French battery maker Saft, a subsidiary of TotalEnergies. unveiled on 19 October 2026 new production lines for solid-state batteries at the plant in Bordeaux, which heralds the scale-up of battery cells based on solid electrolytes rather than liquid ones used in lithium-ion technology.
Saft’s programme includes solid electrolytes based on sulphides as well as polymer electrolytes that are capable of working at room temperature. The company is interested in use cases where the energy density, safety, and performance are particularly critical, such as aviation or space.
Solid-state batteries have garnered a lot of interest from the EV industry, as the technology has the potential to bring higher energy density to the table while mitigating some safety concerns, especially those posed by combustible liquid electrolytes. Saft said the technology could have up to 50% more energy density than traditional lithium-ion batteries, but that will depend on cell design and what battery is being compared to.
The company has also introduced a dry-electrode manufacturing process which it claims can cut production-related carbon dioxide emissions by as much as 40%.
Transitioning solid-state batteries from development to mass production has been difficult. Existing producers must prove cell quality and long cycle life, that battery material interfaces are robust and that they can be manufactured at market-competitive prices. So Saft’s announcement is an industrial milestone, and evidence that solid-state batteries are already being mass-produced for mainstream passenger EVs.
Why it matters
Having a production ability may assist the development of solid-state batteries, and also give expertise to support future applications of electric mobility.
