Professors from American and Korean universities jointly improved the energy density of flexible supercapacitors to approach that of batteries

　　Recently, using a simple layer-by-layer coating technique, researchers from the United States and South Korea have developed a paper-based flexible supercapacitor that has excellent performance of high energy and high power density. Let's learn about the relevant content with the power management editor below.

　　We usually judge the quality of energy storage devices based on three properties: energy density, power density and cycle stability. Compared with batteries , supercapacitors usually have high power density but low energy density, that is, supercapacitors have weaker ability to store electricity than batteries , but their instantaneous charge and discharge capabilities are better than batteries .

　　Therefore, if you want to use capacitors as energy storage devices, their low energy density is the biggest limitation. In order to improve the performance of supercapacitors , Lee and collaborator Jinhan Cho of the Department of Chemical and Bioengineering at Korea University conducted research on improving the energy density of supercapacitors while maintaining their high power output.

　　In the experiment, they first immersed the paper sample in a beaker containing a solution of an amine surfactant material, which can bind gold nanoparticles to the paper; then, they immersed the paper in a solution containing gold nanoparticles. Since the nature of paper is a fiber, and the fiber is porous, the surfactant and nanoparticles will firmly adhere to it after entering the fiber, thus forming a conformal coating on each fiber.

　　By repeating the dipping steps, the researchers had a conductive paper to which they then added alternating layers of metal oxide energy storage materials, such as manganese oxide. "It's basically a very simple process where we do it alternately in a beaker to give the cellulose fibers a good conformal coating," Lee said. "In this way, we can fold the resulting metal paper without damaging the conductivity."

　　The researchers showed that their self-assembly technology improved paper supercapacitors. According to tests, the maximum power and energy density of the metal paper supercapacitor were 15.1 mW/cm2 and 267.3 uW/cm2, respectively, which basically exceeded traditional paper or textile supercapacitors.

　　It is worth noting that in this study, the researchers used gold nanoparticles because the material is easy to use, but they plan to use cheaper metals such as silver or copper to reduce material costs.

　　Although this study involved small paper samples, based on the technical requirements of the solution in real applications, the researchers said it is entirely possible to scale it up using larger tanks or even spraying technology. Regarding the technology, Lee also added: "We have nano-level control over the coating applied to the paper, and if we increase the number of layers, the performance will continue to increase."

　　Next, the research team will test the technology on flexible fabrics, as well as developing flexible batteries that can be used in conjunction with supercapacitors.

　　Regarding the application prospects of this technology, Seung Woo Lee, assistant professor of the School of Mechanical Engineering at Georgia Institute of Technology, said: "This flexible energy storage device provides a unique connection between wearable devices and IoT devices. In the future, it will be used in biomedical sensors, consumer electronics and military electronics. By combining flexible capacitors with electronic devices, it can promote the development of the most advanced portable electronics."

    The above is an introduction to power management in which professors from universities in the United States, South Korea and China jointly improved the energy density performance of flexible supercapacitors to a level close to that of batteries. If you want to know more related information, please pay more attention to eeworld. eeworld Electronic Engineering will provide you with more complete, detailed and updated information.