blogs/mooch.256958/
https://www.e-cigarette-forum.com/blog-entry/baditudes-blogs.7609/
Good luck just learn about safety, and like, well, you'll be okay (probably) if you just learn about safety. Honest.
Anna