Teijin and Tokyo Institute of Technology Develop Extra-Conductive Carbon Nanofiber

December 06, 2011 - Japan

Teijin Limited and the Tokyo Institute of Technology announced today that they have co-developed a highly conductive carbon nanofiber (CNF) with an unprecedented, world's-first 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. It also has a high linearity structure 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 exceptional fiber length, but also from its unique 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.

About the Teijin Group

Based in Tokyo and Osaka, Japan, Teijin is a global technology-driven group operating in eight main fields: aramid fibers, carbon fibers & composites, polyester fibers, plastics, films, medical & pharmaceuticals, fiber products marketing and IT businesses. Teijin Limited, the holding company for the Teijin Group, is listed on the Tokyo and Osaka stock exchanges. The group, comprising 150 companies and 17,542 employees worldwide, had consolidated sales of JPY 815.7 billion (USD 10.6 billion) and total assets of JPY 761.5 billion (USD 9.9 billion) in the fiscal year ending March 31, 2011.