Fabrication Of Compressible Electrodes Based On Melamine Foam And Their Supercapacitor Properties

Supercapacitor,as an indispensable component of deformable electronic products,is often required to be flexible,collapsible,scalable and compressible.It is important to develop supercapacitors with compressibility.At present,the biggest barrier of compressible supercapacitors is how to maintai n stable electrochemical performance under mechanical deformation.In the thesis,the melamine foam as compressible electrode substrate can provide sufficient mechanical properties,and meanwhile the framework surface of melamine foam can load the active material to meet the high capacity requirements.The main work is the following:1.carbon nanotubes with high conductivity were used to conductive treatment for melamine foam substrate to ensure the conductivity of the electrodes.KMnO₄can react with carbon nanotubes on the surface of the conductive sponge to introduce the high pseudocapacitance material of Mn O₂ for further enhancing the capacity of compressible electrode.The presence of Mn O₂ was proved by X ray diffraction and transmission electron microscopy.The electrochemical performance of the Mn O₂@CNTs sponge electrode was tseted in the Na₂SO₄ electrolyte under the three electrode system.MnO₂@CNTs sponge electrode can reach the specific capacitance of 600 F g^-1,and at the same time,shows good rate and cycle stability.More importantly,the melamine foam substrate still has high mechanical property with the loaded carbon nanotube and Mn O₂,and can maintain stable electrochemical performance under compression.2.polypyrrole was loaded on the surface of the melamine foam by in situ chemical oxidation polymerization.By optimizing the amount of monomer and polymerization time,the compressible electrode of melamine foam suitably covered by polypyrrole was obtained.Through comparing the different electrolyte,the electrochemical performance of polypyrrole sponge was more stable in the Na₂SO₄electrolyte,and the specific capacitance of polypyrrole sponge was 257 F g^-1.In the mechanical test,polypyrrole sponge electrode also exhibited the excellent property of compression-springback and stable electrochemical properties.In conclusion,high performance compressible electrodes were prepared by loading the active materials of Mn O₂ and polypyrrole on the melamine foam,meeting the mechanical behavior and the stable electrochemical properties of compressible capacitors.This method provides a new idea for the preparation of compressible electrodes.