In 2015, Elon Musk made a bold prediction that vehicle electrification would increase lithium-ion battery demand — by a lot.

At the time, Tesla was delivering around 50,000 vehicles a year.

That year, the company broke ground on its battery Gigafactory production site in Nevada. That site would churn out enough batteries to power 500,000 Teslas per year. And more sites like this were needed, Musk claimed.

It’s clear that Musk’s vision panned out, with the company on track to deliver more than 1M vehicles this year alone. This foresight allowed Tesla to become a dominant leader in the EV battery tech space. But as EV adoption becomes more mainstream, startups — with backing from legacy auto OEMs, among other players — have popped up to compete with Tesla on battery tech.