SPIRAL REDOX FLOW BATTERY

Spiral Energy Storage
German Innovation for Europe’s Energy Future

A compact, cylindrical energy storage system with an environmentally friendly electrolyte, designed to enable stable power distribution and high power density, while allowing cost-effective manufacturing and low operating costs.

Renewable energy is now the most cost-effective form of electricity generation — however, it is inherently intermittent. Solar power only generates electricity when the sun is shining, and wind turbines only produce energy when the wind is blowing. Without reliable large-scale energy storage, surplus renewable energy is wasted, power grids become unstable, and fossil-fuel backup power plants remain necessary.

Europe urgently needs a safer, lower-cost, and scalable solution for long-duration energy storage to reach the cenergy transition.

Current storage technologies have major limitations:

Lithium-Ionen Battery:

• Critical raw materials such as lithium, cobalt, nickel, and graphite are required, leading to geopolitical dependencies as well as significant environmental impact.

• Capacity loss over time.

• Temperature sensitivity and fire/explosion risk: expensive control and monitoring technologies are required; additional systems are needed to maintain stable operating temperatures.

Vanadium-Redox-Flow Battery:

• High manufacturing costs due to the chemically aggressive vanadium-based medium.

• The stacked graphite plates make the product heavy, bulky, and complex.

• Dependence on vanadium, a geopolitically highly concentrated raw material.

ADVANTAGES OF A RFB

Spiraltec GmbH has developed the Spiral-Wound Redox Flow Battery (SW-RFB)

— a next-generation energy storage system protected by European patent EP 3 900 095 B1.

Instead of using hundreds of stacked graphite plates like conventional flow batteries, the SW-RFB uses a compact spiral-wound cylindrical design, based on Spiraltec’s proven industrial winding technology.

Lightweight electrode design

• Uses thin graphite-coated copper foils

• Reduces weight and material cost significantly

Permanent hermetic sealing

• Potting resin creates a maintenance-free seal

• Prevents leaks and long-term mechanical failure

Vanadium-free electrolyte

• Developed with Allegro Energy

• Non-hazardous and non-aggressive chemistry

• Compatible with low-cost materials

The SW-RFB is designed specifically for utility-scale, long-duration energy storage.

• Long operational life

• No lithium, cobalt, or vanadium

• No thermal runaway or fire risk

• Minimal degradation over time

• Fully modular and scalable to GW level

• Low maintenance requirements

• Recyclable and environmentally friendly

Unlike lithium-ion batteries, the SW-RFB separates energy capacity from power output. This means storage duration can be increased simply by adding more electrolyte — without redesigning the battery system.

The SW-RFB is more than a battery — it is a platform for enabling reliable renewable energy at scale.

By combining:

• safer chemistry,

• lower-cost materials,

• scalable modular design,

• and long operational life

The technology offers a realistic path toward affordable, long-duration energy storage for Germany, Europe, and global renewable grids.

Cooperation

Are you interested in further developing the product together with us

or testing our prototype RFB at your company?

Please contact us:

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