If you wanted to invest in lithium, someone should warn you that individuals without special knowledge should not get involved with picking commodities. You'll be buying a lot of volatility with no increase in expected return.
These are the top three holdings in Global X Lithium & Battery Tech ETF (https://www.globalxfunds.com/funds/lit), together composing about 43% of that fund's holdings.
There was another quote in TFA about the potential to over build mining capacity and flood the market.
But sure, buy this and hope it "surges" more than the general market. Given that billions of devices already have lithium cells in them and the historical performance of the Lithium ETF is still quite disappointing compared to the broader market, I wouldn't hold my breath that this time is any different.