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Carbon Nanofibers

The filament between two scales. Carbon nanofibers offer much of the strength and conductivity of carbon nanotubes in a larger, easier-to-handle filament, and the boundary between the two is one of the most contested lines in the carbon family.

150nm
Filament diameter
Vapour-grown VGCF-H grade
~3GPa
Tensile strength
2.5 to 3.5 in the literature
15m²/g
Surface area
Low for a nanocarbon, suits batteries
99.99+%
Carbon content
Graphitised battery grade

What is carbon nanofibers

Carbon nanofibers, or CNFs, are cylindrical carbon nanostructures around 150 nanometres in diameter for the dominant vapour-grown grades, finer or coarser by production route, with lengths from a few microns to quasi-continuous electrospun mats. Most commercial material is vapour-grown (VGCNF), with graphitic layers arranged in stacked-cup, fishbone or ribbon morphologies rather than the seamless concentric tubes of carbon nanotubes. That structure gives a high aspect ratio and an edge-rich surface that bonds and functionalises more readily than a perfect tube wall, at the cost of somewhat lower crystallinity. The boundary with multi-walled carbon nanotubes is genuinely contested: some market analysts count vapour-grown carbon fiber as a carbon nanotube, since filaments of around 150 nanometres are structurally similar to conventional CNTs, and suppliers sell the same vapour-grown grades described as multi-walled carbon nanotubes. That matters when reading market data, because CNF and CNT figures overlap and cannot simply be added together.

Material properties

What makes carbon nanofibers exceptional

Tensile strength2.5 to 3.5 GPa for vapour-grown filaments
StiffnessModulus from 100 to 500 GPa with graphitisation
Electrical conductivityAround 6,000 S/m as a compacted powder
Thermal conductivityOrders above a 0.2 W/m·K polymer matrix
Low surface area15 m²/g BET, limiting electrolyte breakdown
Tailorable surface chemistryEdge planes take oxidation, grafting and coatings
High aspect ratioLong filaments that form percolating networks
DispersibilityEasier to disperse and bond than nanotubes

Market outlook

A market scaling fast

Carbon nanofiber production is concentrated in a small number of specialist plants. Resonac, the largest established producer, expanded its vapour-grown capacity at its Kawasaki plant in Japan to 400 tonnes a year from October 2023, up from 300, while emerging CO2-to-carbon entrants and catalogue suppliers operate at tens of tonnes a year. No reliable global market figure exists: published CNF market sizes often conflate carbon nanofibers with cellulose nanofibrils, which share the abbreviation, and some analysts count vapour-grown material within the carbon nanotube market instead, so CNF and CNT figures overlap.

400 t
Largest producer capacity per year, vapour-grown, 2023
Tens of t
Capacity of smaller catalogue suppliers
8
Application sectors tracked

Standards and certification

Key Carbon Nanofibers standards

Recent coverage

What we’re reporting

All carbon nanofibers articles

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At a glance

Diameter~150 nm (vapour-grown)
LengthMicrons, route-dependent
StructureStacked-cup, fishbone
Made byVapour growth (VGCNF)
Largest usesComposites, batteries