- Who & where: CustomCells, a German maker of high‑performance lithium‑ion cells with sites in Itzehoe (Schleswig‑Holstein) and Tübingen (Baden‑Württemberg). CustomCells
- What: Filed for insolvency proceedings for its key operating entities; the Kiel local court appointed Dr. Malte Köster (WILLMERKÖSTER) as preliminary administrator. Business operations continued during preliminary proceedings. CustomCells
- When: Filing announced April 30, 2025; formal opening of proceedings followed on July 1, 2025. CustomCells
- Why: Payment default of its largest customer Lilium (the eVTOL developer) left “tens of millions of euros” in receivables unpaid; attempts to secure public‑sector support or new investors in time were unsuccessful. CustomCells
- Immediate employee impact: Wages were secured through June 2025 and operations continued while an investor search was relaunched. CustomCells
- Rescue deal: On July 3, 2025 a family‑office consortium led by existing investor ABACON and SALVIA signed a takeover agreement; ~80% of jobs in Itzehoe to be retained. CustomCells
- Site status: Itzehoe continues R&D and production for existing customers; Tübingen—already shut when the filing was made—will not reopen. CustomCells
- Context: Lilium’s financial collapse—self‑administration in Oct 2024, a second insolvency in Feb 2025—was the decisive external shock. AOPA
What is CustomCells—and why it mattered
Founded in 2012 as a Fraunhofer spin‑off, CustomCells built a reputation for tailor‑made, high‑performance cells for demanding niches—from e‑aviation and motorsport to defense and mining—operating pilot and small‑series facilities in Itzehoe and Tübingen with 200+ employees. That “premium, custom” positioning made it one of the few battery manufacturers actually based in Germany. CustomCells
The trigger: a customer crisis becomes a supplier crisis
On April 30, 2025, CustomCells said its finances were hit primarily by the insolvency and non‑payment of its largest customer Lilium, leaving receivables in the tens of millions. With investor talks and public‑sector support efforts falling short, the company sought court protection, while assuring that operations would continue and staff salaries were guaranteed through June 2025. CustomCells
Lilium’s turmoil has been long in the making: its German entities entered self‑administration in October 2024, and after an attempted rescue fell through, it filed for insolvency again in February 2025—a double blow that cascaded through its supply chain. AOPA
The legal mechanics: what the filing actually meant
Under German law, preliminary insolvency allows court‑supervised stabilization while an administrator evaluates restructuring or sale. The Kiel court appointed Dr. Malte Köster as preliminary administrator. CustomCells emphasized that at the time of filing, the holding company was not affected (the application covered the operating entities in Itzehoe and Tübingen). CustomCells
Employee and operations outlook (spring → summer 2025)
Throughout May–June, production and R&D continued while the investor process restarted; press and sector outlets echoed that more than 200 employees had been briefed and that payroll was secured through June. electrive.com
On July 1, 2025, insolvency proceedings were formally opened—and the very next day a buyer stepped forward. On July 3, CustomCells announced a takeover agreement with a consortium of family offices around ABACON and SALVIA. The plan: retain ~80% of jobs in Itzehoe, continue ongoing customer programs, and wind down Tübingen, which had already been closed when the filing was made due to the fallout from Lilium. CustomCells
Independent trade press corroborated the contours of the deal—Itzehoe continues, Tübingen remains closed, and completion is tied to insolvency timelines. Battery-News
Customers and sectors affected
The rescue statement highlights existing customers across defense & security, aviation, motorsport, and mining—notably, NATO system integrators sourcing qualified cells for naval use—suggesting that core niche, high‑spec programs at Itzehoe will keep running under the new owners. CustomCells
Why the collapse reverberates beyond one supplier
CustomCells’ troubles underscore two structural risks:
- Customer concentration risk in emerging industries
Betting big on a single flagship program (e.g., eVTOL) multiplies exposure when macro or funding conditions turn. Lilium’s dual insolvency events made that exposure painfully concrete. AOPA - Tougher battery‑market conditions and capital scarcity
CustomCells explicitly cited failed efforts to secure regional, federal and EU support, alongside sector headwinds. Across Europe, larger players have also been re‑scoping battery ambitions—for instance, Porsche recently scrapped mass‑production plans at its Cellforce unit, citing weak EV demand and scale‑economics, choosing to refocus on R&D. That backdrop helps explain why new capital for small‑series cell production has been harder to mobilize. CustomCells
The timeline (concise)
- Oct 2024 — Lilium’s German subsidiaries enter self‑administration. AOPA
- Feb 21–25, 2025 — Lilium files again after rescue funding collapses. Aviation International News
- Apr 30, 2025 — CustomCells files for insolvency for Itzehoe & Tübingen operating entities; wages secured to June; admin Dr. Malte Köster appointed. CustomCells
- May 2025 — Trade press confirms operations continue; ~200 staff informed; investor process restarts. electrive.com
- Jul 1, 2025 — Insolvency proceedings officially opened. CustomCells
- Jul 3–7, 2025 — Takeover agreement with ABACON + SALVIA consortium; plan retains ~80% of Itzehoe jobs, Tübingen stays closed; media note a “fresh start.” ChemEurope
What to watch next
- Closing and integration: Watch for final regulatory and creditor approvals and the transfer of assets to the new owners. The Itzehoe tech cluster is slated to retain both R&D and small‑series production for existing programs. CustomCells
- Customer mix: Expect a pivot toward defense, motorsport, industrial and specialty mobility customers—programs with steadier funding cycles than eVTOL. CustomCells
- Germany/EU battery policy signals: CustomCells’ statement that institutional support efforts failed will feed ongoing debates about how Europe funds pilot‑to‑industrial transitions in battery tech. CustomCells
- Industry ripple effects: With large automakers paring back in‑house battery manufacturing and focusing on R&D partnerships, niche producers may need deeper anchor customers (defense/industrial) or consortia ownership to weather cycles. Reuters
Sources & further reading
- CustomCells press release (Apr 30, 2025) — filing details, administrator appointment, wage protection to June, and cause (Lilium payment default). CustomCells
- Electrive (Apr 30, 2025) — background, employee count, operations‑continue note. electrive.com
- Battery‑News (May 5, 2025) — summary of filing and context. Battery-News
- CustomCells newsroom (Jul 3, 2025) — investor consortium (ABACON, SALVIA), ~80% Itzehoe jobs, Tübingen closure. CustomCells
- Battery‑News (Jul 4, 2025) — independent report confirming buyer, site/job outcomes. Battery-News
- Electrive (Jul 3, 2025) — follow‑up on “fresh start”. electrive.com
- Lilium context: AOPA (Oct 30, 2024) and AIN/Vertical (Feb 2025) on insolvency timeline. AOPA
- Sector backdrop: Porsche’s 2025 Cellforce realignment away from mass cell production (company and major‑press reports). Porsche Newsroom
Bottom line
CustomCells didn’t fail because its technology under‑performed; it was pulled under by a collapsing anchor customer and a tighter capital climate. Thanks to a quick sale out of insolvency, the Itzehoe nucleus of R&D and production survives—with a leaner footprint, a different owner set, and (likely) a more conservative customer portfolio. The Tübingen pilot plant, however, is part of the price of that survival. CustomCells
