Mercedes and Factorial partner on next?generation solid?state batteries
Mercedes-Benz (OTC: MBGAF) is teaming up with U.S. battery startup Factorial to develop a solid-state battery platform intended to stretch electric-vehicle range and tighten costs. The companies say the technology is on track for production before the decade concludes, a timeline that would bring a major shift to how EVs are built and how far they can travel on a charge.
Meet Solstice: Factorial’s solid?state pack
Factorial’s solid-state battery, called Solstice, targets a range boost of roughly 80% over today’s industry averages. It’s designed for an energy density of 450 watt-hours per kilogram—an ambitious figure meant to translate to higher efficiency and stronger performance than conventional lithium-ion packs.
Why solid?state matters
Unlike traditional batteries that rely on a liquid electrolyte, solid-state designs use a solid electrolyte. That one change can lower the risk of fire, cut weight, and help vehicles go farther between charges. It can also open the door to simpler, potentially more affordable vehicle designs. The catch: scaling solid-state technology has been hard. Many automakers and their partners have struggled to move from promising lab results to mass production.
A market looking for a lift
With parts of the EV market—especially in Europe—showing signs of stagnation, manufacturers are searching for ways to add range without piling on cost. That urgency is steering attention to battery innovation. Factorial has already built a quasi-solid-state battery that fits into existing production approaches, and Mercedes, along with other manufacturers, is testing it now. Expectations are that this version could reach public roads by 2026.
Investment, partners, and the road to scale
Mercedes has taken an equity stake in Factorial, which raised $200 million in funding last year. The effort isn’t happening in isolation: Stellantis (NYSE: STLA) and Hyundai (OTC: HYMTF) are also part of the partnership network, underscoring how much the industry wants a workable path to advanced batteries at scale.
Building for manufacturability first
Factorial CEO Siyu Huang says the company started with quasi-solid-state cells because they can be produced on lines similar to those used for mainstream lithium-ion batteries. That choice shortens the scale-up curve—a practical way to meet near-term demand while the full solid-state system matures. In the next step, replacing the liquid electrolyte with a solid one is expected to further reduce fire hazards and allow more compact battery packs.
Cost, cooling, and the full vehicle bill
Huang also points out that cell price is only part of the equation. What matters is the total cost to build the vehicle. Solid-state designs are expected to do away with some of the heavy, expensive cooling hardware that today’s lithium-ion packs require. Fewer thermal-management components can mean lower weight and less complexity—both helpful when you’re chasing cost targets.
What Mercedes expects from the tech
Mercedes Chief Technology Officer Markus Schaefer sees substantial upside if Factorial’s cells deliver as planned. He projects about a 40% jump in energy density versus Mercedes’ current high-performance batteries. Gains like that can be spent in two ways: build smaller, lighter packs to cut vehicle weight and cost, or keep pack size steady and offer much longer range without trading away performance. Either path pushes the EV experience forward.
Materials that could reshape the body
If packs get lighter, Mercedes says it could rethink body materials—potentially opting for steel in some EV structures instead of relying so heavily on high-strength aluminum, which is pricier and more taxing to produce. Alongside Factorial, Mercedes is working with Taiwanese battery maker ProLogium and exploring high-silicon anodes as another route to higher density. Multiple bets, one goal: more energy in less space.
Outlook
There’s still real work ahead to make solid-state batteries reliable, manufacturable, and cost-effective at volume. Even so, Schaefer is optimistic about Factorial’s timeline for Solstice and believes the targets can be met with solid engineering. If they are, the payoff is straightforward: safer, denser batteries that let EVs go farther, weigh less, and cost less to build—a cleaner, simpler stack from cell to chassis.
Frequently Asked Questions
What is Solstice, and who’s developing it?
Solstice is Factorial’s solid-state battery platform, developed in partnership with Mercedes-Benz (OTC: MBGAF). It’s designed to deliver higher energy density and a significant improvement in driving range compared with today’s lithium-ion packs.
When could Solstice reach production?
The companies are targeting production before the decade concludes. In the near term, a quasi-solid-state version that Factorial has already built and validated is being tested by Mercedes and other manufacturers, with expectations to appear on roads by 2026.
How is a solid-state battery different from a lithium-ion battery?
Solid-state batteries replace the liquid electrolyte in a lithium-ion battery with a solid electrolyte. That shift is expected to lower fire risk, improve energy density, and reduce the need for heavy cooling systems—changes that can make vehicles lighter, simpler, and potentially less expensive to build.
Who else is backing Factorial’s effort?
In addition to Mercedes, Factorial’s partners include Stellantis (NYSE: STLA) and Hyundai (OTC: HYMTF). Factorial also raised $200 million last year, reflecting broader industry support for bringing advanced batteries to scale.
What challenges still stand in the way?
The biggest hurdles are scaling production while maintaining safety, performance, and cost targets. Even with quasi-solid-state cells that fit existing lines, moving to full solid-state requires solving manufacturing, thermal, and packaging issues without adding weight or expense.
