According to Green Car Advisor: "Toyota appears to be making good on its promise, delivered at the Los Angeles Auto Show last month, to develop solid-state battery technology for electric-drive vehicles. Successful development of such batteries would be a big deal as they can store more energy - for longer range between charges - and cost much less to produce than the lithium-ion batteries now considered state-of-the-art.... Toyota Motor Sales U.S.A. President and CEO Jim Lentz said at the L.A. Auto Show that, in addition to an accelerated roll-out schedule for more conventional hybrids and the Prius plug-in hybrid electric, the company was working on solid-state battery advancements. The technology's in its infancy, though, and commercial production is still considered to be years away."
I've always wondered why Toyota has been resisting lithium ion batteries and staying with nickel metal hydrides for so long. And this delves into more questions I have: Why no pure electric vehicles in the product pipleline except for the RAV4 with Tesla? Why is the Prius Plug-in taking so long to come to market, and why does it only go 12 miles on battery alone?
Toyota takes its time adapting toward new technology and away from the habits under the hood of the award winning Prius. I do think that when Toyota brings solid-state battery technology to the market, it will be well made. And it probably helps explain why Toyota made the deal with Tesla Motors to build the RAV4 electric version together using the Tesla technology instead of doing it on their own. Doing it their own way is the normal Toyota modus operandi, so things are changing.