Mercedes Prototype Shatters Range Records with Solid-State Power
The promise of the “forever battery” took a tangible leap forward this week as preliminary data from a highly anticipated European test run began circulating among automotive engineers. A prototype Mercedes-Benz EQS, equipped with experimental solid-state cells developed by partner Factorial Energy, successfully completed a continuous 749-mile journey from Stuttgart, Germany, to the outskirts of Stockholm, Sweden, on a single charge. This real-world demonstration marks one of the first times a major automaker has publicly exceeded the 700-mile barrier in road conditions, effectively doubling the reliable range of many current lithium-ion flagships.
For years, solid-state batteries have been the “vaporware” of the electric vehicle industry—promised by startups but unseen in dealerships. The technology replaces the flammable liquid electrolyte found in conventional lithium-ion cells with a stable solid material, allowing for higher energy density and significantly reduced fire risk. During the recent test, the Mercedes prototype reportedly maintained an energy efficiency rate that suggests the new cells can handle highway speeds without the rapid degradation that plagues current EV batteries during long-haul travel.
The breakthrough comes just weeks after Toyota solidified its own timeline during a manufacturing briefing in Tokyo. In an October update, Toyota executives confirmed that their proprietary solid-state massive production lines are scheduled to go live by 2027, with a limited rollout of vehicles capable of a 10-minute fast charge. The Japanese giant has been collaborating with Idemitsu Kosan to solve the cracking issues that previously occurred in solid electrolytes during repeated charging cycles.
“We are moving from the laboratory phase to the homologation phase,” stated Dr. Jurgen Weber, a battery systems analyst based in Munich who has tracked the partnership between Mercedes and Factorial. “The question is no longer if the chemistry works, but if it can be manufactured at a price point that doesn’t restrict these vehicles to the ultra-luxury segment. Right now, the cost per kilowatt-hour for these solid-state units is roughly four times that of a standard nickel-manganese-cobalt pack.”
Despite the engineering triumph, mass adoption remains years away. The manufacturing process requires a completely dry environment to prevent moisture from contaminating the solid electrolyte, necessitating expensive retrofits to existing gigafactories. While the 749-mile range eliminates “range anxiety” entirely for the average consumer, the initial wave of solid-state EVs expected in late 2027 and 2028 will likely carry premium price tags well into the six-figure range.
The implications for grid infrastructure are equally massive. If vehicles can charge 80% of a 100kWh battery in under ten minutes, as Toyota claims their upcoming tech allows, current Level 3 charging stations will become obsolete. A shift to 450kW or even 600kW chargers will be necessary to feed these dense energy storage systems, forcing a new wave of infrastructure investment across the European Union and North America.
