Saft Starts Solid-State Battery Cell Production in Bordeaux

• Saft opened solid-state battery cell lines in Bordeaux on Oct. 19, claiming up to 50% higher energy density than lithium-ion.
• The lines handle sulfide and polymer electrolytes, while China holds over 80% of global lithium-ion cell capacity, the IEA says.
• Saft has delivered semi-solid cells from the lines to Safran, and the program adds solid-state cells from 2027.

Saft, the battery unit of TotalEnergies SE, opened production lines in Bordeaux on Oct. 19 for solid-state cells that it says hold up to 50% more energy than conventional lithium-ion batteries.

The lines run two chemistries: sulfide-based all-solid-state cells and polymer-based semi-solid cells. Saft says it is the first French manufacturer able to develop and produce both at room temperature. Its dry electrode process cuts carbon dioxide emissions at that stage by up to 40%, the company said in a statement. Saft did not disclose output or investment, and it did not mention electric cars. It is aiming first at aircraft and spacecraft.

Europe starts from a small base. China holds more than 80% of global lithium-ion cell capacity, which topped 4 TWh at the end of 2025, the International Energy Agency says. The European Union and the United States hold 6% to 7% each. All-solid-state cells are still made only at small scale for testing, according to the agency.

The lines in numbers

• Up to 50% higher energy density than conventional lithium-ion batteries, according to Saft.
• About 33% less cell mass or volume for the same stored energy at that density gain (list.solar calculation).
• Up to 40% lower CO2 emissions at the electrode stage, from a dry electrode process.
• 2 electrolyte families on one set of lines: sulfide for all-solid-state cells and polymer for semi-solid cells.
• 2027 is when Saft's aviation partnership with Safran expands from semi-solid to solid-state cells and batteries.
• More than 10 GWh of grid batteries deployed or under way by Saft across nearly 170 projects, about 59 MWh per project (list.solar calculation).

Saft's products power more than 400 satellites in orbit and equip nearly 80% of commercial aircraft, the company said in June. Since TotalEnergies bought it in 2016, it has also become a supplier of grid-scale battery storage.

The new lines have already shipped product. On Oct. 15, Saft said it had delivered the first semi-solid cells made there to Safran for tests of electric and hybrid aircraft designs.

The lines turn "several years of research into real industrial capacity," Saft said in the statement.

Safran will test most of the cells at its System Test Center in Niort, western France. From 2027, the partners plan to add solid-state cells and batteries.