Comparative studies on two-electrode symmetric supercapacitors based on polypyrrole: Poly(4- styrenesulfonate) with different molecular weights of poly(4-styrenesulfonate)

Abstract

Poly(4-styrenesulfonate)-conducting polymer (PSS-CP) is advantageous for thin-film electrode manufacturing due to its high conductivity, high charge storage, structural stability, and excellent ink dispersion. In this work, comparative studies of two-electrode symmetric supercapacitors using Polypyrrole:Poly(4-styrenesulfonate) (PPy:PSS), with different molecular weights (M w 's) of Poly(4-styrenesulfonate) (PSS) as the electrodes, were performed. PPy:PSS can be easily prepared using a simple solution process that enables the mass production of thin-film electrodes with improved electrical and electrochemical properties. As-prepared PPy:PSS, with different PSS molecular weights, were assembled into two-electrode supercapacitors based on coin cell structures. It was confirmed that the electrical and electrochemical properties of PPy:PSS were improved with increasing PSS molecular weight. The coin cell, using PPy:PSS with a PSS molecular weight of 1.0 × 10 6 g/mol, exhibited higher areal capacitance (175.3 mF/cm 2 ), higher volumetric capacitance (584.2 F/cm 3 ), and longer cycling stability (86.3% after 5000 cycles) compared to those of PPy:PSS with PSS molecular weights of 2.0 × 10 5 and 7.0 × 10 4 g/mol. This work provides an efficient approach for producing cost-effective and miniaturized supercapacitors with high conductivity and high specific capacitance for practical applications in a variety of electronic devices.