Teijin Techno Products Limited, a Teijin group company producing advanced aramid fibres, announced today that it has developed the world’s first mass-producible aramid nanofibre to offer reliable heat and oxidation resistance together with high quality.

“Until now, aramid nanofibres have been produced only in laboratories, so this first commercially viable product represents a significant step forward in the evolution of this promising new material,” Teijin said in a statement this morning.

Teijin Techno Products’ nanofibre, which is uniformly sized with a diameter of just several hundred nanometres, is based on Teijin’s proprietary Teijinconex heat-resistant meta-aramid and will be marketed in the form of nonwoven sheet for separators in lithium ion batteries (LIBs). Commercial production is targeted at 2014.

The highly heat-resistant aramid nanofibre sheet is said to maintain its shape even at 300°C and is also highly resistant to oxidation. Such features are expected to enhance the safety of high-power, high-capacity, energy-dense LIBs for vehicles and stationary storage, offering significant advantages over conventional separators in terms of reducing the risk of ignition in high-capacity, energy-dense applications.

Other features

Other features that Teijin Techno Products expects to achieve with aramid nanofibre nonwoven sheet for battery separators include:

High porosity promotes smooth mobility of the electrolyte, resulting in higher output and faster charging

Large surface area, a feature of nanofibres, as well as high porosity, hold the electrolyte effectively to maintain battery performance at low temperatures, when ion conductivity drops.

As a nonwoven sheet, absorbs electrolyte more rapidly than conventional polyolefin-based separators, helping to shorten the time required to pour electrolyte into the battery, thereby reducing the production cost of large batteries

Teijin Techno Products expects to develop other applications for its thin, heat-resistant aramid nanofibre sheet, such as separators for capacitors; high-performance, heat-resistant filters; and heat-resistant cleaners for office automation equipment.

The Teijin Group has also developed two types of separators based on porous polyethylene film, one coated with a fluorine-based compound for high heat-resistance and adhesion to polymer electrolyte, and the other coated with Teijinconex meta-aramid for excellent heat-resistance and dimensional stability, both of which will be commercialized in June under the Lielsort brand. The addition of aramid nanofibre sheet will further strengthen Teijin’s presence in the high-end LIB separator market.

Teijin is a technology-driven global group offering advanced solutions in the areas of sustainable transportation, information and electronics, safety and protection, environment and energy, and healthcare. Its main fields of operation are high-performance fibres such as aramid, carbon fibres and  composites, healthcare, films, resin and plastic processing, polyester fibres, products converting and IT. The group has around 150 companies and over 17,000 employees spread out over 20 countries worldwide. It posted consolidated sales of JPY 815.7 billion (USD 9.9 billion) and total assets of JPY 761.5 billion (USD9.3 billion) in the fiscal year ending March 31, 2011.