The main problem is just that getting a product from a one-off in a lab to a cost-competitive mass-market product is hard and can take a lot of time, to say the least.

For example, Don Sadoway initially published about a molten metal battery in 2009. He gave a Ted talk in 2012. They’ve run into assorted setbacks along the way and are apparently just starting to deploy the first commercial test systems this year.

It’s less that these breakthroughs are bullshit, and more that commercializing these things is hard. The articles about the breakthroughs are often bullshit, though, or at least way too rosy.