Professor Kyu-Young Park of the Institute of Ferrous & Eco Materials Technology, Department of Materials Science & Engineering, POSTECH led a research team that collaborated with Samsung SDI, Northwestern University, and Chung-Ang University to develop technology that will significantly increase the lifespan and energy density of electric vehicle (EV) batteries. The study was recently published in ACS Nano.
A battery used in electric vehicles must continue functioning even after being charged and drained numerous times. However, the existing technology has a significant problem: the battery’s positive active elements constantly expand and contract during the charging and discharging process, leading to small cracks inside the battery.
The battery’s performance significantly declines with time. Researchers are trying to stop this by strengthening the cathode active materials or adding reinforcing dopants, but these methods are not yet viable.
The key to this discovery is the ‘nano-spring coating’ technique, which can create elastic structures. The researchers applied a multi-walled carbon nanotube (MWCNT) on the surface of battery electrode materials.
This absorbed strain energy is created during the charging and discharging processes, preventing cracks and limiting electrode thickness variations, hence improving stability. The team successfully and effectively controlled cracks within the battery, extending its lifespan and enhancing performance.
This approach reduces resistance caused by volume variations in the material using only a small amount (0.5wt%, weight percentage) of conductive material. It can achieve a high energy density of 570 Wh/kg or higher. It also has a high longevity, with 78% of the initial battery capacity remaining after 1,000 charge and discharge cycles or more.
This technique, in particular, may be easily integrated into existing battery manufacturing processes, allowing for rapid scale production and commercialization. This advancement is likely to surpass current restrictions in battery technology, paving the way for more efficient and long-lasting EV batteries, which can help design superior electric vehicles.
With a different approach from existing ones, this research effectively controlled changes that could occur to a battery during the charging and discharging process. This technology can be widely used not only in the secondary battery industry but also in various industries where material durability is important.
Kyu-Young Park, Professor, Pohang University of Science and Technology
This research was funded by Samsung SDI, the Ministry of Trade, Industry, and Energy, and the Ministry of Science and Information Technology’s basic research fund.
Journal Reference:
Lim, J.-H. et. al. (2025) Enhancing Mechanical Resilience in Li-Ion Battery Cathodes with Nanoscale Elastic Framework Coatings. ACS Nano. doi.org/10.1021/acsnano.4c14980
