In-situ encapsulation of nickel nanoparticles in polypyrrole nanofibres with enhanced performance for supercapacitor

In this study, a polypyrrole/nickel (PPy/Ni) nanocomposite has been synthesized through an in situ polymerization method. X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectrometer confirm the formation of PPy in the PPy/Ni nanocomposite. From the scanning and transmission electron microscopy images, one can see that the nickel nanoparticles, which are approximately 21 nm, are encapsulated in the PPy nanofibres. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy are used to test the electrochemical performance of the PPy/Ni electrode. The specific capacitance of the PPy/Ni is approximately 488 F g−1 at a current density of 250 mA g−1, which is superior to that of pure PPy (408 F g−1) and also demonstrates good cyclability and low charge-transfer resistance.