Battery felts for redox flow batteries

Ideal properties for an efficient charge exchange

Permeable electrodes made of SIGRACELL carbon and graphite felts are the first choice for high-temperature batteries like redox flow batteries. Our felts are used for anodes as well as cathodes. Thanks to a unique combination of electrical conductivity, electrochemical stability, high porosity and good elasticity, they facilitate an efficient charge exchange between the electrolyte and the bipolar plate.

The sizes we provide are even enough to cover the needs of large-scale redox flow systems. We supply battery felts in standard sizes up to 1350 mm (53") in width in 25 m (82 ft) rolls. Beyond that, we produce carbon and graphite felts in customer- specific dimensions.

The complete in-house value chain ensures quality in the production of SGL Carbon's SIGRACELL battery felts. — The entire in-house value chain ensures the quality of SIGRACELL^® battery felts from SGL Carbon and thus contributes to optimizing battery performance.

Typical properties	Carbonized felts e.g. KFD2.5	Graphitized felts e.g. GFA3.0	Graphitized felts e.g GFD4.6	Thermally activated graphite felts GFA3.0 activated	Thermally activated graphite felts GFD4.6 activated
Fiber precursor	PAN	Rayon	PAN	Rayon	PAN
Chemical resistivity	○	++	+++	++	+++
Low area-specific resistance ⊥ ¹⁾	-	++	++	+++	+++
BET surface area	○	○	○	++	+++
Compressibility	+	++	+	++	+
Total impurities	-	+	+++	+	+++
Costs	+++	++	+	+	○