Lilium & Customcells start battery production

Germany’s eVTOL startup Lilium and Customcells are ramping up production of high-silicon battery cells to get ready for certification. The battery company is now delivering cells from its plant in the German town of Tübingen every week and will produce thousands of cells per year in the future.

Lilium exclusively licenses silicon anode cell technology of its Californian partner company Ionblox and increased its stake in the developer only last month. Ionblox specialises in battery cells for low-emission aviation and is currently working to scale up.

Lilium already made a deal with Customcells in 2021 to secure cell production in Germany. Customcells, also a partner to Porsche, guarantees production capacity in Tübingen, where it works with equipment manufacturer Manz AG.

In today’s news, Lilium and Customcells announced the scale-up mentioned above to weekly output. This follows their successful leverage of the pre-lithiation process that the companies are further industrialising towards volume production. The pre-lithiation process developed by Ionblox inserts additional lithium to compensate for the loss of lithium during the first cycle.

Lilium claims recent test results from an independent laboratory 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 discharge (1C/1C cycles).

Dirk Abendroth, CEO of Customcells, said that together they had proven the feasibility of mass production of high-performance lithium-ion batteries for eVTOL jets. “Now we are automating our production towards large quantities.”

Lilium jet shall take off next year but is weighed down

Lilium is optimistic that the batteries will help them towards certification. The company says that the production line was on track to meet aviation standards for traceability and process control using a combination of standard cell production processes and a pre-lithiation method for high silicon content cells.

Lilium, therefore, wants to start building its first six aircraft to go into certification this year ahead of the first crewed flight in the second half of 2024.

While the timeline has been longstanding, it now appears that the startup is still missing capital to take off. “We are about 300 million dollars short of the first crewed flight,” Lilium co-founder Daniel Wiegand told the German publication Handelsblatt. At the same time, Lilium cannot raise money on the stock market since its share price has lost over 90 per cent since the IPO in September 2021. While Lilium retained €206 million at the end of 2022, it expects to spend €125 million in the first half of 2023 alone, so the money will not last until certification without further funding.

In terms of Lilium’s product, flights with uncrewed Lilium eVTOLs with 30-sheathed and tiltable rotors have been successful. The current demonstrator has reached the full speed of 250 kilometres per hour for the first time, Lilium writes in its letter to shareholders.

The German zero-emission aircraft developer also mentions the first pre-delivery payments from eVolare and new customers, including ifly (Greece), bringing the total order pipeline to 640 Lilium Jets. Lilium has also signed agreements with global aerospace suppliers, including Collins Aerospace and GKN Aerospace, and has begun ramping up collaboration with existing suppliers, including layup moulds built by Aciturri for type-conforming composite fuselage.

customcells.org (battery ramp-up), handelsblatt.com (capital shortage, in German), lilium.com (letter to shareholders)