Renault’s electric vehicle subsidiary Ampere has signed a development agreement with Spanish battery startup Basquevolt to accelerate the creation and validation of lithium-metal batteries for future electric vehicles.
The collaboration will focus on producing and testing so-called “pre-A” prototype cells, an early stage in battery development used to assess core design concepts before full engineering validation. Renault said Basquevolt’s technology has already demonstrated the potential for very high energy density while reducing overall battery pack costs.
According to the companies, the lithium-metal cells will use a polymer electrolyte that simplifies manufacturing. This approach could lower capital expenditure for battery plants by about 30% per gigawatt-hour of capacity and reduce energy consumption during production by a similar margin.
The technology also promises benefits at the vehicle level. “By combining the advantages of polymer electrolyte with advanced anode, the technology has the potential to enable compact, lightweight battery packs with superior thermal stability and fast-charging capabilities,” Renault said, though it did not provide detailed performance figures. Earlier research by Basquevolt indicated multilayer cells could reach energy densities of around 450 Wh/kg.
Despite their theoretical advantages, lithium-metal batteries face significant technical challenges, particularly limited lifespan due to dendrite formation—needle-like lithium deposits that can penetrate separators and cause internal short circuits. The partners did not disclose how they plan to mitigate this issue, which has hindered commercialization of the technology.
Basquevolt, founded in 2022, focuses on solid-state and polymer-electrolyte battery research and plans to establish a production line with capacity of up to 10 GWh. The initiative is backed by the Basque regional government and energy and industrial companies including Iberdrola, CIE Automotive, Enagás, EIT InnoEnergy and CIC energiGUNE.
Pablo Fernández, chief executive of Basquevolt, said the agreement represents a key step toward commercialization. “Entering this next phase with Ampere marks a major milestone in our mission to bring polymer electrolyte technology closer to the mass market,” he said.
Nicolas Racquet, Ampere’s vice president for vehicle and powertrain engineering, said the partnership aims to validate performance under real automotive conditions and accelerate deployment of next-generation batteries.
