2026 OEM Claims vs. Actual Dates
Every major automaker and cell maker working on solid-state batteries has, at some point, put a year on when a real customer will be able to buy a car with one inside. Those years keep moving. This post lines up the current public claims from five of the most closely watched programmes:
- Toyota
- QuantumScape
- Samsung SDI
- Solid Power
- Factorial Energy
Against what has actually been demonstrated, as best it can be verified from company statements and independent reporting as of September 2026. For the deeper background on the chemistry choices behind these programmes, see our existing coverage of solid-state battery fundamentals and solid-state packaging, and for Toyota specifically, the full Toyota battery development timeline already on the site.
A pattern is worth flagging up front: the gap between a claim and a shipped car has, so far, tracked manufacturing scale-up rather than cell chemistry. Every programme below has working cells in a lab or a test vehicle; none has yet run a gigafactory-scale line producing them for sale. That’s the detail a “2027” headline tends to leave out.
Claims vs. what’s been shown, September 2026
| Company | Latest public target | What’s actually been demonstrated |
|---|---|---|
| Toyota | First solid-state EVs, 2027–2028, ~1,000–1,200 km range and ~10-minute fast charge | Electrolyte partner Idemitsu Kosan broke ground on a dedicated production plant in January 2026; target has already slipped once, from an original 2020 debut through 2023 and 2026 before settling on 2027–2028 |
| QuantumScape | B-sample cells to automaker partners (led by VW’s PowerCo); no public EV launch date | Opened its “Eagle Line” pilot production facility in San Jose in February 2026, built around its faster “Cobra” separator process; still pilot-scale, not yet a qualified automotive production line |
| Samsung SDI | Mass production start, second half of 2027, at its Ulsan plant | Running a pilot line at its Suwon R&D centre and has committed roughly 25 trillion won (~US$17bn) through 2040 to Ulsan and Cheonan capacity; sample cells are out to automotive and robotics customers but Ulsan production has not started |
| Solid Power | Electrolyte output sized for roughly 800,000 EVs/year by 2028; no firm vehicle launch date | BMW has road-tested Solid Power cells in a modified i7 test mule around Munich; BMW’s own comments suggest this generation of i7 is unlikely to carry them into production, pushing a realistic debut into the early 2030s |
| Factorial Energy | 2026 demonstration fleet with Stellantis; Mercedes-Benz test vehicle already running | A Stellantis-badged Dodge Charger Daytona development vehicle began road testing on Factorial’s FEST cells in June 2026; Mercedes-Benz separately reported over 1,200 km on a single charge in a modified test vehicle. Both are demonstration fleets, not retail production |
Toyota: three timelines in five years
Toyota’s own public statements give the clearest before-and-after of any programme here, mostly because the company has been willing to keep restating the target as it moves. An original ambition to have solid-state cells in production vehicles by 2020 gave way to 2023, then to a 2026 date tied to the BEV Factory roadmap, and now sits at 2027–2028 (see the full sourced timeline on our Toyota page for the individual announcements). The most concrete recent step is physical: Idemitsu Kosan, Toyota’s electrolyte partner, broke ground on a large-scale solid-electrolyte plant in January 2026, with the facility due to finish in 2027. This in itself is informative, since it means the electrolyte supply chain for a 2027 vehicle launch is only being built now, not already running.
QuantumScape and Samsung SDI: pilot lines are live, qualified production isn’t
QuantumScape doesn’t publish a target year for a car you can buy, its public commitments stop at supplying B-sample cells to automaker partners, principally Volkswagen’s PowerCo. What changed in 2026 is that this stopped being theoretical: the Eagle Line pilot facility in San Jose started up in February 2026, built around a new separator process the company calls Cobra, which it describes as faster and more compact than its predecessor. That’s a genuine manufacturing milestone, but a pilot line sized for customer sampling is a different thing from a qualified automotive production line, and QuantumScape has been careful not to claim otherwise.
Samsung SDI has gone further in public: it has named 2027’s second half and its Ulsan plant as the mass-production start for a sulfide-based cell it’s targeting at over 900 Wh/L. That’s a specific claim to hold the company to. As of September 2026 the validated work is still happening at a pilot line in Suwon, with sample cells shipped out for evaluation rather than a production line running at Ulsan. The scale of Samsung SDI’s stated investment, on the order of 25 trillion won through 2040 across Ulsan and Cheonan, suggests the 2027 date is being taken seriously internally, but it’s still eighteen months of ramp-up between now and the claimed start.
Solid Power and Factorial: two different definitions of “in a car”
Solid Power’s cells are furthest from a production date but closest to a real chassis: BMW has been road-testing them in a modified i7 around Munich. BMW’s own commentary is that this generation of i7 probably won’t carry the technology into production, which is a useful reminder that a test mule on public roads is a validation exercise, not a pre-production signal. Solid Power’s own stated milestone is sizing electrolyte output for around 800,000 vehicles a year by 2028, which is a supply-chain target, not a vehicle launch date.
Factorial Energy’s semi-solid FEST cells are the one entry in this table already running in more than one OEM’s test fleet at once: a Stellantis-branded Dodge Charger Daytona began road testing in June 2026, and Mercedes-Benz separately put a modified test vehicle over 1,200 km on a single charge. Both are demonstration fleets rather than retail vehicles, and Factorial’s own architecture is a semi-solid hybrid rather than the fully solid electrolyte that Toyota, QuantumScape and Samsung SDI are pursuing. Worth keeping in mind when comparing it directly against the others in this list, since it’s a genuinely different manufacturability trade-off, not just an earlier-stage version of the same technology.
What to watch for next
The honest read of these five programmes in September 2026 is: pilot lines are real and increasingly running, but every claimed production date still sits at least twelve to eighteen months out, and every one of these companies has either already slipped a date once (Toyota) or is making a first public commitment that hasn’t been tested by time yet (Samsung SDI). The single most useful thing to track from here isn’t the next press release with a range or charge-time number in it: it’s whether the pilot lines convert into qualified, automotive-grade production lines on the schedule each company has now committed to.
References
- QuantumScape Inaugurates Eagle Line for Solid-State Battery Pilot Production, QuantumScape investor relations, 4 February 2026
- Samsung SDI targets 2027 mass production of solid-state batteries, Korea JoongAng Daily, 2026
- Samsung SDI Plans Mass Production of Solid-State Batteries Starting in 2027, Battery-News, 3 August 2026
- Toyota partner breaks ground on all-solid-state EV battery plant, Electrek, 30 January 2026
- Toyota is yet again delaying EV battery plans, Electrek, 7 November 2025
- Here’s how close to production solid-state batteries really are, Alloy, 2026 (BMW/Solid Power i7 test programme)
- Stellantis and Factorial Integrate Advanced Solid-State Battery into Stellantis Development Vehicle and Launch Road Testing, Factorial Energy investor relations, 11 June 2026
See also: Toyota Batteries, 10 things about SSBs that you are often not told, Things about Solid State Packaging that you are often not told, Grain Boundary Dendrite Growth in Solid-State Electrolytes