Power infrastructure firm Skeleton Technologies has raised €33 million ($39m) ahead of a planned US IPO next year.

The company, which develops graphene-based supercapacitors for the utility and AI data center markets, says the larger-than-expected round takes its total private funding to €392 million ($462m).

The new round expands Skeleton’s investor base with the addition of Axon Partners Group, SmartCap, and Taiwania Capital, with more investors set to be announced as part of a larger round ahead of the 2027 IPO.

“As AI infrastructure continues to scale, reliable, high-performance power solutions have become critical,” said Taavi Madiberk, CEO and co-founder of Skeleton Technologies. “This funding round brings additional strategic partners to the table and strengthens our ability to deliver the next generation of power solutions that cut AI data center energy consumption by 40 percent, increase computing power by 40 percent, and enable faster power grid connection.”

Skeleton’s system is a high-power energy-storage device designed to handle sharp load fluctuations in grids and AI data centers in under a millisecond. The company claims that its systems enable AI data centers to smooth power demand and reduce energy consumption.

The company was launched in 2009 in Tartu, Estonia. Its first customer was the European Space Agency and has seen uptake across the German automotive sector, with use in BMW’s i7 and M-series models.

It opened its first US manufacturing facility in Houston, Texas, earlier this year, following on from two European factories that launched in November 2025 – a $270 million facility in Germany and a $60m plant in Finland.

Other investors in the firm include Siemens Financial Services, Marubeni Corporation, FirstFloor Capital, and EIT InnoEnergy.

Madiberk added: “We are pleased to strengthen our investor base with new partners such as Axon, whose technology investment and growth-stage expertise will support Skeleton’s IPO preparations. Through Taiwania Capital, we are also deepening our relationship with the Taiwanese chip industry, creating more strategic opportunities as demand from AI data centers continues to grow.”