BMW Tests Solid-State Battery Tech in i7 Prototype
BMW has fitted its i7 test vehicle with large-format, all-solid-state battery (ASSB) cells from Solid Power and deployed it on the roads around Munich. These advanced cells promise greater energy density within a compact structure, allowing future electric vehicles to travel further without increasing battery size or weight.
Since 2022, BMW and Solid Power have accelerated collaboration through a dedicated technology transfer agreement. Both companies remain confident in the potential of genuine ASSB technology, which could enable extended driving ranges while maintaining a lightweight battery pack—an essential combination for premium electric mobility.
Solid Power’s President and CEO, John Van Scoter, said, “Solid Power is extremely proud that our partnership with BMW has resulted in the first demonstration of truly all-solid-state battery cells in a vehicle. We believe in the promise of ASSBs and continue to drive innovation of our sulphide electrolyte to support that future for EVs.”
Martin Schuster, Vice President of Battery Cell and Cell Module at BMW, added, “Our BMW i7 ASSB test vehicle on the road is a perfect example of the BMW Group's technology-open mindset. We are continuously advancing the development of new battery cell technologies and expanding our know-how with valuable partners such as Solid Power.”
The concept battery inside the BMW i7 prototype combines established Gen5 design principles—such as prismatic cells in modules—with new integration methods tailored for Solid Power’s ASSB cells. Engineers will study cell expansion, control of operating pressure, and thermal management to fine-tune the technology for real-world use.
By integrating Solid Power’s sulphide-based electrolyte cells into a complete battery pack, BMW aims to gain critical data through its ongoing test programme. These insights will inform the future development of commercially viable ASSB systems.
Solid Power produced the innovative cells in close cooperation with BMW’s experts. Both parties acknowledge that several key development stages remain before ASSB technology can reach production maturity. Their joint efforts began in 2016 through a formal development agreement, which BMW reinforced with an investment during Solid Power’s 2021 financing round.
At the end of 2022, BMW and Solid Power expanded their partnership further. BMW will now run a prototype solid-state cell production line at its Cell Manufacturing Competence Centre (CMCC) in Parsdorf, supported by a research and development licence and guided by Solid Power’s technical expertise.
Since 2008, BMW has steadily built its battery cell know-how, consolidating efforts at the Battery Cell Competence Centre (BCCC) in Munich since 2019. The BCCC covers the entire battery value chain, from R&D and cell design to production readiness.
BMW collaborates with a global network of around 300 partners to speed up innovation, ranging from established firms and start-ups to leading universities. The partnership with Solid Power aligns perfectly with BMW’s strategic aim to develop cutting-edge battery technologies through equal-footing collaborations, securing the company's access to breakthroughs in global battery cell research.
