Binder-Free NiS@PPy Nanocomposite Cathode for High-Performance Supercapacitors

Abstract

Industrialization and the increase in the world population increase the need for energy. Supercapacitors are preferred because of their features such as high specific power, long life, environmental friendliness, fast charge, and discharge rates. Supercapacitors are divided into two categories as EDLC and pseudo capacitors. Pseudo capacitors use materials that exhibit pseudo capacitance, such as transition metal oxides/sulphides and conductive polymers. Electrochemical studies and synthesis methods of polymerbased metal oxide composites, polyaniline and polypyrrole are examined in detail. Evaluating the various methods used in the preparation of supercapacitor electrodes, an idea is presented on the selection of suitable materials for electrochemical applications. Conductive polymers have good capacitance behavior but low cyclic stability. Transition metal sulfides exhibit electrochemical performance with high capacitance values and excellent redox reversibility. This study investigates NiS/PPy polymer as supercapacitor electrode material. The NiS structure was synthesized using Na2S and nickel foam. NiS-PPy coating was carried out by electrochemical coating method. Structures were characterized by XRD and SEM, electrochemical studies such as cyclic voltammetry (CV), galvanostatic discharge (GCD) were carried out. By incorporating NiS into the PPy matrix, the C value was increased from 22.22 to 1404 F g -1