Clarios and Altris are stepping up their sodium ion battery tech partnership to start pilot-scale and small-series production in Slovakia.
The companies said on September 14 they had made significant progress in developing Na ion batteries for low-voltage and high-power applications since they revealed plans last January to launch serial production before the end of the decade.
Now the partners will expand their work at InoBat’s Volta facility in Slovakia, for what they described as product maturation, customer evaluations and industrialisation-readiness activities.
InoBat’s facility was commissioned in 2024. The site includes R&D labs, quality testing, and a pilot line capable of producing up to 50,000 cells annually. It is running customer qualification programmes and serves as a key enabler for future serial production.
Clarios said the partners had recently completed fresh validation work to further mature Na ion technology for future commercial applications, including successful summer validation under demanding operating conditions and continued validation with key automotive, heavy-duty and off-highway customers.
In addition, cell testing is said to have extended cold-cranking capability from the previously -25°C (-13 °F) low internal resistance and high power density to temperatures as low as -40°C.
This marks a significant advancement in Na ion low-temperature performance and broadening its applicability in demanding operating environments, the partners said.
Altris CEO Christer Bergquist said: “Automotive low-voltage is one of the most demanding validation environments for sodium ion technology, and Altris’ cathode material has now come through it.
“Proving the chemistry at that standard, with a material that uses no lithium, nickel or cobalt and can be produced in Europe at scale, is what makes the next phase possible.”
Sweden-based Altris, founded in 2017, is spearheading developing of its proprietary ‘Altris Prussian White’ cathode material, alongside electrolytes, battery cells and Na ion batteries.
Volvo’s venture capital arm became a key investor in Altris in 2025. The undisclosed investment by Volvo Cars Tech Fund was made in Altris’ B1 funding round.
