KIST leads next-generation energy storage technology with development of supercapacitor that overcomes limitations

A research team led by Dr. Bon-Cheol Ku and Dr. Seo Gyun Kim of the Carbon Composite Materials Research Center at the Korea Institute of Science and Technology (KIST) and Professor Yuanzhe Piao of Seoul National University (SNU) has developed a high-performance supercapacitor that is expected to become the next generation of energy storage devices. The technology developed by the researchers overcomes the limitations of existing supercapacitors by utilizing an innovative fiber structure composed of single-walled carbon nanotubes (CNTs) and the conductive polymer polyaniline (PANI).

Compared to conventional batteries, supercapacitors offer faster charging and higher power density, with less degradation over tens of thousands of charge and discharge cycles. However, their relatively low energy density limits their use over long periods of time, which has limited their use in practical applications such as electric vehicles and drones.

To solve this problem, the researchers uniformly chemically bonded single-walled carbon nanotubes (CNTs), which are highly conductive, with polyaniline (PANI), which is processable and inexpensive, at the nanoscale. This creates a sophisticated fiber structure that simultaneously enhances the flow of electrons and ions, resulting in a supercapacitor that can store more energy while releasing it at a faster rate.

The developed supercapacitor has been shown to maintain stable performance even after more than 100,000 charge and discharge tests and is durable even in high-voltage environments. Thanks to these characteristics, the technology can be utilized as a replacement or complement to existing battery systems. In electric vehicles, for example, it can provide efficient power delivery with fast charging to improve both range and performance. Other applications, such as drones and robots, could benefit from increased operational time and greater reliability. In addition, the developed composite fiber (CNT-PANI) has high mechanical flexibility, so it can be rolled and folded, enabling it to be applied to next-generation electronic devices such as wearable devices.

Another major achievement of the research is the reduction of production costs and the possibility of mass production. Despite their excellent properties, single-walled carbon nanotubes (CNTs) have been difficult to commercialize due to their high production costs, but the researchers solved this problem by compounding them with the low-cost conductive polymer polyaniline (PANI). Furthermore, they have laid the foundation for mass production through a simple process, and recently succeeded in developing film-like structures based on this technology, further advancing commercialization. In the future, it will be utilized as a key enabling technology for the transition to a carbon-neutral society across various industries such as electric vehicles, robots, drones, and wearable devices.

"This technology overcomes the shortcomings of supercapacitors by using single-walled carbon nanotubes and conductive polymers," said Dr. Bon-Cheol Ku of KIST. "We will continue to develop and industrialize ultra-high-performance carbon fibers based on carbon nanotubes."

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KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://www.kist.re.kr/eng/index.do

This research was supported by the Ministry of Science and ICT (Minister Yoo Sang-im) through the KIST Institutional Program, Regional Innovation Leading Technology Development Project (RS-2019-NR040066), Academic Research Platform Construction Pilot Project (RS-2023-00304729), and the Ministry of Trade, Industry and Energy (Minister Ahn Duk-geun) through the Material Component Technology Development Project (RS-2023-00258521). The research was published in the latest issue of the international journal 'Composites Part B: Engineering' (IF: 12.7, JCR: 0.3%), and domestic and U.S. patent applications have been filed.