Nissan has unveiled a prototype of what it calls a game-changing solid-state battery. The Japanese automaker says the new technology will deliver a 600-mile range and a 10-minute charging time. If true, this would obliterate the biggest hurdles for electric vehicles: range anxiety and slow charging.

I travelled to Nissan’s research facility in Yokohama to see the prototype. The battery is small, about the size of a tablet. But the claims are huge. Nissan says it will be production-ready by 2028.

“We have solved the fundamental problems,” said Kazuhiro Doi, Nissan’s head of battery research. He wouldn’t show me the internal chemistry but said the battery uses a sulfide solid electrolyte. This is similar to work by Toyota and Samsung. But Nissan claims a significant advantage in cost and scalability.

The key metric is energy density. Nissan says its solid-state battery achieves 1,000 watt-hours per litre. That’s roughly double current lithium-ion packs. This allows for a smaller, lighter battery with the same range. Or a huge range with a similar-sized pack.

But experts urge caution. “Solid-state batteries have been five years away for twenty years,” said Dr. Emma Kendrick, a battery researcher at the University of Birmingham. “The materials are difficult to manufacture reliably. Sulfide electrolytes are reactive with moisture. And the interface between solid electrodes and solid electrolyte can cause resistance.”

Nissan admitted to me that they have only built small cells so far. Scaling up to automotive packs is a huge challenge. They also need to prove the battery can handle thousands of charge cycles without degrading.

Still, the announcement has stirred excitement. Nissan’s stock rose 4% on the Tokyo exchange. Analysts see this as a potential breakthrough that could reshape the EV market.

What does it mean for drivers? A 600-mile range would allow London to Edinburgh on a single charge. The 10-minute charge time matches a petrol stop. But only if the charging infrastructure can deliver the required power. A 100kWh pack charged in 10 minutes needs 600kW chargers. Current fast chargers are 150kW to 350kW.

Nissan says it is developing new charging stations. It also plans to reduce battery costs by 50% compared to current lithium-ion. If true, this could make EVs cheaper than petrol cars.

But the timeline is ambitious. Nissan aims to start production in 2028. That’s five years away. I asked Doi if they were overpromising. He said: “We learn from our mistakes. The Leaf was a pioneer. This is our next step.”

The Leaf, Nissan’s first mass-market EV, launched in 2010. It had a 73-mile range. Now, the Ariya offers 300 miles. The jump to 600 miles would be dramatic.

Competitors are watching closely. Toyota has also promised solid-state batteries by 2027. Volkswagen and BMW have partnerships with startup QuantumScape. But no one has yet mass-produced a solid-state battery for cars.

Nissan’s secret weapon is its in-house manufacturing. The company makes its own batteries at the Yokohama plant. This could give them an edge in scaling.

I pressed Doi on the biggest remaining challenge. “Cycle life,” he admitted. “We need to ensure the battery lasts 10 years or more. That is our focus now.”

If Nissan succeeds, the impact would be enormous. Not just for cars but for grid storage, aviation, and shipping. The solid-state battery has been the holy grail. Nissan might just be the one to catch it.