Studies on improved stability and electrochemical activity of metal oxides/sulfides‐based polymer nanocomposites for energy storage applications

Abstract

Poly (3‐methylthiophene) (P3MT) was modified by nickel oxide (NiO) and nickel sulfide (NiS) nanoparticles to enhance its electrochemical performance. The surface influence, crystalline structure, and electrochemical performance of the P3MT/NiO/NiS material were characterized and compared with that of pristine P3MT. It is found that surface modification can improve the structural stability of P3MT without decreasing its available specific capacitance. The electrochemical properties of synthesized P3MT/NiO/NiS electrode were evaluated using cyclic voltammetry and alternating current impedance techniques in 3 M KOH electrolyte. Specific capacitances of 253, 764, 932, and 1434 F g−1 were obtained for P3MT, P3MT/NiO, P3MT/NiS, and P3MT/NiO/NiS, respectively at 5 A g−1. This improvement is attributed to the synergistic effect of Ni2+ ions in the P3MT/NiO/NiS electrode material. The P3MT/NiO/NiS electrode in KOH has average specific energy and specific power densities of 1032 Wh kg−1 and 6192 W/kg, respectively. Only 2% of the capacitance's initial value is lost after 10,000 cycles. The resulting P3MT/NiO/NiS nanocomposite had very stable and porous layered structures. This work demonstrates that P3MT/NiO/NiS nanomaterials exhibit good structural stability and electrochemical performance, and are good material for supercapacitor applications.Highlights The P3MT/NiO/NiS nanocomposite is fabricated and characterized as supercapacitor electrode. The incorporation of NiO/NiS in the poly (3‐methylthiophene) has improved the electrochemical performance. The P3MT/NiO/NiS electrodes retained 98% of their specific capacitance after 10,000 cycles. The P3MT/NiO/NiS nanocomposite electrode showed specific capacitance of 1434 F g−1 at 5 A g−1. The stability of the nanocomposite was enhanced without altering its morphology and chemical structure.