Not trying to be snarky here, but wasn't this Elon Musk's entire thesis on Tesla's success by bringing the massive produced EV (aka Model 3) affordable and all-around better than conventional ICEs?
https://futurism.com/analyst-questions-elon-musks-10-year-ev...
This article was dated in 2017 but I am pretty sure Musk mentioned "economy of scale" will bring down the cost of lithium batteries which in turn make the massively produced EVs like Model 3 more affordable.
https://www.tesla.com/blog/secret-tesla-motors-master-plan-j...
Dated 2006 (not directly mentioning of cost of Lithium batteries though).