Very tough business. My best friend is CFO of a small cap EV battery materials company. He can't tell me a lot because they are a public company but apparently it's a pain in the ass business. 

Probably your best bet if you wanted to get exposure would be to buy an etf if you don't have some level of expertise in the industry. 

grayruby

I wonder how many people you have to trust to invest in a mineral generically

k00b

tech

Lithium discovery in US volcano could be biggest deposit ever found

Might be a good investment to increase wealth, but not store it long term.