Solid-state batteries are often presented as the next great leap for electric cars, promising more range, faster charging, better safety, and perhaps lower costs.
But Robin Zeng Yuqun, founder and chairman of CATL, the world’s largest EV battery maker, has given that optimism a reality check. And when such an authority speaks, it’s worth listening.
Far from mass-market deployment
In an interview with Chinese business magazine Caijing, Zeng said true solid-state batteries are still far from mass-market deployment and that reaching a million-car scale before 2030 is “very unlikely”.
His warning matters because CATL is not a bystander dismissing a rival technology. The key distinction is that Zeng was talking about “true” solid-state batteries, not the semi-solid or hybrid designs already appearing in some Chinese vehicles.
A true solid-state battery replaces the liquid electrolyte in today’s lithium-ion cells with a solid electrolyte. In theory, this could enable higher energy density, improved fire safety, and lithium-metal anodes that could store more energy in the same space.
Making millions of cells cheaply
In practice, however, the challenge is not making one impressive lab cell. It is making millions of cells cheaply, safely, and consistently, then proving they can survive years of vibration, heat, fast charging, freezing temperatures, and repeated cycling in real cars.
Zeng highlighted the solid-solid interface as a central problem: ions must move smoothly between solid materials that do not naturally maintain perfect contact.
CATL currently rates solid-state at level 4 on a nine-step technology-readiness scale, meaning it is still in a technology-development phase, not close to a mature mass-market product.
That does not mean solid-state is dead. It means the timeline is likely less dramatic than the headlines. Toyota is targeting practical EV use around 2027 or 2028, with support from Sumitomo Metal Mining and Idemitsu Kosan on key materials.
Nissan wants to launch EVs with in-house all-solid-state batteries in fiscal year 2028 and is preparing a pilot line in Yokohama. Honda has opened a demonstration production line in Japan to test mass-production methods and costs. Samsung SDI says it aims for all-solid-state mass production in 2027.
Europe and US moving forward
European and American projects are also moving from laboratory claims into vehicles. Mercedes-Benz has tested an EQS prototype with a solid-state battery and wants to bring the technology into series production by the end of the decade.
BMW is testing large-format all-solid-state cells from Solid Power in an i7. Volkswagen’s battery company PowerCo has a licensing agreement with QuantumScape that could eventually allow 40 GWh of annual production, expandable to 80 GWh, if technical milestones are met. Stellantis has begun road testing a Dodge Charger Daytona development vehicle using solid-state cells from Factorial.
So the race is real, but the language matters. “Road testing”, “pilot line”, “demonstration vehicle,” and “first practical use” are not the same as cheap batteries in millions of family cars.
BYD’s own timeline, with demonstrations around 2027 and broader scale only after 2030, is a useful benchmark. It is close to CATL’s warning, not a contradiction of it.
For the average EV driver, the likely post-2030 reality is not that every car suddenly gets a solid-state battery. The first wave will probably appear in expensive cars, long-range models, and performance vehicles, where lower weight, higher energy density, and possible fast-charging gains justify the cost.
Smaller and lighter battery pack
A premium EV could get a smaller and lighter pack for the same range, or more range without a larger battery. Safety may improve because solid electrolytes are generally less flammable than liquid ones, but a full battery pack remains a complex high-energy system, not a risk-free device.
For mass-market drivers, the benefits may take longer. If solid-state cells remain expensive, affordable EVs may still be better served by LFP batteries, which are cheap, durable, cobalt-free, and already widely produced.
Sodium-ion batteries could become attractive for short-range cars, two-wheelers, cold-weather use, and stationary storage because they reduce dependence on lithium. Nickel-rich NMC and manganese-rich batteries may remain useful where high energy density outweighs cost.
There is also a common misunderstanding: solid-state is not a chemistry in the same way as NMC, LFP, or sodium-ion are chemistries. It is mainly an architecture built around a solid electrolyte.
A future solid-state battery could still use lithium, nickel-rich cathodes, or other materials. The industry is therefore not choosing simply between “solid-state” and “LFP”, but between many combinations of cathode, anode, electrolyte, cost, safety, durability, and supply chain.
Still years to be able to compete
The International Energy Agency has also warned that early solid-state volumes will likely be limited and that it may take years after first roll-out before the technology can compete with today’s lithium-ion batteries on cost.
That is a high bar, because conventional batteries are still improving. LFP is getting better, NMC is becoming more energy-dense, LMFP and manganese-rich chemistries are emerging, and sodium-ion is moving from promise to production.
Nor is there another obvious miracle battery waiting just behind solid-state. Lithium-sulfur, lithium-air, metal-air, and other advanced chemistries promise major gains on paper, especially in weight, raw-material use, or theoretical energy density.
But most remain even further from automotive mass production than solid-state, with unresolved problems around cycle life, power, efficiency, safety, packaging, or cost.
Over the next decade, the bigger change is therefore likely to come from cumulative improvements rather than a single spectacular replacement: better LFP, LMFP, manganese-rich cathodes, silicon-rich anodes, sodium-ion for selected use cases, semi-solid cells, and, eventually, some true solid-state batteries where the economics work.
