A breakthrough in the manufacture of supercapacitors: polyaniline electropolymerization technology
Since the first patent in 1957, supercapacitors have been valued by academia and industry. As the importance of sustainable and renewable energy becomes more prominent, the potential applications of supercapacitors are gradually expanding into power backup systems, electric vehicles, digital communication equipment and other fields. With their high power density, long cycle life, low maintenance costs and environmental safety, supercapacitors are considered one of the innovative methods for reliable energy storage.
There are two main types of supercapacitors: electrochemical double-layer capacitors and pseudocapacitors, depending on the charge storage mechanism. Electrochemical double-layer capacitors store charge on a separated opposite charge at the electrode/electrolyte interface, while pseudocapacitors store charge through a reversible fast Faraday reaction. In pseudocapacitors, charge storage is strictly limited to the electrode surface. The electrode materials of supercapacitors have an important influence on their electrochemical performance, and commonly used materials include carbon-based materials, transition metal oxides and conductive polymers.
Conductive polymers are attracting attention because of their unique properties, especially polyaniline. Polyaniline is considered to be one of the most promising conductive polymers due to its advantages of easy synthesis, doping, dehydrogenation, good chemical stability, strong mechanical versatility and low cost. However, the stability of polyaniline during cycling remains a challenge.
To enhance the stability of polyaniline and improve the performance of supercapacitors, the researchers prepared supercapacitor electrodes by electropolymerizing polyaniline on graphite foil and depositing a thin layer of polybenzenesulfonic acid (PSS). Electrochemical deposition of polyaniline ensures that polyaniline nucleation and growth occur on the electrode surface while providing greater deposition control.
The experimental results show that this preparation method obtains a high-performance polyaniline:PSS flexible electrode material. The electrode has high capacitance and high capacity retention, with a specific volume and specific capacity of 2600MF·cm-2 and 555.4F·, respectively. G-1。 This achievement is mainly due to the synergistic and complementary effects between polyaniline and PSS, which have obvious advantages in performance compared to single-material electrodes.
In addition, by constructing a symmetrical supercapacitor, the specific volume of the polyaniline:PSS electrode was further increased to 159.8F· G-1, and cycle stability is also improved after 1000 and 10000 cycles. The study also shows that the electrode material and the entire device are highly flexible, which offers potential possibilities for practical applications.
In summary, the electropolymerization technology of polyaniline provides a new breakthrough in the manufacture of supercapacitors. By depositing a thin PSS layer and using a bi-material electrode, the polyaniline:PSS electrode exhibits excellent capacitance performance and cycling stability. The results of this study provide new ideas for improving the stability of polyaniline and developing conductive polymer-based supercapacitors with high specific volume, while also ensuring excellent capabilities in practical applications.
