High-performance magnesium ion supercapacitor developed
Team led by Professor Yoon Young-soo of Korea University collaborated with Inha University and Kangwon National University
Results published in the leading international journal Advanced Energy Materials
The team led by Professor Yoon Young-soo of the KU-KIST Graduate School of Converging Science and Technology developed a next-generation magnesium ion supercapacitor utilizing a magnesium-ion-based charge carrier and an active electrode material with nanoporous carbons.
The study was published online (June 23) in the leading journal Advanced Energy Materials, and featured on the back cover. The participating teams were led by Professor Yoon Young-soo of the KU-KIST Graduate School of Converging Science, Professor Jin Hyoung-joon of Inha University’s Department of Polymer Science and Engineering, and Professor Lim Hyung-kyu of Kangwon National University’s Division of Chemical Engineering and Bioengineering. Dr. Lee Sang-moon of the Korea Basic Science Institute was among the participating researchers.
Supercapacitors, along with lithium-ion batteries, are widely used energy storage devices. Unlike lithium-ion batteries that store energy through chemical reactions within active materials (energy storage materials), supercapacitors store energy through the physical adsorption and desorption of charge carriers on electrode surfaces. This allows supercapacitors to store energy much faster than lithium-ion batteries, allowing a long battery life but limiting energy density.
Given that energy density is the product of capacity and voltage, the team focused on increasing voltage to enhance energy density. Magnesium ions tend to react strongly with glyme as they have a smaller ionic radius but approximately two times the charge of lithium ions. Using the strong interactions between magnesium and glyme charge carriers, the team succeeded in developing a magnesium ion supercapacitor capable of stable charge delivery at high voltages. In addition, the team proved for the first time that the porous properties of carbon-based electrodes, featuring especially large specific surface areas, help to enhance the stability of the charge carriers.The proposed magnesium ion supercapacitor offers a high energy density exceeding 100Wh/kg and a high power density exceeding 10,000 W/kg, which are both approximately twice the magnitude of those of conventional supercapacitors. Considering that research on multivalent ions is still in its infancy, the findings are expected to have a huge impact on the development of multivalent ion-based supercapacitors.