BMW is taking another step toward the holy grail of electric vehicle (EV) battery tech as real-world testing of all-solid-state batteries (ASSBs) is now underway in a prototype i7.
The carmaker has partnered with US-based Solid Power to put its large-format, sulphide-based battery cells to the test on public roads for the first time.
Betting big on solid gains
The prototype BMW i7, currently roaming the streets of Munich, marks the first real-world integration of Solid Power’s ASSB cells into a complete vehicle battery pack.
These prismatic Gen5-based modules are built around a core promise: higher energy density with less bulk. That could mean longer driving ranges without the weight penalty of traditional lithium-ion systems.
BMW and Solid Power have been in cahoots since 2017, but this phase of the partnership kicks things up a gear.
As of late 2022, BMW began building out its own solid-state cell prototype line in Parsdorf, using Solid Power’s research and development license to expand in-house capabilities.
The collaboration reflects BMW’s broader battery ambitions - sharpened since 2008 and now funnelled through its Munich-based Battery Cell Competence Centre (BCCC), which houses the full value chain from R&D to cell production.
The chemistry of change
The battery pack in the test i7 uses sulphide-based electrolytes, and part of the trial will focus on how these cells expand, handle pressure, and manage temperature under real-world conditions.
The idea is to glean insights not just about performance, but also about how to manufacture and scale ASSB packs reliably.
“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,” said John Van Scoter, President and CEO of Solid Power. “We believe in the promise of ASSBs and continue to drive innovation of our sulfide electrolyte in support of that future for EVs.”
Not just a tech demo
Martin Schuster, Vice President of Battery Cell and Cell Module at BMW Group, framed the i7 test mule as more than just a fancy science project: “Our BMW i7 ASSB test vehicle on the road is a perfect example of the BMW Group’s technology-open mindset.”
And it’s not just about one car. BMW says the results from this programme will help refine future development of all-solid-state tech - seen by many as the next big leap in EV evolution.
No production dates have been set, but signs point to BMW laying the groundwork to make ASSBs a real-world proposition, not just a lab experiment.
