[philipkglass]

I agree that scaling is hard and progress is slow. I think that a major breakthrough has made it into cars, though: lithium ion batteries.

The 1990s-vintage GM EV1 used lead-acid or NiMH batteries. The earlier generations of Prius used NiMH batteries too. The Tesla Roadster was the first highway-legal serial production EV to use lithium ion batteries. It took 17 years after lithium ion batteries saw first commercial use in small electronic devices (commercial batteries out in 1991, Roadster in 2008). Because, as you say, scaling is hard.

Of course the first Roadsters now seem like old hat and every auto maker is using lithium ion batteries. We're eager for the next, better kind of lithium battery. But just getting autos to use any kind of lithium battery was a big enough change that it deserved the "breakthrough" moniker, IMO.

[flyinghamster]

A major driving factor in the advancement of lithium-ion batteries for automotive use was the patent issues surrounding large-format NiMH batteries.* Once Chevron got its grubby hands on the NiMH patents, the technology was effectively dead in the water.

* https://en.wikipedia.org/wiki/Patent_encumbrance_of_large_au...

Interesting that Patent #6969567 expires a week from today. I doubt that will lead to a revival of NiMH technology, though.

[tankerdude]

Agreed that that was definitely the big initial breakthrough.

We need this next one sooner or later for mass adoption.

As Musk says, show me him a battery with the breakthrough and the manufacturing process for it. If it's good, he'd switch it out to that battery. No one has succeeded yet at that challenge.