Toyota has reaffirmed its commitment to launching solid-state battery electric vehicles by 2027-2028, promising revolutionary 40-year battery lifespans and over 621 miles of range. But with a decade-long history of missed targets and competitors already testing similar technology on public roads, the world’s largest automaker faces a critical credibility test in the global race to commercialize next-generation EV batteries.

Toyota Reaffirms “On Schedule” Timeline Despite Past Delays

Toyota executive Keiji Kaita, president of the company’s Carbon Neutral Advanced Engineering Development Centre, confirmed at the Japan Mobility Show that solid-state battery (SSB) production remains on track for the 2027-2028 timeframe. Speaking to media in Tokyo, Kaita emphasized the technology would deliver “high power, compact size, long range and long life.”

The announcement comes with impressive technical claims. Toyota’s solid-state batteries are targeting a 40-year lifespan while maintaining 90% capacity—four times longer than current lithium-ion batteries. The company also promises over 1,000 kilometers (621 miles) of range and significantly reduced charging times compared to conventional battery technology.

Toyota has partnered with Sumitomo Metal Mining to mass-produce cathode materials for its solid-state batteries, with the mining company targeting production by Japan’s fiscal year 2028. The collaboration builds on joint research dating back to 2021, focusing on developing cathode materials that resist degradation during repeated charge-discharge cycles.

The Credibility Problem: A Decade of Broken Promises

Toyota’s latest timeline reaffirmation comes with substantial baggage. The automaker initially promised solid-state batteries in production vehicles by 2020, then pushed the target to 2023, then 2026, and now 2027-2028. Just two days after Kaita’s Japan Mobility Show statement, Electrek reported that Toyota was again delaying EV battery plans, citing slowing demand despite global EV sales topping 2 million units monthly for the first time in September 2025.

“Toyota has been making empty promises about EV batteries for almost a decade now,” one industry observer noted. The company’s repeated delays stand in stark contrast to its public commitments, raising questions about whether the 2027-2028 timeline will prove any more reliable than previous targets.

The pattern extends beyond just battery promises. Toyota reduced its 2026 EV production targets in September 2024, signaling a broader retreat from aggressive electrification commitments even as the company touts breakthrough battery technology.

Technical Specifications and Performance Claims

Toyota’s solid-state batteries will still use lithium chemistry but replace liquid electrolytes with solid materials, improving safety and energy density. “Compared to traditional batteries, the SSB’s life-span may be four times longer,” Kaita explained at the Japan Mobility Show. “So the production carbon footprint is a quarter relatively [of a lithium-ion battery], and we think SSBs have that potential.”

The longevity claim centers on capacity retention. While conventional lithium-ion batteries typically maintain 90% capacity for around 10 years, Toyota’s solid-state technology aims to retain that same 90% capacity threshold for 40 years—potentially outlasting multiple vehicle lifecycles.

Beyond lifespan, the batteries promise higher power density in a more compact package, enabling either smaller battery packs for the same range or significantly extended range without increasing vehicle weight. The technology also offers improved safety, with solid electrolytes less prone to thermal runaway and fire risks compared to liquid-based systems.

Premium or Mass Market? Toyota Stays Vague on Deployment Strategy

Toyota has conspicuously avoided specifying which vehicles will debut solid-state batteries first, creating speculation about whether the technology will launch in premium Lexus models or mass-market vehicles. “It needs to be a model which can leverage those qualities: high power, compact size, long range and long life,” Kaita told reporters. “We leave it up to your imagination.”

Industry speculation points to two divergent strategies. A premium launch could debut in the Lexus Electrified Sport Concept, a potential successor to the legendary LFA supercar, where cutting-edge battery technology would command premium pricing while showcasing Toyota’s technological capabilities.

Alternatively, Toyota could pursue volume deployment, integrating solid-state batteries into high-volume models like the next-generation Corolla, Prius, or RAV4. This mass-market approach would accelerate technology amortization and potentially give Toyota a decisive competitive advantage in family vehicle segments where range and packaging efficiency matter most.

