Our research on supercapacitors focuses on the development of environmentally friendly synthesis strategies for electrode materials based on carbon allotropes and intrinsically electrically conductive polymers.
Typical carbon allotropes for applications in capacitors are activated carbon (AC), graphite derivatives such as graphite oxide (GO), reduced graphite oxide rGO), graphene and its derivatives, graphite nanoplates (GNP) or also different types of carbon nanotubes (CNT). Carbon derivatives typically act as electrochemical double-layer capacitor (EDLCs). Charge and discharge is achieved by rapid ion adsorption and desorption, requiring a high specific surface area for high power density. However, the energy density of EDLC materials is usually low. Intrinsically conductive polymers such as polypyrrole (PPy) or polyaniline (PANI) act as pseudo-capacitors. They are characterized by high energy densities; however, their long-term stability in cyclic applications and the rate capability are lower than that of carbon materials. The combination of high-surface area carbon structures with the ICPs should thus enable high performance electrode materials for supercapacitors.
In the development of high-performance electrode materials, we focus on:
- Influence of manufacturing conditions
- Use of natural chemicals for the reduction of GO
- Use of natural chemicals as dispersion aid
- Effect of natural substances on the surface modification of carbon structures with ICP.
Among others, citric acid, dopamine and tannic acid are used.
Foto: In-situ synthesized PANI on the surface of GNP
Based on the products, printable pastes are to be developed in the current EU project InComEss, which will enable the simple production of high-performance and durable supercapacitors for energy-autonomous IoT applications, among others.
Publications to Supercapacitors
- Xueyan Zhao, Jürgen Pionteck: Electrochemical Performance of Polydopamine Modified PANI/rGO Composites: Dependency on Preparation Sequence, J. Appl. Pol. Sci. (2021) 138, 50663
- Xueyan Zhao, Minoj Gnanaseelan, Dieter Jehnichen, Frank Simon, Jürgen Pionteck: Green and facile synthesis of polyaniline/tannic acid/rGO composites for supercapacitor purpose, J Mater Sci (2019) 15, 10809-10824
- Xueyan Zhao, Olga Grätz, Jürgen Pionteck: Effect of dopant and oxidant on the electrochemical properties of polyaniline/graphite nanoplate composites, Polym. Int. (2018) 67, 1429-1437