The researchers addressed the limitations of traditional energy storage devices by employing transition metal-based materials for the electrodes. Specifically, they designed electrodes using a nickel-based carbonate and hydroxide composite material, further enhancing performance with the incorporation of metal ions such as Mn, Co, Cu, Fe, and Zn. This innovation led to substantial improvements in conductivity, stability, and overall efficiency.
The resulting device demonstrated an impressive energy density of 35.5 Wh kg-far surpassing previous benchmarks of 5-20 Wh kg. Additionally, the power density reached 2555.6 W kg, which is more than double the previous average of approximately 1000 W kg. This advancement allows for rapid energy delivery, making it suitable for high-power applications. Long-term durability was also validated, with minimal degradation observed across repeated charge-discharge cycles.
Taking the innovation further, the team developed a hybrid energy system combining silicon solar cells with supercapacitors. This integration enables real-time solar energy capture and storage, achieving a storage efficiency of 63% and an overall system efficiency of 5.17%. The combined system represents a key step toward commercializing self-charging energy technologies.
"This study is a significant achievement, as it marks the development of Korea's first self-charging energy storage device combining supercapacitors with solar cells. By utilizing transition metal-based composite materials, we have overcome the limitations of energy storage devices and presented a sustainable energy solution," said Jeongmin Kim, Senior Researcher at DGIST. Damin Lee of Kyungpook National University added, "We will continue to conduct follow-up research to further improve the efficiency of the self-charging device and enhance its potential for commercialization."
Research Report:Design of high-performance binary carbonate/hydroxide Ni-based supercapacitors for photo-storage systems
