Saft opens solid-state battery line in Bordeaux

At its Bordeaux facility in southwestern France, Saft has inaugurated its first solid-state battery production line. Saft, a subsidiary of TotalEnergies, says it is the first French manufacturer able to develop and produce solid-electrolyte batteries that combine sulfide and polymer technologies at room temperature.

In a conventional lithium-ion battery, the electrolyte is a liquid, the medium through which charged particles travel between the two poles. A solid-state battery swaps that liquid for a solid. Saft says this promises better safety and an energy density up to 50% higher than conventional lithium-ion cells, energy density being the amount of energy a battery stores for a given weight or size.

The manufacturing side matters as much as the chemistry. Some steps, including dry coating, use less energy, and eliminating solvents lowers the environmental footprint of making the cells. Saft puts the reduction in carbon dioxide emissions at up to 40% for this stage of the process.

Saft's first targets are aircraft and spacecraft, where battery safety, performance and energy density are critical. In aviation, the company has already delivered semi-solid cells for evaluating future electric and hybrid aircraft designs, and it sees solid-state technology as potentially important for the gradual electrification of air transport. Space is a potential market for the same reasons.

What changes, and for whom? For now, the first customers are aircraft and space programmes that need the most energy in the least weight and the highest safety margins. Stationary storage, the large batteries that hold electricity for power grids, is a possible later market, but Saft says that depends on meeting that sector's technical and economic requirements. The announcement gives no output volumes, prices or delivery dates, and the performance figures are the company's own. Independent tests in real operating conditions will decide how far the promised gains hold.