CMBLU, a German developer of lithium-free flow batteries for large-scale energy storage, announced on 30 April 2026 that it had secured €50m (about $59m) in the first closing of its Series C financing round.
Samsung Ventures joined as an investor, and all existing investors took part again, according to pv magazine, which cited the company's statement. Converge Digest named construction group STRABAG SE as an existing backer. Neither of those reports named a lead investor, while Inforcapital and Nordic 9 said Samsung Ventures led the round, so the lead is not settled here. This article does not name one.
CMBLU said the round lifts its valuation above €1bn, which it described as the threshold for unicorn status. The company is based in Alzenau, Germany. The size of the final close was not given.
“Our SolidFlow technology is redefining energy storage by combining inherent safety with a streamlined permitting pathway”Constantin Eis, CEO, CMBLU
What CMBLU makes
CMBLU's product is SolidFlow, a redox-flow battery that does not use lithium and is designed for long-duration storage. According to Converge Digest, it is positioned for 10 or more hours of dispatchable capacity, uses non-flammable, water-based electrolytes and solid storage materials, and lets power and energy capacity be scaled independently.
The company cites uses such as supplying a 1 GW data centre for five hours or a 500 MW facility for ten hours. In its statement, it pointed to the ability to provide discharge capacity over ten hours or more as a key selling point.
Constantin Eis, the chief executive, said: "Our SolidFlow technology is redefining energy storage by combining inherent safety with a streamlined permitting pathway." Inforcapital said Eis, a former executive at Lichtblick and Home24, has run the company since 2024.
Customers and track record
In February 2026, pv magazine reported, CMBLU signed a framework agreement with the utility Uniper for 5 GWh of storage systems. Converge Digest also reported the 5 GWh deal.
STRABAG, the Austrian construction group, made a $106.7m (€100m) equity investment in CMBLU in October 2023, its first investment in an energy storage technology developer, according to the investor's release carried by Battery Power Online. At the time, CMBLU described its batteries as combining redox-flow and solid-state approaches, using earth-abundant organic materials, and said they could scale to the gigawatt-hour range. It named pilot projects with WEC Energy Group in Wisconsin and Salt River Project in Arizona, plus several sites in Europe.
Inforcapital reported that total funding to date exceeds €250m and that the company was founded in 2014. Nordic 9 gave a lower total of $164.9m raised to date. The two totals differ, so neither is used as the company's official figure.
What the money is for
The company said the fresh capital will expand and scale production and speed up projects in Europe and the United States. Converge Digest reported that manufacturing expansion is planned in Germany, the US and Greece, and that proceeds will fund manufacturing scale-up and early deployments.
The round is a first close, which means the company can add further investors to the Series C. The company did not disclose how much more it hopes to raise, nor its revenue or headcount. Inforcapital put the workforce at about 250, a figure not repeated elsewhere.
The round is a first close, which means the company can add further investors to the Series C. The company did not disclose how much more it hopes to raise, nor its revenue. Inforcapital put the workforce at about 250, a figure not repeated elsewhere.
Company website: cmblu.com