Skeleton Technologies
About Skeleton Technologies
Skeleton Technologies is a Energy Storage startup based in Tallinn, Estonia that has raised $430M in venture capital across 7 funding rounds since 2009. The company reached Pre-IPO stage in May 2026 with a $36M round led by institutional investors. Skeleton Technologies's investor base includes 12 institutional funds, with Siemens Financial Services leading the most recent equity round.
Skeleton Technologies is a deep-tech energy storage company that develops and manufactures curved-graphene ultracapacitors and hybrid SuperBatteries for AI data centers, grid stability, electric vehicles, and heavy transportation. Founded in Estonia and operating large-scale manufacturing facilities in Germany and Finland, the company's patented Curved Graphene technology delivers significantly higher power and energy density than conventional supercapacitors without relying on lithium, cobalt, or nickel. With over 70 patent families and Global Cleantech 100 Hall of Fame status (seven consecutive recognitions), Skeleton is planning a US IPO in 2027 after raising nearly €400 million in total equity financing.
Skeleton Technologies Funding Rounds Timeline
7 rounds · $430M raised · since 2009
| Round | Date | Amount | Valuation | Lead investor | Co-investors |
|---|---|---|---|---|---|
| Pre-IPO Round | May 2026 | $36M | — | — | Axon Partners Group, SmartCap, Taiwania Capital |
| Series E | October 2023 | $117M | — | Siemens Financial Services | Marubeni Corporation, CBMM, EIT InnoEnergy, MM Grupp, Harju Elekter |
| Series D | January 2022 | $41M | — | Taavet+Sten | Nidoco AB, EIT InnoEnergy |
| Series D | 2020–2021 | $76M | — | EIT InnoEnergy | FirstFloor Capital, MM Grupp, Harju Elekter, Marubeni Corporation |
| Series C | August 2016 | $29M | — | FirstFloor Capital | Harju Elekter |
Investors in Skeleton Technologies
12 institutional investors across 7 rounds
Lead investors
Co-investors
Recent news about Skeleton Technologies
- FundingSkeleton Technologies Raises €33M Pre-IPO Round, Plans US IPO in 2027May 2026
Questions about Skeleton Technologies
How much has Skeleton Technologies raised?
Skeleton Technologies has raised $430M across 7 funding rounds since 2009.
Who are the investors of Skeleton Technologies?
Skeleton Technologies's investors include Siemens Financial Services, EIT InnoEnergy, FirstFloor Capital, Taavet+Sten, Marubeni Corporation, CBMM, Axon Partners Group, SmartCap, Taiwania Capital, MM Grupp, Harju Elekter, Nidoco AB.
When was Skeleton Technologies's last funding round?
Skeleton Technologies's most recent round was a $36M Pre-IPO Round in May 2026.
Where is Skeleton Technologies headquartered?
Skeleton Technologies is headquartered in Tallinn, Estonia, and was founded in 2009 by Taavi Madiberk, Oliver Ahlberg, Jaan Leis, Anti Perkson.