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.
Their own comparison shows the index matching or beating the Lithium ETF in every metric.
* LIT since inception: 38.48%
* Index over same period: 45.82%
You also have zero diversification with a resource ETF. If you really want to buy into only Lithium then I won't try to talk you out of it.
But maybe consider Vanguard Growth ETF (VUG), the average return over 5 years is 14.4%, or nearly double that of LIT. [1]
[1] https://institutional.vanguard.com/iippdf/pdfs/FS967R.pdf