Here is an article from July 2017. 6+ years ago they were "right around the corner". I know they've talked about it before that, but that's just one example of Toyota being "no seriously we're almost there" on this supposed tech that I could find while on mobile.

The problem isn't the battery tech. They've made the battery. They just can't figure out how the hell to mass manufacture it for a reasonable cost to compete with Lithium Ion.

I hope they succeed and take over the world of EVs by storm, but there are only so many times they can claim to be "right around the corner" before you start to wonder if they'll ever actually get it.