Solid-state timeline: published today, right of reply offered

Two questions, and Toyota is welcome to answer here. We will publish the reply unedited.

Is it 2027, or 2028? And what volume does commercialisation mean in the first year?

Here is why they are fair questions.

What Toyota said

In October 2023, announcing its partnership with Idemitsu Kosan, Toyota said on its own newsroom that between 2027 and 2028 “we will start to produce solid-state batteries for use in battery electric vehicles”, and would then lay the foundation for mass production. In the same announcement it gave its target for commercialisation as 2027 or 2028.

A range, not a date. And Toyota separates commercialisation from full-scale mass production, which is a distinction worth keeping.

What has happened since

6 September 2024. METI certified Toyota’s development and production plans for all-solid-state batteries under Japan’s Supply Assurance Plan for Batteries.

8 October 2025. Toyota and Sumitomo Metal Mining agreed to jointly develop mass production of cathode materials for all-solid-state batteries. Toyota restated the 2027 to 2028 target.

29 January 2026. Idemitsu took a final investment decision and began construction of a facility for solid electrolytes at its Chiba complex, built by Chiyoda, aiming to complete in 2027, with planned capacity of several hundred tonnes a year.

Each is real, dated and verifiable. Together they are a supply chain being assembled.

The part worth sitting with

The solid electrolyte is what makes an all-solid-state battery solid-state. Idemitsu describes the facility building it as a large pilot, intended to establish mass-production technology, completing in 2027.

So the material process is still at the validation stage in the first year of Toyota’s own window.

One thing that is not from Toyota

The 1,200 kilometre range figure repeated widely comes from secondary coverage rather than from Toyota. We could not find Toyota committing to a range for a production solid-state vehicle. If it exists, we would like the source.

So, to Toyota

You have held this target longer than anyone else in the field, and that deserves saying. Most solid-state timelines announced in 2023 have already moved. Yours has not.

Which makes the remaining question a narrow one.

2027, or 2028? And how many cars in the first year?

We will publish any answer unedited, and correct anything here that is wrong.