Researchers in South Korea have resolved the drawbacks of supercapacitors, which have struggled with commercialization due to low energy density. A supercapacitor is a device that temporarily stores large amounts of electricity.
Researchers including Kwon Bon-cheol, a senior researcher at the Carbon Nanomaterials Research Center at the Korea Institute of Science and Technology (KIST), and Kim Seo-kyun, senior researcher, along with Professor Park Won-cheol from Seoul National University, announced on the 30th that they have developed a high-performance supercapacitor that is attracting attention as a next-generation energy storage device. The research results were published on the 15th in the international journal "Composites Part B: Engineering," and both South Korean and U.S. patent applications have been completed.
Supercapacitors have the advantage of faster charging and higher power density compared to regular batteries. Power density indicates how quickly electricity can be discharged. However, the energy density, which refers to the amount of energy that can be stored per unit weight or volume, is relatively low. Because of this, there are limitations for long-term use, making it difficult to apply in electric vehicles or drones.
To solve these problems, the researchers created a new fiber by uniformly chemically bonding highly conductive single-walled carbon nanotubes (CNT) with polyaniline (PANI), which has advantages in processability and cost.
Carbon nanotubes are fine bundles of carbon atoms connected hexagonally like a honeycomb, exhibiting excellent conductivity. The fibers intertwined with carbon nanotubes create pathways for electricity to flow quickly, enabling rapid charging and discharging. The material polyaniline has exceptional electric storage capacity.
By using the two materials together, it was possible to create a supercapacitor that delivers electricity quickly while allowing for greater energy storage. The researchers stated that the supercapacitor developed this time maintained stable performance after over 100,000 charge-discharge tests and showed excellent durability even in high-voltage environments.
This technology can be used to replace or complement existing battery systems. For example, when applied to electric vehicles, it can provide rapid charging and an efficient power supply, improving both driving range and performance. In fields such as drones or robotics, various effects like increased operating time and enhanced stability are also expected. Additionally, the developed composite fiber (CNT-PANI) has high mechanical flexibility, making it applicable to next-generation electronic devices like wearable gadgets.
Another significant achievement of this research is the reduction of production costs and the securing of mass production potential. Despite the excellent characteristics of single-walled carbon nanotubes, their high production costs have posed challenges for commercialization. However, through the composite technology with inexpensive conductive polymer polyaniline, the researchers have lowered the costs. Furthermore, they have also established a process base that allows for mass production through simple processes and recently succeeded in developing a film-type structure.
Kwon Bon-cheol, the senior researcher, noted, "This technology has overcome the weaknesses of supercapacitors by using single-walled carbon nanotubes and conductive polymers," and added, "We plan to focus on the development and industrialization of carbon fiber based on carbon nanotubes in the future."
References
Composites Part B: Engineering (2025), DOI: https://doi.org/10.1016/j.compositesb.2025.112179