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New Extra-Conductive Carbon Nanofiber

13 December 2011

Teijin Limited and the Tokyo Institute of Technology announced today that they have co-developed a highly conductive carbon nanofiber (CNF) with an elliptical cross-section consisting of well-developed graphite layers ordered in single direction.

The extra-conductive CNF has a length of 20 micrometers, or 10 times that of conventional CNF, and a diameter measuring a maximum 100 to 300 nanometers and a minimum 50 to 100 nanometers. According to Teijin, it also has high linearity offering 30-40% greater electrical conductivity compared to conventional CNF. As the material is produced with a melt-spinning process, a common production method for ordinary chemical fibers, the new CNF can be manufactured by utilizing existing facilities without significant new capital investment. Furthermore, CNF of high purity can be manufactured because no catalyst is used during the production process.

The research team discovered that the low electric resistance of the new CNT derives not only from its fiber length, but also from its structure of well-developed graphite layers ordered in a single direction throughout the cross-section. Conventional CNF has a cross-section made up of numerous concentric graphite layers.

Another notable feature of the new CNF is its numerous edges of loop-shaped graphene layers. These layers stick out from the fiber surface in high density, thereby promoting chemical reactivity, giving the new CNF higher connectivity with resins and also greater dispersion in liquid substances, properties that have been difficult to achieve with conventional carbon fibers.

The primary application envisioned for the new CNF is for battery components, including lithium-ion batteries for electric vehicles, capacitors, electrode additives, plastic additives, fuel-cell gas-diffusion layers and plastic reinforcing materials.