Solid-state batteries—which pack more energy into each unit of volume than current batteries and will stretch the range of electric vehicles—have long felt just out of reach. But they’re getting close, and recent progress helps to clarify when the first models may arrive. Samsung SDI said in March that it will produce solid-state batteries for use in high-end vehicles by 2027.

The vehicles would be able to travel more than 600 miles before needing to be recharged. Samsung, based in South Korea, didn’t say which automakers would use the battery, but the company has relationships with GM, Hyundai, and Stellantis. A range of 600 miles would be roughly double the ranges of today’s most popular models.

| Samsung’s announcement puts it ahead of Toyota, which told investors in January that it’s on track to develop a solid-state battery by 2027 or 2028 , followed by a ramp-up to mass production. QuantumScape, based in California, said in July that it had reached an agreement to license its solid-state battery technology to Volkswagen to develop for mass production. The announcement didn’t include a timetable for when those vehicles might be available to consumers.

Most EV batteries on the market today have a liquid or gel electrolyte, the material through which lithium ions flow as the battery charges and discharges. In a solid-state battery, the electrolyte is a solid, usually ceramic or polymer. The design allows for much higher energy density, faster charging times.