The Korea Electrotechnology Research Institute (KERI) has succeeded in effectively dispersing CNTs, which have a strong tendency to aggregate, and has opened the way for applying CNTs to secondary battery dry processes. Expectations are high that this will contribute to the realization of high-capacity next-generation secondary batteries.

KERI announced on the 25th that Dr. Han Joong-tak's team at the Nano Convergence Research Center developed the world's first 'highly dispersible carbon nanotube (CNT) powder manufacturing technology' that can be easily applied to the eco-friendly dry process of next-generation secondary batteries.

CNTs are a new material that is 100 times stronger than steel and has electrical conductivity comparable to copper. They are made up of carbon atoms linked in hexagonal rings to form a long cylinder. CNT is a one-dimensional nano material that is flexible and has excellent electrical conductivity compared to carbon black, which is used as a conductive material in existing secondary batteries.

If CNTs are used as a conductive material for next-generation secondary batteries, the energy density can be significantly increased even with just a small amount of addition.

On the other hand, CNTs have a very strong tendency to clump together, so they have a tangled structure and there is a problem that they do not mix well with other materials in the secondary battery, such as binders and active materials.

In particular, in the case of the dry process, there is a problem of having to uniformly mix CNTs with other materials under solvent-free conditions, and this has been identified as one of the challenges that the battery industry needs to solve.

The achievement of Dr. Han Joong-tak's team is the development of a technology to make CNTs into powder form, minimizing agglomeration and easily dispersing them with active materials or binder materials in a dry process. Through years of research, the research team succeeded in controlling the CNTs so that they do not clump together and remain separated even in the powder state.

This opens the way to manufacturing high-capacity batteries by creating a conductive material with long one-dimensional CNT structures even in difficult dry processes. Even without using solvents, well-dispersed, highly conductive CNTs can greatly contribute to improving the performance of next-generation secondary batteries by electrically connecting other materials inside.

KERI's Dr. Han-Joong Tak said, "The dry process is environmentally friendly because it does not use toxic solvents, and of course, there is no need to recover them, so the process is simple. The production cost is also low, so it is attracting attention from global electric vehicle companies." He added, "We are the first in the world to effectively disperse CNTs in the dry process to create a conductive material, and it will be of great help in securing a leading edge in next-generation secondary battery technology."

KERI, which has completed domestic patent application related to the performance, is conducting various verifications, including applying the 'high-dispersion CNT powder manufacturing technology' to high-capacity, thick-film cathodes/anodes.

In addition, we expect that this achievement will attract much attention from related industries, such as lithium-sulfur batteries and all-solid-state batteries that require dry processes as next-generation batteries, and we plan to find companies in demand and transfer the technology.

Meanwhile, KERI is a government-funded research institute under the National Research Council of Science and Technology, Ministry of Science and ICT. This research was conducted with the support of KERI Basic Project and the National Research Council of Science and Technology Creative Convergence Research Project.