The deployment question carries strategic weight. A premium-only launch would suggest Toyota views solid-state batteries as a technology showcase rather than a volume game-changer, while mass-market integration would signal serious intent to reshape the EV competitive landscape.

Competitors Already Testing on Public Roads

While Toyota makes promises, competitors are putting prototype solid-state batteries through real-world validation. Mercedes-Benz achieved 749 miles (1,205 kilometers) in a modified EQS sedan in September 2025, traveling from Stuttgart, Germany to Malmö, Sweden without charging. The test vehicle still had 85 miles of range remaining when it arrived.

“The solid-state battery is a true gamechanger for electric mobility,” Mercedes CTO Markus Schäfer stated. “Our goal is to bring innovations like this into series production by the end of the decade.” Mercedes developed the battery system in collaboration with U.S.-based Factorial Energy, using the company’s FEST (Factorial Electrolyte System Technology) lithium-metal cells.

Stellantis and Factorial validated 375 Wh/kg semi-solid-state cells in April 2025, demonstrating 18-minute charging from 15% to 90% with plans for demonstration fleets by 2026. The collaboration represents a $75 million investment Stellantis made in Factorial back in 2021.

Chinese automaker Chery recently claimed 600 Wh/kg energy density in a solid-state battery prototype, targeting 808 miles of range with pilot production in 2026 and mass rollout in 2027. Nissan, despite severe financial challenges, opened a solid-state battery pilot production line and targets fiscal year 2028 for commercial launch.

EVXL’s Take

Toyota’s solid-state battery announcement follows a familiar pattern: impressive technical claims paired with timelines the company has repeatedly failed to meet. We’ve been hearing about Toyota’s breakthrough battery technology since before 2020, and each deadline has come and gone with little more than revised promises and new partnerships to show for it.

What makes this announcement particularly frustrating is the timing. Just as Chinese automakers like Chery claim 808-mile range solid-state batteries targeting 2027 production, and Mercedes completes real-world tests achieving 749 miles on a single charge, Toyota offers another round of “trust us, it’s coming” assurances. The competitive gap between promise and execution grows more glaring with each passing year.

The broader context makes Toyota’s credibility problem worse. The company slashed its 2026 EV production targets while competitors ramp up, and has consistently advocated for a hybrid-first strategy rather than full electrification. This isn’t a company that’s been caught off guard by the EV transition—it’s a company that’s been actively hedging against it while talking up future technology that never seems to materialize on schedule.

Consider the competitive landscape we’ve documented: Nissan targeting 2028 despite financial crisis, Stellantis planning demonstration fleets by 2026, and Chinese battery giants CATL and BYD—who control 55% of global battery sales—both targeting solid-state launches around 2027. The race is happening now, not in some distant future Toyota keeps pushing further out.

The 40-year lifespan claim is genuinely impressive if realized, potentially transforming battery economics by enabling reuse across multiple vehicle lifecycles. But impressive claims mean nothing without production vehicles. Mercedes isn’t just making promises—they’re putting test miles on actual solid-state battery vehicles. Chery isn’t just talking about energy density—they’re building pilot production facilities. Toyota’s decade of delays has created a credibility gap that technical specifications alone can’t bridge.

Here’s the question that matters: Will Toyota deploy these batteries in a premium Lexus to maximize profit margins on expensive new technology, or will they integrate them into mass-market vehicles like the Corolla to actually compete with Chinese manufacturers who are targeting volume production? The answer will reveal whether Toyota sees solid-state batteries as a technology showcase or a competitive necessity. Given the company’s recent EV strategy retreat, we’re not optimistic about aggressive deployment even if the technology does finally materialize.

Until Toyota puts actual solid-state battery vehicles in customer hands, every new announcement is just another entry in a long list of promises that keep getting pushed back. The technology sounds transformative. The company’s track record suggests we shouldn’t hold our breath.

What do you think? Share your thoughts in the comments below.