Germany’s eVTOL startup Lilium and battery cell production partner, Customcells, are ramping up battery cell production of Lilium’s high silicon content cells. The battery company is now delivering cells from the Customcells production line in Tübingen, Germany, every week and will produce thousands of cells per year in the future.
The production line is on track to meet aviation standards for traceability and process control using a combination of standard cell production processes and a pre-lithiation process for high silicon content cells.
Lilium partners with Californian company Ionblox for its exclusive silicon anode cell technology that allows for greater energy and power density combined with high cycle life. Ionblox specializes in battery cells for low-emission aviation and is currently working to scale up.
Following their partnership announcement in 2021, Customcells and Lilium are now successfully leveraging a pre-lithiation process that the companies are further industrializing toward volume production. The pre-lithiation process, a key advantage for enabling greater energy and power density, inserts additional lithium to compensate for the loss of lithium during the first cycle.
Additionally, Customcells’ production traceability will enable Lilium to meet aviation standards, and support production certification needs by delivering process-level and cell-level data to Lilium. Lilium remains on track to start production of its type-conforming aircraft later this year and plans for the first crewed flight of the type-conforming aircraft in the second half of 2024.
Lilium already has agreements in place for aerostructures, avionics, battery cells, energy management systems, e-motors, propulsion systems, aircraft interiors, and landing gear, among others. This announcement follows recent test results from a third-party independent laboratory which showed 88% energy retention, above the targeted 80% – in Ionblox’s full-size prototype battery cells being developed for the Lilium Jet after 800 charging cycles with 100% depth of discharge (1C/1C cycles).
“The multi-year development collaboration between Lilium and Customcells has been successful: together, we have proven the feasibility of mass production of high-performance lithium-ion batteries for eVTOL jets. Now we are automating our production step by step towards large quantities,” said Dirk Abendroth, CEO of Customcells Group.