Develops lithium-sulfur battery cells with crystalline sulfur for aviation, electromobility and stationary energy storage.
theion GmbH
Berlin (Adlershof)New on Amplifa
About theion
theion GmbH is a battery company founded in Berlin in 2020 that develops lithium-sulfur battery cells based on its proprietary Crystal Battery technology. The core of the technology is Direct Crystal Imprinting (DCi): polycrystalline sulfur wafers are grown from molten sulfur within seconds — without slurry coating, solvents or drying. The cathodes consist of more than 88 wt.-% sulfur, and the anode is a patented lithium-metal host foil with a lightweight polymer host and special coating; a proprietary solid-state polymer electrolyte operates in the wafer's cavities. At its Tech Centre in the Adlershof Science and Technology Park, the company has synthesis, glovebox and cycling laboratories as well as a semi-automatic pouch cell assembly line with 1 MWh capacity for customer samples. Target industries include air mobility (eVTOL), aerospace, land-based electromobility, stationary energy storage and portable electronics. The team of around 20 scientists, engineers and entrepreneurs is led by CEO Dr. Ulrich Ehmes and co-founder Marek Slavik; the technology is protected by eleven filed patents, three of which have been granted.
- Site
- Berlin
- Processes
- Manufacture of lithium-sulfur battery cells (Crystal Battery), Direct Crystal Imprinting (DCi) – growing polycrystalline sulfur wafers directly from, Cathode coating using particulate solution and UV irradiation (instead of slurry coating), Semi-automatic pouch cell assembly (cell sampling, 1 MWh cell assembly), Coin cell development (reference designs) and validation, Cycle testing / cell characterization (Cycling Lab), Development of lithium-sulfur battery cells (Crystal Battery), Sulfur Crystal Wafer production (Direct Crystal Imprinting, DCi)
- Materials
- Sulfur (crystalline, monoclinic gamma allotrope), Lithium metal (host foil as anode), Solid-state polymer electrolyte (proprietary), Lightweight polymer host with special coating (anode), Direct Crystal Imprinting (DCi), Cathode coating with particulate solution and UV irradiation
- Founded
- 2020
- Employees
- 20
- Industries
- Air mobility / eVTOL / electric aviation, Aerospace, Electromobility (land), Stationary energy storage (grid, residential, industrial), Portable electronics
- 01
Sulfur preparation and crystal growing (DCi, Direct Crystal Imprinting)
- 02
Cathode coating using particulate solution and UV irradiation
- 03
Manufacture of the lithium-metal host anode
- 04
Cell assembly (semi-automatic pouch cell assembly line)
- 05
Cell characterization and cycle testing (Cycling Lab)
Materials & Processes
Sulfur (crystalline, monoclinic gamma allotrope)
Active cathode material of the Crystal Battery; globally available as an industrial by-product without harmful mining.
Lithium metal (host foil as anode)
Patented host anode that prevents dendritic growth and has been validated by third parties for over 2,000 cycles.
Solid-state polymer electrolyte (proprietary)
Proprietary polymer electrolyte that operates in the cavities of the sulfur wafer.
Direct Crystal Imprinting (DCi)
Process for growing polycrystalline sulfur wafers directly from molten sulfur within seconds, without slurry coating and solvents.
Cathode coating with particulate solution and UV irradiation
Coating process that creates a layer against the polysulfide shuttle effect, instead of slurry coating.
Locations
Berlin
DEHeadquarters and Tech Centre (Adlershof Science and Technology Park)
- Lot size
- Cell sampling / customer samples
- Materials
- Sulfur, lithium, solid-state polymer electrolyte
- Semi-automatic pouch cell assembly line (1 MWh)
- Glovebox laboratory
- Synthesis laboratory
- Cycling laboratory (cell testing)
Industries
Processes & technical limits
| Processes | Tolerance | Max. part | Weight | Lot size | Materials |
|---|---|---|---|---|---|
| Manufacture of lithium-sulfur battery cells (Crystal Battery)Plastics | – | – | – | – | Sulfur, Lithium, Solid-state polymer electrolyte |
| Direct Crystal Imprinting (DCi) – growing polycrystalline sulfur wafers directly fromCasting | – | – | – | – | Sulfur |
| Cathode coating using particulate solution and UV irradiation (instead of slurry coating)Surface | – | – | – | – | Sulfur |
| Semi-automatic pouch cell assembly (cell sampling, 1 MWh cell assembly)Assembly | – | – | – | – | Sulfur, Lithium |
| Coin cell development (reference designs) and validationTesting | – | – | – | – | Sulfur, Lithium |
| Cycle testing / cell characterization (Cycling Lab)Testing | – | – | – | – | Sulfur, Lithium |
4 Anlagen & Maschinen
| Machine | Manufacturer / model | Quantity | Working area | Year built | Site |
|---|---|---|---|---|---|
| Semi-automatic pouch cell assembly line (cell sampling, 1 MWh) | – | – | – | – | Berlin Adlershof, Tech Centre |
| Glovebox laboratory | – | – | – | – | Berlin Adlershof |
| Synthesis laboratory | – | – | – | – | Berlin Adlershof |
| Cycling laboratory (cell testing) | – | – | – | – | Berlin Adlershof |
Additional services
Company History
- 2020
Foundation of theion GmbH in Berlin by Marek Slavik; the name is derived from the Ancient Greek word for sulfur.
- 2022
Dr. Ulrich Ehmes joins as CEO (since February 2022).
- 2024
Third-party validation of the patented lithium-metal host anode with over 2,000 cycles by an independent German research institute.
- 2024
Collaboration with camLine: AI-assisted reduction of R&D test times by 98% (42 days to 15 hours).
- 2024
Opening of the new Tech Centre in the Adlershof Science and Technology Park, Berlin (13 June 2024).
- 2025
Closing of the Series A financing round of EUR 15 million; investors include Enpal, Team Global and Geschwister Oetker Beteiligungen KG.
- 2025
Start of the three-year LiSSy research project on lithium-sulfur batteries (consortium lead; funded by the BMFTR, total budget EUR 5.3 million; partners: QuanteQ, Fraunhofer ISIT, Helmholtz-Zentrum Berlin).
- 2025
Financing round of USD 16.4 million reported for scaling; technology protected by eleven filed patents, three of which have been granted.