‘Carbon nanobrush’ might improve battery performance.
NEC Corp says it has developed a carbon material called “carbon nanobrush” for the first time in the world.
The material can improve the performances of storage batteries and sensors and add conductivity to plastic, rubber, NEC said.
A carbon nanobrush consists of carbon nanohorns (CNHs) assembled like fibers. It is about 100nm in diameter and about 1-10μm in length.
In regard to CNH-based carbon materials, there is a spherical CNH, which consists of CNHs assembled into the shape of a sphere. Both CNH and spherical CNH have a high dispersibility and hardly condense. But they are different in conductivity.
The conductivity of CNH is 10 times or more higher than that of spherical CNH. This is because the distance among spherical CNHs dispersed in a base material is relatively large while, in the case of carbon nanobrush, electrons pass through a string of fabric structures, making it easy for electricity to flow.
For example, when a carbon nanobrush is used as a conductive material of a storage battery’s electrode, it can increase charging/discharging speed by 10-15%, NEC said.
In addition, CNH has a large specific surface area. Therefore, it has a high “adsorptivity,” which enables to retain different substances on the surface. With this characteristic, CNH can be used as a high-performance adsorbent.
Carbon nanobrush is made by applying laser light to a carbon-rod target including iron catalyst. It is almost the same as the manufacturing method for spherical CNH, but a carbon-rod target that does not contain iron is used for spherical CNH. Volume production equivalent to that of spherical CNH (1kg/day) becomes possible just by changing the target, NEC said.
NEC plans to test the material and advance development for commercialization in collaboration with material manufacturers and research institutes. It intends to start to provide samples in fiscal 2017.